阅读说明：本技术 一种双向拉伸聚乙烯柔面哑光薄膜组合物和薄膜及其应用 (Biaxially oriented polyethylene soft-surface matte film composition, film and application thereof ) 是由 韦丽明 黎倬辰 于 2020-04-09 设计创作，主要内容包括：本发明涉及薄膜加工技术领域,公开了一种双向拉伸聚乙烯柔面哑光薄膜组合物和薄膜及其应用。所述组合物包括第一功能层料、支撑层料和第三功能层料,其中,所述第一功能层料含有第一柔面哑光功能材料,所述第一柔面哑光功能材料为共混物经共混改性制备得到的产物,其中,所述共混物含有第一多碳聚乙烯和助剂,所述助剂含有低压高密度聚乙烯和可选的活化硅微球。采用该组合物制备的薄膜具有消光、柔和观感和触感、高雾度、低光泽度、直线易撕性和高抗穿刺性。(The invention relates to the technical field of film processing, and discloses a biaxially oriented polyethylene soft-surface matte film composition, a film and application thereof. The composition comprises a first functional layer material, a support layer material and a third functional layer material, wherein the first functional layer material contains a first soft-surface matte functional material, the first soft-surface matte functional material is a product prepared by blending and modifying a blend, the blend contains first polycarbopolyethylene and an auxiliary agent, and the auxiliary agent contains low-pressure high-density polyethylene and optional activated silicon microspheres. Films prepared using the composition have a matte, soft look and feel, high haze, low gloss, straight line tear, and high puncture resistance.)

1. The biaxially oriented polyethylene soft-surface matte film composition comprises a first functional layer material, a supporting layer material and a third functional layer material, and is characterized in that the first functional layer material contains a first soft-surface matte functional material, the first soft-surface matte functional material is a product prepared by blending and modifying a blend, wherein the blend contains a first polycarbopolyethylene and an auxiliary agent, and the auxiliary agent contains a low-pressure high-density polyethylene and optional activated silicon microspheres.

2. The composition of claim 1, wherein the low pressure high density polyethylene has a melt flow rate of 7 to 10g/10min at 190 ℃ under a 2.16kg load and a density of 0.94 to 0.97g/cm³；

Preferably, the activated silicon microspheres are obtained by treating silicon microspheres with a silane coupling agent;

preferably, the silane coupling agent is 3-aminopropyltriethoxysilane and/or 3-aminopropyltrimethoxysilane;

preferably, the weight ratio of the silicon microspheres to the silane coupling agent is 1: (0.01-0.5);

preferably, the weight ratio of the low-pressure high-density polyethylene to the activated silicon microspheres is 1: (0-2).

3. The composition of claim 1 wherein the first polycarbon polyethylene is from 5 to 50 weight percent and the adjunct is from 50 to 95 weight percent, based on the total weight of the blend.

4. The composition of claim 1, wherein the first functional layer further comprises a second polycarbon polymer and optionally homo-and/or co-polypropylene, and wherein the second polycarbon polymer is present in an amount of 5-40 wt%, the first soft-side matte functional material is present in an amount of 20-95 wt%, and the homo-and/or co-polypropylene is present in an amount of 0-40 wt%, based on the total weight of the first functional layer;

preferably, the support layer material contains a third multi-carbon polymer and optional homo-polypropylene and/or co-polypropylene, and the content of the third multi-carbon polymer is 80-100 wt% and the total content of the homo-polypropylene and/or the co-polypropylene is 0-20 wt% based on the total weight of the support layer material;

preferably, the third functional layer material contains a fourth polycarbon polymer, a non-migrating inorganic slip agent, an optional second soft-surface matte functional material, and an optional homo-polypropylene and/or co-polypropylene, and based on the total weight of the third functional layer material, the content of the fourth polycarbon polymer is 20 to 99.5 wt%, the content of the non-migrating inorganic slip agent is 0.5 to 15 wt%, the content of the second soft-surface matte functional material is 0 to 55 wt%, and the total content of the homo-polypropylene and/or co-polypropylene is 0 to 10 wt%.

5. The composition of claim 4, wherein the first, second, third, and fourth polycarbopolymers are the same or different and are each independently C₄-C₈Polyethylene of (2), preferably C₆-C₈The polyethylene of (1).

6. The composition of claim 4 or 5, wherein the first soft-sided matte functional material and the second soft-sided matte functional material are the same or different.

7. A biaxially oriented polyethylene matte film prepared from the composition according to any one of claims 1 to 6, wherein the film comprises a first functional layer, a support layer and a third functional layer which are sequentially stacked, wherein the first functional layer is obtained by extruding a first functional layer material, the support layer is obtained by extruding a support layer material and the third functional layer is obtained by extruding a third functional layer material.

8. The film of claim 7 wherein the thickness of the first functional layer is 0.5-5 μ ι η, the thickness of the support layer is 8-140 μ ι η, and the thickness of the third functional layer is 0.5-5 μ ι η;

preferably, the thickness of the biaxially oriented polyethylene soft-surface matte film is 6-200 μm, preferably 9-150 μm.

9. The film of claim 7 wherein the biaxially oriented polyethylene matte film is produced by coextrusion and biaxial orientation.

10. Use of the biaxially oriented polyethylene soft-face matte film of any of claims 7-9 in one or more of protective films, print composites, coatings and advertising decorations.

Technical Field

The invention relates to the field of processing of polyethylene matte films, in particular to a biaxially oriented polyethylene soft-surface matte film composition, a film and application thereof.

Background

Materials are the material basis for human production, and polymeric materials are widely used in the packaging industry. With the improvement of living standard and the variety of aesthetic, consumers and producers can pursue the quality and visual effect of the package to the utmost.

At present, most of plastic flexible packages are made of films of different materials by glue tight joint (compounding). For example, the individual product composite packaging structure of rice is: BOPA film (biaxially oriented polyamide film)// adhesive// PE film (polyethylene film); nut class composite packaging structure: BOPP film (biaxially oriented polypropylene film)// adhesive// paper// adhesive// BOPET aluminized film (biaxially oriented polyester film)// PE film (polyethylene film).

On the other hand, with the increase of the demand and the output of the packaging materials, the classification and the recovery of the waste multi-material composite packaging are not easy, and at present, an effective method for separating and classifying and recovering the films of different composite materials still does not exist. More and more practical situations are that the waste packaging materials buried in the land can cause soil impoverishment and deterioration, and the yield of crops is reduced or not produced; incineration of waste plastics produces a large amount of CO₂Toxic gases such as CO and the like and residual heavy metals in ash content aggravate environmental pollution and greenhouse effect; a great deal of research has found that marine life is being endangered by waste packaging materials. The research and development of the packaging material with consistent internal and external materials can not only take the functions and the exquisite appearance into consideration, but also the sound of plastic packaging which is easy to completely recycle is increasing, and the protection of the green earth is urgent.

The inner layer of the existing soft plastic composite packaging bag is mostly made of polyethylene or polypropylene film.

Therefore, the Biaxially Oriented Polyethylene (BOPE) soft-surface matte (extinction) film used for the outer layer of the composite packaging bag is researched and developed, has extinction, soft look and feel, high haze, low glossiness, straight-line tearability and high puncture resistance, meets the market requirements of protective films, printing composition, plating, coating or advertisement decoration and the like in function and appearance, can be compounded with the inner layer polyethylene film into a soft plastic packaging bag which is consistent in inner and outer materials and can be integrally recycled, and has important social and economic significance.

Disclosure of Invention

The invention aims to overcome the problems of poor straight-line tearability, poor puncture resistance and difficult recycling of a film for a packaging material in the prior art, and provides a biaxially oriented polyethylene soft-surface matte film composition, a film and application thereof. Films prepared using the composition have a matte, soft look and feel, high haze, low gloss, straight line tear, and high puncture resistance.

In order to achieve the above object, the first aspect of the present invention provides a biaxially oriented polyethylene soft-surface matte film composition, which includes a first functional layer material, a support layer material, and a third functional layer material, where the first functional layer material includes a first soft-surface matte functional material, and the first soft-surface matte functional material is a product prepared by blending and modifying a blend, where the blend includes a first polycarbon polyethylene and an auxiliary agent, and the auxiliary agent includes a low-pressure high-density polyethylene and optionally activated silicon microspheres.

The invention provides a biaxially oriented polyethylene soft-surface matte film prepared from the composition, wherein the film comprises a first functional layer, a support layer and a third functional layer which are sequentially stacked, wherein the first functional layer is obtained by extruding the first functional layer material, the support layer is obtained by extruding the support layer material, and the third functional layer is obtained by extruding the third functional layer material.

The invention provides the application of the biaxially oriented polyethylene soft-surface matte film in one or more of protection film, printing and compounding, plating, coating and advertisement decoration.

According to the technical scheme, the first soft-surface matte (extinction) auxiliary agent and the first polycarbopolyethylene are used as components of the biaxially oriented polyethylene soft-surface matte (extinction) film, so that the biaxially oriented polyethylene soft-surface matte (extinction) film has extinction, soft appearance and touch, high haze, low glossiness, straight-line easy tearing property and high puncture resistance, and can be produced on line on the existing biaxially oriented production line without modifying existing equipment.

Drawings

FIG. 1 is an SEM photograph of the surface of a thin film prepared in example 1 of the present invention;

FIG. 2 is an SEM photograph of the surface of a first functional layer in a thin film prepared in example 1 of the present invention;

FIG. 3 is an SEM photograph of the surface of a third functional layer in a thin film produced in example 1 of the present invention;

FIG. 4 is a schematic flow chart of a process for preparing a biaxially oriented polyethylene matte (matte) film by using a biaxial orientation method according to the present invention.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a biaxially oriented polyethylene soft-surface matte film composition, which comprises a first functional layer material, a support layer material and a third functional layer material, wherein the first functional layer material contains a first soft-surface matte functional material, the first soft-surface matte functional material is a product prepared by blending and modifying a blend, the blend contains a first polycarbopolyethylene and an auxiliary agent, and the auxiliary agent contains a low-pressure high-density polyethylene and optional activated silicon microspheres.

According to the invention, "blending modification" specifically means that the components in the blend are fed in proportion, melted and plasticated in a screw extruder, extruded, cooled and cut into granules.

In the present invention, the biaxially oriented polyethylene may be represented by BOPE.

According to the invention, the low-pressure high-density polyethylene has a melt flow rate of 7 to 10g/10min at 190 ℃ under a load of 2.16kg and a density of 0.94 to 0.97g/cm³(ii) a Preferably, the low pressure high density polyethylene has a melt flow rate of 8 to 9.5g/10min at 190 ℃ under a load of 2.16kg and a density of 0.95 to 0.96g/cm³。

According to the invention, the activated silicon microspheres are obtained by treating silicon microspheres with a silane coupling agent.

According to the invention, the silane coupling agent is 3-aminopropyltriethoxysilane and/or 3-aminopropyltrimethoxysilane, preferably 3-aminopropyltriethoxysilane. 3-aminopropyltriethoxysilane having a viscosity at 25 ℃ of 1.5-1.7cs, preferably 1.6cs, and a density of 0.94-0.95g/cm³Preferably 0.946g/cm³And a closed cup flash point of 96 ℃, wherein the term "closed cup flash point" as used herein means the lowest temperature of a sample when the sample is heated under a predetermined condition and a mixture of steam and ambient air of the sample is brought into contact with a flame when the sample reaches a certain temperature, thereby causing a flash phenomenon and causing flash combustion.

According to the invention, the silicon microspheres have an average particle size of 2.5-3.5 μm, preferably 2.8-3.2 μm.

According to the invention, the weight ratio of the silicon microspheres to the silane coupling agent is 1: (0.01-0.5), preferably 1: (0.01-0.4), more preferably 1: 0.2.

according to the invention, the weight ratio of the low-pressure high-density polyethylene to the activated silicon microspheres is 1:

(0-2), preferably 1: (0.2-1).

According to the invention, said first soft-surface matte functionThe material can be prepared by self or obtained by commercial products, for example, the material can be obtained from Shanghai Ruo Yi New Material science and technology company, and is the type MF5050E soft-surface matte (delustering) functional material. In the invention, the soft-surface matte (delustering) functional material with the model of MF5050E contains C₆Polyethylene (in the present invention, polyethylene is polymerized using, in addition to ethylene, which is a main raw material of polyethylene, a small amount of other comonomer such as 1-butene (4 carbons), 1-butene, l-hexene (6 carbons) or 1-octene (8 carbons), and thus, in the present invention, C is₆Polyethylene refers to a copolymer obtained by copolymerization of ethylene, preferably C₆Polyethylene refers to a copolymer obtained by copolymerizing ethylene, 1-butene, l-hexene or 1-octene monomers), low-pressure high-density polyethylene and activated silicon microspheres, wherein the activated silicon microspheres are obtained by treating silicon microspheres with a silane coupling agent, the silane coupling agent is 3-aminopropyltriethoxysilane, and the weight ratio of the silicon microspheres to the silane coupling agent is 1: 0.2, and the weight ratio of the low-pressure high-density polyethylene to the activated silicon microspheres is 1: 0.5. the first polycarbopolyethylene (C) is based on the total weight of the blend (the first soft-surface matte functional material)₆Polyethylene) was 30 wt%, and the auxiliaries (high-density polyethylene and activated silica microspheres) were 70 wt%.

According to the invention, the biaxially oriented polyethylene soft-surface matte (extinction) film contains the first polycarbon polyethylene, the second polycarbon polyethylene, the third polycarbon polyethylene and the fourth polycarbon polyethylene, so that the prepared polyethylene film has excellent puncture resistance and is easy to recycle.

According to the invention, the first, second, third and fourth polycarbopolymers are the same or different and are each independently C₄-C₈Polyethylene of (2), preferably C₆-C₈The polyethylene of (1).

In the present invention, C is₄-C₈The polyethylene (C) is a copolymer obtained by copolymerizing ethylene, preferably C₄-C₈The polyethylene of (a) means a copolymer obtained by copolymerizing ethylene, l-hexene and/or 1-octene monomers.

In the present invention, C is₆-C₈The polyethylene (C) is a copolymer obtained by copolymerizing ethylene, preferably C₆-C₈The polyethylene of (a) means a copolymer obtained by copolymerizing ethylene, l-hexene and/or 1-octene monomers.

In one aspect, the first, second, third and fourth polycarbopolyethylenes are C₄-C₈Polyethylene of (2), preferably C₆-C₈In the production of linear low density polyethylene (LL DPE), preferably by adding C₆(1-hexene) and C₈The (1-octene) unsaturated olefin comonomer copolymerizes with ethylene, reducing the density of the polymer, thereby controlling the melt flow index (MFR) of the polymer product, improving machinability and heat resistance. The higher the carbon number of the comonomer, the better the overall properties of the polymer.

On the other hand, the linear molecular chain of the polycarbon polyethylene contains C₆(1-hexene) and/or C₈(1-octene) branched structure. The resin is melted and plasticized by an extruder and extruded into thick sheets from a die head, and fine spherulites and thinner lamellar crystals can be obtained by chilling with a chill roll or water bath, which is beneficial to subsequent stretching. Preheating to a proper temperature range (in high elastic state) above the glass transition temperature and below the melting point, and sequentially stretching in longitudinal and transverse directions by a certain multiple under the action of mechanical force to orient and orderly arrange molecular chains or crystal planes in a direction parallel to the plane of the film, wherein C is₆(1-hexene) and/or C₈The (1-octene) branched chains are mutually wound to form a compact space network structure, heat setting is carried out under a tensioning state to fix an oriented macromolecular structure, and the prepared biaxially oriented polyethylene film is cooled and set to obtain high mechanical properties (tensile strength, puncture strength, elastic modulus and the like) and excellent linear tearability along the stretching direction.

According to the invention, the first and second polycarbon polyethyleneThe ethylene, the third polycarbopolyethylene and the fourth polycarbopolyethylene are commercially available, for example, from Beijing chemical research institute of petrochemical corporation of China, model numbers: BOPE-3. Melt flow rate (190 deg.C, 2.16kg) of 2.2-3.0g/10min, and density (melt bar, boiled) of 0.9230g/cm³The content of the n-hexane extract is less than or equal to 0.5 wt%. In the invention, the density is directly measured by adopting the densimeter, wherein helium is used for air flow, the temperature of the measuring chamber needs to be controlled by boiled water, the precision of measured data is higher, and the accuracy is also good.

According to the invention, the first polycarbon polyethylene is 5-50 wt% and the auxiliary agent is 50-95 wt%, based on the total weight of the blend; preferably, the first polycarbopolyethylene is present in an amount of from 25 to 45 weight percent and the adjuvant is present in an amount of from 55 to 75 weight percent, based on the total weight of the blend.

According to the invention, the first functional layer material also contains a second multi-carbon polymer and optional homo-polypropylene and/or co-polypropylene, and based on the total weight of the first functional layer material, the content of the second multi-carbon polymer is 5-40 wt%, the content of the first soft-surface matte (extinction) functional material is 20-95 wt%, and the total content of the homo-polypropylene and/or co-polypropylene is 0-40 wt%; preferably, the content of the second polycarbopolymer is 10-25 wt%, the content of the first soft-surface matte (extinction) functional material is 55-85 wt%, and the total content of the homo-polypropylene and/or the co-polypropylene is 5-20 wt%; more preferably, the content of the second polycarbon polymer is 10-20 wt%, the content of the first soft-surface matte (extinction) functional material is 65-85 wt%, and the total content of the homo-polypropylene and/or the co-polypropylene is 5-15 wt%, based on the total weight of the first functional layer material.

According to the invention, the support layer material contains a third multi-carbon polymer and optional homo-polypropylene and/or co-polypropylene, and based on the total weight of the support layer material, the content of the third multi-carbon polymer is 80-100 wt%, and the total content of the homo-polypropylene and/or co-polypropylene is 0-20 wt%; preferably, the third polycarbon polymer is present in an amount of 90 to 95 wt%, and the homo-and/or co-polypropylene is present in an amount of 5 to 10 wt%, based on the total weight of the support layer.

According to the invention, the third functional layer material contains a fourth polycarbon polymer, a non-migration inorganic slipping agent, an optional second soft-surface matte (extinction) functional material and optional homo-polypropylene and/or co-polypropylene, and based on the total weight of the third functional layer material, the content of the fourth polycarbon polymer is 20-99.5 wt%, the content of the non-migration inorganic slipping agent is 0.5-15 wt%, the content of the second soft-surface matte (extinction) functional material is 0-55 wt%, and the total content of the homo-polypropylene and/or co-polypropylene is 0-10 wt%; preferably, based on the total weight of the third functional layer material, the content of the fourth polycarbon polymer is 42-94 wt%, the content of the non-migrating inorganic slipping agent is 1-10 wt%, the content of the second soft-surface matte (extinction) functional material is 5-40 wt%, and the total content of the homo-polypropylene and/or the co-polypropylene is 0-8 wt%.

According to the invention, the non-migrating inorganic slip agent is MB3005EB, is a blend of a fourth polycarbopolymer and fine silica powder, the particle size D50 of which is 3 microns; the ratio of the fourth polycarbon polymer to silica is 1: (0.02-0.30).

According to the invention, the inventor of the invention finds out through a large number of scientific experiments that: the polyethylene film comprises a first polycarbon polyethylene, a second polycarbon polyethylene, a third polycarbon polyethylene and a fourth polycarbon polyethylene, and has high melt strength under specific process conditions, higher mechanical properties (tensile strength, puncture strength, elastic modulus, and the like) and excellent straight-line tearability along the tensile direction.

According to the invention, the inventor of the invention finds out through a large number of scientific experiments that: by adding the first polycarbon polyethylene and the auxiliary agent composition for blending, a sea-island phenomenon is formed due to different cooling crystallization rates, wherein sea is a continuous phase and is observed as a plane by a scanning electron microscope and is far away from a lens black continuous phase plane; the island is a discontinuous phase, and a white convex part close to the lens is observed by a scanning electron microscope; see fig. 1. In the successive stretching process, the melt elasticity responds differently to stretching to cause rough surfaces with different surface heights, and when light irradiates the rough surfaces, diffuse reflection occurs to generate a matte (extinction) effect. The prepared film has the advantages of extinction, soft appearance and touch, high haze and low glossiness.

According to the invention, the first soft-surface matte (extinction) functional material, the second soft-surface matte (extinction) functional material and the third soft-surface matte (extinction) functional material are the same or different.

In a second aspect, the invention provides a biaxially oriented polyethylene soft-surface matte (matte) film prepared from the composition, wherein the film comprises a first functional layer, a support layer and a third functional layer which are stacked in sequence, the first functional layer is obtained by extruding the first functional layer material, the support layer is obtained by extruding the support layer material, and the third functional layer is obtained by extruding the third functional layer material.

According to the invention, the thickness of the first functional layer is 0.5 to 5 μm, the thickness of the support layer is 8 to 140 μm, and the thickness of the third functional layer is 0.5 to 5 μm; preferably, the thickness of the first functional layer is 0.8 to 3 μm, the thickness of the support layer is 9.4 to 94 μm, and the thickness of the third functional layer is 0.8 to 3 μm.

According to the invention, the biaxially oriented polyethylene matte (matte) film has a thickness of 6 to 200. mu.m, preferably 9 to 150. mu.m, more preferably 9 to 100. mu.m, more preferably 12 to 85. mu.m, and most preferably 18 to 60 μm.

According to the invention, the biaxially oriented polyethylene matte (matte) film is prepared by coextrusion and biaxial orientation.

In the invention, a method for preparing a biaxially oriented polyethylene soft-surface matte (extinction) film by using a biaxially oriented method is adopted, wherein the linear speed of a biaxially oriented production line is 100-550m/min, and the width of the production line is 1.5-11.0 m. Specifically, refer to the schematic preparation flow shown in fig. 4.

Preparing materials:

the first functional layer material contains a second multi-carbon polymer, a first soft-surface matte (extinction) functional material and optional homo-polypropylene and/or co-polypropylene, and based on the total weight of the first functional layer material, the content of the second multi-carbon polyethylene is 5-40 wt%, the content of the first soft-surface matte (extinction) functional material is 20-95 wt%, and the content of homo-polypropylene or co-polypropylene is 0-40 wt%;

the support layer material contains a third multi-carbon polymer and optional homo-polypropylene and/or co-polypropylene, wherein the third multi-carbon polymer accounts for 80-100 wt% of the total weight of the support layer material, and the total weight of the homo-polypropylene and/or co-polypropylene accounts for 0-20 wt%;

the third functional layer material contains a fourth polycarbon polymer, a non-migration inorganic slipping agent, an optional second soft-surface matte (extinction) functional material and an optional homo-polypropylene and/or co-polypropylene, and based on the total weight of the third functional layer material, the fourth polycarbon polymer accounts for 20-99.5 wt%, the non-migration inorganic slipping agent accounts for 0.5-15 wt%, the second soft-surface matte (extinction) functional material accounts for 0-55 wt%, and the homo-polypropylene and/or co-polypropylene accounts for 0-10 wt%.

Preparing ingredients: respectively putting the components of the first functional layer material, the support layer material and the third functional layer material into respective corresponding low-speed mixers according to the weight percentage, and premixing for 30 minutes;

feeding: and respectively sucking the premixed first functional layer material, the support layer material and the third functional layer material into corresponding precise scales under negative pressure, wherein the thicknesses of the first functional layer material, the support layer material and the third functional layer material are determined according to the dosage of the first functional layer material, the support layer material and the third functional layer material.

Plasticating and extruding: respectively extruding the resins of the first functional layer, the supporting layer and the third functional layer by adopting a plurality of extruders, and melting and extruding at the temperature of 185-250 ℃;

and (3) flaw-resistant melt filtration: the multilayer filter screens with 80, 100, 150, 200, 250, 300 meshes and the like are freely combined and sequentially overlapped;

cooling crystallization and sheet setting: extruding a melt from a die head, air cooling by an air knife, cooling by a chilling roller, and cooling by water bath of a water tank to form a thick sheet with fine microsphere crystals and thinner lamellar crystals, wherein a gap of a die lip is 0.5-4 mm, the water temperature of the chilling roller is controlled at 15-35 ℃, and the water temperature difference between a water inlet and a water outlet is controlled at +/-2 ℃; controlling the water temperature of the cooling water tank to be 25-35 ℃;

longitudinal preheating, stretching and shaping: preheating by a plurality of groups of preheating rollers with the temperature of 108-125 ℃; the temperature of the stretching roller is set to be 110-125 ℃, two-stage stretching is carried out, and the total stretching ratio is controlled to be 4.0-5.5; and (3) longitudinal stretching and shaping zone: the temperature is controlled at 108-125 ℃;

transverse preheating, stretching and transverse stretching and shaping: the temperature of the preheating zone is set to be 108-125 ℃; the transverse stretching magnification is between 6 and 12; transverse stretching and shaping area: the temperature is controlled at 110-130 ℃;

traction and thickness measurement: the total thickness of the biaxially oriented polyethylene matte (matte) film was measured.

Corona and winding: corona treatment may or may not be selected depending on the film application. Carrying out corona treatment on the film by a high-frequency electronic discharger, wherein the surface tension value of the lower wire is 40 mN/m; and (5) winding the film after shaping. The winding device is automatically controlled by the winding surface tension control device so as to achieve the best winding effect.

Aging, slitting and rolling: standing for 1-2 days at 25 + -5 deg.C and 60% RH to further stabilize size and performance; and cutting out corresponding finished product width specifications.

The third aspect of the invention provides the application of the biaxially oriented polyethylene soft-surface matte (extinction) film in one or more of protection film, printing and compounding, plating, coating and advertising decoration.

Among them, coating may also be referred to as gumming.

The inventors of the present invention have surprisingly found that: the second polycarbon polyethylene, the third polycarbon polyethylene and the fourth polycarbon polyethylene are added in the processing technology of the biaxial stretching film, under the specific technological conditions, the melt strength is high, and higher mechanical properties (tensile strength, puncture strength, elastic modulus, and the like) and excellent straight-line tearability along the stretching direction are obtained; the invention adds the first polycarbon polyethylene and the assistant composition to blend, and the sea-island phenomenon is formed due to different cooling crystallization rates. In the successive stretching process, the melt elasticity responds differently to stretching to cause rough surfaces with different surface heights, and when light irradiates the rough surfaces, diffuse reflection occurs. The prepared film has the advantages of extinction, soft appearance and touch, high haze, low glossiness, straight easy tearing property and high puncture resistance, and the functions and the appearance of the film meet the market requirements of high-end protective films, printing and compounding, plating, coating or advertisement decoration and the like, and the existing equipment does not need to be modified.

The present invention will be described in detail below by way of examples.

In the following examples and comparative examples:

the standard environment for sample condition regulation and test is specified in GB/T2918, and the test environment conditions are 23 deg.C + -2 deg.C, relative humidity 50% + -1%, and the sample is pre-treated for 8hr under the conditions.

(1) And (3) testing surface roughness: the test is carried out by using a MarSurf M300C contact pin type surface roughness instrument according to GB10610-89 rules and methods for measuring surface roughness by contact pin instruments.

(2) And (3) testing puncture resistance: the test was carried out according to the regulations of GB/T37841-2019 method for testing puncture resistance of plastic films and sheets.

(3) Haze test: the measurement was carried out according to the regulations of GB/T2410-2008 "measurement of light transmittance and haze of transparent plastics".

(4) And (3) testing the glossiness: the test is carried out according to the regulation of GB 8807-88 plastic mirror surface gloss test method and is carried out by a 45-degree gloss meter.