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CN-122008661-A - High-barrier composite film, preparation method and application thereof in IBC storage and transportation ocean transportation

CN122008661ACN 122008661 ACN122008661 ACN 122008661ACN-122008661-A

Abstract

The invention relates to the technical field of polymer composite film materials, in particular to a photodegradable high-barrier composite film, and discloses a high-barrier composite film, a preparation method and application thereof in IBC (intermediate bulk carrier) storage and transportation ocean transportation, wherein the composite film is of a PE/TIE/PA/TIE/PE five-layer co-extrusion structure, an allylation photosensitizer is contained in a PE layer, and a glycidoxypropylation photosensitizer is contained in a PA layer. The invention provides a preparation method of a PE/PA multilayer co-extrusion composite film with a photocatalytic degradation function, the composite film prepared by the preparation method maintains excellent comprehensive performance in the storage and transportation use period (under the light-shielding condition), meets the service condition requirement of an IBC lining bag, and can be subjected to high-efficiency degradation under the ultraviolet environment after being abandoned, so that the degradation period of the composite film in the natural illumination environment is obviously shortened, and the problem of persistent white pollution caused by abandoned PE/PA composite films in the prior art is solved.

Inventors

  • CHU JINGJING
  • FU XIN
  • ZHU LEI

Assignees

  • 安徽紫金新材料科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260407

Claims (10)

  1. 1. The high-barrier composite film is characterized by being of a PE/TIE/PA/TIE/PE five-layer co-extrusion structure; The PE layer contains an allylation photosensitizer, and the allylation photosensitizer is bonded to a PE molecular chain through a C-C covalent bond by a free radical grafting reaction; the PA layer contains a glycidoxypropylated photosensitizer, and the glycidoxypropylated photosensitizer is bonded on a PA molecular chain through a ring-opening reaction of an epoxy group and a PA molecular chain end group; The allylation photosensitizer and the epoxypropylation photosensitizer are composite photosensitizers formed by anchoring an anthraquinone silane coupling agent on the surface of nano TiO 2 through a Ti-O-Si covalent bond; The TIE layer is a maleic anhydride grafted polyethylene bonding resin layer; The composite film keeps structural stability under the light-shielding condition, and realizes oxidative degradation under the irradiation of ultraviolet light through the synergistic effect of anthraquinone photosensitization and nano TiO 2 photocatalysis.
  2. 2. The high-barrier composite film according to claim 1, wherein the allylated photosensitizer is a composite photosensitizer formed by an allylated anthraquinone silane coupling agent anchored to the surface of nano-TiO 2 through a Ti-O-Si covalent bond; the mass ratio of the allylated photosensitizer to the allylated anthraquinone silane coupling agent to the nano TiO 2 is (0.15-0.20) 1; The chemical structural formula of the allyl anthraquinone silane coupling agent is as follows: 。
  3. 3. the high-barrier composite film according to claim 1, wherein the epoxypropyl photosensitizer is a composite photosensitizer formed by epoxypropyl anthraquinone silane coupling agent anchored to the surface of nano TiO 2 through a Ti-O-Si covalent bond; The mass ratio of the epoxy propyl anthraquinone silane coupling agent to the nano TiO 2 in the epoxy propyl photosensitizer is (0.08-0.12) 1; the chemical structural formula of the epoxy propyl anthraquinone silane coupling agent is as follows: 。
  4. 4. The high-barrier composite film according to claim 1, wherein the formulation and the amount of each film layer of the high-barrier composite film are as follows: The PE layer comprises 40-80wt% of LDPE, 19-59wt% of PE master batch and 0.1-1.5wt% of antioxidant 1010, wherein the sum of the three components is 100wt%, and the dosage of the PE layer is 20-25 parts by weight; The formula of the PA layer is 40-80wt% of PA6 and 20-60wt% of PA master batch, the sum of the two components is 100wt%, and the dosage of the PA layer is 40-50 parts by weight; the TIE layer is 100wt% MAH-g-PE, and the amount of the TIE layer is 3-8 parts by weight.
  5. 5. The high barrier composite film of claim 4, wherein the PE masterbatch is formulated as follows: 850-950 parts by weight of LDPE; 80-120 parts by weight of allylated photosensitizer; 3-8 parts by weight of DCP; 8-12 parts of white oil.
  6. 6. The high barrier composite film of claim 4, wherein the PA masterbatch is formulated as: 850-950 parts by weight of PA 6; 80-120 parts by weight of epoxypropylation photosensitizer; 1.5-2 parts by weight of stearic acid dispersant.
  7. 7. The method for preparing a high barrier composite film according to any one of claims 1 to 6, comprising the steps of: Step one, taking 2-amino anthraquinone as a starting material, and respectively preparing allyl type anthraquinone silane coupling agent and epoxypropyl type anthraquinone silane coupling agent through N-alkylation, allylation and epoxidation reaction; Hydrolyzing trimethoxy silicon base of an allylic anthraquinone silane coupling agent into silicon hydroxyl in an aqueous organic solvent, then carrying out dehydration condensation reaction with nano titanium dioxide in the presence of an acid catalyst, and carrying out covalent bonding on the nano titanium dioxide to obtain an allylic photosensitizer; The epoxypropyl anthraquinone silane coupling agent is treated by the same method to prepare epoxypropyl photosensitizer; Premixing DCP dissolved by white oil and allylation photosensitizer, and then carrying out melt blending reaction with LDPE resin by a co-rotating twin-screw extruder to extrude, granulate and dry to obtain PE master batch; Premixing PA6 resin accounting for 40-50wt% of the total formulation with the epoxypropyl photosensitizer pretreated by stearic acid, carrying out melt blending granulation by a homodromous double-screw extruder under a high-shear screw configuration to obtain pre-dispersed master batch, premixing the pre-dispersed master batch and the residual formulation amount of PA6 resin, carrying out reactive melt blending extrusion by the homodromous double-screw extruder, granulating, and drying to obtain PA master batch; and step four, preparing the high-barrier composite film by a five-layer coextrusion film blowing process according to the formula of the high-barrier composite film.
  8. 8. The method for preparing the high-barrier composite film according to claim 7, wherein the method for preparing the allyl anthraquinone silane coupling agent is as follows: taking 2.1-2.8 mol equivalent of 2-amino anthraquinone and 1 mol equivalent of 3-bromopropyl trimethoxy silane as raw materials, taking potassium carbonate as an acid binding agent, carrying out N-monoalkylation reaction in anhydrous DMF, and introducing 3-trimethoxy silicon propyl chain on amino nitrogen to generate a secondary amine type intermediate; And nucleophilic substitution of SN 2 on the allylbromide by the lone pair electron on the secondary amine nitrogen of the secondary amine type intermediate is carried out, so as to generate the allylanthraquinone silane coupling agent.
  9. 9. The preparation method of the high-barrier composite film according to claim 8, wherein the preparation method of the epoxy propyl anthraquinone silane coupling agent is characterized in that the terminal olefin of the allyl anthraquinone silane coupling agent is subjected to a specific epoxidation reaction under the condition that a m-chloroperoxybenzoic acid/methylene dichloride system is neutral to weak acid anhydrous environment to generate the epoxy propyl anthraquinone silane coupling agent.
  10. 10. Use of a high barrier composite film according to any of claims 1-6 for the manufacture of IBC liner bags which maintain structural integrity in a light protected environment during storage and transportation and achieve photocatalytic oxidative degradation in a post-disposal natural light environment.

Description

High-barrier composite film, preparation method and application thereof in IBC storage and transportation ocean transportation Technical Field The invention relates to the technical field of polymer composite film materials, in particular to a photodegradable high-barrier composite film, and specifically relates to a high-barrier composite film, a preparation method and application thereof in IBC (intermediate bulk carrier) storage and transportation in ocean. Background IBC (INTERMEDIATE BULK CONTAINER, medium bulk container) is widely used for storage and transportation of liquid or pasty goods in chemical industry, medicine, food, paint and other industries. IBCs are typically composed of a rigid outer frame with a disposable flexible liner bag, with a nominal volume typically between 275L-1000L. The lining bag bears the core functions of containing and isolating cargoes, and has excellent mechanical strength, chemical inertness, gas barrier property and heat sealing performance so as to meet the severe working condition requirement of long-period ocean transportation. The lining bag is made of a multi-layer coextrusion composite film composed of Polyethylene (PE) and polyamide (PA, nylon). PE is a nonpolar semi-crystalline polymer (the surface energy is about 28-35mJ/m 2), has excellent chemical inertness, heat sealing performance and main mechanical strength, and PA is a strong polar semi-crystalline polymer (the surface energy is about 40-46mJ/m 2 and slightly different with the brand of PA), and has excellent barrier performance to O 2、CO2 and organic solvent vapor. However, because of the significant surface energy difference between PE and PA, and the large Flory-Huggins interaction parameter χ, the thermodynamically high incompatibility, the lack of effective chemical bonding and molecular chain entanglement at the interface during direct co-extrusion, the extremely low interlayer peel strength (typically <1.0N/15 mm), and the extremely easy occurrence of interlayer delamination failure under the action of composite stresses such as ocean transport vibration, impact and hydrostatic pressure. In order to solve the problem of interfacial compatibility between PE and PA, a symmetrical five-layer co-extrusion structure PE/TIE/PA/TIE/PE is commonly adopted in industry, and a TIE layer is maleic anhydride grafted polyethylene (MAH-g-PE) bonding resin, and the interfacial bonding mechanism is divided into the following two layers: Firstly, chemically bonding with a PA layer, namely nucleophilic addition ring opening is carried out on five-membered ring anhydride on a MAH grafted side group and a PA chain end primary amino (-NH 2) at a coextrusion processing temperature (usually 200-250 ℃), an amic acid intermediate containing an amide bond (-CO-NH-) and free carboxylic acid (-COOH) is generated at an initial stage, and the amic acid intermediate is further dehydrated and cyclized at a high temperature, and finally, an imide bond (-CO-N (R) -CO-) is used as a main covalent bonding form to be anchored at a PA interface; And secondly, the physical compatibility with the PE layer is that the main polyethylene skeleton of MAH-g-PE is fully compatible with the thermodynamics of the adjacent PE structure layer (Flory-Huggins parameter χ is about 0), and the interfaces of the main polyethylene skeleton and the adjacent PE structure layer are fully diffused by molecular chains and intertwined by chain segments in the melt co-extrusion process, and a continuous physical anchoring network is formed after cooling crystallization. The chemical bonding and physical compatible dual synergistic mechanism can enable the interlayer peeling strength of the five-layer co-extrusion film to reach 4-8N/15mm (different according to the MAH grafting rate, the processing technology and the testing conditions), and meets the structural integrity requirement of the IBC lining bag under the storage and transportation working condition. However, the disposable flexible lining bag brings convenience for storage and transportation, causes remarkable pressure on the ecological environment, has a degradation period of PE in the natural environment of hundreds of years, and belongs to a polymer material difficult to degrade, and the PE/PA multilayer composite structure has extremely high difficulty in interlayer close combination and component separation and recovery, so that the technical feasibility and economic feasibility of layering stripping in the existing mechanical recovery process are seriously insufficient. Therefore, a large number of abandoned lining bags have extremely long degradation period in natural environment, and the separation and recovery difficulty of the composite structure are high, and persistent white pollution is easy to cause after one-time use and abandonment. Disclosure of Invention The invention aims to provide a PE/PA multilayer coextrusion composite film with a photocatalytic degradation function and a p