A matte scratch-resistant anti-extraction polyolefin film, and a preparation method and application thereof

Abstract

The application relates to the field of film materials, and more particularly to a smooth-surface scratch-resistant anti-extrusion polyolefin film and a preparation method and application thereof. The smooth-surface scratch-resistant anti-extrusion polyolefin film comprises, in mass parts, at least: 30-60 parts of polyolefin resin, 30-50 parts of auxiliary adjusting resin, 5-20 parts of rigidifying mother granules, 0.1-1 part of surface lubricant, 0.3-0.8 part of light stabilizer, 2-3 parts of compatilizer and 2-5 parts of toughening agent. The finally-prepared polyolefin film material has excellent mechanical properties, a smooth surface, high surface hardness, no material extrusion phenomenon, can simultaneously have good corrosion resistance, water resistance, aging resistance and other performances, can meet the performance requirements of the polyolefin film material in the prior art field, and has more excellent use quality and service life.

Description

Technical Field

[0001] This application relates to the field of membrane materials, and more specifically mentions a smooth, scratch-resistant, and anti-exudation polyolefin film, its preparation method, and its application. Background Technology

[0002] Polyolefin films (such as polyethylene (PE), polypropylene (PP) and their copolymers) are widely used in food packaging, electronic product protective films, medical device encapsulation, and industrial protective films due to their advantages such as being lightweight, transparent, chemically stable, and low-cost. With the upgrading of consumption and the development of industrial precision, the market is placing higher demands on film performance, such as smoothness and resistance to corrosion and aging. Furthermore, traditional polyolefin materials have low surface hardness during use, making them easily scratched, and added additives can easily migrate from the material interior to the surface, causing precipitation problems that affect the product's appearance and lifespan.

[0003] To address these issues, researchers are continuously exploring methods to improve polyolefin film materials. For example, high-performance additives, such as inorganic nanoparticles, high-hardness polymers, and slip agents, are used to enhance the various properties of polyolefin film materials. However, while these technologies have improved the scratch resistance and anti-aging properties of polyolefin materials to some extent, certain limitations remain. First, for applications requiring a glossy surface, existing scratch-resistant technologies may not simultaneously meet the requirements of high transparency and high gloss. Second, although some additives can enhance the scratch resistance of materials, their compatibility with the substrate remains a challenge, potentially leading to a decline in the overall performance of the material. Finally, ensuring that additives do not leach to the surface during long-term use, thus maintaining product consistency and aesthetics, remains a problem that urgently needs to be solved.

[0004] Therefore, the present invention aims to provide a new smooth, scratch-resistant, and anti-exudation polyolefin film and its preparation method, in order to overcome the shortcomings of the prior art, especially in ensuring that the film has excellent scratch resistance while effectively preventing the exudation of additives and maintaining good optical properties. Summary of the Invention

[0005] In summary, how to prepare a smooth polyolefin film material with superior overall performance has become an important research topic for those skilled in the art. Through in-depth research in this technical field, the applicant has finally proposed a smooth, scratch-resistant, and anti-exudation polyolefin film and its preparation method in this application. The resulting polyolefin film material not only has excellent mechanical properties, but also a smooth surface, high surface hardness, and no exudation phenomenon. It can also simultaneously possess good corrosion resistance, waterproofing, and aging resistance, meeting multiple performance requirements of existing technologies for polyolefin film materials, and exhibiting superior performance quality and service life.

[0006] A smooth, scratch-resistant, and anti-exudation polyolefin film, comprising, by weight, at least the following raw materials: 30-60 parts polyolefin resin, 30-50 parts auxiliary conditioning resin, 5-20 parts stiffening masterbatch, 0.1-1 parts surface lubricant, 0.3-0.8 parts light stabilizer, 2-3 parts compatibilizer, and 2-5 parts toughening agent.

[0007] In a preferred embodiment, the polyolefin resin is a homopolymer polypropylene resin or a homopolymer polyethylene resin.

[0008] In a preferred embodiment, the polyolefin resin is a homopolymer polypropylene resin.

[0009] In a preferred embodiment, the polyolefin resin has a melt flow rate of 3-15 g / 10 min and a melt flow rate of 230°C / 2.16 kg.

[0010] In a preferred embodiment, the polyolefin resin has a melt flow rate of 4-10 g / 10 min and a melting point of 230°C / 2.16 kg.

[0011] In a preferred embodiment, the auxiliary regulating resin is a functional polypropylene resin or a functional polyethylene resin.

[0012] In a preferred embodiment, the auxiliary regulating resin is a functional polypropylene resin.

[0013] In a preferred embodiment, the mass ratio of the polyolefin resin, the auxiliary adjusting resin, and the stiffening masterbatch is (4.5-6):(4-5):(1-1.5).

[0014] In a preferred embodiment, the mass ratio of the polyolefin resin, the auxiliary adjusting resin, and the stiffening masterbatch is (4.8-5.5):(4.2-4.6):(1-1.2).

[0015] In a preferred embodiment, the preparation method of the stiffening masterbatch specifically includes the following steps: S1: Glycidyl methacrylate and vinyltriethoxysilane are mixed and then dicumyl peroxide is added. The mixture is heated and stirred for pre-activation to obtain a pre-activated monomer; S2: High-grade paraffin and LDPE are added to a mixer. After mixing, the pre-activated monomer, dibenzyl sorbitol, dimer acid, and triphenyl phosphate are added. The mixture is then heated and mixed again; S3: After mixing, the mixture is granulated by a twin-screw extruder, underwater pelletized, dehydrated, vibrated, sieved, and dried until the moisture content is ≤0.1%.

[0016] In a preferred embodiment, the preparation method of the stiffening masterbatch specifically includes the following steps: S1: Glycidyl methacrylate and vinyltriethoxysilane are mixed and then dicumyl peroxide is added. The mixture is heated to 60-70°C and stirred for 30-35 minutes for pre-activation to obtain a pre-activated monomer.

[0017] S2: Add high-grade paraffin wax and LDPE to a mixer, heat to 150-155℃, mix at 50-60 rpm for 6-8 minutes, then add pre-activated monomers, dibenzylidene sorbitol, dimer acid and triphenyl phosphate, continue heating to 170-175℃, mix at 70-80 rpm for 10-15 minutes; S3: After mixing, granulate using a twin-screw extruder at a temperature range of 165-195℃, underwater pelletizing, then dewater, vibrate sieve and dry until the moisture content is ≤0.1% to obtain the final product.

[0018] In a preferred embodiment, the mass ratio of glycidyl methacrylate to vinyltriethoxysilane is (1.5-2):(0.8-1.5).

[0019] In a preferred embodiment, the mass ratio of the high-grade paraffin, LDPE, preactivated monomer, dibenzyl sorbitol, dimer acid, and triphenyl phosphate is (5-6):(3-4):(0.5-0.9):(0.8-1.4):(0.2-0.5):(0.1-0.4).

[0020] In a preferred embodiment, the mass ratio of the advanced paraffin, LDPE, preactivated monomer, dibenzyl sorbitol, dimer acid, and triphenyl phosphate is (5-5.5):(3-3.5):(0.6-0.8):(0.9-1.1):(0.3-0.4):(0.2-0.3).

[0021] The addition of stiffening masterbatch significantly improves the rigidity, scratch resistance, and waterproof and corrosion-resistant properties of the film, while optimizing processing stability and component compatibility. During melt processing, the high-grade paraffin and low-molecular-weight polyethylene in the carrier matrix form a continuous phase with enhanced fluidity, promoting the uniform dispersion of functional components into the polyolefin matrix. The functional reinforcing agent, dibenzyl sorbitol, spontaneously assembles into a nanoscale fiber framework during the cooling crystallization stage. This framework physically restricts the movement of polypropylene molecular chains, directly increasing the elastic modulus and surface hardness of the film. Simultaneously, the long-chain aliphatic hydrocarbon structure of the dimer acid embeds into the amorphous region of the polyolefin, releasing internal stress and passively inhibiting crack tip propagation, thus providing the film with a tough buffer.

[0022] On the other hand, the epoxy groups of glycidyl methacrylate undergo ring-opening under high-temperature shearing, and graft with the carboxyl or hydroxyl groups at the end of the polypropylene molecular chain to form a covalently anchored interface, completely eliminating the phase separation between the inorganic filler and the organic resin. Meanwhile, vinyltriethoxysilane hydrolyzes to generate silanol groups during melt processing. Some of these groups condense to form siloxane crosslinking to enhance water resistance, while others react with the carbon chains of polyolefins through free radical reactions to construct an organic-inorganic hybrid protective layer. Finally, triphenyl phosphate is adsorbed at the inorganic / organic interface through its polar phosphate groups to reduce surface energy, and the phenyl structure is interspersed in the gaps between polymer chains to inhibit plastic deformation, thus synergistically blocking the scraping stress transmission path.

[0023] In a preferred embodiment, the surface lubricant is at least one of erucamide, oleamide, silicone powder, oxidized polyethylene wax, and castor oil and its derivatives.

[0024] In a preferred embodiment, the surface lubricant is oleamide, oxidized polyethylene wax, or castor oil and its derivatives.

[0025] In a preferred embodiment, the surface lubricant is oleic acid amide.

[0026] In a preferred embodiment, the light stabilizer is at least one of benzotriazoles, triazines, hindered amines, and nano-cerium oxide.

[0027] In a preferred embodiment, the light stabilizer is a benzotriazole or a triazine.

[0028] In a preferred embodiment, the light stabilizer is a benzotriazole.

[0029] In a preferred embodiment, the compatibilizer is at least one selected from ethylene-acrylic acid copolymer, maleic anhydride-grafted polyethylene, butyl acrylate-ethylene copolymer, and acrylic acid block copolymer.

[0030] In a preferred embodiment, the compatibilizer is an ethylene-acrylic acid copolymer or maleic anhydride-grafted polyethylene.

[0031] In a preferred embodiment, the compatibilizer is an ethylene-acrylic acid copolymer.

[0032] In a preferred embodiment, the toughening agent is at least one selected from ethylene-octene copolymer, hydrogenated styrene-butadiene-styrene, maleic anhydride-grafted styrene-butadiene-styrene, and ethylene-vinyl acetate.

[0033] In a preferred embodiment, the toughening agent is an ethylene-octene copolymer or a hydrogenated styrene-butadiene-styrene.

[0034] In a preferred embodiment, the toughening agent is hydrogenated styrene-butadiene-styrene.

[0035] In a preferred embodiment, the smooth, scratch-resistant, and anti-exudation polyolefin film, by weight, further comprises: 3-12 parts of reinforcing composition, 0.2-0.6 parts of antioxidant, 1-2 parts of hydrophobic agent, and 0.5-1 parts of anchoring agent.

[0036] In a preferred embodiment, the mass ratio of the polyolefin resin to the additive composition is (4.5-6):(0.5-1).

[0037] In a preferred embodiment, the mass ratio of the polyolefin resin to the additive composition is (4.8–5.5):(0.6–0.8).

[0038] In a preferred embodiment, the reinforcing composition is a combination of octadecyltrimethoxysilane, perfluorodecyl acrylate and pentaerythritol tetrakis(3-mercaptopropionic acid) ester.

[0039] In a preferred embodiment, the mass ratio of octadecyltrimethoxysilane, perfluorodecyl acrylate, and [other components] is (2-4):(1-3):(0.6-1.8).

[0040] In a preferred embodiment, the mass ratio of octadecyltrimethoxysilane, perfluorodecyl acrylate, and octadecyltrimethoxysilane is (2.5-3):(1.8-2.2):(1-1.3).

[0041] By further employing a reinforcing composition as a key raw material, the octadecyltrimethoxysilane it contains undergoes methoxyl hydrolysis during the melt extrusion stage. The resulting silanol groups condense with the hydroxyl groups at the ends of the polyolefin chains to form covalent bonds. During cooling, the long alkyl chains are oriented to the film surface by van der Waals forces, forming a low surface energy monolayer. This arrangement significantly reduces the frictional resistance between the melt and the mold, imparting super-leveling properties to the melt, greatly reducing surface roughness, and achieving a near-mirror gloss. Furthermore, the combined effect of these three factors—silane reducing surface energy to provide a driving force for fluorocarbon chain migration; mercapto crosslinking to provide free radical reaction sites for fluorine chain anchoring; and fluorocarbon chains filling the gaps between silane molecules to eliminate interfacial defects—ultimately forms a gradient protective architecture on the surface consisting of an "organosilicon drag-reducing layer - sulfur crosslinking reinforcement layer - fluorine molecular barrier layer," comprehensively improving overall performance.

[0042] In a preferred embodiment, the antioxidant is at least one of antioxidant 168, antioxidant 1010, antioxidant 1076, and antioxidant 245.

[0043] In a preferred embodiment, the antioxidant is antioxidant 1076 or antioxidant 245.

[0044] In a preferred embodiment, the antioxidant is antioxidant 1076.

[0045] In a preferred embodiment, the hydrophobic agent is at least one of hydrophobic silica, organically modified montmorillonite, polysiloxane, and fluorinated alumina.

[0046] In a preferred embodiment, the hydrophobic agent is hydrophobic silica or fluorinated aluminum oxide.

[0047] In a preferred embodiment, the hydrophobic agent is hydrophobic silicon dioxide.

[0048] In a preferred embodiment, the anchoring agent is at least one of hyperbranched polyester, epoxy chain extender resin, and carboxylated polyolefin.

[0049] In a preferred embodiment, the anchoring agent is a hyperbranched polyester or an epoxy chain extender resin.

[0050] In a preferred embodiment, the anchoring agent is a hyperbranched polyester.

[0051] A method for preparing the above-mentioned smooth, scratch-resistant, and anti-exudation polyolefin film specifically includes the following steps: S1: Dry the polyolefin resin and auxiliary conditioning resin with hot air until the moisture content is ≤0.1%, and mix it with the stiffening masterbatch and the reinforcing composition. Stir at 300-400 rpm for 4-5 min, then add the remaining raw materials and continue stirring at 200-250 rpm for 4-5 min to obtain a premix; S2: Add the premix to a single-screw extruder and melt extrude it in the range of 180-230℃, then blow-form it with a blow-up ratio of (2.5-3):1 and a draw ratio of (4-4.5):1, and then cool and set it; S3: Perform corona treatment, and after the surface tension is ≥40mN / m, wind it up to obtain the final product.

[0052] This application further defines the application of the above-mentioned smooth, scratch-resistant, and anti-exudation polyolefin film in packaging materials, encapsulation materials, cold chain logistics, and protective film materials.

[0053] This application has practical significance and beneficial effects:

[0054] 1. The polyolefin film material finally obtained in this application not only has excellent mechanical properties, but also has a smooth surface, high surface hardness, and no material exudation. It can also have good corrosion resistance, waterproof and aging resistance, and meet the multiple performance requirements of polyolefin film materials in the existing technology field, and has better service quality and service life.

[0055] 2. This application significantly improves the rigidity, scratch resistance, and waterproof and corrosion-resistant properties of the film by adding stiffening masterbatch, while optimizing processing stability and component compatibility. During melt processing, the high-grade paraffin and low-molecular-weight polyethylene in the carrier matrix form a continuous phase with enhanced fluidity, promoting the uniform dispersion of functional components into the polyolefin matrix. The functional reinforcing agent, dibenzyl sorbitol, spontaneously assembles into a nanoscale fiber framework during the cooling crystallization stage, restricting the movement of polypropylene molecular chains through physical entanglement, directly improving the elastic modulus and surface hardness of the film. Simultaneously, the long-chain aliphatic hydrocarbon structure of the dimer acid embeds into the amorphous region of the polyolefin, releasing internal stress and passively inhibiting crack tip propagation, thus providing the film with a tough buffer.

[0056] 3. Further addition of a reinforcing composition as a key raw material involves the octadecyltrimethoxysilane, which undergoes methoxyl hydrolysis during melt extrusion. The resulting silanol groups condense with the hydroxyl groups at the ends of the polyolefin chains to form covalent bonds. During cooling, the long alkyl chains align to the film surface via van der Waals forces, forming a low surface energy monolayer. This alignment significantly reduces the frictional resistance between the melt and the mold, imparting super-leveling properties to the melt and greatly reducing surface roughness to achieve a near-mirror gloss. Furthermore, the combined effect of these three components—silane reducing surface energy to provide a driving force for fluorocarbon chain migration; mercapto crosslinking to provide free radical reaction sites for fluorine chain anchoring; and fluorocarbon chains filling the gaps between silane molecules to eliminate interfacial defects—results in a gradient protective architecture of "organosilicon drag-reducing layer - sulfur crosslinking reinforcement layer - fluorine molecular barrier layer" on the surface, comprehensively improving overall performance. Attached Figure Description

[0057] Figure 1 This is a photograph of the glossy, scratch-resistant, and anti-exudation polyolefin film prepared according to Example 1 of this application.

[0058] Figure 2 This is a diagram showing the workshop layout of the winding process for the smooth, scratch-resistant, and anti-exudation polyolefin film prepared in Example 1 of this application.

[0059] Figure 3 This is a sample image of the light transmittance test of the glossy, scratch-resistant, and anti-exudation polyolefin film prepared in Example 1 of this application.

[0060] Figure 4 This is a sample image of the light transmittance test of the glossy, scratch-resistant, and anti-exudation polyolefin film prepared in Comparative Example 1 of this application. Detailed Implementation

[0061] In the embodiments and comparative examples of the specific implementation, unless otherwise specified, the specific preparation methods, manufacturers and models of certain raw materials are implemented with reference to the following scheme.

[0062] Example 1 of preparation of rigidity-enhancing masterbatch:

[0063] The preparation method of the enhanced-strength masterbatch, by weight, specifically includes the following steps: S1: 1.8 parts glycidyl methacrylate and 1.2 parts vinyltriethoxysilane are mixed, and 0.08 parts dicumyl peroxide is added. The mixture is heated to 65°C and stirred for 30 min for pre-activation to obtain a pre-activated monomer; S2: 5.4 parts high-grade paraffin and 3.2 parts LDPE are added to a mixer, the mixture is heated to 155°C, and mixed at 60 rpm for 8 min. Then, 0.7 parts pre-activated monomer, 1.1 parts dibenzyl sorbitol, 0.4 parts dimer acid and 0.3 parts triphenyl phosphate are added. The mixture is further heated to 175°C and mixed at 70 rpm for 12 min; S3: After mixing, the mixture is granulated by a twin-screw extruder at a temperature range of 165°C / 175°C / 185°C / 195°C. The mixture is then granulated underwater, dehydrated, vibrated, sieved and dried until the moisture content is ≤0.1%.

[0064] Example 2 of preparation of rigidity-enhancing masterbatch:

[0065] The preparation method of the enhanced-strength masterbatch, by weight, specifically includes the following steps: S1: 1.5 parts glycidyl methacrylate and 1.5 parts vinyltriethoxysilane are mixed, and 0.1 parts dicumyl peroxide is added. The mixture is heated to 65°C and stirred for 30 min for pre-activation to obtain a pre-activated monomer; S2: 5 parts high-grade paraffin and 4 parts LDPE are added to a mixer, the mixture is heated to 155°C and mixed at 60 rpm for 8 min. Then, 0.9 parts pre-activated monomer, 0.8 parts dibenzyl sorbitol, 0.2 parts dimer acid and 0.4 parts triphenyl phosphate are added. The mixture is further heated to 175°C and mixed at 70 rpm for 12 min; S3: After mixing, the mixture is granulated by a twin-screw extruder at a temperature range of 165°C / 175°C / 185°C / 195°C. The mixture is then granulated underwater, dehydrated, vibrated, sieved and dried until the moisture content is ≤0.1%.

[0066] Manufacturers and models of certain raw materials:

[0067] Homopolymer polypropylene resin, PP-1126NK, melt flow rate 4.5 g / 10 min, 230℃, 2.16 kg, from a Thai petrochemical company.

[0068] Functional polypropylene resin, PP-V30G, from Sinopec Maoming Company.

[0069] Premium paraffin wax, from Beijing Likang Weiye Technology Co., Ltd.

[0070] LDPE, LDPE-5301 blow molding grade, is from Hanwha Corporation of South Korea.

[0071] C36 dimer acid, from McLean Corporation.

[0072] Ethylene-acrylic acid copolymer, 53070 blow molding grade, from DuPont, USA.

[0073] Hydrogenated styrene-butadiene-styrene, SEBS-6150, from TSRC Corporation, Taiwan, China.

[0074] Hyperbranched polyester, Lankeluo L-6129, supplied by Guangdong Lankeluo Supply Company.

[0075] Hydrophobic silica, with an average particle size of 20nm, is from Nanjing Baoket Company.

[0076] Example 1

[0077] A smooth, scratch-resistant, and exudation-resistant polyolefin film, comprising, by weight, at least the following raw materials: 52.5 parts polyolefin resin, 45 parts auxiliary conditioning resin, 11.5 parts stiffening masterbatch, 0.6 parts surface lubricant, 0.4 parts light stabilizer, 2.5 parts compatibilizer, 3.8 parts toughening agent, 7.5 parts reinforcing composition, 0.4 parts antioxidant, 1.2 parts hydrophobic agent, and 0.8 parts anchoring agent.

[0078] The polyolefin resin is a homopolymer polypropylene resin, and the auxiliary conditioning resin is a functional polypropylene resin.

[0079] Example 1: Preparation of stiffening masterbatch using stiffening masterbatch.

[0080] The surface lubricant is oleamide, and the light stabilizer is benzotriazole. 326; the compatibilizer is ethylene-acrylic acid copolymer; the toughening agent is hydrogenated styrene-butadiene-styrene.

[0081] The reinforcing composition is octadecyltrimethoxysilane, perfluorodecyl acrylate and

[0082] The composition of pentaerythritol tetrakis(3-mercaptopropionic acid) ester has a mass ratio of 2.8:2.2:1.

[0083] The antioxidant is antioxidant 1076; the hydrophobic agent is hydrophobic silica; and the anchoring agent is hyperbranched polyester.

[0084] A method for preparing the above-mentioned smooth, scratch-resistant, and anti-exudation polyolefin film specifically includes the following steps: S1: The polyolefin resin and auxiliary conditioning resin are hot-air dried to a moisture content ≤0.1%, and then mixed with stiffening masterbatch and reinforcing composition. After high-speed stirring at 400 rpm for 5 min, the remaining raw materials are added and stirring is continued at 250 rpm for 5 min to obtain a premix; S2: The premix is ​​added to a single-screw extruder and melt-extruded within the temperature range of 180℃ / 200℃ / 220℃ / 210℃, followed by blow molding.

[0085] The blow-up ratio is 2.5:1 and the draw ratio is 4:1, followed by cooling and shaping; S3: corona treatment, the surface tension of the treatment is ≥40mN / m, and then the product is wound up.

[0086] The actual product of the smooth, scratch-resistant, and anti-exudation polyolefin film prepared in this embodiment is shown below. Figure 1 As shown.

[0087] The overview of the workshop for the winding process of this implementation of smooth, scratch-resistant, and anti-exudation polyolefin film is as follows: Figure 2 As shown.

[0088] Example 2

[0089] This embodiment differs from Embodiment 1 only in the following aspects: A smooth, scratch-resistant, and exudation-resistant polyolefin film, by weight, comprises at least the following raw materials: 60 parts polyolefin resin, 40 parts auxiliary conditioning resin, 10 parts stiffening masterbatch, 0.5 parts surface lubricant, 0.5 parts light stabilizer, 2.6 parts compatibilizer, 3.6 parts toughening agent, 5.5 parts reinforcing composition, 0.4 parts antioxidant, 1.1 parts hydrophobic agent, and 0.7 parts anchoring agent.

[0090] Example 2: The stiffening masterbatch was prepared using stiffening masterbatch.

[0091] All other implementation schemes are the same.

[0092] Example 3

[0093] This embodiment differs from Embodiment 1 only in the following aspects: A smooth, scratch-resistant, and exudative polyolefin film, by weight, comprises at least the following raw materials: 45 parts polyolefin resin, 50 parts auxiliary conditioning resin, 15 parts stiffening masterbatch, 0.6 parts surface lubricant, 0.5 parts light stabilizer, 2.8 parts compatibilizer, 3.8 parts toughening agent, 8.5 parts reinforcing composition, 0.4 parts antioxidant, 1.3 parts hydrophobic agent, and 0.9 parts anchoring agent.

[0094] Example 2: The stiffening masterbatch was prepared using stiffening masterbatch.

[0095] All other implementation schemes are the same.

[0096] Comparative Example 1

[0097] The only difference between this comparative example and Example 1 is as follows: A smooth, scratch-resistant, and exudative polyolefin film, by weight, comprises at least the following raw materials: 61.5 parts polyolefin resin, 45 parts auxiliary conditioning resin, 2.5 parts stiffening masterbatch, 0.6 parts surface lubricant, 0.4 parts light stabilizer, 2.5 parts compatibilizer, 3.8 parts toughening agent, 7.5 parts reinforcing composition, 0.4 parts antioxidant, 1.2 parts hydrophobic agent, and 0.8 parts anchoring agent.

[0098] All other implementation schemes are the same.

[0099] Comparative Example 2

[0100] The only difference between this comparative example and Example 1 is as follows: A smooth, scratch-resistant, and exudative polyolefin film, by weight, comprises at least the following raw materials: 58.5 parts polyolefin resin, 45 parts auxiliary conditioning resin, 11.5 parts stiffening masterbatch, 0.6 parts surface lubricant, 0.4 parts light stabilizer, 2.5 parts compatibilizer, 3.8 parts toughening agent, 1.5 parts reinforcing composition, 0.4 parts antioxidant, 1.2 parts hydrophobic agent, and 0.8 parts anchoring agent.

[0101] All other implementation schemes are the same.

[0102] Comparative Example 3

[0103] The only difference between this comparative example and Example 1 is as follows: The preparation method of the enhanced masterbatch, by mass, specifically includes the following steps: S1: 0.5 parts glycidyl methacrylate and 2.5 parts vinyltriethoxysilane are mixed and then 0.08 parts dicumyl peroxide is added. The mixture is heated to 65°C and stirred for 30 min for pre-activation to obtain a pre-activated monomer; S2: 5.4 parts high-grade paraffin and 3.2 parts LDPE are added to a mixer. The mixture is heated to 155°C and mixed at 60 rpm for 8 min. Then, 1.5 parts pre-activated monomer, 0.5 parts dibenzyl sorbitol, 0.2 parts dimer acid and 0.1 parts triphenyl phosphate are added. The mixture is heated to 175°C and mixed at 70 rpm for 12 min; S3: After mixing, the mixture is granulated by a twin-screw extruder at a temperature range of 165°C / 175°C / 185°C / 195°C. The mixture is then granulated underwater, dehydrated, vibrated, sieved and dried until the moisture content is ≤0.1%.

[0104] All other implementation schemes are the same.

[0105] Comparative Example 4

[0106] The only difference between this comparative example and Example 1 is as follows: The preparation method of the enhanced masterbatch, by mass, specifically includes the following steps: S1: 1.8 parts glycidyl methacrylate and 1.2 parts vinyltriethoxysilane are mixed and then 0.08 parts dicumyl peroxide is added. The mixture is heated to 65°C and stirred for 30 min for pre-activation to obtain a pre-activated monomer; S2: 8 parts high-grade paraffin and 1.2 parts LDPE are added to a mixer. The mixture is heated to 155°C and mixed at 60 rpm for 8 min. Then, 0.2 parts pre-activated monomer, 1.5 parts dibenzyl sorbitol, 1.2 parts dimer acid and 1.1 parts triphenyl phosphate are added. The mixture is heated to 175°C and mixed at 70 rpm for 12 min; S3: After mixing, the mixture is granulated by a twin-screw extruder at a temperature range of 165°C / 175°C / 185°C / 195°C. The mixture is then granulated underwater, dehydrated, vibrated, sieved and dried until the moisture content is ≤0.1%.

[0107] All other implementation schemes are the same.

[0108] Comparative Example 5

[0109] The only difference between this comparative example and Example 1 is that the reinforcing composition is a combination of octadecyltrimethoxysilane, perfluorodecyl acrylate and pentaerythritol tetrakis(3-mercaptopropionic acid) in a mass ratio of 2.8:2.2:1.

[0110] All other implementation schemes are the same.

[0111] Comparative Example 6

[0112] The only difference between this comparative example and Example 1 is that the reinforcing composition is a combination of octadecyltrimethoxysilane, perfluorodecyl acrylate and pentaerythritol tetrakis(3-mercaptopropionic acid) in a mass ratio of 2.8:2.2:1.

[0113] All other implementation schemes are the same.

[0114] Performance testing

[0115] 1. Light transmittance: Light transmittance was tested according to standard GB / T 2410-2008, and the average value of 10 tests was recorded in Table 1. The test samples of Example 1 and Comparative Example 2 are shown below. Figure 3 and Figure 4 As shown; where, Figure 3 (Example 1) Compared to Figure 4 (Comparative Example 1) No precipitation phenomenon was observed, thus exhibiting better light transmittance.

[0116] 2. Water resistance: Refer to standard ISO 15106-3:2003, 38℃±0.5℃ / 90%±2%RH, test area 100cm². 2 The test lasted for 24 hours, and the average of 10 tests was recorded in Table 1.

[0117] 3. Mechanical properties: Referring to standard ISO 527-3:2018, the transverse and longitudinal tensile strength results are taken as the average of 10 tests and recorded in Table 1; the film material is subjected to longitudinal tension of 180N until it breaks, and the longitudinal tensile length of the film material is recorded. The results are taken as the average of 10 tests and recorded in Table 1.

[0118] 4. Salt spray resistance: Refer to standard ISO 9227:2017, 5% NaCl, cycle: spray 2h-dry 1h-wet 4h-freeze-25℃ 1h, cumulative 720h, test the change rate of photoluminescence before and after, and the result is the average of 10 tests and is recorded in Table 1.

[0119] 5. Scratch / Abrasion Resistance: The films prepared in the examples and comparative examples were cut into flat sheet samples of 100×100mm with a thickness of 30μm. Before the test, the samples were kept at a constant temperature and humidity of 25℃ / 50%RH for 48h. The pencil lead was exposed by 3-4mm with a special pencil sharpener and polished with 400-grit sandpaper until it was flat and sharp. The sample was placed flat on a hard glass plate with the pencil at a 45° angle to the film surface. A weight of 750g was applied and the pencil was pushed forward at a speed of 0.5mm / s. The length of the scratch mark was ≥10mm. The edge of the scratch was observed under a microscope and the scratch depth was obtained. The results were the average of 10 tests and included in Table 1.

[0120] Table 1 Performance Test Results

[0121]

[0122]

[0123] Based on the final performance test results of the examples and comparative examples, comparative examples 1 and 2 showed a significant decrease in their respective effects in the film system due to the use of less stiffening masterbatch and reinforcing composition. This decrease directly affected the various properties of the final film, resulting in a significant performance gap between comparative examples 1 and 2 and examples 1 and 3.

[0124] In contrast, Comparative Examples 3 to 6 did not follow the optimal technical solution for preparing the stiffening masterbatch and compounding the reinforcing combination, resulting in the final raw material products failing to achieve optimal performance in the thin film system, thus causing a significant decline in the performance of the thin film material.

Claims

1. A smooth, scratch-resistant, and anti-exudation polyolefin film, characterized in that: By weight, the raw materials include at least: 30-60 parts of polyolefin resin, 30-50 parts of auxiliary conditioning resin, 5-20 parts of stiffening masterbatch, 0.1-1 parts of surface lubricant, 0.3-0.8 parts of light stabilizer, 2-3 parts of compatibilizer, 2-5 parts of toughening agent, 3-12 parts of reinforcing composition, 0.2-0.6 parts of antioxidant, 1-2 parts of hydrophobic agent, and 0.5-1 part of anchoring agent; The polyolefin resin is a homopolymer polypropylene resin with a melt flow rate of 3~15g / 10min and a melt flow rate of 230℃ / 2.16kg. The auxiliary conditioning resin is functional polypropylene resin PP-V30G; The preparation method of the stiffening masterbatch includes: S1: Glycidyl methacrylate and vinyltriethoxysilane are mixed and then dicumyl peroxide is added. The mixture is heated and stirred for pre-activation to obtain a pre-activated monomer; S2: High-grade paraffin and LDPE are added to a mixer. After mixing, the pre-activated monomer, dibenzyl sorbitol, dimer acid, and triphenyl phosphate are added. The mixture is then heated and mixed again; S3: After mixing, the mixture is granulated by a twin-screw extruder, underwater pelletized, dehydrated, and dried to obtain the final product. The mass ratio of the high-grade paraffin, LDPE, pre-activated monomer, dibenzyl sorbitol, dimer acid, and triphenyl phosphate is (5~6):(3~4):(0.5~0.9):(0.8~1.4):(0.2~0.5):(0.1~0.4). The mass ratio of glycidyl methacrylate to vinyltriethoxysilane is (1.5~2):(0.8~1.5). The reinforcing composition is a combination of octadecyltrimethoxysilane, perfluorodecyl acrylate and pentaerythritol tetrakis(3-mercaptopropionic acid) ester, in a mass ratio of (2~4):(1~3):(0.6~1.8).

2. The smooth, scratch-resistant, and anti-exudation polyolefin film according to claim 1, characterized in that: The mass ratio of the polyolefin resin to the stiffening masterbatch is (4.5~6):(4~5):(1~1.5).

3. The smooth, scratch-resistant, and anti-exudation polyolefin film according to claim 2, characterized in that: The surface lubricant is at least one of erucamide, oleamide, silicone powder, oxidized polyethylene wax, and castor oil.

4. The smooth, scratch-resistant, and anti-expansion polyolefin film according to claim 3, characterized in that: The compatibilizer is at least one of ethylene-acrylic acid copolymer, maleic anhydride-grafted polyethylene, butyl acrylate-ethylene copolymer, and acrylic block copolymer.

5. A method for preparing a smooth, scratch-resistant, and anti-exudation polyolefin film according to any one of claims 1 to 4, characterized in that: S1: Dry the polyolefin resin and auxiliary conditioning resin with hot air until the moisture content is ≤0.1%, and mix it with the stiffening masterbatch and the reinforcing composition. Stir at 300~400 rpm for 4~5 min, then add the remaining raw materials and continue stirring at 200~250 rpm for 4~5 min to obtain a premix; S2: Add the premix to a single screw extruder and melt extrude it in the range of 180~230℃, then blow-form it with a blow-up ratio of (2.5~3):1 and a draw ratio of (4~4.5):1, and then cool and set it; S3: Corona treatment is performed until the surface tension is ≥40mN / m, and then the mixture is wound up to obtain the final product.

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