A matt film with a primer coating and a method for manufacturing the same

Abstract

The present application relates to the field of film, particularly to a kind of containing primer matt film and its preparation method, matt film includes primer layer, core layer and matt layer;Primer layer includes EVA, 2-5wt% modified polyhydroxy polyethylene glycol diglycidyl ether and 3-15wt% GMA-g-PP;Modified polyhydroxy polyethylene glycol diglycidyl ether is obtained by grafting modification from 3,4-dihydroxyphenylacetic acid, grafting rate is 12-20%, the grafting rate of GMA in GMA-g-PP is 6-10wt%;Core layer includes homopolymerization polypropylene;Matt layer includes random copolymer polypropylene and 40-50wt% high density polyethylene.The matt film of the present application does not need primer AC agent, primer layer and hot melt adhesive layer have good initial adhesion, improve production efficiency, and primer layer and core layer have good interlayer bonding force, improve the delamination, peeling and other problems between the primer layer and core layer of traditional matt film containing primer.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of thin films, in particular to a matt film with a primer coating and a preparation method thereof. BACKGROUND

[0002] BOPP film is a kind of packaging film which is stretched longitudinally first and then transversely, generally a 3 to 5 layer co-extrusion composite structure, the film presents good mechanical properties and optical properties after multiple stretching, it has the advantages of light weight, good printing performance and good moisture resistance, etc., and is known as the "Queen of Packaging". At present, BOPP film is widely used in paper-plastic lamination application, among which ethylene-vinyl acetate copolymer (EVA) hot melt adhesive hot lamination BOPP film is a typical application of green packaging.

[0003] In the production of traditional ethylene-vinyl acetate copolymer (EVA) hot melt adhesive hot lamination BOPP film, due to the poor bonding force of EVA and homopolypropylene (homopolymer PP), AC agent (high molecular weight polyethylene imine aqueous solution) is coated offline before gluing, and then EVA is coated to form a hot melt adhesive layer. Since the organic solvent used in the coating of AC agent is harmful to the human body and the environment, and the process efficiency of offline gluing and film lamination is low, a BOPP film with primer coating is developed on the market, which includes a primer layer as a surface layer, replacing the traditional AC agent, and EVA is directly coated on the primer layer to form a hot melt adhesive layer in downstream application, so as to avoid offline gluing, improve process efficiency and reduce environmental pollution.

[0004] However, the inventors have found through a large number of practices that the BOPP film with primer coating on the market has the following problems: first, the initial bonding force between the primer layer and the hot melt adhesive layer is insufficient, and at least 48 hours are needed to wait for good bonding strength after EVA is coated on the primer layer, resulting in low production efficiency; second, the primer layer and the core layer are prone to delamination and peeling. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a matt film with primer coating and a preparation method thereof, which eliminates the process of primer AC agent by modifying the joint action of polyhydroxy polyethylene glycol diglycidyl ether and glycidyl methacrylate grafted polypropylene, on the one hand, the primer layer and the coated hot melt adhesive layer have good initial bonding force, and stable bonding force is formed in a short time, improving production efficiency, on the other hand, the primer layer and the core layer of the matt film have good interlayer bonding force, which improves the delamination and peeling problems between the primer layer and the core layer of the traditional matt film with primer coating.

[0006] The technical scheme of the present application is realized by the following way:

[0007] The application discloses a primer-containing matt film, which comprises a primer layer, a core layer and a matt layer arranged in sequence; the primer layer comprises ethylene-vinyl acetate copolymer, 2-5 wt% modified polyhydroxy polyethylene glycol diglycidyl ether and 3-15 wt% glycidyl methacrylate grafted polypropylene; the modified polyhydroxy polyethylene glycol diglycidyl ether is obtained by grafting modification of 3,4-dihydroxyphenylacetic acid on polyhydroxy polyethylene glycol diglycidyl ether, the grafting rate of 3,4-dihydroxyphenylacetic acid in the modified polyhydroxy polyethylene glycol diglycidyl ether is 12-20%, and the grafting rate of glycidyl methacrylate in the glycidyl methacrylate grafted polypropylene is 6-10 wt%; the core layer comprises homopolymerized polypropylene; and the matt layer comprises random copolymerized polypropylene and 40-50 wt% high-density polyethylene.

[0008] The inventor finds that the initial adhesion between the primer layer and the hot melt adhesive layer of the existing primer-containing BOPP film is low, mainly because the interaction force between the components of the primer layer and the hot melt adhesive layer is insufficient and cannot quickly form effective penetration.

[0009] The modified polyhydroxy polyethylene glycol diglycidyl ether is obtained by grafting modification of 3,4-dihydroxyphenylacetic acid on polyhydroxy polyethylene glycol diglycidyl ether, on one hand, the modified polyhydroxy polyethylene glycol diglycidyl ether has a flexible molecular long chain, a strong molecular chain activity and abundant hydroxyl groups, can act as a 'bridge' between the primer layer and the hot melt adhesive layer, forms strong hydrogen bond interactions with ester groups in the EVA component of the hot melt adhesive layer and with components containing ester groups in the primer layer, and is beneficial to improving the initial adhesion between the primer layer and the hot melt adhesive layer; on the other hand, after the modification of polyhydroxy polyethylene glycol diglycidyl ether by 3,4-dihydroxyphenylacetic acid, part of the hydroxyl groups in the modified polyhydroxy polyethylene glycol diglycidyl ether form esterification branched chain structures with 3,4-dihydroxyphenylacetic acid, can form an interfacial network interpenetrating structure between the primer layer and the hot melt adhesive layer, endow the modified polyhydroxy polyethylene glycol diglycidyl ether with suitable hydrophobicity, ensure the compatibility of the modified polyhydroxy polyethylene glycol diglycidyl ether with other components in the primer layer, and on the other hand, the o-diphenol structure in 3,4-dihydroxyphenylacetic acid is beneficial to enhancing the cohesive energy of polymer molecular chains and the initial adhesion between the primer layer and the hot melt adhesive layer.

[0010] If the adding amount of the modified polyhydroxyl polyethylene glycol diglycidyl ether is less than 2 wt%, the improvement of the initial adhesion between the primer layer and the hot melt adhesive layer is not obvious, so that the primer layer and the hot melt adhesive layer cannot form stable adhesion in a short time; if the adding amount of the modified polyhydroxyl polyethylene glycol diglycidyl ether is greater than 5 wt%, the hydrogen bond force between the components of the primer layer is too strong, which is easy to form a physical network crosslinking structure and cannot be applied to the co-extrusion biaxial stretching process, and also causes the adhesion of the primer layer to be too large, which is not conducive to the stretching film formation and the smoothness of the film winding and unwinding.

[0011] In order to ensure the initial adhesion between the primer layer and the hot melt adhesive layer, the grafting rate of 3,4-dihydroxyphenylacetic acid in the modified polyhydroxyl polyethylene glycol diglycidyl ether is limited to 12-20%, if the grafting rate of 3,4-dihydroxyphenylacetic acid in the modified polyhydroxyl polyethylene glycol diglycidyl ether is less than 12%, the hydrophilicity of the modified polyhydroxyl polyethylene glycol diglycidyl ether cannot be reduced, which causes poor compatibility in the primer layer and is not conducive to effectively enhancing the initial adhesion between the primer layer and the hot melt adhesive layer, if the grafting rate of 3,4-dihydroxyphenylacetic acid in the modified polyhydroxyl polyethylene glycol diglycidyl ether is greater than 20%, the steric hindrance is too large, which weakens the intermolecular hydrogen bond between the modified polyhydroxyl polyethylene glycol diglycidyl ether and the hot melt adhesive layer, and is not conducive to enhancing the initial adhesion between the primer layer and the hot melt adhesive layer, and also causes the polarity difference between the primer layer and the core layer to be too large, which causes the interlayer peeling phenomenon between the core layer and the primer layer.

[0012] To improve the interlayer adhesion between the core layer and the primer layer, while reducing the adverse effects on the interlayer adhesion caused by the addition of the polar modified polyhydroxy polyethylene glycol diglycidyl ether, the present application also adds 3-15 wt% of glycidyl methacrylate grafted polypropylene (GMA-g-PP) to the primer layer, and limits the grafting rate of glycidyl methacrylate in GMA-g-PP to 6-10 wt%. Glycidyl methacrylate grafted polypropylene (GMA-g-PP) is a modified polypropylene prepared by grafting glycidyl methacrylate (GMA) onto the polypropylene (PP) backbone. GMA-g-PP combines the properties of PP and GMA, on the one hand, the epoxy groups and methacrylate groups of GMA-g-PP can form strong forces with the polar components in the primer layer, on the other hand, the PP matrix in GMA-g-PP has good compatibility with the homopolymer polypropylene in the core layer, thus enhancing the interlayer adhesion between the core layer and the primer layer. If the addition amount of GMA-g-PP is > 15 wt%, it will cause the overall melting point of the primer layer to be too high, the primer layer requires more heat during production, and requires a higher temperature during stretching. The increase in stretching temperature will cause the ethylene-vinyl acetate copolymer and the modified polyhydroxy polyethylene glycol diglycidyl ether in the primer layer to stick to the roller, ultimately resulting in the inability to form a film due to the inability to match the stretching temperature. If the addition amount of GMA-g-PP is < 3 wt%, a network structure cannot be formed, which is not conducive to enhancing the long-term adhesion between the core layer and the primer layer, resulting in the core layer and the primer layer being prone to separation and delamination at local positions. If the grafting rate of glycidyl methacrylate in GMA-g-PP is < 6%, the polarity of the polypropylene matrix cannot be effectively improved, the interfacial interlayer adhesion between the primer layer and the core layer cannot be improved, and interlayer separation is prone to occur. If the grafting rate of glycidyl methacrylate in GMA-g-PP is > 10 wt%, there are too many polar groups, resulting in a decrease in the thermal stability of the primer layer, and the film cannot be unwound during production, which is not conducive to the smoothness of the film unwinding. Preferably, the polypropylene backbone of the glycidyl methacrylate grafted polypropylene is homopolymer polypropylene, which is the same as the homopolymer polypropylene in the core layer.

[0013] Further, the content of vinyl acetate monomer in the ethylene-vinyl acetate copolymer is 15-20 wt%, and the melt index of the ethylene-vinyl acetate copolymer measured at 190°C under a load of 2.16 kg is 10-20 g / 10 min.

[0014] Further, the number average molecular weight of the polyethylene glycol diglycidyl ether in the modified polyhydroxyl polyethylene glycol diglycidyl ether is 10000-20000 g / mol. In the case of ensuring the effect of the modified polyhydroxyl polyethylene glycol diglycidyl ether on improving the initial adhesion, considering the matching of the temperature and melt flow of the co-extrusion biaxial stretching process, and at the same time ensuring the smoothness of the production of the film, the number average molecular weight of the polyethylene glycol diglycidyl ether in the modified polyhydroxyl polyethylene glycol diglycidyl ether is controlled to be 10000-20000 g / mol. If the molecular weight is too small, the melting point of the modified polyhydroxyl polyethylene glycol diglycidyl ether is too low, which is not conducive to the matching of the melt of other components of the primer layer, and the phenomenon of sticking of the primer layer to the roller may occur. If the molecular weight is too large, the flexibility of the main chain of the modified polyhydroxyl polyethylene glycol diglycidyl ether is not good, which cannot effectively ensure the initial adhesion between the primer layer and the hot melt adhesive layer.

[0015] Further, the melting point of the ethylene-vinyl acetate copolymer is 80-110℃, the melting point of the modified polyhydroxyl polyethylene glycol diglycidyl ether is 70-80℃, and the melting point of the glycidyl methacrylate grafted polypropylene is 130-150℃. Considering the matching of the temperature and melt flow of the co-extrusion biaxial stretching process, the melting point of the modified polyhydroxyl polyethylene glycol diglycidyl ether is limited to 70-80℃, which is conducive to ensuring the matching of the primer layer with the main component EVA and the dispersion of the primer layer.

[0016] Further, the melt index of the glycidyl methacrylate grafted polypropylene is 10-30 g / 10 min under the condition of 230℃ and 2.16 kg, which is conducive to the matching of the melt flow of other components of the primer layer.

[0017] Further, the melt index of the random copolymer polypropylene is 7-12 g / 10 min under the condition of 230℃ and 2.16 kg, and the melt index of the high-density polyethylene is 8-14 g / 10 min under the condition of 190℃ and 21.6 kg, which is conducive to obtaining a primer-containing matte film with excellent matte effect.

[0018] Further, the random copolymer polypropylene is selected from one or both of ethylene-propylene copolymer polypropylene or ethylene-propylene-butylene copolymer polypropylene.

[0019] Further, the thickness of the primer layer is 0.5-2 μm.

[0020] Further, the core layer comprises 99 wt% of homopolymer polypropylene and 1 wt% of antistatic masterbatch, and the melt index of the homopolymer polypropylene is 3-5 g / 10 min under the condition of 230℃ and 2.16 kg.

[0021] The application also provides a preparation method of the matt film with a primer coating, comprising the following steps: uniformly mixing raw materials of each layer through a high-speed mixer, then feeding the raw materials into a screw extruder through a batcher, converging the melt of each extruder into a thick sheet through a T-shaped die, cooling the thick sheet through a chill roller and then feeding the thick sheet into a chill water tank, longitudinally stretching the thick sheet after passing through a water blowing chamber, then transversely stretching the thick sheet, then performing corona treatment after shaping, and then winding the thick sheet into an aging rack, and finally cutting and packaging the thick sheet into a finished product.

[0022] For better understanding and implementation, the application is described in detail below. DETAILED DESCRIPTION

[0023] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0024] The terms used in the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein means and includes any or all possible combinations of one or more associated listed items.

[0025] The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of apparatuses and methods consistent with some aspects of the present application as detailed in the appended claims. In the description of the present application, it should be understood that the terms "first", "second", "third", etc. are only used to distinguish similar objects, and do not necessarily describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0026] In addition, in the description of the present application, "multiple" means two or more, unless otherwise specified. The association between the associated objects is described by "and / or", which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents a "or" relationship between the associated objects before and after it.

[0027] It is to be understood that the embodiments of the present application are not limited to the precise construction that has been described above and that various modifications and changes can be effected therein by those skilled in the art without departing from the scope of the application. The scope of the present application is limited only by the appended claims.

[0028] As an embodiment of the present application, the present embodiment provides a primer-containing matt film, comprising a primer layer, a core layer and a matt layer arranged in sequence; the primer layer comprises ethylene-vinyl acetate copolymer, 2-5wt% modified polyhydroxy polyethylene glycol diglycidyl ether and 3-15wt% glycidyl methacrylate grafted polypropylene; the modified polyhydroxy polyethylene glycol diglycidyl ether is obtained by grafting modification of 3,4-dihydroxyphenylacetic acid on polyhydroxy polyethylene glycol diglycidyl ether, the grafting rate of 3,4-dihydroxyphenylacetic acid in the modified polyhydroxy polyethylene glycol diglycidyl ether is 12-20%, the grafting rate of glycidyl methacrylate in the glycidyl methacrylate grafted polypropylene is 6-10wt%, the core layer comprises homopolymerized polypropylene; the matt layer comprises random copolymerized polypropylene and 40-50wt% high-density polyethylene.

[0029] Further, the content of vinyl acetate monomer in the ethylene-vinyl acetate copolymer is 15-20wt%, the melt index of the ethylene-vinyl acetate copolymer measured at 190℃ under a load of 2.16kg is 10-20g / 10min.

[0030] Further, the number average molecular weight of polyethylene glycol diglycidyl ether in the modified polyhydroxy polyethylene glycol diglycidyl ether is 10000-20000g / mol.

[0031] Further, the melting point of the ethylene-vinyl acetate copolymer is 80-110℃, the melting point of the modified polyhydroxy polyethylene glycol diglycidyl ether is 70-80℃, and the melting point of the glycidyl methacrylate grafted polypropylene is 130-150℃.

[0032] Further, the melt index of the glycidyl methacrylate grafted polypropylene measured at 230℃ under a load of 2.16kg is 10-30g / 10min.

[0033] Further, the melt index of the random copolymerized polypropylene measured at 230℃ under a load of 2.16kg is 7-12g / 10min, and the melt index of the high-density polyethylene measured at 190℃ under a load of 21.6kg is 8-14g / 10min.

[0034] Further, the random copolymerized polypropylene is selected from one or both of ethylene-propylene copolymerized polypropylene and ethylene-propylene-butylene copolymerized polypropylene.

[0035] Further, the primer layer has a thickness of 0.5-2 μm.

[0036] Further, the core layer comprises 99 wt% of homopolypropylene and 1 wt% of antistatic masterbatch, the homopolypropylene has a melt index of 3-5 g / 10 min at 230℃ under a load of 2.16 kg,

[0037] The application also provides a preparation method of the primer-containing matt film, comprising the following steps: uniformly mixing raw materials of each layer by a high-speed mixer, then feeding the raw materials into a screw extruder through a batcher, measuring the melt of each extruder by a metering pump, and then combining the melts into a thick sheet through a T-shaped die head, cooling the thick sheet by a chilling roller and then feeding the thick sheet into a chilling water tank, longitudinally stretching the thick sheet after passing through a water blowing chamber, then transversely stretching the thick sheet, then performing corona treatment after shaping, and then winding the primer-containing matt film onto an aging rack for treatment, and finally cutting and packaging the primer-containing matt film into a finished product.

[0038] The physical property indexes of the embodiments or the comparative examples and the test methods thereof are as follows:

[0039] Evaluation of initial adhesion between the primer layer and the hot melt adhesive layer: taking the primer-containing matt film prepared in the application, applying EVA hot melt adhesive (VA content: 18 wt%, melt index: 15 g / 10 min) on the surface of the primer layer, the coating thickness is 8 μm, keeping the sample at 25℃ for 5 minutes after coating, cutting the sample into a sample strip with a brightness of 15 mm and a length of 15 cm, using 3M adhesive tape to test the interlayer peeling, and finally using a universal testing machine to determine the peeling force required to peel off the primer-containing matt film and the hot melt adhesive layer, the greater the peeling force, the better the initial adhesion with the hot melt adhesive layer.

[0040] Evaluation of the bonding force between the primer layer and the core layer: taking the primer-containing matt film prepared in the application, compounding the 3M adhesive tape with the primer layer, rolling the film surface back and forth three times with a pressure roller at a speed of about 12 cm / s under a weight of 2.5 kg, requiring that there is no bubble between the primer-containing matt film and the adhesive tape, then placing the sample at 25℃ for 3 minutes, cutting the sample into a sample strip with a width of 15 mm and a length of 15 cm, setting the peeling force to 12 N / 15 mm, and observing the separation of the primer layer and the core layer.

[0041] It should be noted that the polypropylene backbone of the glycidyl methacrylate grafted polypropylene is homopolypropylene, which is the same as the homopolypropylene in the core layer, and the proportions in the embodiments or the comparative examples are all weight percentages.

[0042] Example 1

[0043] The embodiment provides a primer-containing matt film, which comprises a primer layer, a core layer and a matt layer arranged in sequence. The preparation method of the primer-containing matt film comprises the following steps:

[0044] The base coat resin was prepared by mixing 95 wt% of ethylene-vinyl acetate copolymer (melting point 95°C, melt index 15 g / 10 min at 190°C, 2.16 kg, vinyl acetate monomer content 18 wt%), 3 wt% of glycidyl methacrylate grafted polypropylene (melting point 150°C, melt index 10 g / 10 min at 230°C, 2.16 kg, glycidyl methacrylate grafting rate 6%) and 2 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 70°C, 3,4-dihydroxyphenylacetic acid grafting rate 12%, number average molecular weight of polyethylene glycol diglycidyl ether 10000 g / mol) uniformly.

[0045] The core layer resin was prepared by mixing 99 wt% of homopolymer polypropylene (melt index 3.2 g / 10 min at 230°C, 2.16 kg) and 1 wt% of antistatic masterbatch (carrier homopolymer polypropylene, antistatic agent effective concentration in antistatic masterbatch 40 wt%) uniformly.

[0046] The mat layer resin was prepared by mixing 50 wt% of high density polyethylene (melt index 10 g / 10 min at 190°C, 21.6 kg) and 50 wt% of ethylene-propylene copolymer polypropylene (melt index 7.1 g / 10 min at 230°C, 2.16 kg) uniformly.

[0047] The preparation method of the BOPP film of the present embodiment comprises the following steps: uniformly mixing the raw materials of each layer through a high-speed mixer, then respectively feeding into three screw extruders (the base coat layer and the mat layer are single-screw extruders, the core layer is a double-screw extruder, the base coat layer extrusion temperature is 235°C, the mat layer extrusion temperature is set to 245°C, and the core layer extrusion temperature is 250°C) through a batcher, the melts of the three extruders are metered through a melt metering pump, then converge into a thick sheet through a long flow channel in a T-shaped die, the thick sheet is cooled through a chill roll and enters a chill water tank, then enters a longitudinal stretching area after passing through a blow chamber, longitudinal stretching is performed (base coat layer: preheating zone temperature 70°C, stretching zone temperature 60°C, setting zone temperature 65°C; mat layer: preheating zone temperature 135°C, stretching zone temperature 130°C, setting zone temperature 130°C; longitudinal stretching ratio 5 times), then enters a transverse stretching area, transverse stretching is performed (stretching temperature 160°C, transverse stretching ratio 8 times), then performs corona treatment after setting, and then is wound onto an aging rack for treatment, and after the treatment is completed, is cut and packaged into finished products.

[0048] The total thickness of the film is 15 pm, wherein the primer layer has a thickness of 1.5 pm and the matting layer has a thickness of 2 pm.

[0049] Example 2

[0050] The primer-matting film of the present example comprises a primer layer, a core layer and a matting layer arranged in sequence. The preparation method of the primer-matting film of the present example comprises the following steps:

[0051] Preparation of the primer layer resin: 87 wt% of ethylene-vinyl acetate copolymer (melting point of 95 °C, melt index of 15 g / 10 min measured at 190 °C under a load of 2.16 kg, content of vinyl acetate monomer of 18 wt%), 10 wt% of glycidyl methacrylate grafted polypropylene (melting point of 140 °C, melt index of 20 g / 10 min measured at 230 °C under a load of 2.16 kg, grafting rate of glycidyl methacrylate of 8%) and 3 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75 °C, grafting rate of 3,4-dihydroxyphenylacetic acid of 16%, number average molecular weight of polyethylene glycol diglycidyl ether of 15000 g / mol) are uniformly mixed to obtain the primer layer resin.

[0052] Preparation of the matting layer resin: 50 wt% of high-density polyethylene (melt index of 10 g / 10 min measured at 190 °C under a load of 21.6 kg) and 50 wt% of ethylene-propylene copolymerized polypropylene (melt index of 7.1 g / 10 min measured at 230 °C under a load of 2.16 kg) are uniformly mixed to obtain the matting layer resin.

[0053] The preparation method of the primer-matting film of the present example is the same as that of Example 1, and thus is not described herein.

[0054] The total thickness of the film is 15 pm, wherein the primer layer has a thickness of 1.5 pm and the matting layer has a thickness of 2 pm.

[0055] Example 3

[0056] The primer-matting film of the present example comprises a primer layer, a core layer and a matting layer arranged in sequence. The preparation method of the primer-matting film of the present example comprises the following steps:

[0057] The primer layer resin was prepared by uniformly mixing 80 wt% of ethylene-vinyl acetate copolymer (melting point 95°C, melt index 15 g / 10 min at 190°C, 2.16 kg, and vinyl acetate monomer content 18 wt%), 15 wt% of glycidyl methacrylate grafted polypropylene (melting point 150°C, melt index 30 g / 10 min at 230°C, 2.16 kg, and glycidyl methacrylate grafting rate 10%), and 5 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 80°C, 3,4-dihydroxyphenyl acetic acid grafting rate 20%, and polyethylene glycol diglycidyl ether number average molecular weight 20,000 g / mol).

[0058] The mat layer resin was prepared by uniformly mixing 50 wt% of high-density polyethylene (melt index 10 g / 10 min at 190°C, 21.6 kg) and 50 wt% of ethylene-propylene copolymerized polypropylene (melt index 7.1 g / 10 min at 230°C, 2.16 kg).

[0059] The preparation method of the primer layer-mat film of the present example was the same as that of Example 1, and thus is not described herein.

[0060] The total thickness of the film was 15 µm, in which the primer layer was 1.5 µm thick and the mat layer was 2 µm thick.

[0061] Comparative Example 1

[0062] The present comparative example provides a primer layer-mat film including a primer layer, a core layer, and a mat layer sequentially arranged. The preparation method of the primer layer-mat film of the present comparative example includes the following steps:

[0063] The primer layer resin was prepared by uniformly mixing 89.5 wt% of ethylene-vinyl acetate copolymer (melting point 95°C, melt index 15 g / 10 min at 190°C, 2.16 kg, and vinyl acetate monomer content 18 wt%), 10 wt% of glycidyl methacrylate grafted polypropylene (melting point 140°C, melt index 20 g / 10 min at 230°C, 2.16 kg, and glycidyl methacrylate grafting rate 8%), and 0.5 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate 16%, and polyethylene glycol diglycidyl ether number average molecular weight 15000 g / mol).

[0064] The core layer resin was prepared by uniformly mixing 99 wt% of homopolymer polypropylene (melt index 3.2 g / 10 min at 230°C, 2.16 kg) and 1 wt% of antistatic masterbatch (carrier homopolymer polypropylene and antistatic agent effective concentration in the antistatic masterbatch 40 wt%).

[0065] The mat layer resin was prepared by uniformly mixing 50 wt% of high-density polyethylene (melt index 10 g / 10 min at 190°C, 21.6 kg) and 50 wt% of ethylene-propylene copolymer polypropylene (melt index 7.1 g / 10 min at 230°C, 2.16 kg).

[0066] The primer layer resin was prepared by uniformly mixing 89.5 wt% of ethylene-vinyl acetate copolymer (melting point 95°C, melt index 15 g / 10 min at 190°C, 2.16 kg, and vinyl acetate monomer content 18 wt%), 10 wt% of glycidyl methacrylate grafted polypropylene (melting point 140°C, melt index 20 g / 10 min at 230°C, 2.16 kg, and glycidyl methacrylate grafting rate 8%), and 0.5 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate 16%, and polyethylene glycol diglycidyl ether number average molecular weight 15000 g / mol).

[0067] The total thickness of the film was 15 µm, of which the primer layer was 1.5 µm thick and the mat layer was 2 µm thick.

[0068] Comparative Example 2

[0069] The primer layer resin was prepared by uniformly mixing 89.5 wt% of ethylene-vinyl acetate copolymer (melting point 95°C, melt index 15 g / 10 min at 190°C, 2.16 kg, and vinyl acetate monomer content 18 wt%), 10 wt% of glycidyl methacrylate grafted polypropylene (melting point 140°C, melt index 20 g / 10 min at 230°C, 2.16 kg, and glycidyl methacrylate grafting rate 8%), and 0.5 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate 16%, and polyethylene glycol diglycidyl ether number average molecular weight 15000 g / mol).

[0070] The primer layer resin was prepared by uniformly mixing 83 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 8%), and 7 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 16%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0071] The core layer resin was prepared by uniformly mixing 99 wt% of a homopolymer polypropylene (melt index of 3.2 g / 10 min at 230°C under a load of 2.16 kg) and 1 wt% of an antistatic master batch (carrier being a homopolymer polypropylene and effective concentration of the antistatic agent in the antistatic master batch being 40 wt%).

[0072] The mat layer resin was prepared by uniformly mixing 50 wt% of a high-density polyethylene (melt index of 10 g / 10 min at 190°C under a load of 21.6 kg) and 50 wt% of an ethylene-propylene copolymer polypropylene (melt index of 7.1 g / 10 min at 230°C under a load of 2.16 kg).

[0073] The primer layer resin was prepared by uniformly mixing 83 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 8%), and 7 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 16%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0074] The total thickness of the film was 15 µm, in which the primer layer was 1.5 µm thick and the mat layer was 2 µm thick.

[0075] Comparative Example 3

[0076] The primer layer resin was prepared by uniformly mixing 83 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 8%), and 7 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 16%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0077] Preparation of the base coating resin: 96 wt% ethylene-vinyl acetate copolymer (melting point 95℃, melt index of 15 g / 10 min measured at 190℃ and 2.16 kg, vinyl acetate monomer content 18 wt%), 1 wt% glycidyl methacrylate grafted polypropylene (melting point 140℃, melt index of 20 g / 10 min measured at 230℃ and 2.16 kg, glycidyl methacrylate grafting rate 8%) and 3 wt% modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75℃, 3,4-dihydroxyphenylacetic acid grafting rate 16%, number average molecular weight of polyethylene glycol diglycidyl ether 15000 g / mol) were mixed evenly to obtain the base coating resin.

[0078] Core layer resin preparation: 99 wt% homopolymer polypropylene (melt index of 3.2 g / 10 min was measured at 230℃ and 2.16 kg) and 1 wt% antistatic masterbatch (carrier is homopolymer polypropylene, and the effective concentration of antistatic agent in the antistatic masterbatch is 40 wt%) were mixed evenly to obtain core layer resin.

[0079] Preparation of matte layer resin: 50 wt% high-density polyethylene (melt index of 10 g / 10 min was measured at 190℃ and 21.6 kg) and 50 wt% ethylene-propylene copolymer polypropylene (melt index of 7.1 g / 10 min was measured at 230℃ and 2.16 kg) were mixed evenly to obtain matte layer resin.

[0080] The preparation method of the matte film containing the primer in this comparative example is the same as that in Example 1, so it will not be described again.

[0081] The total thickness of the film is 15µm, of which the thickness of the base coating is 1.5µm and the thickness of the matte layer is 2µm.

[0082] Comparative Example 4

[0083] This comparative example provides a matte film containing a primer coating, comprising a primer layer, a core layer, and a matte layer sequentially disposed therefrom. The preparation method of each resin layer of the matte film containing the primer coating in this comparative example includes the following steps:

[0084] The primer layer resin was prepared by uniformly mixing 77 wt% of ethylene-vinyl acetate copolymer (melting point 95°C, melt index 15 g / 10 min at 190°C, 2.16 kg, and vinyl acetate monomer content 18 wt%), 20 wt% of glycidyl methacrylate grafted polypropylene (melting point 140°C, melt index 20 g / 10 min at 230°C, 2.16 kg, and glycidyl methacrylate grafting rate 8%), and 3 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate 16%, and polyethylene glycol diglycidyl ether number average molecular weight 15000 g / mol).

[0085] The core layer resin was prepared by uniformly mixing 99 wt% of homopolymer polypropylene (melt index 3.2 g / 10 min at 230°C, 2.16 kg) and 1 wt% of antistatic masterbatch (carrier homopolymer polypropylene and antistatic agent effective concentration in the antistatic masterbatch 40 wt%).

[0086] The mat layer resin was prepared by uniformly mixing 50 wt% of high-density polyethylene (melt index 10 g / 10 min at 190°C, 21.6 kg) and 50 wt% of ethylene-propylene copolymer polypropylene (melt index 7.1 g / 10 min at 230°C, 2.16 kg).

[0087] The primer layer resin of the mat film with primer of the present comparative example was prepared by the same method as that of Example 1, and thus a detailed description thereof will not be given.

[0088] The total thickness of the film was 15 µm, in which the primer layer was 1.5 µm thick and the mat layer was 2 µm thick.

[0089] Comparative Example 5

[0090] The mat film with primer of the present comparative example included a primer layer, a core layer, and a mat layer, which were sequentially arranged. The mat film with primer of the present comparative example was prepared by the following steps.

[0091] The primer layer resin was prepared by uniformly mixing 87 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 2%), and 3 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 16%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0092] The core layer resin was prepared by uniformly mixing 99 wt% of a homopolymer polypropylene (melt index of 3.2 g / 10 min at 230°C under a load of 2.16 kg) and 1 wt% of an antistatic master batch (carrier being a homopolymer polypropylene and effective concentration of the antistatic agent in the antistatic master batch being 40 wt%).

[0093] The mat layer resin was prepared by uniformly mixing 50 wt% of a high-density polyethylene (melt index of 10 g / 10 min at 190°C under a load of 21.6 kg) and 50 wt% of an ethylene-propylene copolymer polypropylene (melt index of 7.1 g / 10 min at 230°C under a load of 2.16 kg).

[0094] The primer layer resin was prepared by uniformly mixing 87 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 2%), and 3 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 16%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0095] The total thickness of the film was 15 µm, in which the primer layer was 1.5 µm thick and the mat layer was 2 µm thick.

[0096] Comparative Example 6

[0097] The primer layer resin was prepared by uniformly mixing 87 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 2%), and 3 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 16%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0098] The primer layer resin was prepared by uniformly mixing 87 wt% of ethylene-vinyl acetate copolymer (melting point 95°C, melt index 15 g / 10 min at 190°C, 2.16 kg, and vinyl acetate monomer content 18 wt%), 10 wt% of glycidyl methacrylate grafted polypropylene (melting point 140°C, melt index 20 g / 10 min at 230°C, 2.16 kg, and glycidyl methacrylate grafting rate 15%), and 3 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate 16%, and polyethylene glycol diglycidyl ether number average molecular weight 15000 g / mol).

[0099] The core layer resin was prepared by uniformly mixing 99 wt% of homopolymer polypropylene (melt index 3.2 g / 10 min at 230°C, 2.16 kg) and 1 wt% of antistatic masterbatch (carrier homopolymer polypropylene and antistatic agent effective concentration in the antistatic masterbatch 40 wt%).

[0100] The mat layer resin was prepared by uniformly mixing 50 wt% of high-density polyethylene (melt index 10 g / 10 min at 190°C, 21.6 kg) and 50 wt% of ethylene-propylene copolymer polypropylene (melt index 7.1 g / 10 min at 230°C, 2.16 kg).

[0101] The primer layer resin of the mat film with primer of the present comparative example was prepared by the same method as that of Example 1, and thus a repeated description will be omitted.

[0102] The total thickness of the film was 15 µm, in which the primer layer was 1.5 µm thick and the mat layer was 2 µm thick.

[0103] Comparative Example 7

[0104] The mat film with primer of the present comparative example included a primer layer, a core layer, and a mat layer, which were sequentially arranged. The mat film with primer of the present comparative example was prepared by the following steps.

[0105] The primer layer resin was prepared by uniformly mixing 87 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 8%), and 3 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 5%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0106] The core layer resin was prepared by uniformly mixing 99 wt% of a homopolymer polypropylene (melt index of 3.2 g / 10 min at 230°C under a load of 2.16 kg) and 1 wt% of an antistatic master batch (carrier being a homopolymer polypropylene and effective concentration of the antistatic agent in the antistatic master batch being 40 wt%).

[0107] The mat layer resin was prepared by uniformly mixing 50 wt% of a high-density polyethylene (melt index of 10 g / 10 min at 190°C under a load of 21.6 kg) and 50 wt% of an ethylene-propylene copolymer polypropylene (melt index of 7.1 g / 10 min at 230°C under a load of 2.16 kg).

[0108] The primer layer resin was prepared by uniformly mixing 87 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 8%), and 3 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 5%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0109] The total thickness of the film was 15 µm, in which the primer layer was 1.5 µm thick and the mat layer was 2 µm thick.

[0110] Comparative Example 8

[0111] The primer layer resin was prepared by uniformly mixing 87 wt% of an ethylene-vinyl acetate copolymer (melting point of 95°C, melt index of 15 g / 10 min at 190°C under a load of 2.16 kg, and vinyl acetate monomer content of 18 wt%), 10 wt% of a glycidyl methacrylate grafted polypropylene (melting point of 140°C, melt index of 20 g / 10 min at 230°C under a load of 2.16 kg, and glycidyl methacrylate grafting rate of 8%), and 3 wt% of a modified polyhydroxy polyethylene glycol diglycidyl ether (melting point of 75°C, 3,4-dihydroxyphenyl acetic acid grafting rate of 5%, and number average molecular weight of the polyethylene glycol diglycidyl ether of 15,000 g / mol).

[0112] Preparation of the base coating resin: 87 wt% ethylene-vinyl acetate copolymer (melting point 95℃, melt index of 15 g / 10 min measured at 190℃ and 2.16 kg, vinyl acetate monomer content 18 wt%), 10 wt% glycidyl methacrylate grafted polypropylene (melting point 140℃, melt index of 20 g / 10 min measured at 230℃ and 2.16 kg, glycidyl methacrylate grafting rate 8%) and 3 wt% modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75℃, 3,4-dihydroxyphenylacetic acid grafting rate 25%, number average molecular weight of polyethylene glycol diglycidyl ether 15000 g / mol) were mixed evenly to obtain the base coating resin.

[0113] Core layer resin preparation: 99 wt% homopolymer polypropylene (melt index of 3.2 g / 10 min was measured at 230℃ and 2.16 kg) and 1 wt% antistatic masterbatch (carrier is homopolymer polypropylene, and the effective concentration of antistatic agent in the antistatic masterbatch is 40 wt%) were mixed evenly to obtain core layer resin.

[0114] Preparation of matte layer resin: 50 wt% high-density polyethylene (melt index of 10 g / 10 min was measured at 190℃ and 21.6 kg) and 50 wt% ethylene-propylene copolymer polypropylene (melt index of 7.1 g / 10 min was measured at 230℃ and 2.16 kg) were mixed evenly to obtain matte layer resin.

[0115] The preparation method of the matte film containing the primer in this comparative example is the same as that in Example 1, so it will not be described again.

[0116] The total thickness of the film is 15µm, of which the thickness of the base coating is 1.5µm and the thickness of the matte layer is 2µm.

[0117] Comparative Example 9

[0118] This comparative example provides a matte film containing a primer coating, comprising a primer layer, a core layer, and a matte layer sequentially disposed therefrom. The preparation method of each resin layer of the matte film containing the primer coating in this comparative example includes the following steps:

[0119] Preparation of the base coating resin: 87 wt% ethylene-vinyl acetate copolymer (melting point 95℃, melt index of 15 g / 10 min measured at 190℃ and 2.16 kg, vinyl acetate monomer content 18 wt%), 10 wt% glycidyl methacrylate grafted polypropylene (melting point 140℃, melt index of 20 g / 10 min measured at 230℃ and 2.16 kg, glycidyl methacrylate grafting rate 8%) and 3 wt% modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75℃, 3,4-dihydroxyphenylacetic acid grafting rate 16%, number average molecular weight of polyethylene glycol diglycidyl ether 5000 g / mol) were mixed evenly to obtain the base coating resin.

[0120] Core layer resin preparation: 99 wt% homopolymer polypropylene (melt index of 3.2 g / 10 min was measured at 230℃ and 2.16 kg) and 1 wt% antistatic masterbatch (carrier is homopolymer polypropylene, and the effective concentration of antistatic agent in the antistatic masterbatch is 40 wt%) were mixed evenly to obtain core layer resin.

[0121] Preparation of matte layer resin: 50 wt% high-density polyethylene (melt index of 10 g / 10 min was measured at 190℃ and 21.6 kg) and 50 wt% ethylene-propylene copolymer polypropylene (melt index of 7.1 g / 10 min was measured at 230℃ and 2.16 kg) were mixed evenly to obtain matte layer resin.

[0122] The preparation method of the matte film containing the primer in this comparative example is the same as that in Example 1, so it will not be described again.

[0123] The total thickness of the film is 15µm, of which the thickness of the base coating is 1.5µm and the thickness of the matte layer is 2µm.

[0124] Comparative Example 10

[0125] This comparative example provides a matte film containing a primer coating, comprising a primer layer, a core layer, and a matte layer sequentially disposed therefrom. The preparation method of each resin layer of the matte film containing the primer coating in this comparative example includes the following steps:

[0126] The primer layer resin was prepared by uniformly mixing 87 wt% of ethylene-vinyl acetate copolymer (melting point 95°C, melt index 15 g / 10 min at 190°C, 2.16 kg, and vinyl acetate monomer content 18 wt%), 10 wt% of glycidyl methacrylate grafted polypropylene (melting point 140°C, melt index 20 g / 10 min at 230°C, 2.16 kg, and glycidyl methacrylate grafting rate 8%), and 3 wt% of modified polyhydroxy polyethylene glycol diglycidyl ether (melting point 75°C, 3,4-dihydroxyphenylacetic acid grafting rate 16%, and polyethylene glycol diglycidyl ether number average molecular weight 30000 g / mol).

[0127] The core layer resin was prepared by uniformly mixing 99 wt% of homopolymer polypropylene (melt index 3.2 g / 10 min at 230°C, 2.16 kg) and 1 wt% of antistatic masterbatch (carrier homopolymer polypropylene and antistatic agent effective concentration in the antistatic masterbatch 40 wt%).

[0128] The matting layer resin was prepared by uniformly mixing 50 wt% of high-density polyethylene (melt index 10 g / 10 min at 190°C, 21.6 kg) and 50 wt% of ethylene-propylene copolymer polypropylene (melt index 7.1 g / 10 min at 230°C, 2.16 kg).

[0129] The preparation method of the primer-containing matting film of the present comparative example was the same as that of Example 1, and thus will not be described again.

[0130] The total thickness of the film was 15 µm, wherein the primer layer was 1.5 µm thick and the matting layer was 2 µm thick.

[0131] The performance tests of the primer-containing matting films of Examples 1 to 3 and Comparative Examples 1 to 10 are shown in Table 1 below.

[0132] Table 1

[0133]

[0134] From the performance test data above, it can be seen that the primer-containing matting films of Examples 1 to 3 of the present application have good initial adhesion between the primer layer and the hot melt adhesive layer, good interlayer adhesion between the primer layer and the core layer, and no delamination or peeling between the primer layer and the core layer, and have good film-forming performance during production, and good uncoiling and winding smoothness of the matting film product.

[0135] The amount of modified polyhydroxy polyethylene glycol diglycidyl ether added in the primer layer of the comparative example 1 is too small, and the improvement of the initial adhesion between the primer layer and the hot melt adhesive layer is not obvious. The initial adhesion between the primer layer and the hot melt adhesive layer is low, and the film forming property is poor during production.

[0136] The amount of modified polyhydroxy polyethylene glycol diglycidyl ether added in the primer layer of the comparative example 2 is too large, and the hydrogen bonding force between the components of the primer layer is too strong. It is easy to form a physical network cross-linked structure and cannot be applied to the co-extrusion and double stretching process. At the same time, it will also cause the adhesion of the primer layer to be too large, and the film forming property is poor and the smoothness of the uncoiling of the extinction film product is poor during production.

[0137] The amount of glycidyl methacrylate grafted polypropylene added in the primer layer of the extinction film of the comparative example 3 is too small, which is not conducive to the formation of a network structure and the enhancement of the long-term adhesion between the core layer and the primer layer. The separation and delamination phenomenon easily occurs between the core layer and the primer layer at local positions.

[0138] The amount of glycidyl methacrylate grafted polypropylene added in the primer layer of the extinction film of the comparative example 4 is too large, and the overall melting point of the primer layer is too high. The primer layer requires more heat during production and needs a higher stretching temperature. The increase of the stretching temperature causes the ethylene-vinyl acetate copolymer and the modified polyhydroxy polyethylene glycol diglycidyl ether in the primer layer to stick to the roller. Finally, the stretching temperature cannot be matched, and the film cannot be formed.

[0139] The grafting rate of glycidyl methacrylate in the glycidyl methacrylate grafted polypropylene in the primer layer of the extinction film of the comparative example 5 is too low. It cannot effectively improve the polarity of the polypropylene matrix, and thus cannot effectively improve the interfacial adhesion between the primer layer and the core layer. The interlayer separation phenomenon occurs between the core layer and the primer layer, and the film forming property is poor.

[0140] The grafting rate of glycidyl methacrylate in the glycidyl methacrylate grafted polypropylene in the primer layer of the extinction film of the comparative example 6 is too high. Too many polar groups cause the thermal stability of the primer layer to decrease, and the film cannot be uncoiled during production. The smoothness of the uncoiling of the film is poor.

[0141] The grafting rate of 3,4-dihydroxyphenylacetic acid in the modified polyhydroxy polyethylene glycol diglycidyl ether in the primer layer of the extinction film of the comparative example 7 is too low. It cannot effectively reduce the hydrophilicity of the modified polyhydroxy polyethylene glycol diglycidyl ether, resulting in poor compatibility of the primer layer. The initial adhesion between the primer layer and the hot melt adhesive layer is poor.

[0142] The grafting rate of 3,4-dihydroxyphenylacetic acid in the modified polyhydroxy polyethylene glycol diglycidyl ether in the primer layer of the primer-containing matte film of Comparative Example 8 is too high, and the steric hindrance is too large, which weakens the intermolecular hydrogen bond between the primer layer and the hot melt adhesive layer, and the initial adhesion of the primer layer and the hot melt adhesive layer is poor, and the polarity difference between the primer layer and the core layer is too large, which causes the interlayer peeling between the core layer and the primer layer.

[0143] The number average molecular weight of the polyethylene glycol diglycidyl ether in the modified polyhydroxy polyethylene glycol diglycidyl ether in the primer layer of the primer-containing matte film of Comparative Example 9 is too small, and the melting point of the modified polyhydroxy polyethylene glycol diglycidyl ether is too low, which is not conducive to the melt compatibility with other components of the primer layer, and the primer layer appears to be sticky.

[0144] The number average molecular weight of the polyethylene glycol diglycidyl ether in the modified polyhydroxy polyethylene glycol diglycidyl ether in the primer layer of the primer-containing matte film of Comparative Example 10 is too large, and the flexibility of the main chain of the modified polyhydroxy polyethylene glycol diglycidyl ether is poor, and the initial adhesion between the primer layer and the hot melt adhesive layer is poor.

[0145] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, and the present application also intends to include these modifications and improvements.

Claims

1. A base-coated matte film, characterized by, The coating film comprises a primer layer, a core layer and a matt layer arranged in sequence; the primer layer comprises ethylene-vinyl acetate copolymer, 2-5wt% modified polyhydroxy polyethylene glycol diglycidyl ether and 3-15wt% glycidyl methacrylate grafted polypropylene; the content of vinyl acetate monomer in the ethylene-vinyl acetate copolymer is 15-20wt%, the melt index of the ethylene-vinyl acetate copolymer measured at 190℃ under a load of 2.16kg is 10-20g / 10min; the modified polyhydroxy polyethylene glycol diglycidyl ether is obtained by grafting modification of 3,4-dihydroxyphenylacetic acid on polyhydroxy polyethylene glycol diglycidyl ether, the grafting rate of 3,4-dihydroxyphenylacetic acid in the modified polyhydroxy polyethylene glycol diglycidyl ether is 12-20%; the grafting rate of glycidyl methacrylate in the glycidyl methacrylate grafted polypropylene is 6-10wt%; the core layer comprises 99wt% homopolymerized polypropylene and 1wt% antistatic master batch, the melt index of the homopolymerized polypropylene measured at 230℃ under a load of 2.16kg is 3-5g / 10min; the matt layer comprises random copolymerized polypropylene and 40-50wt% high-density polyethylene.

2. The matte film with a base coat according to claim 1, wherein The number average molecular weight of the polyethylene glycol diglycidyl ether in the modified polyhydroxy polyethylene glycol diglycidyl ether is 10000-20000g / mol.

3. The matte film with a base coat according to claim 1, wherein The melting point of the ethylene-vinyl acetate copolymer is 80-110℃, the melting point of the modified polyhydroxy polyethylene glycol diglycidyl ether is 70-80℃, and the melting point of the glycidyl methacrylate grafted polypropylene is 130-150℃.

4. The matte film with a base coat according to claim 1, wherein The melt index of the glycidyl methacrylate grafted polypropylene measured at 230℃ under a load of 2.16kg is 10-30g / 10min.

5. The matte film with a base coat according to claim 1, wherein The melt index of the random copolymerized polypropylene measured at 230℃ under a load of 2.16kg is 7-12g / 10min, and the melt index of the high-density polyethylene measured at 190℃ under a load of 21.6kg is 8-14g / 10min.

6. The matte film with a base coat according to claim 1, wherein The random copolymerized polypropylene is selected from one or both of ethylene-propylene copolymerized polypropylene and ethylene-propylene-butylene copolymerized polypropylene.

7. The matte film with a base coat according to claim 1, wherein The thickness of the primer layer is 0.5-2μm.

8. A method of producing the flatting film with a base coat according to any one of claims 1 to 7, characterized by, The method comprises the following steps: uniformly mixing raw materials of each layer by a high-speed mixer, then feeding the raw materials into a screw extruder through a batcher, converging the melt of each extruder into a thick sheet through a T-shaped die, cooling the thick sheet by a chill roll and then feeding the thick sheet into a chill water tank, longitudinally stretching the thick sheet after passing through a water blowing chamber, then transversely stretching the thick sheet, then performing corona treatment after shaping, and then winding the thick sheet onto an aging rack, cutting and packaging the thick sheet into a finished product after the treatment is completed.

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