Renewable BOPP (Biaxially-oriented Polypropylene) film as well as preparation process and application thereof

Abstract

The invention belongs to the technical field of plastic films, and particularly provides a renewable BOPP film as well as a preparation process and application thereof. The renewable BOPP film comprises an upper surface layer, a core layer and a lower surface layer, and anti-sticking master batches obtained by mixing and granulating homo-polypropylene, maleic anhydride grafted polypropylene and composite fibers are added into the upper surface layer and the lower surface layer, the composite fiber is composed of polyphenylene sulfide-nylon base fiber, silicon dioxide and gel microspheres, wherein the silicon dioxide and the gel microspheres are attached to the surface of the polyphenylene sulfide-nylon base fiber. The renewable BOPP film prepared by the invention has the advantages of good wear resistance and mechanical properties.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of plastic film, in particular to a renewable BOPP film, a preparation process and application thereof. BACKGROUND

[0002] As an important polymer material product, biaxially oriented polypropylene (BOPP) film occupies a key position in the modern industrial field due to its excellent optical performance, chemical stability and cost advantage. BOPP film is a kind of film material which is processed by stretching polypropylene resin into a thick sheet along the longitudinal and transverse directions. The molecular chains form an ordered arrangement in the stretching process, thereby giving the film a high crystallinity and mechanical strength. Compared with the unstretched polypropylene film, the comprehensive performance of BOPP film is significantly improved, and it becomes one of the preferred materials in the packaging, electronics, printing and other industries. In the field of daily commodity packaging film, the application of BOPP film can be divided into several branches. In food daily commodities, it is often used as a snack packaging bag, a bread outer film, etc., which can show the color of food with high transparency and delay oxidation with good sealing performance. For example, potato chip bags use BOPP composite film to achieve moisture-proof and fresh-keeping. In personal care daily commodities, the bottle label film of shampoo and shower gel is usually made of BOPP material. Its excellent printing performance can clearly present product information, and its water resistance can adapt to the humid environment. In household cleaning daily commodities, the outer packaging bag of washing-up liquid and laundry detergent often uses BOPP film, which has certain chemical resistance and can resist the erosion of cleaning agent components. In addition, in the independent packaging of small daily commodities such as toothbrushes and combs, BOPP film can reduce packaging costs with its light and thin characteristics, while providing dust protection. However, there are still some problems in the application of BOPP film in packaging, which limits its further development in the high-end packaging field. In terms of toughness, conventional BOPP film is prone to embrittlement in low temperature environment and is prone to breakage under external impact, which is difficult to meet the needs of frozen food packaging. In addition, the film is prone to produce holes or tears when it is collided during transportation and storage, which affects the integrity of the packaging. For the packaging of articles containing sharp corners, the film is also prone to be pierced, losing the barrier function and affecting the service life of the packaging. In addition, scratches are easy to occur on the surface of BOPP film during transportation and use, which will reduce its optical performance and product display effect. Therefore, it is necessary to make BOPP film have good wear resistance and mechanical properties to bring good user experience in the application process.

[0003] In summary, although the application of BOPP film in the packaging field is very extensive, there are still many deficiencies in many aspects, and it is urgent to improve the preparation process to improve its comprehensive performance to meet the needs of higher requirement packaging applications. SUMMARY

[0004] In order to further improve the wear resistance and mechanical properties of the BOPP film, the application provides a renewable BOPP film, a preparation process and application thereof.

[0005] In a first aspect, the application provides a renewable BOPP film, comprising an upper surface layer, a core layer and a lower surface layer. The upper surface layer and the lower surface layer both comprise the following components: anti-sticking masterbatch and homopolypropylene. The core layer comprises the following components: homopolypropylene and renewable polypropylene material. The anti-sticking masterbatch is obtained by mixing homopolypropylene, maleic anhydride grafted polypropylene and composite fibers and granulating. The composite fiber is composed of polyphenylene sulfide-nylon base fiber and silica and gel microspheres attached to the surface of the polyphenylene sulfide-nylon base fiber.

[0006] Further, the preparation method of the composite fiber comprises the following steps: M1: Dissolve polyvinyl alcohol in phosphoric acid aqueous solution, add methacrylamide and organic acid, and perform crosslinking reaction, dry the product after the reaction is completed, and grind to obtain gel microspheres; M2: Disperse polyphenylene sulfide-nylon base fiber in a solvent, then add tetraethyl orthosilicate and γ-mercaptopropyl triethoxysilane, adjust the pH value with NaOH, add gel microspheres after a period of reaction, continue to react, wash and dry after the reaction is completed, to obtain the composite fiber.

[0007] Further, the preparation method of the polyphenylene sulfide-nylon base fiber comprises the following steps: 1) Mix hydroxylated nylon and polyphenylene sulfide, dry, and then perform melt spinning to obtain primary fibers; 2) Continue to draw and heat set the primary fibers to obtain polyphenylene sulfide-nylon base fibers.

[0008] Further, the average length of the polyphenylene sulfide-nylon base fiber is 1-1.5 mm.

[0009] Further, in step 1), the preparation method of the hydroxylated nylon comprises the following steps: S1: Mix polyol and trimellitic anhydride, and perform esterification reaction under the action of a catalyst, then add polyol again, and then add p-toluenesulfonic acid to perform chain extension reaction, and after the reaction is completed, rotary evaporation is performed to obtain hyperbranched molecules; S2: Mix nylon 66 and hyperbranched molecules, and melt extrude to form a hydroxylated nylon.

[0010] Further, in the step 1), the temperature of the melt spinning nozzle is 310-330 DEG C, the spinning speed is 800-1200 m / min, and the spinneret hole diameter is 0.18-0.3 mm.

[0011] Further, in the step 1), the mass ratio of the hydroxylated nylon and the polyphenylene sulfide is 1:(9-12).

[0012] Further, in the step S2, the mass ratio of the nylon 66 and the hyperbranched molecule is (20-30):1.

[0013] Further, the upper and lower surface layers each comprise the following components by weight: anti-sticking masterbatch 2-5 parts, homopolymer polypropylene 95-100 parts. The core layer comprises the following components: homopolymer polypropylene 25-70 parts, and recycled polypropylene 30-70 parts.

[0014] In a second aspect, the application provides a preparation process of the renewable BOPP film, comprising the following steps: using a three-layer co-extrusion casting technology, mixing the components of the upper surface layer, the core layer and the lower surface layer in proportion, extruding, casting, and obtaining a thick piece; after the thick piece is subjected to longitudinal stretching and transverse stretching, it is subjected to a setting treatment, and finally subjected to edge cutting and winding treatment, to obtain the renewable BOPP film.

[0015] In a third aspect, the application provides an application of the renewable BOPP film in the outer packaging film of daily necessities.

[0016] Compared with the prior art, the application has the following beneficial effects: 1. The composite fibers form an interlaced "skeleton structure" in the BOPP, which can effectively resist the penetration of sharp objects, and improve the toughness and durability of the film, and the composite fibers have excellent heat resistance, so that the hot deformation temperature of the BOPP film is improved, and the shrinkage or softening under high temperature environment is reduced.

[0017] 2. The mercapto-silicon dioxide on the surface of the composite fibers reacts with maleic anhydride in the preparation process of the anti-sticking masterbatch, which can improve the bonding force between the composite fibers and the polypropylene, improve the dispersibility of the composite fibers in the polypropylene matrix, form a more uniform and stable stress dispersion structure, and improve the mechanical properties of the film; at the same time, the silica adheres to the surface of the composite fibers, which enhances the wear resistance of the fibers, and further improves the anti-slip and wear resistance of the film.

[0018] 3. Hyperbranched molecules containing terminal hydroxyl groups are blended and melted with nylon. Some terminal hydroxyl groups interact with the amide groups in the nylon via intermolecular interactions, which enhances the binding force between the hyperbranched molecules and the nylon, allowing the hyperbranched molecules to be more evenly dispersed in the nylon. This also allows some terminal hydroxyl groups to remain on the surface of the nylon and combine with the hydroxyl groups on the surface of silica, thereby enhancing the binding force between silica and the fiber, preventing silica from slipping and falling off when subjected to friction, and maintaining the stability of the composite fiber performance. At the same time, the addition of nylon further enhances the toughness of the composite fiber, which has a beneficial effect on the mechanical properties of the film.

[0019] 4. The gel microspheres form an elastic buffer structure on the fiber surface. When the plastic film is impacted by external force, the particles can absorb energy through their own deformation, thereby improving the impact toughness of the film; part of the silica covers the surface of the gel microspheres, and the shell formed retains high hardness, which can directly resist surface friction. The inner elastic core can absorb external force through elastic deformation, reduce the instantaneous stress on the shell, maintain the anti-wear effect, and reduce the wear rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a scanning electron microscope image of the composite fiber of Example 1 of the present application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] Where “including,” “having,” and “comprising” are used herein, it is intended to cover a non-exclusive inclusion, and another component may also be added unless a clear limiting term such as “only,” “consisting of,” etc. is used.

[0024] The words "preferably," "more preferably," "most preferably," and the like, in the specification, mean that in certain situations, one or more of the described implementations can provide certain advantages. However, other implementations also can be preferred for a particular situation, and the instant specification does not imply that any one implementation is preferred over another implementation or that a particular implementation is preferred over another implementation in all circumstances. Moreover, the recitation of one or more preferred implementations does not imply that other implementations are not useful, and are not intended to exclude other implementations from the scope of the instant specification. That is, in the instant specification, "preferably," "more preferably," "most preferably," and the like, merely mean that a better result can be obtained in certain circumstances, but does not imply that other implementations are not useful, and are not intended to exclude other implementations from the scope of the instant specification.

[0025] In the instant specification, "further," "even further," "in particular," and the like are used to describe optional features, and do not imply that other implementations are not optional, and are not intended to exclude other implementations from the scope of the instant specification.

[0026] In the instant specification, "at least one" means one or more, such as one, two, and more than two. "A plurality" or "a plurality of" means at least two, such as two, three, or more. "A plurality of" or "plurality of" means at least two, such as two, three, or more, unless otherwise indicated. In the description of the instant specification, "a number of" means at least one, such as one, two, or the like, unless otherwise indicated.

[0027] When a range of values is disclosed, unless otherwise expressly stated, the disclosure covers all ranges and individual values between the minimum and maximum values of the range. Further, when a range of values is provided, it is intended to include the minimum and maximum values of the range, as well as every value between the minimum and maximum values of the range. Additionally, it is intended that the disclosure covers all ranges and individual values between the minimum and maximum values of the range, unless otherwise indicated. In other words, every range of values disclosed in the instant specification is intended to be a sub-range within a broader range, unless otherwise indicated.

[0028] Unless otherwise specified, all steps of the instant specification can be performed in any order. For example, the method comprising steps (a) and (b) means that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method comprising step (c) means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b), and (c), or steps (a), (c), and (b), or steps (c), (a), and (b), and the like. Unless otherwise specified, a singular form of a term can include a plural form, and is not understood to be limited to one.

[0029] In the instant specification, "above" or "below" includes the number itself. For example, 1 or below includes 1.

[0030] In the present application, room temperature refers to 0-40℃, including but not limited to 10-40℃, or further 20-30℃.

[0031] The present application provides a renewable BOPP film through a large number of experimental researches, which comprises an upper surface layer, a core layer and a lower surface layer. The upper surface layer and the lower surface layer both comprise the following components: anti-sticking masterbatch, homopolypropylene; The core layer comprises the following components: homopolypropylene, renewable polypropylene, antistatic masterbatch; The anti-sticking masterbatch is obtained by mixing homopolypropylene, maleic anhydride grafted polypropylene and composite fibers and granulating. The composite fiber is composed of polyphenylene sulfide-nylon base fiber and silica and gel microspheres attached to the surface of the polyphenylene sulfide-nylon base fiber.

[0032] In some embodiments of the present application, the preparation method of the anti-sticking masterbatch comprises the following steps: adding homopolypropylene, maleic anhydride grafted polypropylene and composite fibers into a feeding system, and blending and melt granulating through a double-screw extruder to obtain the anti-sticking masterbatch.

[0033] In some embodiments of the present application, the preparation method of the composite fiber comprises the following steps: M1: dissolving polyvinyl alcohol in phosphoric acid aqueous solution, adding methacrylamide and organic acid, and performing crosslinking reaction, then drying the product after the reaction is completed, and grinding to obtain gel microspheres; M2: dispersing polyphenylene sulfide-nylon base fiber in a solvent, then adding tetraethyl orthosilicate and γ-mercaptopropyl triethoxysilane, adjusting pH value with NaOH, adding gel microspheres after reacting for a period of time, continuing to react, washing after the reaction is completed, and drying to obtain the composite fiber.

[0034] In some embodiments of the present application, in the step M2, the preparation method of the polyphenylene sulfide-nylon base fiber comprises the following steps: 1) mixing hydroxylated nylon and polyphenylene sulfide, drying, and then melt spinning to obtain primary fibers; 2) continuing to draw and heat set the primary fibers to obtain polyphenylene sulfide-nylon base fiber.

[0035] In some embodiments of the present application, in the step 1), the mass ratio of hydroxylated nylon to polyphenylene sulfide is 1:(9-12).

[0036] In some specific embodiments of the present application, the mass ratio of hydroxylated nylon to polyphenylene sulfide can be 1:(9-10), 1:(10-11), 1:(11-12); typically but not limitedly, for example, it can be 1:9, 1:10, 1:12.

[0037] In some embodiments of the present application, in the step 1), the temperature of the melt spinning nozzle is 310-330℃, the spinning speed is 800-1200m / min, and the spinning plate aperture is 0.18-0.3mm.

[0038] In some embodiments of the present application, the temperature of the melt spinning nozzle can be 310-315℃, 315-320℃, 320-325℃, 325-330℃; typically but not limitedly, for example, it can be 310℃, 315℃; the spinning speed can be 800-900m / min, 900-1000m / min, 1000-1100m / min, 1100-1200m / min; typically but not limitedly, for example, it can be 1000m / min; the spinning plate aperture can be 0.18-0.2mm, 0.2-0.22mm, 0.22-0.24mm, 0.24-0.26mm, 0.26-0.28mm, 0.28-0.3mm; typically but not limitedly, for example, it can be 0.2mm, 0.21mm.

[0039] In some embodiments of the present application, in the step 1), the preparation method of the hydroxylated nylon comprises the following steps: S1: mixing polyol and trimellitic anhydride, and performing esterification reaction under the action of a catalyst; after the reaction is completed, polyol is added again, p-toluenesulfonic acid is then added, and chain extension reaction is performed; after the reaction is completed, rotary evaporation is performed to obtain hyperbranched molecules; S2: mixing nylon 66 and the hyperbranched molecules, and melt extruding to form a hydroxylated nylon.

[0040] In some embodiments of the present application, in the step S2, the mass ratio of the nylon 66 and the hyperbranched molecules is (20-30):1.

[0041] In some embodiments of the present application, the mass ratio of the nylon 66 and the hyperbranched molecules can be (20-21):1, (21-22):1, (22-23):1, (23-24):1, (24-25):1, (25-26):1, (26-27):1, (27-28):1, (28-29):1, (29-30):1; typically but not limitedly, for example, it can be 20:1, 25:1.

[0042] In some embodiments of the present application, by weight, the upper and lower surface layers each comprise the following components: 2-5 parts of anti-sticking masterbatch, and 95-100 parts of homopolymer polypropylene. The core layer comprises the following components: 25-70 parts of homopolymer polypropylene, and 30-70 parts of recycled polypropylene.

[0043] The present application is further illustrated by the following examples, but the scope of the present application is not limited by the examples.

[0044] When the examples give numerical ranges, it is to be understood that unless the application specifically states to the contrary, each numerical range is a continuum, and that every number within the range and each point within the continuum are also specifically disclosed. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Unless otherwise indicated, all conditions, including the reaction conditions, are at room or ambient temperature (about 20°C to 25°C), or under conventional conditions or those recommended by the manufacturer. Unless otherwise noted, all reagents or ingredients are commercially available or can be readily prepared by one of ordinary skill in the art from commercially available materials. To the extent that any method, device, material or formulation is used in the examples, it is intended to be illustrative only and not limiting of the scope of the application, which is limited only by the claims.

[0045] Example 1 The renewable BOPP film of the present example comprises an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer are both composed of the following components: 4 g of anti-sticking masterbatch, 190 g of homopolypropylene, 0.2 g of erucamide, 0.15 g of glycerol monostearate; the core layer is composed of the following components: 50 g of homopolypropylene, 140 g of renewable polypropylene, 8 g of maleic anhydride grafted polypropylene, 0.1 g of EP548s nucleating agent; the average thickness of the upper surface layer is 6.9 μm, the average thickness of the lower surface layer is 7.04 μm, and the average total thickness of the renewable BOPP film is 35.22 μm.

[0046] The preparation method of the polyphenylene sulfide-nylon base fiber of the present example is as follows: 1) Put 13.6 g of glycerol and 54 g of trimellitic anhydride into a 250 mL three-necked flask, mix uniformly, adjust the temperature to 160°C, add 1 g of zinc sulfate under a nitrogen atmosphere, stir for 4 h, then adjust the temperature to 120°C, add 18.5 g of glycerol, then add 2 g of p-toluenesulfonic acid, react for 3 h, after the reaction is completed, spin, filter, centrifuge, and obtain hyperbranched molecules; 2) Weigh 200 g of nylon 66 and 8 g of hyperbranched molecules into a high-speed mixer, mix at a speed of 800 r / min for 5 min, put the mixed material into the hopper of a twin-screw extruder, melt extrude, the head temperature of the twin-screw extruder is 230°C, granulate the strip material obtained by the twin-screw extruder by a granulator, dry, and obtain hydroxylated nylon; 3) 2 g of hydroxylated nylon and 18 g of polyphenylene sulfide were weighed and mixed, and dried in a vacuum drying oven at a temperature of 120°C for 6 h. After drying, melt spinning was performed at a temperature of 310°C, a spinning speed of 1000 m / min, and a spinneret hole diameter of 0.2 mm to obtain a nascent fiber; 4) The nascent fiber was further drawn and heat set using a three-stage hot roller drawing machine and a hot air circulating setting machine. The first roller temperature was 110°C, the second roller temperature was 135°C, the third roller temperature was 170°C, the draw ratio was 3.5-4, and the heat setting temperature was 165°C. After cooling, the polyphenylene sulfide-nylon base fiber with an average length of 1.5 mm was obtained by crushing.

[0047] The preparation method of the composite fiber of the present embodiment is as follows: M1: 150 mL of a 42% mass percentage concentration phosphoric acid aqueous solution was weighed into a three-necked flask, followed by 15 g of polyvinyl alcohol. The mixture was heated to 85°C and stirred for 3 h. Then 6 g of methacrylamide, 1.2 g of citric acid, and 0.1 g of ammonium persulfate were added, and the mixture was reacted for 2 h. After the reaction, the product was dried and crushed, and then added to a medium stirring mill. Then 70 g of deionized water was added, and the mixture was ground for 35 min. The grinding medium was zirconium oxide beads with an average diameter of 0.6 mm, and the amount of zirconium oxide beads added was 75 g. The rotation speed was 1100 rpm. After filtration and drying, the gel microspheres were obtained.

[0048] M2: 10 g of polyphenylene sulfide-nylon base fiber was weighed into a beaker, and 90 g of ethanol and 100 g of deionized water were added. The mixture was uniformly dispersed by ultrasonic dispersion. Then 6.5 g of tetraethyl orthosilicate and 0.15 mL of γ-mercaptopropyl triethoxysilane were added. The pH value was adjusted to 13 using NaOH. After reacting for 1 h, 1 g of gel microspheres was added, and the mixture was further reacted for 2.5 h. After the reaction, the mixture was filtered, washed, and dried to obtain the composite fiber.

[0049] The preparation method of the anti-adhesion masterbatch of the present embodiment is as follows: 180 g of homopolymerized polypropylene and 10 g of maleic anhydride grafted polypropylene were placed in an electric heating air drying oven and dried at 80°C for 5 h. The dried material was mixed with 10 g of composite fiber, and melt blending extrusion was performed using a twin-screw extruder. The temperature settings of the twin-screw extruder were as follows: Zone 1: 155°C, Zone 2: 165°C, Zone 3: 175°C, Zone 4: 185°C, Zone 5: 195°C, Zone 6: 190°C, Zone 7: 185°C, and the die head: 185°C. The sample strip obtained from the twin-screw extruder was granulated using a pelletizer, and dried to obtain the anti-adhesion masterbatch.

[0050] The preparation process of the BOPP film of the embodiment is as follows: the components of each layer are mixed uniformly according to the proportion, and then the melt of each layer is co-extruded through a three-layer die, the melt extrusion temperature of the upper and lower surface layers is 220-245 DEG C, the melt extrusion temperature of the core layer is 235-255 DEG C, and then the thick sheet is cast through a cooling roller at 10-15 DEG C, and then the temperature is adjusted to 130 DEG C for longitudinal stretching by 4.5 times, and then the temperature is adjusted to 160 DEG C for transverse stretching, the transverse stretching multiple is 8, and then the temperature is adjusted to 150 DEG C for setting treatment, and finally the edge cutting and winding treatment are performed to obtain the renewable BOPP film.

[0051] Example 2 The renewable BOPP film of the embodiment comprises an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer each comprise the following components: 10 g of anti-sticking masterbatch, 200 g of homopolypropylene, 0.3 g of erucic acid amide and 0.2 g of glycerol monostearate; the core layer comprises the following components: 140 g of homopolypropylene, 60 g of renewable polypropylene, 4 g of maleic anhydride grafted polypropylene and 0.15 g of EP548s nucleating agent; the average thickness of the upper surface layer is 7.49 μm, the average thickness of the lower surface layer is 8.03 μm, and the average total thickness of the renewable BOPP film is 35.16 μm.

[0052] The preparation method of the polyphenylene sulfide-nylon base fiber of the embodiment is as follows: 1) 14 g of glycerol and 54 g of trimellitic anhydride are put into a 250 mL three-necked flask, mixed uniformly, and then the temperature is adjusted to 160 DEG C, 1 g of zinc sulfate is added under a nitrogen atmosphere, and stirred for 4 h, and then the temperature is adjusted to 120 DEG C, 18 g of glycerol is added, 2 g of p-toluenesulfonic acid is added, and reacted for 3 h, and then rotary evaporation, filtration and centrifugation are performed to obtain hyperbranched molecules; 2) 200 g of nylon 66 and 10 g of hyperbranched molecules are weighed and added to a high-speed mixer, mixed for 5 min at a speed of 800 r / min, and then the mixed material is added to the hopper of a twin-screw extruder, and melt-extruded, the temperature of the die head of the twin-screw extruder is 230 DEG C, the strip material obtained by the twin-screw extruder is granulated by a granulator, and dried to obtain hydroxylated nylon; 3) 2 g of hydroxylated nylon and 18 g of polyphenylene sulfide are mixed and dried in a vacuum drying oven at a temperature of 120 DEG C for 6 h, and then melt-spun after drying, the temperature of melt spinning is 315 DEG C, the spinning speed is 1000 m / min, the pore size of the spinneret used is 0.21 mm, and the as-spun fiber is obtained; 4) The as-spun fiber is continuously drawn and heat set using a three-stage hot roll draw frame and a hot air circulating setting machine, the temperature of the first roll is 110 DEG C, the temperature of the second roll is 135 DEG C, the temperature of the third roll is 170 DEG C, the draw ratio is 3.5-4, the heat setting temperature is 165 DEG C, and the obtained polyphenylene sulfide-nylon base fiber with an average length of 1 mm is obtained after being crushed after cooling.

[0053] The preparation method of the composite fiber of the present embodiment is as follows: M1: 150 mL of a 41.5% mass percentage concentration phosphoric acid aqueous solution is measured and added to a three-necked flask, then 15 g of polyvinyl alcohol is added, heated to 85 DEG C, stirred for 3 h, then 6 g of methacrylamide, 1.2 g of citric acid and 0.1 g of ammonium persulfate are added, reacted for 2 h, and after the reaction is completed, the product is dried, crushed, added to a medium stirring mill, then 70 g of deionized water is added, ground for 35 min, the grinding medium is zirconium oxide beads with an average diameter of 0.6 mm, the amount of zirconium oxide beads added is 75 g, the rotation speed is 1000 rpm, filtered, dried, and the gel microspheres are obtained.

[0054] M2: 10 g of polyphenylene sulfide-nylon base fiber is weighed into a beaker, 90 g of ethanol and 100 g of deionized water are added, ultrasonically dispersed uniformly, then 6.5 g of tetraethyl orthosilicate and 0.15 mL of gamma-mercaptopropyl triethoxysilane are added, the pH value is adjusted to 13 with NaOH, reacted for 1 h, then 1.2 g of gel microspheres is added, and the reaction is continued for 2.5 h, after the reaction is completed, it is filtered, washed, and dried, and the composite fiber is obtained.

[0055] The preparation method of the anti-adhesion masterbatch of the present embodiment is as follows: 180 g of homopolymerized polypropylene and 10 g of maleic anhydride grafted polypropylene are placed in an electric heating air drying oven, dried at 80 DEG C for 5 h, the dried material is mixed with 8 g of composite fiber, melt blended and extruded using a twin-screw extruder, the temperature of the twin-screw extruder is set as follows: zone 1 155 DEG C, zone 2 165 DEG C, zone 3 175 DEG C, zone 4 185 DEG C, zone 5 195 DEG C, zone 6 190 DEG C, zone 7 185 DEG C, and the die head 185 DEG C, the sample strip obtained from the twin-screw extruder is granulated using a pelletizer, dried, and the anti-adhesion masterbatch is obtained.

[0056] The preparation process of the BOPP film of the present embodiment is as follows: the components of each layer are mixed uniformly according to the proportion, melted using the extruder of each layer, and co-extruded through a three-layer die, the melt extrusion temperature of the upper and lower surface layers is 220-245 DEG C, the melt extrusion temperature of the core layer is 235-255 DEG C, and then a thick sheet with a thickness of 1 mm is cast through a cooling roll at a temperature of 10-15 DEG C, the temperature is adjusted to 160 DEG C after preheating at 130 DEG C, and the film is stretched longitudinally by 4.6 times, then the temperature is adjusted to 160 DEG C for transverse stretching, the transverse stretching ratio is 8.5, the film is treated for setting at a temperature of 150 DEG C, and finally edge cutting and winding are performed, and the renewable BOPP film is obtained.

[0057] Example 3 The renewable BOPP film of this example comprises an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer are both composed of the following components: 5 g anti-sticking masterbatch, 197 g homopolymer polypropylene, 0.3 g erucic acid amide, 0.2 g glycerol monostearate; the core layer is composed of the following components: 100 g homopolymer polypropylene, 100 g renewable polypropylene, 7 g maleic anhydride grafted polypropylene, 0.15 g EP548s nucleating agent; the average thickness of the upper surface layer is 7.32 μm, the average thickness of the lower surface layer is 7.19 μm, and the average total thickness of the renewable BOPP film is 35.51 μm.

[0058] The preparation method of the polyphenylene sulfide-nylon base fiber of this example is as follows: 1) Put 13.6 g of glycerol and 54 g of trimellitic anhydride into a 250 mL three-necked flask, mix uniformly, adjust the temperature to 160°C, add 1 g of zinc sulfate under a nitrogen atmosphere, stir for 4 h, then adjust the temperature to 120°C, add 20 g of glycerol, then add 2 g of p-toluenesulfonic acid, react for 3 h, after the reaction is completed, spin, filter, centrifuge, and obtain hyperbranched molecules; 2) Weigh 200 g of nylon 66 and 7 g of hyperbranched molecules into a high-speed mixer, mix at a speed of 800 r / min for 5 min, add the mixed material to the hopper of a twin-screw extruder, melt extrude, the temperature of the die head of the twin-screw extruder is 230°C, granulate the strip material from the twin-screw extruder by a granulator, dry, and obtain hydroxylated nylon; 3) Mix 3 g of hydroxylated nylon and 18 g of polyphenylene sulfide, dry in a vacuum drying oven at a temperature of 120°C for 6 h, after drying is completed, melt spin, the temperature of the melt spinning is 310°C, the spinning speed is 1000 m / min, the pore size of the spinneret used is 0.2 mm, and obtain a primary fiber; 4) Continue to stretch and heat set the primary fiber using a three-stage hot roller drafting machine and a hot air circulating setting machine, the temperature of the first roller is 110°C, the temperature of the second roller is 135°C, the temperature of the third roller is 170°C, the stretching multiple is 3.5-4, the heat setting temperature is 165°C, after cooling, crush, and obtain polyphenylene sulfide-nylon base fibers with an average length of 1 mm.

[0059] The preparation method of the composite fiber of this example is as follows: M1: 150 mL of a 42% by mass aqueous phosphoric acid solution was measured into a three-necked flask, followed by 15 g of polyvinyl alcohol, heated to 90°C, and stirred for 3 h. Then 7 g of methacrylamide, 1.2 g of citric acid, and 0.1 g of ammonium persulfate were added, and the reaction was carried out for 2 h. After the reaction, the product was dried and crushed, and was put into a medium stirred mill. Then 70 g of deionized water was added, and the product was ground for 40 min. The grinding medium was zirconium oxide beads with an average diameter of 0.6 mm, and the amount of the zirconium oxide beads added was 75 g. The rotation speed was 1100 rpm. After filtration and drying, the gel microspheres were obtained.

[0060] M2: 10 g of polyphenylene sulfide-nylon base fiber was weighed into a beaker, 90 g of ethanol and 100 g of deionized water were added, and the mixture was uniformly dispersed by ultrasonic treatment. Then 6.5 g of tetraethyl orthosilicate and 0.15 mL of γ-mercaptopropyltriethoxysilane were added, and the pH value was adjusted to 13 with NaOH. After 1 h of reaction, 1 g of gel microspheres was added, and the reaction was continued for 2.5 h. After the reaction, the product was filtered, washed, and dried to obtain the composite fiber.

[0061] The preparation method of the anti-sticking masterbatch of the present embodiment is as follows: 180 g of homopolymerized polypropylene and 10 g of maleic anhydride grafted polypropylene were placed in an electric heating air drying oven, and dried at 80°C for 5 h. The dried material was mixed with 5 g of composite fiber, and melt blended and extruded using a twin-screw extruder. The temperature settings of the twin-screw extruder were as follows: zone 1, 155°C; zone 2, 165°C; zone 3, 175°C; zone 4, 185°C; zone 5, 195°C; zone 6, 190°C; zone 7, 185°C; and the die head, 185°C. The sample strip obtained from the twin-screw extruder was granulated using a pelletizer, and dried to obtain the anti-sticking masterbatch.

[0062] The preparation process of the BOPP film of the present embodiment is as follows: the components of each layer were mixed according to the proportions, and were melt-extruded through a three-layer die after melting using an extruder for each layer. The melt-extrusion temperature of the upper and lower surface layers was 220-245°C, and the melt-extrusion temperature of the core layer was 235-255°C. Then the thick sheet with a thickness of 1 mm was cast through a cooling roller at a temperature of 10-15°C. After preheating at 130°C, the thick sheet was longitudinally stretched by 4.5 times, and then the temperature was adjusted to 160°C for transverse stretching. The transverse stretching multiple was 8. Then the temperature was adjusted to 150°C for setting treatment. Finally, the edges were cut and the film was wound up to obtain the renewable BOPP film.

[0063] Control group 1 The renewable BOPP film of the control group comprises an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer each comprise the following components: 4 g of anti-sticking masterbatch, 190 g of homopolypropylene, 0.2 g of erucic acid amide, and 0.15 g of glycerol monostearate; the core layer comprises the following components: 50 g of homopolypropylene, 140 g of renewable polypropylene, 8 g of maleic anhydride grafted polypropylene, and 0.1 g of EP548s nucleating agent; the average thickness of the upper surface layer is 7.08 μm, the average thickness of the lower surface layer is 7.02 μm, and the average total thickness of the renewable BOPP film is 35.16 μm.

[0064] The preparation method of the composite fiber of the control group is as follows: 10 g of polyphenylene sulfide-nylon base fiber is weighed into a beaker, 90 g of ethanol and 100 g of deionized water are added, and ultrasonic dispersion is performed until uniform, then 6.5 g of tetraethyl orthosilicate and 0.15 mL of γ-mercaptopropyl triethoxysilane are added, the pH value is adjusted to 13 with NaOH, and reaction is performed for 3.5 h; after the reaction is completed, filtration, washing and drying are performed to obtain the composite fiber.

[0065] The other steps are the same as in Example 1.

[0066] Control group 2 The renewable BOPP film of the control group comprises an upper surface layer, a core layer and a lower surface layer; the upper surface layer and the lower surface layer each comprise the following components: 4 g of anti-sticking masterbatch, 190 g of homopolypropylene, 0.2 g of erucic acid amide, and 0.15 g of glycerol monostearate; the core layer comprises the following components: 50 g of homopolypropylene, 140 g of renewable polypropylene, 8 g of maleic anhydride grafted polypropylene, and 0.1 g of EP548s nucleating agent; the average thickness of the upper surface layer is 7.08 μm, the average thickness of the lower surface layer is 7.02 μm, and the average total thickness of the renewable BOPP film is 35.16 μm.

[0067] The preparation method of the polyphenylene sulfide fiber of the control group is as follows: 1) 20 g of polyphenylene sulfide is weighed, dried in a vacuum drying oven at a temperature of 120°C for 6 h, and then melt spun; the melt spinning temperature is 310°C, the spinning speed is 1000 m / min, and the hole diameter of the used spinneret is 0.2 mm to obtain the as-spun fiber; 2) the as-spun fiber is further drawn and heat set using a three-stage hot roller drafting machine and a hot air circulating setting machine; the first roller temperature is 110°C, the second roller temperature is 135°C, the third roller temperature is 170°C, the draw ratio is 3.5-4, and the heat setting temperature is 165°C; after cooling, the polyphenylene sulfide fiber with an average length of 1.5 mm is obtained by crushing.

[0068] The preparation method of the composite fiber of the present embodiment is as follows: 10 g of polyphenylene sulfide fiber is weighed into a beaker, 90 g of ethanol and 100 g of deionized water are added, and ultrasonic dispersion is performed until uniform, then 6.5 g of tetraethyl orthosilicate and 0.15 mL of γ-mercaptopropyl triethoxysilane are added, the pH value is adjusted to 13 with NaOH, and the reaction is performed for 3.5 h. After the reaction is completed, filtration, washing, and drying are performed to obtain the composite fiber.

[0069] The other steps are the same as those in Embodiment 1.

[0070] Performance detection 1. The renewable BOPP films of Examples 1-3 and Control Groups 1-2 were subjected to various performance tests, and the test methods and data are shown in Table 1.

[0071] 2. The composite fiber prepared in Example 1 was observed using a scanning electron microscope, and the obtained image is shown in Figure 1 .

[0072] Table 1: Performance test methods and data It can be seen from the analysis of Examples 1-3 and Control Groups 1-2 in combination with Table 1 that, in the process of preparing the renewable BOPP film, the addition of the composite fiber doped with hydroxylated nylon and deposited with silica and gel microspheres has a good enhancing effect on the mechanical properties and friction resistance of the renewable BOPP film. The composite fiber prepared in the examples has good compatibility and bonding force with the film matrix, which enhances the mechanical properties of the film while also making the film have good dimensional stability.

[0073] Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A renewable BOPP film, characterized by: Including upper surface layer, core layer and lower surface layer; The upper surface layer and the lower surface layer both comprise the following components: anti-sticking masterbatch, homopolymer polypropylene; The core layer comprises the following components: homopolymer polypropylene, recycled polypropylene; The anti-sticking masterbatch is obtained by mixing and granulating homopolymer polypropylene, maleic anhydride grafted polypropylene and composite fiber; The composite fiber consists of polyphenylene sulfide-nylon basic fiber and silicon dioxide and gel microspheres attached to the surface of the polyphenylene sulfide-nylon basic fiber.

2. The renewable BOPP film according to claim 1, characterized in that: The preparation method of the composite fiber comprises the following steps: M1: Dissolve polyvinyl alcohol in a phosphoric acid aqueous solution, add methacrylamide and an organic acid to carry out a cross-linking reaction, and after the reaction is completed, dry and grind the product to obtain gel microspheres; M2: Take polyphenylene sulfide-nylon base fiber and disperse it in a solvent. Then add ethyl orthosilicate and γ-mercaptopropyltriethoxysilane. Adjust the pH value with NaOH. After a period of reaction, add gel microspheres and continue the reaction. After the reaction is completed, wash and dry to obtain a composite fiber.

3. The renewable BOPP film according to claim 1 or 2, characterized in that: The preparation method of the polyphenylene sulfide-nylon base fiber comprises the following steps: 1) Hydroxylated nylon and polyphenylene sulfide are mixed, dried, and melt-spun to obtain spun fibers; 2) The nascent fiber is further drawn and heat-set to obtain polyphenylene sulfide-nylon base fiber.

4. The renewable BOPP film according to claim 3, characterized in that: In step 1), the preparation method of hydroxylated nylon comprises the following steps: S1: Mixing polyol and trimellitic anhydride, performing an esterification reaction in the presence of a catalyst, adding polyol again after the reaction, and then adding p-toluenesulfonic acid to perform a chain extension reaction, and then rotary evaporation to obtain a hyperbranched molecule; S2: Nylon 66 and hyperbranched molecules are mixed and melt-extruded to obtain hydroxylated nylon.

5. The renewable BOPP film according to claim 3, characterized in that: In the step 1), the nozzle temperature of the melt spinning is 310-330° C., the spinning speed is 800-1200 m / min, and the spinneret aperture is 0.18-0.3 mm.

6. The renewable BOPP film according to claim 3, characterized in that: In the step 1), the mass ratio of hydroxylated nylon to polyphenylene sulfide is 1:(9-12).

7. The renewable BOPP film according to claim 4, characterized in that: In step S2, the mass ratio of nylon 66 to hyperbranched molecules is (20-30):

1.

8. The renewable BOPP film according to claim 1, characterized in that: The upper surface layer and the lower surface layer each comprise the following components by weight: 2-5 parts of anti-sticking masterbatch and 95-100 parts of homopolypropylene; The core layer comprises the following components: 25-70 parts of homopolypropylene and 30-70 parts of recycled polypropylene.

9. A process for preparing the renewable BOPP film according to claim 1, characterized in that: The method comprises the following steps: using three-layer co-extrusion casting technology, mixing the components of the upper surface layer, the core layer and the lower surface layer in proportion, extruding, casting and obtaining a thick sheet; after the thick sheet is longitudinally stretched and transversely stretched, it is subjected to shaping treatment, and finally trimming and winding treatment is performed to obtain a renewable BOPP film.

10. An application of a renewable BOPP film, characterized in that: The renewable BOPP film according to any one of claims 1 to 8 is used as an outer packaging film for daily necessities.

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