High-frequency high-temperature hot melt adhesive film with shielding function

Abstract

The utility model discloses a high-frequency high-temperature hot melt adhesive film with a shielding function. The high-frequency high-temperature hot melt adhesive film sequentially comprises a substrate layer, a hydrophobic and oleophobic layer, a first bottom coating, a signal shielding adhesive layer, an insulating layer, a second bottom coating and a low-dielectric hot melt adhesive layer, wherein the low-dielectric hot melt adhesive layer is arranged on the second bottom coating and is opposite to the insulating layer. The signal shielding adhesive layer is a functional coating which plays a role in shielding external interference signals, the insulating layer is made of silicon dioxide, and the low-dielectric hot melt adhesive layer is made of polyurethane solvent type hot melt adhesive resin. According to the utility model, the shielding glue layer, the first priming coat, the second priming coat and the insulating layer which are made of mixed materials mixed with nano-silver particles are combined to generate a shielding effect on external electromagnetic signals, and meanwhile, the low-dielectric hot melt glue layer is used, so that cables, workpieces and the like have the advantages of high bonding firmness, no air bubbles, no air holes, low cost and the like. And stability and insulation performance can be maintained at 125 DEG C.

Description

Technical Field

[0001] The utility model relates to the technical field of packaging, in particular to a high-frequency and high-temperature hot-melt adhesive film with a shielding function. Background Art

[0002] There are many types of high-frequency, high-temperature hot-melt adhesive films, which have been widely used in industries such as automotive interiors, automotive wiring, communications, and in the production of handbags and decorative boxes. High-temperature and high-humidity resistance are the development direction of high-end products in this industry. High-frequency, high-temperature hot-melt adhesive films that meet market needs guarantee the following performance indicators:

[0003] 1. The stability of the substrate's high temperature resistance needs to be guaranteed, and this aspect has basically been solved in the market.

[0004] 2. The surface of an ideal hot melt adhesive film product has ideal hydrophobic and oleophobic properties as well as good scratch resistance and toughness.

[0005] 3. In order to improve the peeling force between the hot melt adhesive layer and the substrate and ensure the consistency of surface performance, a substrate primer layer is required as the connection interface.

[0006] 4. An ideal hot melt adhesive film product must have the function of shielding external interference signals. This is a problem that needs to be solved in the market and is also one of the innovations of the present invention.

[0007] 5. Ensure that the combination of the new hot melt adhesive film and the surface of wires and cables or metal wires and other workpieces has a high degree of stability, there is no delamination between the functional layers, and ensure long-term high temperature resistance ≥128℃. Utility Model Content

[0008] In view of this, the present invention provides a high-frequency and high-temperature hot-melt adhesive film with shielding function and a preparation method thereof to meet industrial needs and solve the above-mentioned problems.

[0009] A high-frequency, high-temperature hot-melt adhesive film with shielding functionality comprises, in order, a substrate layer, a hydrophobic and oleophobic layer disposed on the substrate layer, a first primer layer disposed on the substrate layer on a side facing away from the hydrophobic and oleophobic layer, a signal-shielding adhesive layer disposed on the first primer layer on a side facing away from the substrate layer, an insulating layer disposed on the signal-shielding adhesive layer on a side facing away from the first primer layer, a second primer layer disposed on the insulating layer on a side facing away from the signal-shielding adhesive layer, and a low-dielectric hot-melt adhesive layer disposed on the second primer layer on a side facing away from the insulating layer. The signal-shielding adhesive layer is a functional coating that shields external interference signals. The insulating layer is made of silicon dioxide, and the low-dielectric hot-melt adhesive layer is made of a polyurethane solvent-based hot-melt adhesive resin.

[0010] Furthermore, the substrate layer is one of PTFE, PET, PA, PI, PC, PS, PE, PP, and EVA.

[0011] Furthermore, the hydrophobic and oleophobic layer is made of water-based acrylic resin or polyurethane resin, and the thickness of the hydrophobic and oleophobic layer is 1 to 20 μm.

[0012] Furthermore, the first and second primer layers are made of polyethyleneimine, ethylene-acrylic acid copolymer, and aqueous polyester solution, and the coating dry weight of the first and second primer layers is less than or equal to 0.1 g / m2, and the thickness is less than or equal to 0.05 μm.

[0013] Furthermore, the signal shielding adhesive layer is made of polyurethane hot melt adhesive mixed with metallic silver particles of nanometer size.

[0014] Furthermore, the signal shielding adhesive layer is composed of a silver foil and an adhesive layer, the silver foil is bonded between the first primer layer and the adhesive layer, and the material of the adhesive layer is the same as that of the first primer layer.

[0015] Furthermore, the insulating layer is formed by a vacuum evaporation machine using a magnetron sputtering process, and the thickness of the insulating layer is 80 to 200 nm.

[0016] Furthermore, the second primer layer has a coating dry weight of 0.03 to 0.09 g / m2, a solid content of 0.8% to 5.4%, and a thickness of 0.02 to 0.05 μm.

[0017] Furthermore, the low dielectric hot melt adhesive layer is made by solvent-free compounding, dry compounding or extrusion compounding.

[0018] Furthermore, the thickness of the low-dielectric hot-melt adhesive layer is 15 to 150 μm.

[0019] Compared with the prior art, the present invention uses a combination of the shielding adhesive layer, the first and second primer layers, and the insulating layer made of a mixed material of mixed nano-silver particles, which produces a shielding effect on external electromagnetic signals. At the same time, the low-dielectric hot-melt adhesive layer is used, thereby having a high degree of adhesion to cables and workpieces, no bubbles or pores, and can maintain stability and insulation performance at 125°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of the high-frequency and high-temperature hot-melt adhesive film with shielding function provided by the utility model. DETAILED DESCRIPTION

[0021] The following is a further detailed description of specific embodiments of the present invention. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the scope of protection of the present invention.

[0022] like Figure 1 As shown, it is a structural schematic diagram of a high-frequency and high-temperature hot-melt adhesive film with a shielding function provided by the utility model. The high-frequency and high-temperature hot-melt adhesive film with a shielding function includes a substrate layer 10, a hydrophobic and oleophobic layer 20 arranged on the substrate layer 10, a first primer layer 30 arranged on the substrate layer 10 and on the side facing away from the hydrophobic and oleophobic layer 20, a signal shielding adhesive layer 40 arranged on the first primer layer 30 and on the side facing away from the substrate layer 10, an insulating layer 50 arranged on the signal shielding adhesive layer 40 and on the side facing away from the first primer layer 30, a second primer layer 60 arranged on the insulating layer 50 and on the side facing away from the signal shielding adhesive layer 40, and a low-dielectric hot-melt adhesive layer 70 arranged on the second primer layer 60 and on the side facing away from the insulating layer 50. It is conceivable that the high-frequency and high-temperature hot-melt adhesive film with a shielding function also includes other functional layers, such as a release layer, a protective layer, etc., which are technologies well known to those skilled in the art and will not be described in detail here.

[0023] The substrate layer 10 can be made of not only strong and high-temperature resistant substrates such as PTFE, PET, PA, PI, PC, PS, etc., but also soft substrates such as PE, PP, EVA, PP, etc. In this embodiment, the substrate layer 10 is a PTFE film, which can improve the stiffness and tensile strength of the product. Taking advantage of the good stiffness and relatively good tensile strength physical properties of PTFE, it is used as the supporting material for the high-frequency and high-temperature hot-melt adhesive film with shielding function of the utility model. The thickness range of the PTFE film used in the substrate layer 10 is 12 to 25 μm, with a PTFE film of 20 μm thickness being preferred.

[0024] The hydrophobic and oleophobic layer 20 can be made of a water-based acrylic resin or a polyurethane resin, and has a protective effect on the upper surface of the substrate layer 10 and a hydrophobic and oleophobic effect. The hydrophobic and oleophobic layer 20 is formed by a conventional coating process, and the thickness of the hydrophobic and oleophobic layer 20 after coating and drying is 1-20 μm.

[0025] The hydrophobic and oleophobic layer 20 is prepared by first placing an aqueous solution of a protective resin exhibiting hydrophobicity, oleophobicity, toughness, and hardness in a glue tank. This resin can be an acrylic-based hydrophobic and oleophobic resin. The hydrophobic and oleophobic coating thickness of the hot-melt adhesive film product of this embodiment ranges from 1 to 8 μm, and the working concentration of the coating solution is 25%. After the hydrophobic and oleophobic coating 20 is applied to the upper surface of the substrate layer 10 using a 100-mesh anvil roll, the coating is dried with the coating facing outward before being rolled up.

[0026] The first primer layer 30 can be made of polyethyleneimine, ethylene-acrylic acid copolymer, or aqueous polyester solution. The first primer layer 30 can also be coated on the substrate layer 10 by a coating process in the prior art. The coating dry weight of the first primer layer 30 is less than or equal to 0.1 g / m 2 , and the thickness of the first primer layer is less than or equal to 0.05 μm. The first primer layer 30 and the hydrophobic and oleophobic layer 20 are located on either side of the substrate layer 10. The first primer layer 30 serves to improve the bonding strength between the substrate layer 10 and the signal shielding adhesive layer 40. In this embodiment, the coating process can be performed using a concave coating process characterized by micro-dimples, using an 80-100 mesh annular roller, and the solvent type can be a mixture of water and ethanol.

[0027] The function of the signal shielding adhesive layer 40 is to use a coating process to produce a functional coating layer that has a shielding effect on external interference signals, which is coated on the first primer layer 30. The material of the signal shielding adhesive layer 40 can be a polyurethane hot melt adhesive mixed with nano-sized metallic silver particles. Nano-sized metallic silver (Ag) particles are added to the hot melt adhesive in a certain proportion and mixed evenly to produce a coating hot melt adhesive, so that it has the function of shielding electromagnetic signals. The signal shielding adhesive layer 40 has the following several methods, which are as follows:

[0028] The first preparation method is coating, which uses silver particles mixed with coating liquid to complete the shielding function hot melt adhesive coating:

[0029] The signal-shielding adhesive layer 40, which functions to shield external interference signals, is applied to the first primer layer 30 of the substrate layer 10 using a gravure roller. The coating is a mixture of polyurethane resin and nanosilver particles, applied to the first primer layer 30 using a gravure roller. The process involves adding 4-8% nanometer-sized metallic silver particles to a polyurethane hot-melt adhesive. An organic solvent, such as a mixture of butanone and xylene, is then added. The mixture is then uniformly mixed and sealed before application. The working concentration of the coating solution is 25-40%, and the mesh roller has a mesh size of 100-110. After application, the coating is dried with the coating facing outward and then rolled up.

[0030] The second preparation method is extrusion composite method:

[0031] First, nanosilver particles are evenly dissolved into PE resin at a ratio of 4-8%. The PE resin has a melt index (MI) of 6 g / 10 min (190°C, 2.16 kg). PE hot-melt adhesive pellets with a melting point of 120°C are dried and put into an extruder. They are extruded onto the first primer layer 30 at a melt temperature of 225-260°C with a thickness of 10-50 μm. After the action of cooling rollers and extrusion rollers, they are composited with the main substrate film with a CPFE skeleton to form a composite functional substrate for shielding signals.

[0032] The third preparation method is the silver foil dry composite method:

[0033] After the first primer layer 30 is coated on the substrate layer 10 , the silver foil is directly compounded on the first primer layer 30 , and then a layer of adhesive layer is coated on the silver foil. The material of the adhesive layer can be the same as that of the first primer layer 30 .

[0034] The insulating layer 50 can be coated with SiO2 on the signal shielding adhesive layer 40 by vacuum coating, and is located on the side of the signal shielding adhesive layer 40 opposite to the first primer layer 30. The insulating layer 50 is made of SiO2 material. SiO2 has high thermal conductivity and high resistivity for the composite substrate of hot melt adhesive and shielding function, but more importantly, it can make it have stronger insulation and dielectric properties. Therefore, in order to ensure the insulation function of the substrate layer 10 and the signal shielding adhesive layer 40 and the bonding workpieces such as cables, circuit boards, etc., it is preferred to use a SiO2 transparent coating completed by a vacuum evaporation machine using a magnetron sputtering process, with a common thickness range of 80-200nm and a wetting tension of ≥38 dynes / cm.

[0035] The second primer layer 60 is intended to improve the composite strength between the low-dielectric hot-melt adhesive layer 70 and the insulating coating 50 made of the SiO2, and to ensure that the low-dielectric hot-melt adhesive layer 70 does not produce bubble points and that the product does not produce peeling cracks when bent. Furthermore, in order to reduce costs and improve production efficiency, the first primer layer 60 and the first primer layer 30 use the same component solution, that is, a very thin coating made of polyethyleneimine, ethylene-acrylic acid copolymer, or aqueous polyester solution. At the same time, in order to avoid cracks in the insulating layer 50 made of the SiO2 due to its brittleness, the second primer layer 60 is twice as thick as the first primer layer 30, and the coating dry weight is ≤0.2g / m 2 , thickness is ≤0.1μm.

[0036] The low dielectric hot melt adhesive layer 70 is a polyurethane solvent-based hot melt adhesive resin coated on the second primer layer 60. It can also be made of a water-soluble polyurethane hot melt adhesive resin depending on the product, and is composited with the second primer layer 60 through solvent-free composite, dry composite process, and extrusion composite process.

[0037] Compared with the prior art, the present invention uses a combination of the shielding adhesive layer 40, the first and second primer layers 30, 60, and the insulating layer 50, which are made of a mixed material of mixed nano-silver particles, to produce a shielding effect on external electromagnetic signals. At the same time, the low-dielectric hot-melt adhesive layer 70 is used, so that it has a high degree of adhesion to cables and workpieces, is free of bubbles and pores, and can maintain stability and insulation performance at 125°C.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements or improvements within the spirit of the present invention are included in the scope of the claims of the present invention.

Claims

1. A high-frequency, high-temperature hot-melt adhesive film with shielding function, characterized by: The high-frequency, high-temperature hot-melt adhesive film with shielding function includes, in sequence, a substrate layer, a hydrophobic and oleophobic layer arranged on the substrate layer, a first primer layer arranged on the substrate layer and on the side facing away from the hydrophobic and oleophobic layer, a signal shielding adhesive layer arranged on the first primer layer and on the side facing away from the substrate layer, an insulating layer arranged on the signal shielding adhesive layer and on the side facing away from the first primer layer, a second primer layer arranged on the insulating layer and on the side facing away from the signal shielding adhesive layer, and a low-dielectric hot-melt adhesive layer arranged on the second primer layer and on the side facing away from the insulating layer. The signal shielding adhesive layer is a functional coating that shields external interference signals. The insulating layer is made of silicon dioxide, and the low-dielectric hot-melt adhesive layer is made of polyurethane solvent-based hot-melt adhesive resin.

2. The high-frequency and high-temperature hot-melt adhesive film with shielding function according to claim 1, characterized in that: The substrate layer is one of PTFE, PET, PA, PI, PC, PS, PE, PP, and EVA.

3. The high-frequency and high-temperature hot-melt adhesive film with shielding function according to claim 1, characterized in that: The hydrophobic and oleophobic layer is made of water-based acrylic resin or polyurethane resin, and the thickness of the hydrophobic and oleophobic layer is 1 to 20 μm.

4. The high-frequency and high-temperature hot-melt adhesive film with shielding function according to claim 1, characterized in that: The coating dry weight of the first and second primer layers is less than or equal to 0.1 g / m 2 , thickness is less than or equal to 0.05μm.

5. The high-frequency and high-temperature hot-melt adhesive film with shielding function according to claim 1, characterized in that: The signal shielding adhesive layer is composed of a silver foil and an adhesive layer. The silver foil is bonded between the first primer layer and the adhesive layer. The material of the adhesive layer is the same as that of the first primer layer.

6. The high-frequency and high-temperature hot-melt adhesive film with shielding function according to claim 1, characterized in that: The insulating layer is formed by a vacuum evaporation machine using a magnetron sputtering process, and the thickness of the insulating layer is 80-200 nm.

7. The high-frequency and high-temperature hot-melt adhesive film with shielding function according to claim 1, characterized in that: The coating dry weight of the second primer layer is 0.03 to 0.09 g / m 2 , solid content is 0.8%~5.4, and thickness is 0.02~0.05μm.

8. The high-frequency and high-temperature hot-melt adhesive film with shielding function according to claim 1, characterized in that: The low dielectric hot melt adhesive layer is made by solvent-free compounding, dry compounding or extrusion compounding.

9. The high-frequency and high-temperature hot-melt adhesive film with shielding function according to claim 1, characterized in that: The thickness of the low-dielectric hot-melt adhesive layer is 15 to 150 μm.

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