Anti-self-adhesion and antistatic heat-sealing cover tape and preparation method thereof

Abstract

The invention discloses an anti-self-adhesion and antistatic heat-sealing cover tape and a preparation method thereof, the heat-sealing cover tape comprises a base material layer and a heat-sealing layer, and the heat-sealing layer is prepared from the following raw materials in parts by weight: 20-35 parts of ethylene-acrylate-reactive group terpolymer, 50-75 parts of ethylene-reactive group bipolymer, 5-10 parts of conductive filler and 0.05-0.5 part of antioxidant. The preparation process is simple, the time is shorter than that of a liquid coating process, and the production cost is reduced; the preparation process does not need to use an organic solvent, so that a user does not need to worry about the problem of solvent volatilization during use, and environment protection is facilitated. In the formula of the heat sealing layer, the ethylene-acrylate-reactive group terpolymer has high content of acrylate, so that the material has high flexibility and high polarity, and high peel strength can be provided; the ethylene-reactive group bipolymer is a partially crystalline polymer and is not self-adhered at room temperature, and the compatibility of the reactive group enables the material to have better dispersity during melting and mixing.

Description

Technical Field

[0001] This invention relates to the field of heat-sealing tape materials, and in particular to an anti-self-adhesive and antistatic heat-sealing tape and its preparation method. Background Technology

[0002] Cover tape is a key material in the field of electronic packaging, mainly used in the surface mount process of electronic components (such as chips, resistors, capacitors, etc.). The functions of cover tape are: (1) protection function; ① prevent components from being damaged by environmental factors such as dust, moisture, and static electricity during transportation and storage; ② avoid mechanical damage such as scratches and collisions, and ensure the integrity of electronic component pins or pads. (2) fixing function; used in conjunction with carrier tape, electronic components are placed in the grooves of the carrier tape, and then sealed with cover tape to prevent electronic components from shifting or falling off. (3) automation compatibility; ① the peel strength of cover tape needs to be precisely controlled so that it can be peeled off smoothly and stably by the equipment when electronic components are mounted; ② the surface smoothness of cover tape is adapted to the traction and winding of high-speed pick and place machines.

[0003] Heat-sealing tape is manufactured in a wound manner, with the substrate and heat-sealing layer overlapping. Before use, heat-sealing tape may experience self-adhesion and difficulty in unwinding due to storage temperature changes. Furthermore, after sealing the carrier tape, the heat-sealing tape comes into contact with electronic components, and sometimes the tape adheres to these components, affecting their functionality. Additionally, static electricity on the heat-sealing tape can damage sensitive electronic components (such as IC chips). Therefore, there is a need to develop heat-sealing tapes that are both anti-self-adhesive and anti-static to meet market demands.

[0004] Patent CN119529702A discloses a heat-sealing cover tape with anti-self-adhesion properties and its preparation method. A composite adhesive coating liquid is applied to the surface of a pretreated polyethylene film and heated to 60℃~70℃ in an inert gas environment for 5~6 hours, followed by drying and curing to obtain the anti-self-adhesion heat-sealing cover tape. Its manufacturing process is cumbersome, requires stringent conditions, and is time-consuming. Patent CN112500753A discloses an anti-adhesion and antistatic heat-sealing coating and cover tape. The heat-sealing coating is formed by applying a coating liquid with a Tg of 60℃~80℃. The coating liquid consists of 1-3wt% cellulose acetate butyrate, 9-18wt% heat-sealing resin, 76-86wt% solvent, 2-3wt% titanium dioxide conductive particles, and 0.4-0.8wt% dispersant. Its coating liquid uses a large amount of solvent; and the heat-sealing coating contains a large amount of filler, while the thickness of the heat-sealing coating is only 1-4μm, resulting in low peel strength between the heat-sealing cover tape and the carrier tape, posing a risk of incomplete sealing.

[0005] Existing technologies generally suffer from the following problems: 1. Complex processes, long production time, high energy consumption, and high costs. 2. Solvent-based heat-sealing coatings use a large amount of organic solvents; these organic solvents are difficult to recycle after use, have a strong odor, and pollute the environment. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an anti-self-adhesive and antistatic heat-sealing tape and its preparation method, in order to address the shortcomings of the prior art.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a heat-sealing cover tape with anti-self-adhesion and anti-static properties, comprising a substrate layer and a heat-sealing layer stacked together. The raw materials for preparing the heat-sealing layer include, by weight, 20-35 parts of ethylene-acrylate-reactive group terpolymer, 50-75 parts of ethylene-reactive group binary copolymer, 5-10 parts of conductive filler, and 0.05-0.5 parts of antioxidant.

[0008] Preferably, in the ethylene-acrylate-reactive group terpolymer, the acrylate monomer is ethyl acrylate or butyl acrylate, and the reactive group is maleic anhydride or glycidyl methacrylate.

[0009] Preferably, in the ethylene-acrylate-reactive group terpolymer, the acrylate monomer content is 20%-27% by mass, and the reactive group content is 3%-8% by mass.

[0010] Preferably, in the ethylene-acrylate-reactive group terpolymer, the acrylate monomer is butyl acrylate with a mass content of 23%-27%, and the reactive group is glycidyl methacrylate with a mass content of 5%-8%.

[0011] Preferably, in the ethylene-reactive group binary copolymer, the reactive group is maleic anhydride or glycidyl methacrylate, and the mass content of the reactive group is 3%-8%.

[0012] Preferably, the conductive filler is a mixture of needle-shaped conductive titanium dioxide and flake-shaped conductive mica powder.

[0013] Preferably, the mass ratio of conductive titanium dioxide to conductive mica powder in the conductive filler is 4:1 to 8:1.

[0014] Preferably, the antioxidant is one or two of antioxidant 1010, antioxidant 1076, and antioxidant 168.

[0015] The present invention also provides a method for preparing the anti-self-adhesive and antistatic heat-sealing cap tape as described above, comprising the following steps:

[0016] S1. Mix ethylene-acrylate-reactive group terpolymer, ethylene-reactive group binary copolymer, conductive filler and antioxidant in proportion by weight, melt extrusion and granulation to obtain hot melt adhesive granules;

[0017] S2. After the hot melt adhesive granules are melted, the resulting hot melt adhesive is applied to the surface of the substrate through a hot melt coating device to form a hot melt adhesive layer.

[0018] S3. After cooling, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0019] Preferably, the substrate thickness is 15–50 μm.

[0020] Preferably, the method for preparing the anti-self-adhesive and antistatic heat-sealing cap tape includes the following steps:

[0021] S1. Ethylene-acrylate-reactive group terpolymer, ethylene-reactive group binary copolymer, conductive filler and antioxidant are mixed evenly in a high-speed mixer according to the weight ratio, and melt extruded and granulated at 150℃~180℃ to obtain hot melt adhesive granules.

[0022] S2. After melting, vacuum degassing, and filtering impurities, the hot melt adhesive granules are coated onto the surface of a PET substrate using a hot melt coating equipment to form a hot melt adhesive layer with a thickness of 15-50 μm.

[0023] S3. After cooling, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0024] The beneficial effects of this invention are:

[0025] This invention provides an anti-self-adhesive and antistatic heat-sealing tape and its preparation method. The preparation process is simple and shorter than liquid coating processes, reducing production costs. Furthermore, the preparation process of this invention does not require the use of organic solvents, thus eliminating concerns about solvent evaporation and protecting the environment. This invention solves the problems of complex processes and environmental pollution associated with existing technologies.

[0026] The ethylene-acrylate-reactive group terpolymer in the heat-sealing layer formulation of this invention has an acrylate monomer content of 20%-27%. The high acrylate content gives the material high flexibility (low crystallinity) and high polarity, providing high peel strength. The ethylene-reactive group binary copolymer is a partially crystalline polymer that does not self-adhere at room temperature. The compatibility of its reactive groups ensures good dispersibility during melt mixing. The ethylene-acrylate-reactive group terpolymer has a Vicat softening point <40℃, indicating poor temperature resistance. The ethylene-reactive group binary copolymer, a partially crystalline polymer, has a Vicat softening point >80℃. The addition of the ethylene-reactive group binary copolymer improves the material's temperature resistance. A heat-sealing tape prepared by combining 20-35 parts of the ethylene-acrylate-reactive group terpolymer and 50-75 parts of the ethylene-reactive group binary copolymer in this ratio satisfies both the peel strength requirement for sealing with the carrier tape and the effects of anti-self-adhesion and temperature resistance (50℃). Detailed Implementation

[0027] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0028] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0029] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0030] This invention provides a heat-sealing cover tape that is anti-self-adhesive and antistatic, comprising a substrate layer and a heat-sealing layer stacked together. The raw materials for preparing the heat-sealing layer include, by weight: 20-35 parts of ethylene-acrylate-reactive group terpolymer, 50-75 parts of ethylene-reactive group binary copolymer, 5-10 parts of conductive filler, and 0.05-0.5 parts of antioxidant.

[0031] In a preferred embodiment, the ethylene-acrylate-reactive group terpolymer contains ethyl acrylate or butyl acrylate as the acrylate monomer and maleic anhydride or glycidyl methacrylate as the reactive group.

[0032] In a preferred embodiment, the ethylene-acrylate-reactive group terpolymer contains 20%-27% acrylate monomer and 3%-8% reactive groups by mass.

[0033] In a preferred embodiment, the ethylene-acrylate-reactive group terpolymer contains butyl acrylate as the acrylate monomer at a mass content of 23%-27%, and glycidyl methacrylate as the reactive group at a mass content of 5%-8%.

[0034] In a preferred embodiment, the ethylene-acrylate-reactive group terpolymer is selected from Arkema. AX8700 AX8750, Dow Chemical Company One type of PTW.

[0035] In a preferred embodiment, the reactive group in the ethylene-reactive group binary copolymer is maleic anhydride or glycidyl methacrylate, and the mass content of the reactive group is 3%-8%.

[0036] In a preferred embodiment, the ethylene-reactive group copolymer is selected from Arkema. AX8820 One of the AX8840 series.

[0037] In a preferred embodiment, the conductive filler is a mixture of needle-shaped conductive titanium dioxide and flake-shaped conductive mica powder, which is commercially available.

[0038] In a preferred embodiment, the mass ratio of conductive titanium dioxide to conductive mica powder in the conductive filler is 4:1 to 8:1.

[0039] In a preferred embodiment, the antioxidant is one or two of antioxidant 1010, antioxidant 1076, and antioxidant 168, which are commercially available.

[0040] The present invention also provides a method for preparing the anti-self-adhesive and antistatic heat-sealing cap tape as described above, comprising the following steps:

[0041] S1. Mix ethylene-acrylate-reactive group terpolymer, ethylene-reactive group binary copolymer, conductive filler and antioxidant in proportion by weight, melt extrusion and granulation to obtain hot melt adhesive granules;

[0042] S2. After the hot melt adhesive granules are melted, the resulting hot melt adhesive is applied to the surface of the substrate through a hot melt coating device to form a hot melt adhesive layer.

[0043] S3. After cooling, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0044] In a preferred embodiment, the substrate thickness is 15–50 μm.

[0045] In a preferred embodiment, the method for preparing the anti-self-adhesive and antistatic heat-sealing cap tape includes the following steps:

[0046] S1. Ethylene-acrylate-reactive group terpolymer, ethylene-reactive group binary copolymer, conductive filler and antioxidant are mixed evenly in a high-speed mixer according to the weight ratio, and melt extruded and granulated at 150℃~180℃ to obtain hot melt adhesive granules.

[0047] S2. After melting, vacuum degassing, and filtering impurities, the hot melt adhesive granules are coated onto the surface of a PET substrate using a hot melt coating equipment to form a hot melt adhesive layer with a thickness of 15-50 μm.

[0048] S3. After cooling, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0049] The ethylene-acrylate-reactive group terpolymer in the formulation of this invention has an acrylate monomer content of 20%-27%. The high acrylate content gives the material high flexibility (low crystallinity) and high polarity, providing high peel strength. The ethylene-reactive group binary copolymer is a partially crystalline polymer that does not self-adhere at room temperature. The compatibility of its reactive groups ensures good dispersibility during melt mixing. The ethylene-acrylate-reactive group terpolymer has a Vicat softening point <40℃, indicating poor temperature resistance. The ethylene-reactive group binary copolymer, a partially crystalline polymer, has a Vicat softening point >80℃. The addition of the ethylene-reactive group binary copolymer improves the material's temperature resistance. A heat-sealing tape prepared by mixing 20-35 parts of the ethylene-acrylate-reactive group terpolymer and 50-75 parts of the ethylene-reactive group binary copolymer in this ratio satisfies both the peel strength requirement for sealing with the carrier tape and the effects of anti-self-adhesion and temperature resistance (50℃).

[0050] In the formulation of this invention, adding two conductive fillers (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1) results in better conductivity than adding only one type of needle-shaped conductive titanium dioxide. The combination of two conductive powders with different shapes will produce even better conductivity.

[0051] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0052] Example 1

[0053] A heat-sealing tape with anti-self-adhesion and antistatic properties is prepared by the following steps:

[0054] S1. By weight, 21 parts of ethylene-acrylate-reactive group terpolymer (Dow Chemical Company) PTW: 27% butyl acrylate monomer and 6% glycidyl methacrylate monomer, 70 parts ethylene-reactive group copolymer (Arkema). AX8840: 8% glycidyl methacrylate monomer (mass content), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1), 0.3 parts antioxidant (antioxidant 1010: antioxidant 168 = 3:2) were mixed in a high-speed mixer, and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules;

[0055] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0056] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0057] Example 2

[0058] A heat-sealing tape with anti-self-adhesion and antistatic properties is prepared by the following steps:

[0059] S1. By weight, 23 parts of ethylene-acrylate-reactive group terpolymer (Dow Chemical Company) PTW: 27% butyl acrylate monomer and 6% glycidyl methacrylate monomer (by mass), 68 parts ethylene-reactive group copolymer (Arkema). AX8820: 4.5% glycidyl methacrylate monomer (by mass), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1), and 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0060] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0061] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0062] Example 3

[0063] A heat-sealing tape with anti-self-adhesion and antistatic properties is prepared by the following steps:

[0064] S1. By weight, 25 parts of ethylene-acrylate-reactive group terpolymer (Arkema) 8700: 25% butyl acrylate monomer and 8% glycidyl methacrylate monomer (by mass), 66 parts ethylene-reactive group copolymer (Arkema). AX8840: 8% glycidyl methacrylate monomer (mass content), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 6:1), 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0065] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0066] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0067] Example 4

[0068] A heat-sealing tape with anti-self-adhesion and antistatic properties is prepared by the following steps:

[0069] S1. By weight, 28 parts of ethylene-acrylate-reactive group terpolymer (Arkema) 8700: 25% butyl acrylate monomer and 8% glycidyl methacrylate monomer (by mass), 63 parts ethylene-reactive group copolymer (Arkema). AX8820: 4.5% glycidyl methacrylate monomer (by mass), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 6:1), and 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0070] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0071] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0072] Example 5

[0073] A heat-sealing tape with anti-self-adhesion and antistatic properties is prepared by the following steps:

[0074] S1. By weight, 32 parts of ethylene-acrylate-reactive group terpolymer (Arkema) 8750: 25% butyl acrylate monomer and 5% glycidyl methacrylate monomer (by mass), 59 parts ethylene-reactive group copolymer (Arkema). AX8840: 8% glycidyl methacrylate monomer (mass content), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1), 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0075] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0076] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0077] Example 6

[0078] A heat-sealing tape with anti-self-adhesion and antistatic properties is prepared by the following steps:

[0079] S1. By weight, 35 parts of ethylene-acrylate-reactive group terpolymer (Arkema) 8750: 25% butyl acrylate monomer and 5% glycidyl methacrylate monomer (by mass), 56 parts ethylene-reactive group copolymer (Arkema). AX8820: 4.5% glycidyl methacrylate monomer (by mass), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1), and 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0080] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0081] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0082] Comparative Example 1

[0083] A heat-sealing cap tape, the preparation method of which includes the following steps:

[0084] S1. By weight, 91 parts of ethylene-acrylate-reactive group terpolymer (Arkema) 8750: 25% butyl acrylate monomer and 5% glycidyl methacrylate monomer, 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1), and 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules;

[0085] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0086] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0087] Comparative Example 2

[0088] A heat-sealing cap tape, the preparation method of which includes the following steps:

[0089] S1. By weight, 60 parts of ethylene-acrylate-reactive group terpolymer (Arkema) 8750: 25% butyl acrylate monomer and 5% glycidyl methacrylate monomer (by mass), 31 parts ethylene-reactive group copolymer (Arkema). AX8820: 4.5% glycidyl methacrylate monomer (by mass), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1), and 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0090] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0091] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0092] Comparative Example 3

[0093] A heat-sealing cap tape, the preparation method of which includes the following steps:

[0094] S1. By weight, 91 parts of ethylene-reactive group copolymer (Arkema) AX8840: 8% glycidyl methacrylate monomer (mass content), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1), 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0095] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0096] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0097] Comparative Example 4

[0098] A heat-sealing cap tape, the preparation method of which includes the following steps:

[0099] S1. By weight, 12 parts of ethylene-acrylate-reactive group terpolymer (Arkema) 8750: 25% butyl acrylate monomer and 5% glycidyl methacrylate monomer (by mass), 79 parts ethylene-reactive group copolymer (Arkema). AX8840: 8% glycidyl methacrylate monomer (mass content), 8.7 parts conductive filler (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1), 0.3 parts antioxidant (1010:168 = 3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0100] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0101] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0102] Comparative Example 5

[0103] A heat-sealing cap tape, the preparation method of which includes the following steps:

[0104] S1. By weight, 32 parts of ethylene-acrylate-reactive group terpolymer (Arkema) 8750: 25% butyl acrylate monomer and 5% glycidyl methacrylate monomer (by mass), 59 parts ethylene-reactive group copolymer (Arkema). AX8840: 8% glycidyl methacrylate monomer (mass content), 8.7 parts conductive filler needle-shaped conductive titanium dioxide, and 0.3 parts antioxidant (1010:168=3:2) were mixed in a high-speed mixer and then melt-extruded and granulated at 160°C to obtain hot melt adhesive granules.

[0105] S2. After the hot melt adhesive granules are melted, vacuum degassed, and impurities are filtered, the hot melt adhesive is applied to the 20μm PET substrate surface through a hot melt coating equipment, with a coating thickness of 30μm.

[0106] S3. After passing through the cooling roller, the product is wound up and die-cut to obtain the heat-sealed cover tape.

[0107] The specific formulations of the examples and comparative examples are summarized in Table 1 below. All values ​​in the table are in parts by weight.

[0108] Table 1

[0109]

[0110]

[0111] The heat-sealing tapes prepared in the examples and comparative examples were subjected to the following performance tests:

[0112] 1. Peel strength:

[0113] After peeling off the heat-sealing tape and removing the outer 3-5 layers, the sealing knife width used on the semi-automatic sealing and packaging equipment should match that of the carrier tape. The sealing temperature is 170℃, the sealing time is 30 seconds, and after 1 hour, the sample is cut into three 250mm pieces and peeled on a microcomputer tensile testing machine with a tape feed speed of 300mm / min and a peeling angle of 165°-180°. The test length is 200mm.

[0114] The peel strength index is 20-80 gf / in.

[0115] 2. Surface resistivity:

[0116] In an environment with a temperature of 25℃±2℃ and a relative humidity of 65±5%RH, place an insulating rubber pad on the bottom of the PET side of the sample, flatten the sample with the heat-sealed layer facing upwards, and use a Slade SL-030 surface resistance tester to test the resistance value of the heat-sealed layer.

[0117] The surface resistivity is 10. 6 -10 11 Ω.

[0118] 3. Adhesion rate:

[0119] Fix the heat-sealing cap with the substrate side on a flat steel plate, with the heat-sealing layer facing upwards, and place 100 small electronic chips on the heat-sealing layer; after placing it in an environment with a temperature of 25℃±2℃ and a relative humidity of 65±5%RH for 24 hours; rotate the steel plate 180° without shaking it, wait for 20 seconds, and count the number of electronic chips remaining on the heat-sealing layer, X. The adhesion rate is calculated as X / 100*100%.

[0120] The adhesion rate should be <5%.

[0121] 4. Temperature resistance:

[0122] The sample with the heat-sealed cover tape and carrier tape sealed together was placed in an oven at 50°C and 65% RH for 48 hours. The sample was then observed for any tape separation (separation from the carrier tape) and a peel strength test was performed.

[0123] The performance test results are shown in Table 2 below:

[0124] Table 2

[0125]

[0126] Compared to Example 5, the heat-sealing tape prepared in Comparative Example 1, and the heat-sealing tape prepared in Comparative Example 2, compared to Example 6, showed increased peel strength and adhesion rate after sealing with the carrier tape when the proportion of ethylene-acrylate-reactive group terpolymer was higher. Compared to Examples 1 and 3, the heat-sealing tape prepared in Comparative Example 3, and the heat-sealing tape prepared in Comparative Example 4, compared to Example 5, showed significantly reduced peel strength after sealing with the carrier tape when the proportion of ethylene-acrylate-reactive group terpolymer was lower. This demonstrates that ethylene-acrylate-reactive group terpolymer provides high peel strength; ethylene-reactive group binary copolymer prevents self-adhesion at room temperature. Only heat-sealing tapes prepared by combining ethylene-acrylate-reactive group terpolymer and ethylene-reactive group binary copolymer in a suitable ratio can meet the peel strength requirements for sealing with the carrier tape, while also exhibiting anti-self-adhesion and non-adhesion effects to electronic components.

[0127] Compared with Example 5, the heat-sealing cover tape prepared in Comparative Example 1 and Example 6 showed that when the proportion of ethylene-acrylate-reactive group terpolymer added was higher, the peel strength of the heat-sealing cover tape after sealing with the carrier tape increased. However, after being placed in an oven at 50°C and 65% RH for 48 hours, the tape opened up, indicating poor temperature resistance.

[0128] Compared with Example 5, the heat-sealing tape prepared by Comparative Example 5, with the same amount of conductive filler added (8.7%), showed better conductivity when adding two types of conductive fillers (needle-shaped conductive titanium dioxide: flake-shaped conductive mica powder = 5:1) than when adding only one type of needle-shaped conductive titanium dioxide. This shows that the combination of two different shapes of conductive powder will produce better conductivity.

[0129] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A heat-sealing cap tape that is anti-self-adhesive and antistatic, characterized in that, It includes a substrate layer and a heat-sealing layer stacked together. The raw materials for preparing the heat-sealing layer include, by weight, 20-35 parts of ethylene-acrylate-reactive group terpolymer, 50-75 parts of ethylene-reactive group binary copolymer, 5-10 parts of conductive filler, and 0.05-0.5 parts of antioxidant.

2. The anti-self-adhesive and antistatic heat-sealing cap tape according to claim 1, characterized in that, In the ethylene-acrylate-reactive group terpolymer, the acrylate monomer is ethyl acrylate or butyl acrylate, and the reactive group is maleic anhydride or glycidyl methacrylate.

3. The anti-self-adhesive and antistatic heat-sealing cap tape according to claim 2, characterized in that, In the ethylene-acrylate-reactive group terpolymer, the acrylate monomer content is 20%-27% by mass, and the reactive group content is 3%-8% by mass.

4. The anti-self-adhesive and antistatic heat-sealing cap tape according to claim 3, characterized in that, In the ethylene-acrylate-reactive group terpolymer, the acrylate monomer is butyl acrylate with a mass content of 23%-27%, and the reactive group is glycidyl methacrylate with a mass content of 5%-8%.

5. The anti-self-adhesive and antistatic heat-sealing cap tape according to claim 1, characterized in that, In the ethylene-reactive group binary copolymer, the reactive group is maleic anhydride or glycidyl methacrylate, and the mass content of the reactive group is 3%-8%.

6. The anti-self-adhesive and antistatic heat-sealing cap tape according to claim 1, characterized in that, The conductive filler is a mixture of needle-shaped conductive titanium dioxide and flake-shaped conductive mica powder.

7. The anti-self-adhesive and antistatic heat-sealing cap tape according to claim 6, characterized in that, The mass ratio of conductive titanium dioxide to conductive mica powder in conductive fillers is 4:1 to 8:

1.

8. The anti-self-adhesive and antistatic heat-sealing cap tape according to claim 1, characterized in that, The antioxidant is one or two of antioxidant 1010, antioxidant 1076, and antioxidant 168.

9. A method for preparing an anti-self-adhesive, antistatic heat-sealing cap tape as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Mix ethylene-acrylate-reactive group terpolymer, ethylene-reactive group binary copolymer, conductive filler and antioxidant in proportion by weight, melt extrusion and granulation to obtain hot melt adhesive granules; S2. After the hot melt adhesive granules are melted, the resulting hot melt adhesive is applied to the surface of the substrate through a hot melt coating device to form a hot melt adhesive layer. S3. After cooling, the product is wound up and die-cut to obtain the heat-sealed cover tape.

10. The method for preparing the anti-self-adhesive and antistatic heat-sealing cap tape according to claim 9, characterized in that, Includes the following steps: S1. Ethylene-acrylate-reactive group terpolymer, ethylene-reactive group binary copolymer, conductive filler and antioxidant are mixed evenly in a high-speed mixer according to the weight ratio, and melt extruded and granulated at 150℃~180℃ to obtain hot melt adhesive granules. S2. After melting, vacuum degassing, and filtering impurities, the hot melt adhesive granules are coated onto the surface of a PET substrate using a hot melt coating equipment to form a hot melt adhesive layer with a thickness of 15-50 μm. S3. After cooling, the product is wound up and die-cut to obtain the heat-sealed cover tape.

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