Preparation method of an integrated composite shielding foam

Abstract

The present invention provides a preparation method of an integrated composite shielding foam, comprising: pre-treating a polyurethane foam; subjecting the pre-treated polyurethane foam to electroless plating for conductivity treatment, and electroplating on one side of the polyurethane foam after the electroless plating for conductivity treatment through a composite electroplating copper solution to form a carbon nanotube / metal copper composite layer, wherein the composite electroplating copper solution at least comprises copper ions and carbon nanotubes; electroplating nickel on the surface of the polyurethane foam after the composite electroplating of copper to prepare an integrated composite shielding foam; the carbon nanotubes can play a connecting role between the composite metal copper layer and the metal nickel layer, improving the bonding force between the composite metal copper layer and the metal nickel layer; the metal nickel layer is uniformly plated on the surface of the composite shielding foam, while further enhancing the shielding effectiveness of the composite foam, endowing the composite shielding foam with corrosion resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic shielding materials, and particularly relates to a preparation method of an integrated composite shielding foam. Background Art

[0002] With the rapid development of information technology, the application of electromagnetic waves is becoming more and more extensive. However, the abuse of electromagnetic waves will have an adverse impact on people's life, work and health. In order to reduce the harm of electromagnetic waves, people begin to use electromagnetic shielding materials to shield electromagnetic waves. With the development of science and technology, people begin to pursue lightweight and high shielding efficiency electromagnetic shielding materials. At present, lightweight and high shielding efficiency electromagnetic shielding materials are mainly prepared by combining polymers and metals.

[0003] For different scenarios, the requirements for shielding materials are also different. When metal composite shielding materials are applied to humid environments, ordinary metals are easily corroded, affecting the long-term use of the materials and the shielding effect. Summary of the Invention

[0004] In view of this, the present invention provides a preparation method of an integrated composite shielding foam, and obtains an integrated composite shielding foam with a simple and efficient preparation process.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] An embodiment of the present invention provides a preparation method of an integrated composite shielding foam, comprising pretreating a polyurethane foam; subjecting the pretreated polyurethane foam to electroless plating for conductivity treatment; electroplating on one side of the polyurethane foam that has completed the electroless plating for conductivity treatment with a composite electroplating copper solution to form a carbon nanotube / metal copper composite layer, wherein the composite electroplating copper solution at least comprises copper ions and carbon nanotubes;

[0007] Electroplating nickel on the surface of the polyurethane foam that has completed the composite electroplating of copper to prepare an integrated composite shielding foam.

[0008] Among them, for the above-mentioned integrated composite shielding foam, first, the polyurethane foam is pretreated, and then subjected to electroless plating for conductivity treatment. Through composite electroplating, a carbon nanotube / metal copper composite layer grows on one side of the polyurethane foam that has been subjected to electroless plating for conductivity treatment, and a nickel electroplating layer is plated on the outer surface of the composite foam. Thus, the integrated composite shielding foam has a polyurethane foam subjected to electroless plating for conductivity treatment as the substrate, one side is a metal nickel layer, and the other side is a composite metal layer of a carbon nanotube / metal copper composite layer and a metal nickel layer. The specific preparation method is as follows:

[0009] (1) Pretreatment:

[0010] a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 1 - 5 minutes, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0011] b. Place the polyurethane foam in a hot press and compress it at 80 - 100 °C to 1 / 3 of its original thickness, with a thickness of 0.5 - 2 mm.

[0012] (2) Electroless plating for conductivity treatment:

[0013] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it thoroughly;

[0014] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, put the washed polyurethane foam into the solution and soak it for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0015] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the polyurethane foam after hydrophilic treatment in the colloidal palladium activation solution, adjust the solution environment to a negative pressure state, stir for 1 - 10 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0016] d. Decolloidization treatment: Prepare a decolloidization solution, then completely immerse the activated polyurethane foam in the decolloidization solution, adjust the solution environment to a negative pressure state, stir for 1 - 10 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0017] e. Prepare an electroless copper plating solution, place the polyurethane foam after decolloidization treatment in the electroless copper plating solution, adjust the solution environment to a negative pressure state, stir for 20 - 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating for conductivity treatment.

[0018] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution, with the carbon nanotube content being 3 - 6 g / L. Keep the temperature of the electroplating solution at 35 - 45 °C by water bath heating. Place the polyurethane foam after electroless plating for conductivity treatment in the composite electroplated copper solution for single-sided composite electroplating of copper. During the composite electroplating process, maintain air stirring and ultrasonic oscillation. After composite electroplating, a carbon nanotube / metal copper composite layer is obtained, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0019] (4) Prepare an electroplated nickel solution, keep the temperature of the electroplating solution at 50 - 60 °C by water bath heating. Place the polyurethane foam after composite electroplating of copper in the electroplated nickel solution for electroplating. During the electroplating process, maintain air stirring. After electroplating, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0020] Among them, the pore size of the polyurethane foam is 100 - 300 microns; in the carbon nanotube / copper metal composite layer, the outer diameter of the carbon nanotubes is 10 - 100 nanometers, and the length is 0.5 - 10 microns.

[0021] Among them, in the sodium hydroxide alcohol solution, the mass ratio of sodium hydroxide is 1 - 2%.

[0022] Among them, in the process of composite electroplating copper, the electroplating method is pulse electroplating, the average current density is 3.0 - 7.0 amperes per square decimeter, and the electroplating time is 1 - 5 minutes.

[0023] Among them, in the process of electroplating nickel, the electroplating method is pulse electroplating, the average current density is adjusted to 3.0 - 7.0 amperes per square decimeter, and the electroplating time is 0.5 - 3 minutes.

[0024] The present invention provides a preparation method of an integrated composite shielding foam, which relates to the technical field of electromagnetic shielding materials. The steps include: pretreating the polyurethane foam to obtain a polyurethane foam with a porous multi-layer structure; then conducting electroless plating conductivity treatment on it by electroless plating to form a porous multi-layer conductive structure; then conducting carbon nanotube composite and multi-layer metal layer design, and by regulating the electroplating parameters, an integrated composite shielding foam with a multi-layer metal composite and carbon nanotube / metal composite layer structure is obtained, so that the composite foam has good shielding performance and bending resistance performance while having a corrosion resistance effect.

[0025] Compared with the prior art, it has the following beneficial effects:

[0026] (1) The integrated composite shielding foam can destroy the remaining closed-cell structure inside the foam through pretreatment, making the inside of the foam have tiny holes. During the electroless plating conductivity process, the inside of the foam can fully contact the electroless plating solution, and the formed porous multi-layer conductive structure can reflect the incident electromagnetic wave multiple times, improving the shielding efficiency of the material; at the same time, the heating and compression treatment can compress the original thickness of the foam; the nickel metal layer uniformly covers the surface of the composite foam, improving the shielding efficiency of the composite foam further while making the composite foam have a corrosion resistance effect.

[0027] (2) Usually, when electroplating different metals, there will be a situation where the bonding force between dissimilar metals is not good. In the present invention, carbon nanotubes are incorporated when electroplating the copper metal layer. While improving the bending resistance performance of the copper coating, after electroplating the subsequent nickel metal layer, it can play a connecting role between the two metal layers, improving the bonding force between the composite copper metal layer and the nickel metal layer; at the same time, the hollow structure of the carbon nanotubes can allow the incident electromagnetic wave to be reflected multiple times inside, further consuming the electromagnetic wave and improving the shielding performance.

[0028] (3) Through the design of a porous multi-layer conductive structure and multi-layer metal composite, the shielding effect of the two sides of the foam of the present invention on incident electromagnetic waves is different. When electromagnetic waves are incident from the carbon nanotube / copper metal composite layer and the metal nickel layer composite metal layer of the composite foam, the electromagnetic waves are dissipated through "reflection - absorption"; when electromagnetic waves are incident from the metal nickel layer, the electromagnetic waves are dissipated through "absorption - reflection - reabsorption". When electromagnetic waves are incident from the metal nickel layer, the shielding effectiveness is better. Description of the Drawings

[0029] Figure 1 It is a comparison chart of the shielding effectiveness of polyurethane foams composite with different metal layers provided in Example 1, Comparative Example 3, and Comparative Example 4 of the present invention.

[0030] Figure 2 It is a comparison chart of the shielding effectiveness of both sides of an integrated composite shielding foam provided in an embodiment of the present invention. Among them, the shielding effectiveness of the A side of the composite foam refers to the shielding effectiveness when the electromagnetic wave incident surface is the metal nickel layer, and the shielding effectiveness of the B side of the composite foam refers to the shielding effectiveness when the electromagnetic wave incident surface is the carbon nanotube / copper metal composite layer and the metal nickel layer composite metal layer. Detailed Description of the Invention

[0031] The present invention will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] Example 1

[0033] An integrated composite shielding foam prepared in an embodiment of the present invention is as follows:

[0034] (1) Pretreatment:

[0035] a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 3 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0036] b. Place the polyurethane foam in a hot press and compress it at 100 degrees Celsius to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0037] (2) Electroless plating for conductivity treatment:

[0038] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it;

[0039] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, place the washed polyurethane foam in the solution and soak it for 30 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0040] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the hydrophilic-treated polyurethane foam in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0041] d. De-gumming treatment: Prepare a de-gumming solution, then completely immerse the activated polyurethane foam in the de-gumming solution, adjust the solution state to negative pressure, stir for 2 minutes, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0042] e. Prepare an electroless copper plating solution, place the polyurethane foam that has completed the de-gumming treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating for conductivity treatment.

[0043] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 grams per liter. Place the polyurethane foam that has completed the electroless plating for conductivity treatment in the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 degrees Celsius by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 3 minutes, and maintain air stirring and ultrasonic oscillation during the composite electroplating process. After the composite electroplating, a carbon nanotube / metal copper composite layer is obtained, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0044] (4) Prepare an electroplated nickel solution, place the polyurethane foam that has completed the composite electroplating in the electroplated nickel solution for pulsed double-sided electroplating of nickel. Keep the solution temperature at 55 degrees Celsius by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 1 minute, and maintain air stirring during the electroplating process. After completion, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0045] Example 2

[0046] An integrated composite shielding foam prepared according to an embodiment of the present invention is as follows:

[0047] (1) Pretreatment:

[0048] a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 1 minute, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0049] b. Place the polyurethane foam in a hot press and compress it at 100 degrees Celsius to 1 / 3 of its original thickness, with a thickness of 1 millimeter.

[0050] (2) Electroless plating for conductivity treatment:

[0051] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it until it is clean;

[0052] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%. Immerse the washed polyurethane foam in the solution for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0053] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution. Immerse the hydrophilized polyurethane foam completely in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0054] d. Decoloring treatment: Prepare a decoloring solution. Then immerse the activated polyurethane foam completely in the decoloring solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0055] e. Prepare an electroless copper plating solution. Place the polyurethane foam that has completed the decoloring treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating and conductivity treatment.

[0056] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 grams per liter. Place the polyurethane foam that has completed the electroless plating and conductivity treatment in the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 °C by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 3 minutes, and maintain air stirring and ultrasonic oscillation during the composite electroplating process. After the composite electroplating, obtain a carbon nanotube / metal copper composite layer, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0057] (4) Prepare an electroplated nickel solution. Place the polyurethane foam that has completed the composite electroplating in the electroplated nickel solution for pulsed double-sided electroplating of nickel. Keep the solution temperature at 55 °C by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 1 minute, and maintain air stirring during the electroplating process. After completion, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0058] Example 3

[0059] An integrated composite shielding foam prepared according to an embodiment of the present invention is as follows:

[0060] (1) Pretreatment:

[0061] a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 5 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0062] b. Place the polyurethane foam in a hot press and compress it at 100 °C to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0063] (2) Electroless plating for conductivity treatment:

[0064] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it until it is clean.

[0065] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%. Immerse the washed polyurethane foam in the solution for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0066] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution. Immerse the polyurethane foam subjected to hydrophilic treatment completely in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0067] d. Decolloidization treatment: Prepare a decolloidization solution. Then immerse the polyurethane foam subjected to activation treatment completely in the decolloidization solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0068] e. Prepare an electroless copper plating solution. Place the polyurethane foam that has completed the decolloidization treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating for conductivity treatment.

[0069] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 g / L. Place the polyurethane foam that has completed the electroless plating for conductivity treatment in the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 °C by water bath heating, adjust the average current density to 5 A / dm², electroplate for 3 minutes, and maintain air stirring and ultrasonic oscillation during the composite electroplating process. After composite electroplating, a carbon nanotube / metal copper composite layer is obtained, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0070] (4) Prepare an electroplated nickel solution. Place the polyurethane foam that has completed the composite electroplating in the electroplated nickel solution for pulsed double-sided electroplating of nickel. Keep the solution temperature at 55 °C by water bath heating, adjust the average current density to 5 A / dm², electroplate for 1 minute, and maintain air stirring during the electroplating process. After completion, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0071] Example 4

[0072] An integrated composite shielding foam prepared according to an embodiment of the present invention is as follows:

[0073] (1) Pretreatment:

[0074] a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 3 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0075] b. Place the polyurethane foam in a hot press and compress it at 100 °C to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0076] (2) Electroless plating for conductivity treatment:

[0077] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it;

[0078] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, place the washed polyurethane foam in the solution and soak it for 30 minutes, then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0079] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the polyurethane foam subjected to hydrophilic treatment in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0080] d. De-gumming treatment: Prepare a de-gumming solution, then completely immerse the polyurethane foam subjected to activation treatment in the de-gumming solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0081] e. Prepare an electroless copper plating solution, place the polyurethane foam that has completed the de-gumming treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and rinse it thoroughly with pure water on a Buchner funnel stand to complete the electroless plating for conductivity treatment.

[0082] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 g / L. Place the polyurethane foam that has completed the electroless plating for conductivity treatment in the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 °C by water bath heating, adjust the average current density to 5 A / dm², electroplate for 1 minute, and maintain air stirring and ultrasonic vibration during the composite electroplating process. After composite electroplating, a carbon nanotube / metal copper composite layer is obtained, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand.

[0083] (4) Prepare the electroplating nickel solution, place the polyurethane foam that has completed composite electroplating into the electroplating nickel solution for pulsed double-sided electroplating nickel, heat it in a water bath to keep the solution temperature at 55 °C, adjust the average current density to 5 A / dm², electroplate for 1 minute, maintain air agitation during the electroplating process, take it out after completion and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0084] Example 5

[0085] An integrated composite shielding foam prepared in an embodiment of the present invention is as follows:

[0086] (1) Pretreatment:

[0087] a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 3 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0088] b. Place the polyurethane foam in a hot press and compress it at 100 °C to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0089] (2) Electroless plating for conductivity treatment:

[0090] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it;

[0091] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, put the washed polyurethane foam into the solution and soak it for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0092] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the polyurethane foam subjected to hydrophilic treatment in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0093] d. Dejelling treatment: Prepare a dejelling solution, then completely immerse the polyurethane foam subjected to activation treatment in the dejelling solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0094] e. Prepare the electroless copper plating solution, place the polyurethane foam that has completed the dejelling treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating for conductivity treatment.

[0095] (3) Uniformly disperse carbon nanotubes into the electroplating copper solution to obtain a composite electroplating copper solution with a carbon nanotube content of 4 grams per liter. Place the polyurethane foam that has completed electroless plating and conductivity treatment into the composite electroplating copper solution for pulsed single-sided composite electroplating of copper. Heat the solution in a water bath to maintain a temperature of 45 degrees Celsius, adjust the average current density to 5 amperes per square decimeter, and electroplate for 5 minutes. During the composite electroplating process, maintain air stirring and ultrasonic oscillation. After obtaining the carbon nanotube / metal copper composite layer, take it out and place it on a Buchner funnel stand, then rinse it thoroughly with pure water.

[0096] (4) Prepare an electroplating nickel solution. Place the polyurethane foam that has completed composite electroplating into the electroplating nickel solution for pulsed double-sided electroplating of nickel. Heat the solution in a water bath to maintain a temperature of 55 degrees Celsius, adjust the average current density to 5 amperes per square decimeter, and electroplate for 1 minute. During the electroplating process, maintain air stirring. After completion, take it out and place it on a Buchner funnel stand, then rinse it thoroughly with pure water to obtain the integrated composite shielding foam described.

[0097] Example 6

[0098] An integrated composite shielding foam prepared according to an embodiment of the present invention is as follows:

[0099] (1) Pretreatment:

[0100] a. Place the polyurethane foam into a sodium hydroxide alcohol solution, stir for 3 minutes, then take it out and place it on a Buchner funnel stand, and rinse it thoroughly with pure water;

[0101] b. Place the polyurethane foam into a hot press and compress it at 100 degrees Celsius to 1 / 3 of its original thickness, with a thickness of 1 millimeter.

[0102] (2) Electroless plating and conductivity treatment:

[0103] a. Cleaning: Place the pretreated polyurethane foam into absolute ethanol and ultrasonically clean it thoroughly;

[0104] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%. Place the washed polyurethane foam into the solution and soak it for 30 minutes, then take it out and place it on a Buchner funnel stand, and rinse it thoroughly with pure water;

[0105] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution. Completely immerse the polyurethane foam that has undergone hydrophilic treatment into the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand, and rinse it thoroughly with pure water;

[0106] d. De-gumming treatment: Prepare a de-gumming solution, then completely immerse the polyurethane foam that has undergone activation treatment into the de-gumming solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand, and rinse it thoroughly with pure water;

[0107] e. Prepare an electroless copper plating solution, place the polyurethane foam that has completed the peptization treatment into the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating and conductivity treatment.

[0108] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 grams per liter. Place the polyurethane foam that has completed the electroless plating and conductivity treatment into the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 °C by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 3 minutes, and maintain air stirring and ultrasonic oscillation during the composite electroplating process. After the composite electroplating, a carbon nanotube / copper metal composite layer is obtained, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0109] (4) Prepare an electroplated nickel solution, place the polyurethane foam that has completed the composite electroplating into the electroplated nickel solution for pulsed double-sided electroplating of nickel. Keep the solution temperature at 55 °C by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 0.5 minutes, and maintain air stirring during the electroplating process. After completion, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0110] Example 7

[0111] An integrated composite shielding foam prepared in an embodiment of the present invention is as follows:

[0112] (1) Pretreatment:

[0113] a. Place the polyurethane foam into a sodium hydroxide alcohol solution, stir for 3 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0114] b. Place the polyurethane foam into a hot press and compress it at 100 °C to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0115] (2) Electroless plating and conductivity treatment:

[0116] a. Cleaning: Place the pretreated polyurethane foam into absolute ethanol and ultrasonically clean it thoroughly;

[0117] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, place the washed polyurethane foam into the solution and soak it for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0118] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the hydrophilized polyurethane foam in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0119] d. De-gumming treatment: Prepare a de-gumming solution, then completely immerse the activated polyurethane foam in the de-gumming solution, adjust the solution state to negative pressure, stir for 2 minutes, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0120] e. Prepare an electroless copper plating solution, place the polyurethane foam that has completed the de-gumming treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating for conductivity treatment.

[0121] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 grams per liter. Place the polyurethane foam that has completed the electroless plating for conductivity treatment in the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 degrees Celsius by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 3 minutes, and maintain air stirring and ultrasonic oscillation during the composite electroplating process. After the composite electroplating, a carbon nanotube / metal copper composite layer is obtained, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0122] (4) Prepare an electroplated nickel solution, place the polyurethane foam that has completed the composite electroplating in the electroplated nickel solution for pulsed double-sided electroplating of nickel. Keep the solution temperature at 55 degrees Celsius by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 3 minutes, and maintain air stirring during the electroplating process. After completion, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0123] Comparative Example 1

[0124] An integrated composite shielding foam prepared according to an embodiment of the present invention. In the specific implementation manner, the step of soaking in the sodium hydroxide alcohol solution in the pretreatment step is omitted, and other steps are the same as those in Example 1, specifically as follows:

[0125] (1) Place the polyurethane foam in a hot press and compress it at 100 degrees Celsius to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0126] (2) Electroless plating for conductivity treatment:

[0127] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it thoroughly;

[0128] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%. Immerse the washed polyurethane foam in the solution for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0129] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution. Immerse the polyurethane foam that has undergone hydrophilic treatment completely in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0130] d. De-gumming treatment: Prepare a de-gumming solution. Then immerse the polyurethane foam that has undergone activation treatment completely in the de-gumming solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0131] e. Prepare an electroless copper plating solution. Place the polyurethane foam that has completed the de-gumming treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating and conductivity treatment.

[0132] (2) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 grams per liter. Place the polyurethane foam that has completed the electroless plating and conductivity treatment in the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 degrees Celsius by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 3 minutes, and maintain air stirring and ultrasonic oscillation during the composite electroplating process. After the composite electroplating, obtain a carbon nanotube / metal copper composite layer, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0133] (3) Prepare an electroplated nickel solution. Place the polyurethane foam that has completed the composite electroplating in the electroplated nickel solution for pulsed double-sided electroplating of nickel. Keep the solution temperature at 55 degrees Celsius by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 1 minute, and maintain air stirring during the electroplating process. After completion, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0134] Comparative Example 2

[0135] This is an integrated composite shielding foam prepared in the embodiment of the present invention. The specific implementation method omits the heating and compression treatment in the pretreatment step, and the other steps are the same as those in Example 1, specifically as follows:

[0136] (1) Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 3 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0137] (2) Electroless plating and conductivity treatment:

[0138] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it until it is clean;

[0139] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, place the washed polyurethane foam in the solution and soak it for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0140] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the polyurethane foam subjected to hydrophilic treatment in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0141] d. Decoloring treatment: Prepare a decoloring solution, then completely immerse the polyurethane foam subjected to activation treatment in the decoloring solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water;

[0142] e. Prepare an electroless copper plating solution, place the polyurethane foam that has completed the decoloring treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating and conductivity treatment.

[0143] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 grams per liter. Place the polyurethane foam that has completed the electroless plating and conductivity treatment in the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 °C by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 3 minutes, and maintain air stirring and ultrasonic vibration during the composite electroplating process. After composite electroplating, a carbon nanotube / metal copper composite layer is obtained, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0144] (4) Prepare an electroplated nickel solution, place the polyurethane foam that has completed the composite electroplating in the electroplated nickel solution for pulsed double-sided electroplating of nickel. Keep the solution temperature at 55 °C by water bath heating, adjust the average current density to 5 amperes per square decimeter, electroplate for 1 minute, and maintain air stirring during the electroplating process. After completion, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to obtain the described integrated composite shielding foam.

[0145] Comparative Example 3

[0146] An integrated composite shielding foam prepared in the comparative example of the present invention, and a conventional electroplated copper step is adopted in the preparation process, which is specifically as follows:

[0147] (1) Pretreatment:

[0148] a. Place the polyurethane foam in an alcoholic solution of sodium hydroxide, stir for 3 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0149] b. Place the polyurethane foam in a hot press and compress it at 100 °C to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0150] (2) Electroless plating for conductivity treatment:

[0151] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it thoroughly.

[0152] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, put the washed polyurethane foam into the solution and soak it for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0153] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the polyurethane foam subjected to hydrophilic treatment in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0154] d. De-gumming treatment: Prepare a de-gumming solution, then completely immerse the polyurethane foam subjected to activation treatment in the de-gumming solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0155] e. Prepare an electroless copper plating solution, place the polyurethane foam that has completed the de-gumming treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating for conductivity treatment.

[0156] (3) Prepare a conventional electroplating copper solution, place the polyurethane foam that has completed the electroless plating for conductivity treatment in the electroplating copper solution for pulsed single-sided electroplating of copper, maintain the solution temperature at 45 °C by water bath heating, adjust the average current density to 5 A / dm², electroplate for 3 minutes, keep air stirring during the electroplating process, obtain a metallic copper layer, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0157] (4) Prepare an electroplating nickel solution, place the polyurethane foam that has completed the electroplating of copper in the electroplating nickel solution for pulsed double-sided electroplating of nickel, maintain the solution temperature at 55 °C by water bath heating, adjust the average current density to 5 A / dm², electroplate for 3 minutes, keep air stirring during the electroplating process, take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water after completion to obtain the described integrated composite shielding foam.

[0158] Comparative Example 4

[0159] An integrated composite shielding foam prepared as a comparative example of the present invention, omitting the steps of composite electroplating copper and electroplating nickel, is as follows:

[0160] (1) Pretreatment:

[0161] a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 3 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0162] b. Place the polyurethane foam in a hot press and compress it at 100 °C to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0163] (2) Electroless plating for conductivity treatment:

[0164] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it;

[0165] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, place the washed polyurethane foam in the solution and soak it for 30 minutes, then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0166] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the polyurethane foam subjected to hydrophilic treatment in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0167] d. Debinding treatment: Prepare a debinding solution, then completely immerse the polyurethane foam subjected to activation treatment in the debinding solution, adjust the solution state to negative pressure, stir for 2 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0168] e. Prepare an electroless copper plating solution, place the polyurethane foam that has completed the debinding treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 40 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand to complete the electroless plating for conductivity treatment.

[0169] Comparative Example 5

[0170] An integrated composite shielding foam prepared as an example of the present invention, omitting the electroplating nickel process, and the prepared sample does not have corrosion resistance, is as follows:

[0171] (1) Pretreatment:

[0172] a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 3 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand;

[0173] b. Place the polyurethane foam in a hot press and compress it at 100 °C to 1 / 3 of its original thickness, with a thickness of 1 mm.

[0174] (2) Electroless plating for conductive treatment:

[0175] a. Cleaning: Place the pretreated polyurethane foam in absolute ethanol and ultrasonically clean it until it is clean.

[0176] b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%. Immerse the cleaned polyurethane foam in the solution for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0177] c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution. Immerse the polyurethane foam subjected to hydrophilic treatment completely in the colloidal palladium activation solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0178] d. De-gumming treatment: Prepare a de-gumming solution. Then immerse the polyurethane foam subjected to activation treatment completely in the de-gumming solution, adjust the solution state to negative pressure, stir for 2 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0179] e. Prepare an electroless copper plating solution. Place the polyurethane foam that has completed the de-gumming treatment in the electroless copper plating solution, adjust the solution state to negative pressure, stir for 30 minutes, then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water to complete the electroless plating for conductive treatment.

[0180] (3) Uniformly disperse carbon nanotubes into the electroplated copper solution to obtain a composite electroplated copper solution with a carbon nanotube content of 4 g / L. Place the polyurethane foam that has completed the electroless plating for conductive treatment in the composite electroplated copper solution for pulsed single-sided composite electroplating of copper. Keep the solution temperature at 45 °C by water bath heating, adjust the average current density to 5 A / dm², electroplate for 3 minutes, and maintain air stirring and ultrasonic vibration during the composite electroplating process. A carbon nanotube / copper metal composite layer is obtained by composite electroplating, and then take it out and place it on a Buchner funnel stand and rinse it thoroughly with pure water.

[0181] Test the shielding effectiveness of the sample through a network vector analyzer;

[0182] Examine the bending resistance of the sample by comparing the mass loss of the sample after bending 100 times;

[0183] Test the corrosion resistance of the sample through a neutral salt spray test.

[0184] Please refer to Table 1 for a summary of the comparison between all the examples and comparative examples in the present invention. The X-band shielding effectiveness refers to the average shielding effectiveness of this integrated composite shielding foam in the frequency range of 8 - 12 GHz. It can be seen from this:

[0185] (1) It can be seen from the comparison of Example 1, Example 2, and Example 3 that the treatment time of the sodium hydroxide alcohol solution has a great influence on both the X-band shielding effectiveness and the bending resistance. When the treatment time of the sodium hydroxide alcohol solution is insufficient, it will cause the interior of the polyurethane foam not to fully contact the electroless plating solution during electroless plating conductive treatment, resulting in incomplete internal plating layers and affecting the shielding effect. While too long treatment time of the sodium hydroxide alcohol solution will affect the foam structure, reducing the area where the metal layer can be plated and affecting the shielding effectiveness and bending resistance. Combining with Comparative Example 1, it is comprehensively concluded that Example 1 has better shielding effectiveness while ensuring good bending resistance.

[0186] (2) It can be seen from the comparison of Example 1, Example 4, and Example 5 that the longer the time of composite electroplating copper, the better the X-band shielding effectiveness. By comparing the mass loss after bending to characterize the bending resistance, the mass loss of Example 1 is only 0.6 mg after 100 bends, indicating that Example 1 has better shielding effectiveness while ensuring good bending resistance. At the same time, Comparative Example 3 uses conventional electroplating copper, and the obtained integrated composite shielding foam has worse bending resistance and electromagnetic shielding effectiveness than Example 1.

[0187] (3) It can be seen from the comparison of Example 1, Example 6, and Example 7 that the longer the time of electroplating nickel, the better the X-band shielding effectiveness. However, through optical microscope observation before and after bending, too long electroplating time will cause cracking of the nickel layer after bending. By comparing the time when corrosion points appear in the neutral salt spray environment to characterize the corrosion resistance, the sample obtained in Example 1 still has no corrosion points after 96 hours of salt spray test. The samples of Comparative Example 4 and Comparative Example 5 can obviously observe verdigris in the neutral salt spray environment only after 1 hour, indicating corrosion has occurred, which shows that the metallic nickel of the sample in Example 1 completely covers the surface of metallic copper and can play a role in protecting the metallic copper layer. Generally speaking, Example 1 has good corrosion resistance while having good bending resistance.

[0188] (4) Comparative Example 2 uses polyurethane foam without heat compression treatment for electroless plating. The prepared composite foam has a thicker thickness, poor bending resistance, and poor shielding effect, which fully demonstrates the importance of the hot pressing step. By comparing the shielding performance of the polyurethane composite shielding foams prepared in Example 1, Comparative Example 4, and Comparative Example 5, combined with Figure 1 it can be seen that the composite of multiple layers of metals can improve the total shielding performance of the composite material. The average X-band shielding effectiveness of the sample prepared in Example 1 reaches 36.3 dB, exceeding the commercial standard (>20 dB). By observing Figure 2 , there are differences in the shielding effectiveness on both sides of the integrated composite shielding foam prepared in Example 1. When the electromagnetic wave incident surface is the A surface of the composite foam, the shielding effectiveness is better.

[0189]

[0190] Table 1

[0191] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of an integrated composite shielding foam, characterized in that, The method includes the following steps: Pre-treat the polyurethane foam; the pre-treatment of the polyurethane foam includes: a. Place the polyurethane foam in a sodium hydroxide alcohol solution, stir for 1 to 5 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand; b. Place the polyurethane foam in a hot press and compress it at 80 to 100 degrees Celsius to 1 / 3 of its original thickness, with a thickness of 0.5 to 2 millimeters; Conduct electroless plating on the pre-treated polyurethane foam to make it conductive; On one side of the polyurethane foam after the electroless plating for conductivity, electroplate it with a composite electroplating copper solution to form a carbon nanotube / metal copper composite layer, where the composite electroplating copper solution includes at least copper ions and carbon nanotubes; Electroplate nickel on the surface of the polyurethane foam after the electroplating to prepare an integrated composite shielding foam.

2. The preparation method of an integrated composite shielding foam according to claim 1, characterized in that, The pore size of the polyurethane foam is 100 to 300 microns; in the carbon nanotube / metal copper composite layer, the outer diameter of the carbon nanotubes is 10 to 100 nanometers, and the length is 0.5 to 10 microns.

3. The preparation method of an integrated composite shielding foam according to claim 1, characterized in that The conducting electroless plating treatment on the pre-treated polyurethane foam includes: a. Cleaning: Place the heated and compressed polyurethane foam in absolute ethanol and ultrasonically clean it; b. Hydrophilic treatment: Prepare a Triton solution with a concentration of 0.2%, put the washed polyurethane foam into the solution and soak it for 30 minutes, then take it out and rinse it thoroughly with pure water on a Buchner funnel stand; c. Colloidal palladium activation treatment: Prepare a colloidal palladium activation solution, completely immerse the polyurethane foam subjected to hydrophilic treatment in the colloidal palladium activation solution, adjust the solution environment to a negative pressure state, stir for 1 to 10 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand; d. De-gumming treatment: Prepare a de-gumming solution, then completely immerse the activated polyurethane foam in the de-gumming solution, adjust the solution environment to a negative pressure state, stir for 1 to 10 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand; e. Prepare an electroless copper plating solution, place the polyurethane foam after the de-gumming treatment in the electroless copper plating solution, adjust the solution environment to a negative pressure state, stir for 20 to 30 minutes, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand.

4. The preparation method of an integrated composite shielding foam according to claim 1, characterized in that, The electroplating on one side of the polyurethane foam after the conducting electroless plating treatment with a composite electroplating copper solution to form a carbon nanotube / metal copper composite layer includes: Uniformly disperse the carbon nanotubes into the electroplating copper solution to obtain a composite electroplating copper solution, where the carbon nanotube content is 3 to 6 grams per liter, keep the temperature of the electroplating solution at 35 to 45 degrees Celsius by water bath heating, place the polyurethane foam after the conducting electroless plating treatment in the composite electroplating copper solution for single-sided composite electroplating of copper, keep air stirring and ultrasonic oscillation during the composite electroplating process, obtain a carbon nanotube / metal copper composite layer by composite electroplating, and then take it out and rinse it thoroughly with pure water on a Buchner funnel stand.

5. The preparation method of an integrated composite shielding foam according to claim 1, characterized in that, The electroplating nickel on the surface of the polyurethane foam after the electroplating includes: Prepare an electroplating nickel solution, and maintain the temperature of the electroplating solution at 50-60 °C by water bath heating. Place the electroplated polyurethane foam in the electroplating nickel solution for electroplating, keep air stirring during the electroplating process, and after electroplating, take it out and place it on a Buchner funnel stand and rinse it clean with pure water.

6. The preparation method of an integrated composite shielding foam according to claim 1, characterized in that, In the sodium hydroxide alcohol solution, the mass ratio of sodium hydroxide is 1-2%.

7. The preparation method of an integrated composite shielding foam according to claim 1, characterized in that, During the composite electroplating of copper, the electroplating method is pulse electroplating, adjust the average current density to 3.0-7.0 A / dm², and electroplate for 1-5 minutes.

8. The preparation method of an integrated composite shielding foam according to claim 1, characterized in that, During the electroplating of nickel, the electroplating method is pulse electroplating, adjust the average current density to 3.0-7.0 A / dm², and electroplate for 0.5-3 minutes.

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