Production method of multifunctional low static nylon film

Abstract

This invention discloses a method for producing a multifunctional low-static nylon membrane. The nylon membrane consists of a functional layer, an upper surface layer, a base layer, and a lower surface layer distributed from top to bottom. The functional layer is a polyimide containing carborane units. The upper surface layer consists of PA66, aluminum diethyl phosphite, halloysite nanotubes, and an antioxidant. The base layer consists of PA66 and an antistatic agent. The lower surface layer consists of PA66 and organic quaternary phosphate intercalated modified sodium hydroxyl silicate. By adding a small amount of halloysite nanotubes to the PA66 / aluminum diethyl phosphite flame retardant system, the upper surface layer can achieve a synergistic flame retardant effect. Halloysite nanotubes slow down degradation and promote char formation. The aluminum diethyl phosphite-haloysite nanotube composite system can form a continuous and dense char layer during combustion, providing a good barrier effect. Aluminum diethyl phosphite has both gas-phase and condensed-phase flame retardant properties, and the introduction of halloysite nanotubes can interact with ADP in the condensed phase, promoting cross-linking and char formation.

Description

Technical Field

[0001] This invention relates to a method for producing a multifunctional low-static nylon film. Background Technology

[0002] BOPA is biaxially oriented nylon film, an important material for producing various composite packaging materials. Existing BOPA films typically have a three-layer structure: an upper layer, a core layer, and a lower layer. However, nylon has poor flame retardant properties and easily produces dripping and smoke during combustion, affecting its application in many situations. Furthermore, when nylon is exposed to high temperatures for extended periods, it oxidizes upon contact with oxygen in the air. Summary of the Invention

[0003] In view of the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a method for producing a multifunctional low-static nylon film.

[0004] The technical solution of the present invention is: a method for producing a multifunctional low-static nylon film, wherein the nylon film is composed of a functional layer, an upper surface layer, a base layer and a lower surface layer distributed from top to bottom;

[0005] The functional layer is a polyimide containing carborane units;

[0006] The upper surface layer is composed of PA66, aluminum diethylphosphite, halloysite nanotubes, and antioxidants;

[0007] The base layer is composed of PA66 and an antistatic agent;

[0008] The lower surface layer consists of PA6 and organic quaternary phosphate intercalated modified sodium hydroxylite;

[0009] The production method includes the following steps:

[0010] (1) Prepare raw materials according to the components of the upper surface layer, the base layer and the lower surface layer respectively;

[0011] (2) The raw materials of the upper surface layer, the base layer and the lower surface layer are blended separately and sent to their respective extruders for mixing and plasticizing;

[0012] (3) The molten melt is fed into the die head separately. After the melt merges in the die head, it forms a molten sheet through the flat die head opening.

[0013] (4) The sheet is attached to the cooling roller with an air knife and cooled rapidly to form an unshaped sheet. Then, the sheet is shaped into a cast sheet after being cooled in a water bath.

[0014] (5) The cast sheet is stretched to form a thin film;

[0015] (6) Spray a polyimide solution containing carborane units onto the surface of the upper layer, and form a functional layer after curing;

[0016] (7) Test the flame retardant properties of the film;

[0017] (8) The tested film is wound up.

[0018] Furthermore, the preparation method of organic quaternary phosphate salt intercalated modified sodium hydroxylite is as follows: sodium hydroxylite and hexadecyltriphenylphosphine bromide are added to a container and stirred at 80°C for 2 hours. The product is filtered and washed with deionized water until no bromide ions are present in the solution. The product is then dried, ground, and passed through a 48-micron sieve to obtain organic quaternary phosphate salt intercalated modified sodium hydroxylite.

[0019] Furthermore, the components of the functional layer, upper surface layer, base layer, and lower surface layer are in the following mass ratios: functional layer 5%, upper surface layer 15%, base layer 60%, and lower surface layer 20%.

[0020] Furthermore, the components of the upper surface layer, by mass ratio, are: PA66 87.5%, diethylaluminum hypophosphite 10.5%, halloysite nanotubes 1.5%, and antioxidant 0.5%;

[0021] The components of the base layer, by mass ratio, are: PA66 99%, antistatic agent 1%;

[0022] The components of the lower surface layer are in the following mass ratio: PA6 97%, organic quaternary phosphate intercalation modified sodium hydroxyl silicate 3%.

[0023] Furthermore, step (7) includes the following steps:

[0024] (71) Cut out a long strip of film, place the long strip of film on top of a piece of flammable paper, and then place the film and the flammable paper together on the testing table and press down the left and right ends of the film with a pressing device.

[0025] (72) Use an igniter to approach the film block and ignite it. The flame will spray downwards onto the surface of the film block. The flame will last for 30 seconds. Observe whether the film block is ignited.

[0026] (73) Turn off the igniter, loosen the film block of the clamping device, remove the film block covering the flammable paper, and observe whether the flammable paper is ignited.

[0027] The beneficial effects of this invention are as follows: By adding a small amount of halloysite nanotubes to the PA66 / diethylaluminum hypophosphite flame retardant system, the upper surface layer can play a synergistic flame retardant role. Halloysite nanotubes play a role in slowing down degradation and promoting char formation. The diethylaluminum hypophosphite-haloysite nanotube composite system can form a continuous and dense char layer during combustion, which plays a good barrier role. Diethylaluminum hypophosphite has both gas phase and condensed phase flame retardancy. The introduction of halloysite nanotubes can interact with ADP in the condensed phase and promote cross-linking and char formation.

[0028] A polyimide solution containing carborane units is sprayed onto the surface of the upper layer to form a functional layer. A boron oxide passivation protective layer is formed on the surface of the functional layer, which prevents the internal polymer from directly contacting oxygen, thereby reducing the polymer decomposition rate and improving the heat resistance and oxidation stability of the film.

[0029] Some of the interlayers of sodium hydroxysilicate can be inserted by hexadecyltriphenylphosphine bromide modifier. Organic sodium hydroxysilicate exists in the PA6 matrix in two structural forms: intercalation and exfoliation, forming a nano-sodium hydroxysilicate / PA6 composite material with both intercalation and exfoliation. The organic quaternary phosphate salt intercalation modification of sodium hydroxysilicate has a significant effect on improving the tensile strength of PA6. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the nylon membrane of the present invention.

[0031] As shown in the diagram: 100—functional layer, 200—upper surface layer, 300—base layer, 400—lower surface layer. Implementation

[0032] To provide a more intuitive and complete understanding of the technical solution of this invention, the following non-limiting features are described in conjunction with the accompanying drawings:

[0033] like Figure 1 As shown, the production method of multifunctional low-static nylon film, the nylon film is composed of a functional layer 100, an upper surface layer 200, a base layer 300 and a lower surface layer 400 distributed from top to bottom;

[0034] The functional layer is a polyimide containing carborane units;

[0035] The upper surface layer is composed of PA66, aluminum diethylphosphite, halloysite nanotubes, and antioxidants;

[0036] The base layer is composed of PA66 and an antistatic agent;

[0037] The lower surface layer consists of PA6 and organic quaternary phosphate intercalated modified sodium hydroxylite;

[0038] The antioxidant is antioxidant 1010, and the antistatic agent is a mixture of glyceryl stearate and oleamide.

[0039] The production method of multifunctional low-static nylon film includes the following steps:

[0040] (1) Prepare raw materials according to the components of the upper surface layer, the base layer and the lower surface layer respectively;

[0041] (2) The raw materials of the upper surface layer, the base layer and the lower surface layer are blended separately and sent to their respective extruders for mixing and plasticizing;

[0042] (3) The molten melt is fed into the die head separately. After the melt merges in the die head, it forms a molten sheet through the flat die head opening.

[0043] (4) The sheet is attached to the cooling roller with an air knife and cooled rapidly to form an unshaped sheet. Then, the sheet is shaped into a cast sheet after being cooled in a water bath.

[0044] (5) The cast sheet is stretched to form a thin film;

[0045] (6) Spray a polyimide solution containing carborane units onto the surface of the upper layer, and form a functional layer after curing;

[0046] (7) Test the flame retardant properties of the film;

[0047] (8) The tested film is wound up.

[0048] The preparation method of organic quaternary phosphate salt intercalated modified sodium hydroxylite is as follows: sodium hydroxylite and hexadecyltriphenylphosphine bromide are added to a container and stirred at 80°C for 2 hours. The product is filtered and washed with deionized water until no bromide ions are present in the solution. The product is then dried, ground, and passed through a 48-micron sieve to obtain organic quaternary phosphate salt intercalated modified sodium hydroxylite.

[0049] The components of the functional layer, upper surface layer, base layer, and lower surface layer, by mass ratio, are: functional layer 5%, upper surface layer 15%, base layer 60%, and lower surface layer 20%. The components of the upper surface layer, by mass ratio, are: PA66 87.5%, diethylaluminum hypophosphite 10.5%, halloysite nanotubes 1.5%, and antioxidant 0.5%; the components of the base layer, by mass ratio, are: PA66 99% and antistatic agent 1%; the components of the lower surface layer, by mass ratio, are: PA6 97% and organic quaternary phosphate intercalated modified sodium hydroxysilicate 3%.

[0050] Step (7) includes the following steps:

[0051] (71) Cut out a long strip of film, place the long strip of film on top of a piece of flammable paper, and then place the film and the flammable paper together on the testing table and press down the left and right ends of the film with a pressing device.

[0052] (72) Use an igniter to approach the film block and ignite it. The flame will spray downwards onto the surface of the film block. The flame will last for 30 seconds. Observe whether the film block is ignited.

[0053] (73) Turn off the igniter, loosen the film block of the clamping device, remove the film block covering the flammable paper, and observe whether the flammable paper is ignited.

[0054] Since the ultimate purpose of BOPA's flame-retardant properties as a packaging material is to protect the materials it packages, this invention uses a method of testing flammable paper and film blocks together. This allows for a direct observation of whether the paper is ignited, thereby determining the flame-retardant properties of the film.

[0055] The upper surface layer, by adding a small amount of halloysite nanotubes to the PA66 / diethylaluminum hypophosphite flame retardant system, can play a synergistic flame retardant role. Halloysite nanotubes play a role in slowing down degradation and promoting char formation. The diethylaluminum hypophosphite-haloysite nanotube composite system can form a continuous and dense char layer during combustion, which can play a good barrier effect. Diethylaluminum hypophosphite has both gas phase and condensed phase flame retardancy. The introduction of halloysite nanotubes can interact with ADP in the condensed phase and promote cross-linking and char formation.

[0056] A polyimide solution containing carborane units is sprayed onto the surface of the upper layer to form a functional layer. A boron oxide passivation protective layer is formed on the surface of the functional layer, which prevents the internal polymer from directly contacting oxygen, thereby reducing the polymer decomposition rate and improving the heat resistance and oxidation stability of the film.

[0057] Some of the interlayers of sodium hydroxysilicate can be inserted by hexadecyltriphenylphosphine bromide modifier. Organic sodium hydroxysilicate exists in the PA6 matrix in two structural forms: intercalation and exfoliation, forming a nano-sodium hydroxysilicate / PA6 composite material with both intercalation and exfoliation. The organic quaternary phosphate salt intercalation modification of sodium hydroxysilicate has a significant effect on improving the tensile strength of PA6.

Claims

1. A method for producing a multifunctional low-static nylon film, characterized in that: The nylon membrane consists of a functional layer, an upper surface layer, a base layer, and a lower surface layer, distributed from top to bottom. The functional layer is a polyimide containing carborane units; The upper surface layer is composed of PA66, aluminum diethylphosphite, halloysite nanotubes, and antioxidants; The base layer is composed of PA66 and an antistatic agent; The lower surface layer consists of PA6 and organic quaternary phosphate intercalated modified sodium hydroxylite; The production method includes the following steps: (1) Prepare raw materials according to the components of the upper surface layer, the base layer and the lower surface layer respectively; (2) The raw materials of the upper surface layer, the base layer and the lower surface layer are blended separately and sent to their respective extruders for mixing and plasticizing; (3) The molten melt is fed into the die head separately. After the melt merges in the die head, it forms a molten sheet through the flat die head opening. (4) The sheet is attached to the cooling roller with an air knife and cooled rapidly to form an unshaped sheet. Then, the sheet is shaped into a cast sheet after being cooled in a water bath. (5) The cast sheet is stretched to form a thin film; (6) Spray a polyimide solution containing carborane units onto the surface of the upper layer, and form a functional layer after curing; (7) Test the flame retardant properties of the film; (8) The tested film is wound up.

2. The method for producing the multifunctional low-static nylon film according to claim 1, characterized in that: The preparation method of organic quaternary phosphate salt intercalated modified sodium hydroxylite is as follows: sodium hydroxylite and hexadecyltriphenylphosphine bromide are added to a container and stirred at 80°C for 2 hours. The product is filtered and washed with deionized water until no bromide ions are present in the solution. The product is then dried, ground, and passed through a 48-micron sieve to obtain organic quaternary phosphate salt intercalated modified sodium hydroxylite.

3. The method for producing the multifunctional low-static nylon film according to claim 1, characterized in that: The components of the functional layer, upper surface layer, base layer and lower surface layer are in the following mass ratios: functional layer 5%, upper surface layer 15%, base layer 60% and lower surface layer 20%.

4. The method for producing the multifunctional low-static nylon film according to claim 3, characterized in that: The components of the upper surface layer, by mass ratio, are: PA66 87.5%, diethylaluminum hypophosphite 10.5%, halloysite nanotubes 1.5%, and antioxidant 0.5%; The components of the base layer, by mass ratio, are: PA66 99%, antistatic agent 1%; The components of the lower surface layer are in the following mass ratio: PA6 97%, organic quaternary phosphate intercalation modified sodium hydroxyl silicate 3%.

5. The method for producing the multifunctional low-static nylon film according to claim 1, characterized in that: Step (7) includes the following steps: (71) Cut out a long strip of film, place the long strip of film on top of a piece of flammable paper, and then place the film and the flammable paper together on the testing table and press down the left and right ends of the film with a pressing device. (72) Use an igniter to approach the film block and ignite it. The flame will spray downwards onto the surface of the film block. The flame will last for 30 seconds. Observe whether the film block is ignited. (73) Turn off the igniter, loosen the film block of the clamping device, remove the film block covering the flammable paper, and observe whether the flammable paper is ignited.

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