CN-121608434-B - Eleven-layer co-extrusion film, preparation process and application thereof in aviation cable

Abstract

The invention relates to the technical field of research and development of functional films and discloses an eleven-layer co-extrusion film, a preparation process and application thereof in an aviation cable, wherein the eleven-layer co-extrusion film is prepared by taking heptamethyl hydrogen-containing POSS, diallyl amine, diethyl phosphite and 10-undecylenal as raw materials, synthesizing a halogen-free reactive phosphorus-POSS-nitrogen synergistic flame retardant through hydrosilylation, kabachnik-Fields and alkenyl epoxidation reaction, and performing covalent bonding with amino-terminated functional groups in PA6 resin and PA66 resin through epoxy-amino ring-opening reaction to prepare flame retardant PA master batches; and taking the flame-retardant PA master batch as a raw material of the eleven-layer co-extrusion film, and adopting an eleven-layer co-extrusion blow molding process to prepare the eleven-layer co-extrusion film. The invention can obviously improve the flame-retardant performance of the eleven-layer co-extrusion film and simultaneously has the beneficial technical effect of obviously enhancing the high temperature resistance of the eleven-layer co-extrusion film.

Inventors

• CHU JINGJING
• ZHU LEI
• FU XIN
• Kang Ben

Assignees

• 安徽紫金新材料科技股份有限公司

Dates

Publication Date

20260508

Application Date

20260202

Claims (5)

1. 1. The preparation process of the eleven-layer co-extrusion film is characterized by comprising the following steps of: Step one, preparing flame-retardant PA master batch, which specifically comprises the following steps: firstly, synthesizing a halogen-free reactive phosphorus-POSS-nitrogen synergistic flame retardant, wherein the synthesis method comprises the following steps: (a) The preparation method comprises the steps of preparing the partially condensed trihydroxy heptamethyl cage-shaped silsesquioxane by taking methyl trichlorosilane as a raw material and adopting a direct hydrolytic condensation method, and preparing the heptamethyl hydrogen-containing POSS by taking the partially condensed trihydroxy heptamethyl cage-shaped silsesquioxane as the raw material and taking the trichlorosilane as a monomer of a vertex-cap through a vertex-cap ring closure reaction, wherein the chemical structural formula is as follows: ; (b) Under the action of a platinum catalyst, performing hydrosilylation reaction on 2-2.03 molar equivalents of heptamethyl hydrogen-containing POSS and 1 molar equivalent of diallylamine to prepare an intermediate a, wherein the chemical structural formula of the intermediate a is as follows: ; (c) Based on the Kabachnik-Fields reaction mechanism, the intermediate a, 10-undecylenic aldehyde and diethyl phosphite are subjected to condensation reaction to prepare an intermediate b, wherein the chemical structural formula of the intermediate b is as follows: ; (d) Under the action of glacial acetic acid, the alkenyl functional group in the intermediate b is oxidized into an epoxy functional group by adopting hydrogen peroxide to prepare the halogen-free reactive phosphorus-POSS-nitrogen synergistic flame retardant, and the chemical structural formula is as follows: ; Adding the PA6 resin, the PA66 resin and the halogen-free reactive phosphorus-POSS-nitrogen synergistic flame retardant into a high-speed mixer, uniformly stirring, placing into a double-screw extruder, carrying out melt reaction, extrusion and granulation, and grafting the flame retardant onto a PA molecular main chain in a covalent bonding mode through epoxy-amino ring-opening reaction between epoxy functional groups in the flame retardant and terminal amino functional groups in the PA6 resin and the PA66 resin, wherein the content of the flame retardant in the flame retardant PA master batch is 3.0-6.9wt%; step two: takes flame-retardant PA master batch as raw material, the product structure of the eleven layers of co-extrusion films is PA layer a/PA layer b/PA layer c/PA layer d/PA layer e/PA layer f/PA layer g/PA layer h/PA layer i/PA layer j/PA layer k, the corresponding raw material dosage is 5-15 parts by weight/5-10 parts by weight/15-25 parts by weight, the raw material of any PA layer is 100wt% flame-retardant PA master batch, and an eleven-layer coextrusion film with the thickness of 50-150 mu m is prepared by adopting an eleven-layer coextrusion blow molding film forming process; Wherein, the technological parameters of the screw extruder corresponding to any PA layer are set to 255-265 ℃ in the first area, 265-275 ℃ in the second area, 280-290 ℃ in the third area, 290-300 ℃ in the fourth area and 35-45r/min of screw speed.
2. 2. The process for preparing an eleven-layer coextruded film according to claim 1, characterized in that the platinum catalyst is chloroplatinic acid-isopropanol catalyst or Karstedt catalyst.
3. 3. The process for preparing an eleven-layer coextruded film according to claim 1, characterized in that the twin-screw extruder has an extrusion temperature of 250-260 ℃.
4. 4. An eleven-layer coextruded film produced according to the process of any one of claims 1-3.
5. 5. The eleven-layer co-extruded film according to claim 4, wherein the eleven-layer co-extruded film is used as a substrate, and a pressure sensitive adhesive is coated on one side of the substrate to prepare a PA tape, wherein the PA tape is used for coating and fixing an aviation harness used in a normal temperature environment.

Description

Eleven-layer co-extrusion film, preparation process and application thereof in aviation cable Technical Field The invention relates to the technical field of functional film research, development and manufacturing, in particular to an eleven-layer co-extrusion film, a preparation process and application thereof in an aviation cable. Background The aerial cable is used as a core component of an aircraft electrical system and bears key functions of electric energy transmission and signal control. Modern airliner avionics systems contain thousands of cables, and if a distributed wiring mode is adopted, not only is the space occupied huge, but also the requirements of system reliability and maintainability are difficult to meet. Through harness design, the ordered integration and space optimization of the high-density cable can be realized by adopting a multilayer bundling and branching structure. In the aspect of harness protection, aviation harnesses are generally covered and fixed by using adhesive tapes. For high temperature areas such as engine cabins and landing gear cabins, polyimide (PI) adhesive tapes are still standard protective materials for hot end areas due to excellent high temperature resistance (the long-term use temperature can reach more than 200 ℃) and self-extinguishing characteristics. For general wire harnesses in conventional temperature environments (such as cabin control panels, seat adjustment systems, etc.), the high temperature resistance of PI tape is significantly excessive. Polyimide (PI) for manufacturing PI adhesive tapes is one of the engineering plastics with highest cost at present, and compared with polyamide (commonly called nylon, PA for short) which is used as a large amount of general engineering plastics, the cost of raw materials is far lower than that of polyimide, but the flame retardant property of the basic model is insufficient, and modification treatment is needed. Therefore, the invention aims to develop a novel adhesive tape which is based on a low-cost material of modified PA and has excellent flame retardant property, and is used for replacing the wire harness cladding and fixing of the traditional PI adhesive tape in a conventional temperature environment. Disclosure of Invention The invention autonomously synthesizes a halogen-free reactive phosphorus-POSS-nitrogen synergistic flame retardant, grafts the flame retardant PA master batch on the main chain of PA molecules through covalent bonding, takes the flame retardant PA master batch as the raw material of eleven layers of co-extrusion films, adopts eleven layers of co-extrusion blow molding technology, and prepares the eleven layers of co-extrusion films as flame retardant PA film materials, takes the flame retardant PA film materials as the base material of the adhesive tape, and prepares the adhesive tape for coating and fixing aviation harnesses used in the conventional temperature environment. In order to achieve the above purpose, the invention adopts the following technical scheme: An eleven-layer co-extrusion film preparation process comprises the following steps: Preparing flame-retardant PA master batches, wherein the flame-retardant PA master batches are prepared by carrying out epoxy-amino ring-opening reaction on halogen-free reactive phosphorus-POSS-nitrogen synergistic flame retardants and amino-terminated functional groups in PA6 resin and PA66 resin, and the content of the flame retardants in the flame-retardant PA master batches is 3.0-6.9wt%; And secondly, setting the product structure, the film formula and the dosage of the eleven-layer co-extrusion film by taking the flame-retardant PA master batch as a raw material, and adopting an eleven-layer co-extrusion blow molding film forming process to prepare the eleven-layer co-extrusion film. Preferably, the preparation method of the halogen-free reactive phosphorus-POSS-nitrogen synergistic flame retardant comprises the following steps: under the action of a platinum catalyst, performing hydrosilylation reaction between 2-2.03 molar equivalents of heptamethyl hydrogen-containing POSS and 1 molar equivalent of diallylamine to prepare an intermediate a; based on a Kabachnik-Fields reaction mechanism, performing condensation reaction on the intermediate a, 10-undecylenic aldehyde and diethyl phosphite to obtain an intermediate b; Under the action of glacial acetic acid, the alkenyl functional group in the intermediate b is oxidized into an epoxy functional group by adopting hydrogen peroxide, so that the halogen-free reactive phosphorus-POSS-nitrogen synergistic flame retardant is prepared. Preferably, the platinum catalyst is chloroplatinic acid-isopropanol catalyst or Karstedt catalyst. Preferably, the preparation method of the heptamethyl hydrogen-containing POSS comprises the following steps: taking methyltrichlorosilane as a raw material, and preparing incompletely condensed trihydroxy heptamethyl cage-shaped silsesquioxane by adopting