Room-temperature non-sticky double-sided adhesive tape as well as preparation method and application thereof

Abstract

The invention discloses a room-temperature non-sticky double-sided adhesive tape as well as a preparation method and application thereof. The double-sided adhesive tape comprises a carrier film layer, a non-sticky layer, a base film layer, a hot-pressing layer and an optional cover film which are sequentially stacked, the non-adhesive layer comprises a first polyolefin resin and an elastic material; the hot pressing layer comprises second polyolefin resin and tackifying resin; the first polyolefin resin and the second polyolefin resin respectively comprise at least one of alpha-olefin polymer resin and modified polyolefin resin; the melt index of the elastic material at the temperature of 190-230 DEG C under the load of 5.00 kg is 1-100 g / 10 min; the room-temperature uncovering force of the non-sticky layer and the film carrying layer is larger than the room-temperature uncovering force of the hot-pressing layer and the cover film, but smaller than the hot-pressing adhesive force of the hot-pressing layer. The double-sided adhesive tape basically keeps non-sticky at room temperature, and the cover film and the carrier film layer are smoothly stripped before and after the hot-pressing layer is subjected to hot-pressing bonding through different setting of the bonding force between the layers, so that the problems that a traditional adhesive tape is non-uniform in adhesion or the carrier film is stripped to take away an electrode active material and the like are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, in particular to adhesive tape for lithium batteries, and more particularly to a room temperature non-adhesive double-sided adhesive tape and a preparation method and application thereof. Background Art

[0002] Lithium batteries are widely used in mobile phones, laptops, wearable electronic devices, energy storage devices, and other fields due to their high energy density, multiple charge and discharge cycles, long lifespan, and low pollution. In the field of lithium battery manufacturing, double-sided tape has been widely used, significantly improving the safety, stability, and production efficiency of batteries through bonding, sealing, and structural support. Using double-sided tape to protect tabs and solder joints to prevent short circuits and improve safety is currently one of the most important applications of double-sided tape. Tabs are usually fixed to the positive and negative current collectors of the battery by welding. If the tab welding area is not protected, there is a risk of welding slag, burrs, etc. piercing the diaphragm and causing a short circuit in the battery. In addition, lithium ions can easily precipitate at the tab welding area, affecting battery performance. Currently, the main method of applying protection is to use tab weld protection tape through hot pressing and bonding. However, due to the strong viscosity of traditional double-sided tape at room temperature, it is easy to cause many problems when peeling off the carrier film, such as the accidental removal of electrode active materials, which not only causes material waste but also may significantly reduce battery performance. In addition, the high viscosity at room temperature makes it easy to stick to the roller, seriously affecting the construction effect.

[0003] Invention CN117820972A discloses a double-sided protective tape for the welding area of lithium-ion battery tabs and its preparation method. The double-sided protective tape's substrate comprises a rubber layer on one side and a pressure-sensitive adhesive layer that dissolves in electrolyte on the other side. The double-sided protective tape not only protects the tab welding area from lithium deposition but also, after the adhesive layer dissolves, promotes the dissociation of lithium salts, improving the battery's cycling performance and voltage polarization, and facilitating subsequent battery disassembly. However, due to limitations in its adhesive layer dissolution design, debonding may occur during battery cycling, and the post-hot pressing adhesion cannot be maintained long-term. The dissolved pressure-sensitive adhesive layer may also clog the battery separator, affecting ion transport within the battery, reducing overall performance and posing safety risks. Furthermore, the invention does not effectively address the problem of adhesion during carrier film peeling, making it difficult to completely avoid the risk of material loss and performance degradation.

[0004] Invention CN112920724A discloses a double-sided hot-melt pressure-sensitive adhesive tape for lithium batteries and its preparation method. The tape comprises seven layers from bottom to top: a double-sided release film, a first adhesive layer, a first primer, a base film, a second primer, a second adhesive layer, and a third adhesive layer. A water-based primer enhances the adhesion between the hot-melt pressure-sensitive adhesive layer and the base film and further blocks electrolyte penetration. SBS and SIS rubber elastomers are applied to both surfaces, improving electrolyte resistance, adhesion, and penetration. EVM rubber elastomer serves as a non-sticky protective layer at room temperature and can generate its own adhesiveness at high temperatures. This double-sided hot-melt pressure-sensitive adhesive tape has adhesion to both aluminum foil and polyethylene film at room temperature on one side, but has no adhesion to CPP at room temperature on the other side. Due to limitations in material selection and structural control, the tape still faces the risk of accidental adhesion on the adhesive surface at room temperature, and the electrolyte barrier effect of the water-based primer diminishes with long-term immersion.

[0005] Therefore, how to provide a tape structure that can meet the bonding requirements of application scenarios and is easy to construct without affecting the electrochemical performance of electrode active materials or batteries is still a problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0006] In response to the defects existing in the above-mentioned prior art, the present invention provides a room-temperature non-adhesive double-sided tape, a preparation method and application thereof. Through the design of the composition, performance and interlayer adhesion of each layer, the optional cover film and carrier film layer can be smoothly peeled off before and after the hot pressing bonding of the hot pressing layer. While meeting the bonding requirements of application scenarios, especially the protection requirements of the tab weld marks, it avoids the problems of unstable adhesion of existing tapes, or the peeling of the carrier film taking away the electrode active material, and the sticking roller affecting the construction.

[0007] In a first aspect, the present invention provides a room temperature non-adhesive double-sided adhesive tape comprising a carrier film layer, a non-adhesive layer, a base film layer and a heat-pressing layer stacked in sequence;

[0008] In parts by weight, the non-stick layer comprises:

[0009] 60-90 parts of the first polyolefin resin,

[0010] 5-30 parts of elastic material;

[0011] In parts by weight, the hot pressing layer comprises:

[0012] 20-60 parts of the second polyolefin resin,

[0013] 30-70 parts of tackifying resin;

[0014] The first polyolefin resin and the second polyolefin resin respectively include at least one of an α-olefin polymer resin and a modified polyolefin resin;

[0015] The elastic material has a melt index of 1-100 g / 10 min at a temperature of 190-230° C. and a load of 5.00 kg;

[0016] The room temperature peeling force between the non-adhesive layer and the carrier film layer is greater than the room temperature peeling force of the hot pressing layer, but less than the hot pressing bonding force of the hot pressing layer.

[0017] The elastic material is preferably a rubber material, which is beneficial to improving the toughness and low-temperature resistance of the colloid.

[0018] Tackifying resins are mainly used to increase viscosity, improve wettability and increase initial tack. Using tackifying resins with higher softening points is also beneficial to improving the temperature resistance and chemical resistance of the colloid.

[0019] In the room temperature non-adhesive double-sided tape of the present invention, the base film layer is used to provide the tape with good puncture strength; the hot pressing layer, which is only weakly sticky or even basically non-sticky at room temperature, is used to provide a non-sticky effect on one side of the double-sided tape, thereby preventing the tape from adhering to the outside and causing damage to the electrode active material or the tape itself. In particular, the room temperature peeling force between the non-adhesive layer and the carrier film layer is set to be greater than the room temperature peeling force of the hot pressing layer. In the process of unwinding the tape or removing the optional cover film from the hot pressing layer, the adhesion and relative position of the non-adhesive layer and the carrier film layer are basically not affected, and the problem of positioning deviation caused by tape slippage will not occur. On the other hand, after positioning and hot pressing, the hot pressing layer exhibits a hot pressing bonding force with the adherend that is much greater than the room temperature peeling force between the non-adhesive layer and the carrier film layer. Therefore, after hot pressing bonding, when the outermost carrier film layer is peeled off from the surface of the non-adhesive layer, the bonding surface of the hot pressing layer and the overall structure of the remaining tape will not be affected. Moreover, since the carrier film layer itself has basically no stickiness, the electrode active material will not be adhered away even if it is removed after hot pressing.

[0020] After hot pressing bonding, the bonding structure consisting of the non-adhesive layer, the base film layer and the hot pressing layer can be firmly laminated on the surface of the adherend, for example, providing long-term and stable protection of the tab weld mark. In addition, through the design of the adhesive layer material, the bonding structure has good solvent resistance and can maintain a low dissolution rate and swelling rate even after long-term immersion in the electrolyte.

[0021] Furthermore, the room temperature non-adhesive double-sided tape satisfies at least one of the following:

[0022] 1) The carrier film layer is a single-sided release film or a double-sided release film with a thickness of 15-100 μm;

[0023] 2) The thickness of the non-adhesive layer is 0.5-12 μm;

[0024] 3) The thickness of the hot pressing layer is 2-15 μm;

[0025] 4) The base film layer has a thickness of 1-25 μm and includes at least one of a PP film layer, a PI film layer, a PE film layer, a PET film layer, a PPS film layer, and a BOPP film layer.

[0026] Preferably, the carrier film layer is a double-sided release film, the inner release surface of which is connected to the non-adhesive layer and has an inner release force of 5-60 g / inch, and the outer release surface is connected to the hot pressing layer when winding and has an outer release force of 0.1-10 g / inch.

[0027] Furthermore, a cover film is laminated on the outer side of the heat-pressed layer, away from the base film layer. The cover film has a thickness of 10-40 μm. The room-temperature peeling force between the heat-pressed layer and the cover film is 0.1-10 g / inch, which is less than the room-temperature peeling force between the non-adhesive layer and the carrier film layer. In this case, the performance is essentially the same whether the carrier film layer uses a single-sided release film or a double-sided release film.

[0028] Furthermore, the cover film is a release film or an electrostatic film.

[0029] Furthermore, at least one of the non-adhesive layer, the base film layer, and the heat-pressed layer is a colored layer for identification during use.

[0030] Further, the α-olefin polymer resin includes at least one of polyethylene resin (PE), polypropylene resin (PP), ethylene and octene copolymer resin (POE), and amorphous polyalphaolefin resin (APAO);

[0031] The modified polyolefin resin includes at least one of maleic anhydride-modified polyolefin resin, (meth)acrylic acid-modified polyolefin resin, and copolymer-modified polyolefin resin. Specifically, the modified polyolefin resin includes at least one of MA-APAO, MA-POE, MA-PP, MA-PE, AA-APAO, AA-PP, AA-POE, AA-PE, MAA-PP, MAA-PE, MAA-POE, ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), and ethylene-vinyl acetate copolymer (EVA).

[0032] Furthermore, in the first polyolefin resin, the mass ratio of the α-olefin polymer resin to the modified polyolefin resin is (5-65):(15-70), and the peeling force of the non-adhesive layer and the carrier layer at room temperature is 5-60 g / inch;

[0033] In the second polyolefin resin, the mass ratio of α-olefin polymer resin to modified polyolefin resin is (5-30):(10-35), the room temperature peeling force of the hot pressing layer is below 10g / inch, and the hot pressing bonding force is above 100N / m.

[0034] Furthermore, the first polyolefin resin and the second polyolefin resin have different or identical resin compositions.

[0035] Preferably, the first and second polyolefin resins use different resin compositions. For example, in the first polyolefin resin of the non-sticky layer, the α-olefin polymer resin can be a low-molecular-weight amorphous polyα-olefin resin (APAO), which exhibits an amorphous, irregularly arranged microstructure and features low molecular weight (less than 20,000), low viscosity (melt viscosity less than 1500 mPa.s at 190°C), long open time, and a low softening point (100-115°C). The modified polyolefin resin can be a copolymerized modified polyolefin resin, such as EAA, with a molecular weight less than 50,000. In the second polyolefin resin of the hot-pressing layer, the α-olefin polymer resin can be a POE material with a molecular weight of 50,000-180,000, a high-performance thermoplastic elastomer material copolymerized from ethylene and α-olefins (such as octene and butene) using a metallocene catalyst. The modified polyolefin resin can be a maleic anhydride-modified polyolefin resin, such as MA-PP, with a molecular weight of 60,000-180,000.

[0036] In general, the softening point and viscosity (or melt index) of α-olefin polymer resin have a greater impact on it. If the softening point is too low, it is easy to be swollen or dissolved by the electrolyte, and if the softening point is too high, hot pressing cannot activate it to produce good adhesion. The high or low influence of viscosity or melt index characterizes the molecular weight and processability of the material. The grafting rate of modified polyolefin resin has a greater influence, which affects the adhesion of the material to metal materials. The first polyolefin resin is preferably a low molecular weight, high melt index polyolefin resin, and the second polyolefin resin is preferably a high molecular weight, low melt index polyolefin resin.

[0037] Preferably, the initial hot pressing tack of the hot pressing layer is above 200 N / m, and the bubble liquid adhesion of the hot pressing layer is greater than the initial hot pressing tack. Preferably, the bubble liquid adhesion is increased to above 250 N / m, preferably above 300 N / m.

[0038] Preferably, the swelling rate of the non-sticky layer is below 5%, more preferably below 3%; the dissolution rate of the non-sticky layer is below 5%, more preferably below 3%.

[0039] Preferably, the swelling rate of the hot-pressed layer is below 8%, more preferably below 6%; the dissolution rate of the hot-pressed layer is below 5%, preferably below 3%.

[0040] The hot-pressed layer of the present invention has a relatively high overall softening point, preferably above 120°C, and more preferably above 150°C. It exhibits virtually no tack at room temperature and will not stick to rollers, yet exhibits high hot-press bonding strength, making it easy to apply. The hot-pressed layer's softening point is significantly higher than the soaking temperature of 85°C, providing excellent electrolyte resistance and virtually unaffected by the electrolyte. Furthermore, the hot-pressed layer undergoes a high-temperature, high-pressure activation treatment before being immersed in the electrolyte. As the soaking time increases, the colloid in the hot-pressed layer fully infiltrates the surface of the bonded substrate, forming a stable "riveting effect," and the electrolyte prevents the tape from eroding the interior. Consequently, the hot-pressed bonding strength of the hot-pressed layer exhibits an increase after soaking, surpassing the initial bonding strength exhibited by the hot-pressed layer after a short soaking period. Compared to other adhesive tape systems, where the colloid itself is easily swollen and dissolved by the electrolyte, the natural peel strength decreases significantly after soaking, and even worse, it can peel directly after soaking. The adhesive tape of the present invention is particularly suitable for lithium battery applications, such as protecting tab weld marks.

[0041] Furthermore, the non-sticky layer further comprises 5-10 parts of the tackifying resin in parts by weight;

[0042] In parts by weight, the hot pressing layer further comprises 1-20 parts of the elastic material and 1-20 parts of a viscosity regulator.

[0043] Furthermore, the tackifying resin includes at least one of rosin resin, terpene resin, and petroleum resin; preferably, the softening point of the tackifying resin is above 120° C. A higher softening point is beneficial to improving the temperature resistance and chemical resistance of the adhesive layer;

[0044] The elastic material includes at least one of SBS, SIS, and SEBS rubber materials;

[0045] The viscosity modifier includes at least one of paraffin wax, microcrystalline wax, synthetic wax, polyethylene wax, polypropylene wax, and sasol wax.

[0046] Preferably, the molecular weight of the elastic material is above 100,000, and the softening point is above 100°C. More preferably, the molecular weight of the elastic material is above 150,000, and the softening point is above 200°C. The melt index at a temperature of 190-230°C and a load of 5.00kg is 2-50g / 10min, and the styrene content is 15-35wt%. The higher the styrene content, the higher the material body strength; the lower the styrene content, the better the material flexibility.

[0047] In a second aspect, the present invention further provides a method for preparing the aforementioned room temperature non-adhesive double-sided tape, comprising the following steps:

[0048] Step 1: Apply non-stick coating liquid on one side of the carrier film layer, dry it, and then heat-press it onto one side of the base film layer;

[0049] Step 2: coating the hot pressing layer coating liquid on the other side of the base film layer, and drying to obtain the room temperature non-stick double-sided adhesive tape.

[0050] Furthermore, the non-sticky layer coating liquid adopts a solvent-based coating liquid or a water-based coating liquid.

[0051] Furthermore, the hot pressing layer coating liquid adopts a solvent-based coating liquid or a water-based coating liquid.

[0052] Specifically, the solvent-based coating solution is prepared by the following steps:

[0053] A. Add the solvent into the reactor and stir at a speed of 15-30 rpm;

[0054] B. Weigh and add materials, open the reactor and heat to 130-170℃ according to the softening point of the resin;

[0055] C. Increase the stirring speed to 50-70 rpm and stir for 45-90 minutes to fully dissolve;

[0056] D. After the solid content test is qualified, start cooling. When the temperature is ≤60℃, filter the material to obtain the solvent-based coating liquid.

[0057] The solvent content is adjusted according to the coating solid content, and the solid content is controlled at 4-50 wt %. The solvent is selected from at least one of aromatic hydrocarbon solvents, ketone solvents, and aliphatic hydrocarbon solvents.

[0058] When preparing the non-sticky layer coating solution, the preferred order of adding the raw materials is: elastic material, optional tackifying resin, and the first polyolefin resin.

[0059] When preparing the hot pressing layer coating solution, the raw materials are preferably added in the following order: optional elastic material, tackifying resin, second polyolefin resin, and optional viscosity modifier.

[0060] Specifically, the aqueous coating liquid is prepared by the following steps:

[0061] A. Weighing and adding materials: Add the solvent and raw materials into the reactor and start stirring at a speed of ≥30 rpm and a temperature of 60-160°C until a clear mixture A without solid particles is obtained;

[0062] B. In another new reactor, weigh and add deionized water and emulsifier in sequence, set the temperature to 30-50° C., stir at a speed of 20-40 rpm, and stir for 45-90 min to obtain mixture B;

[0063] C. Add mixture B to the above mixture A, set the temperature to 30-50°C, stir at a speed of 60-80 rpm, and stir for 15-45 min to obtain mixture C;

[0064] D. using a high-speed shearing machine or a homogenizer to shear or homogenize the mixture C;

[0065] E. Distilling the treated mixture C to remove the solvent, controlling the temperature at 80-90° C. and stirring at 40-50 rpm to obtain an aqueous coating solution.

[0066] When preparing the non-sticky layer coating solution, the preferred order of adding the raw materials is: elastic material, optional tackifying resin, and the first polyolefin resin.

[0067] When preparing the hot pressing layer coating solution, the raw materials are preferably added in the following order: optional elastic material, tackifying resin, second polyolefin resin, and optional viscosity modifier.

[0068] Furthermore, after step 2, the method further includes the following steps:

[0069] Die cutting in a direction perpendicular to the carrier film layer to remove a portion of the laminated non-adhesive layer, base film layer and heat-pressed layer from the carrier film layer, thereby forming a plurality of spaced adhesive units on the carrier film layer;

[0070] Optionally, a cover film is attached to the outer side of the heat pressing layer away from the base film layer.

[0071] The size and shape of the adhesive unit can be obtained by the above-mentioned die-cutting according to actual application requirements. Each adhesive unit has a non-adhesive layer, a base film layer and a hot pressing layer.

[0072] In the third aspect, the present invention provides an application of the aforementioned room temperature non-adhesive double-sided tape in tab protection, pole piece protection, pole piece edge insulation protection, and finishing tape based on the structure, composition, and performance characteristics of the aforementioned room temperature non-adhesive double-sided tape.

[0073] Using the aforementioned room temperature non-stick double-sided tape in an application scenario includes the following steps:

[0074] S1: Simply peel off the cover film (if there is a cover film), align the hot pressing layer with the adherend and gently stick them together;

[0075] S2: achieving a firm bond between the hot pressing layer and the adherend by hot pressing, the hot pressing conditions being, for example, 80-100°C, 0.1-1.5 MPa, 0.2-0.5s;

[0076] S3: Remove the carrier film layer and complete the tape application operation.

[0077] The room temperature non-stick double-sided adhesive tape provided by the present invention has at least the following beneficial effects:

[0078] (1) The room temperature non-adhesive double-sided tape of the present invention has different adhesive properties designed for each layer through material selection and component blending. In particular, the room temperature peeling force between the non-adhesive layer and the carrier layer is greater than the room temperature peeling force of the hot pressing layer, but less than the hot pressing adhesive force of the hot pressing layer. This tape has at least the following advantages:

[0079] Before use, the double-sided tape remains substantially non-sticky at room temperature and is not prone to adhesion to other components, causing unwanted loss or sliding deviation.

[0080] When in use, the cover film can be easily peeled off without causing peeling or displacement of the carrier film layer and the non-adhesive layer, which helps to accurately fit the hot pressing layer to the adherend;

[0081] The hot pressing layer and the adherend are firmly bonded by hot pressing activation, and the hot pressing layer has a fast thermal activation speed, which can achieve good bonding in a short time;

[0082] The carrier film layer is removed. Since the carrier film layer is non-sticky, the electrode active material will not be stuck away during the removal process. Moreover, the room temperature peeling force between the non-sticky layer and the carrier film layer is smaller than the hot pressing bonding force of the hot pressing layer. Therefore, the removal process will not cause the risk of damaging the bonding interface of the hot pressing layer.

[0083] (2) The room temperature non-adhesive double-sided tape of the present invention has excellent comprehensive performance, strong electrolyte resistance, very low swelling and dissolution rate in the electrolyte, and can maintain high adhesion for a long time, and has broad application prospects in the field of lithium batteries.

[0084] (3) The preparation method of room temperature non-sticky double-sided tape is simple. The non-sticky layer coating liquid and the hot pressing layer coating liquid can use solvent-based coating liquid or water-based coating liquid, which can be completed by drying and hot pressing processes. It is suitable for large-scale automated production. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 It is a structural schematic diagram of the first embodiment of the present invention;

[0086] Figure 2 Schematic diagram of the structure of the second embodiment of the present invention.

[0087] Explanation of reference numerals: 10 - carrier film layer, 20 - non-adhesive layer, 30 - base film layer, 40 - hot pressing layer, 50 - cover film, 100 - bonding unit. DETAILED DESCRIPTION

[0088] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0089] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a," "an," "the," and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, and unless the context clearly indicates otherwise, "a plurality" generally includes at least two.

[0090] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or device comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or device. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or device comprising the element.

[0091] See attached Figure 1-2 , a room temperature non-adhesive double-sided tape, comprising: a carrier film layer 10, a non-adhesive layer 20, a base film layer 30, a hot pressing layer 40 and an optional cover film 50;

[0092] The carrier film layer 10 has a thickness of 15-100 μm and is a single-sided release film or a double-sided release film, preferably a silicon-containing release film. The carrier film layer 10 is disposed on the outer side of the non-adhesive layer 20.

[0093] The cover film 50 has a thickness of 10-40 μm and is a release film, preferably a silicon-containing release film or an electrostatic film. The cover film 50 is disposed on the outer side of the hot pressing layer 40 .

[0094] The adhesive structure includes a non-adhesive layer 20, a base film layer 30 and a hot pressing layer 40, with an overall thickness D of 8-40 μm, preferably 10-30 μm. The specific structure is as follows:

[0095] (1) a non-stick layer 20 having a thickness of 0.5-12 μm, and comprising, by weight:

[0096] 60-90 parts of the first polyolefin resin,

[0097] 5-30 parts of elastic material,

[0098] 0-10 parts of tackifying resin;

[0099] The first polyolefin resin includes at least one of an α-olefin polymer resin and a modified polyolefin resin; preferably, the α-olefin polymer resin in the first polyolefin resin is a low molecular weight amorphous polyα-olefin resin (APAO), which has the characteristics of low molecular weight (below 20,000), low viscosity (melt viscosity at 190°C is below 1500mPa.s), long open time and low softening point (100-115°C); the modified polyolefin resin is a copolymer modified polyolefin resin, such as EAA, with a molecular weight below 50,000.

[0100] The elastic material comprises at least one of SBS, SIS, and SEBS rubber materials. Preferably, the elastic material has a molecular weight of 100,000 or more and a softening point of 100° C. or more. More preferably, the elastic material has a molecular weight of 150,000 or more and a softening point of 200° C. or more. The melt index at a temperature of 190-230° C. and a load of 5 kg is 2-50 g / 10 min. The styrene content is 15-35 wt%.

[0101] The tackifying resin is preferably 5-10 parts, including at least one of rosin resin, terpene resin, and petroleum resin.

[0102] Preferably, in the first polyolefin resin, the mass ratio of the α-olefin polymer resin to the modified polyolefin resin is (5-65):(15-70), and after hot pressing, the peeling force between the non-adhesive layer 20 and the carrier film layer 10 at room temperature is 5-60 g / inch, preferably 10-60 g / inch;

[0103] (2) a base film layer 30 having a thickness of 1-25 μm and comprising at least one of a PP film layer, a PI film layer, a PE film layer, a PET film layer, a PPS film layer, and a BOPP film layer;

[0104] (3) A hot pressing layer 40 having a thickness of 2-15 μm and comprising, by weight:

[0105]

[0106] The second polyolefin resin includes at least one of an α-olefin polymer resin and a modified polyolefin resin; preferably, the α-olefin polymer resin in the second polyolefin resin is a POE material with a molecular weight of 50,000-180,000, which is a high-performance thermoplastic elastomer material copolymerized with ethylene and α-olefin (such as octene and butene) through a metallocene catalyst; the modified polyolefin resin is a maleic anhydride modified polyolefin resin, such as MA-PP, with a molecular weight of 60,000-180,000.

[0107] The tackifying resin includes at least one of rosin resin, terpene resin, and petroleum resin;

[0108] The elastic material is preferably 1-20 parts, including at least one of SBS, SIS, and SEBS rubber materials. Preferably, the elastic material has a molecular weight of more than 100,000 and a softening point of more than 100°C. More preferably, the elastic material has a molecular weight of more than 150,000 and a softening point of more than 200°C. The melt index at a temperature of 190-230°C and a load of 5kg is 2-50g / 10min, and the styrene content is 15-35wt%.

[0109] The viscosity modifier is preferably 1-20 parts, including at least one of paraffin wax, microcrystalline wax, synthetic wax, polyethylene wax, polypropylene wax, and sasol wax.

[0110] Preferably, in the second polyolefin resin, the mass ratio of the α-olefin polymer resin to the modified polyolefin resin is (5-30):(10-35), and the hot pressing layer may have weak adhesion at room temperature, for example, the room temperature peeling force is below 10g / inch, and the hot pressing bonding force is above 100N / m.

[0111] The room-temperature peeling force between the non-adhesive layer 20 and the carrier film layer 10 is greater than the room-temperature peeling force of the hot-pressing layer 40, but less than the hot-pressing adhesion force of the hot-pressing layer 40. During winding, unwinding, storage, transportation, or when removing the cover film 50 from the surface of the hot-pressing layer 40, the adhesion and relative position between the non-adhesive layer 20 and the carrier film layer 10 are not affected. Furthermore, when removing the carrier film layer 10 after hot-pressing adhesion, the adhesive structure is not torn off, and the electrode active material is not damaged by adhesion.

[0112] Based on the aforementioned exemplary material selection, specifically, the α-olefin polymer resin includes at least one of polyethylene resin (PE), polypropylene resin (PP), ethylene and octene copolymer resin (POE), and amorphous polyalphaolefin resin (APAO);

[0113] The modified polyolefin resin includes at least one of maleic anhydride-modified polyolefin resin, (meth)acrylic acid-modified polyolefin resin, and copolymer-modified polyolefin resin. Specifically, the modified polyolefin resin includes at least one of MA-APAO, MA-POE, MA-PP, MA-PE, AA-APAO, AA-PP, AA-POE, AA-PE, MAA-PP, MAA-PE, MAA-POE, ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), and ethylene-vinyl acetate copolymer (EVA).

[0114] See attached Figure 1 In the first embodiment, the carrier film layer 10, the non-adhesive layer 20, the base film layer 30 and the hot pressing layer 40 are sequentially stacked and prepared by the following method:

[0115] Step 1: Apply a non-sticky layer 20 coating solution on one side of the carrier film 10, dry it, and then heat-press and laminate it to one side of the base film 30;

[0116] Step 2: Coat the hot pressing layer 40 coating liquid on the other side of the base film layer 30 and dry it to obtain the room temperature non-stick double-sided tape.

[0117] Optionally, a cover film 50 is attached to the outer side of the heat pressing layer 40 away from the base film layer 30 .

[0118] See attached Figure 2 In the second embodiment, the following steps are further included after step 2:

[0119] Die-cutting is performed perpendicular to the carrier film layer 10. Due to the relatively weak adhesion between the non-adhesive layer 20 and the carrier film layer 10, a portion of the stacked non-adhesive layer 20, base film layer 30, and hot-pressing layer 40 is removed from the carrier film layer 10, forming a plurality of spaced adhesive units 100 on the carrier film layer. Each adhesive unit 100 comprises a bonded structure comprising the non-adhesive layer 20, base film layer 30, and hot-pressing layer 40. The cross-sectional shape and size of the adhesive units 100, along a direction parallel to the carrier film layer 10, are determined and die-cut based on the application scenario to meet the adhesive protection requirements of different battery sizes and areas, including but not limited to continuous patterns, discontinuous patterns, and combinations thereof.

[0120] For example, with the extension direction X (or longitudinal direction) of the double-sided tape and the perpendicular direction Y (or transverse direction) of the tape extension direction as reference, when the adhesive unit 100 is die-cut into a rectangular cross-sectional shape with intervals, the following options are optional:

[0121] 1) The length of the bonding unit 100 in the extension direction X is 1-5 mm (i.e., the wide side of the rectangle);

[0122] 2) The length of the bonding unit 100 in the vertical direction Y is 5-20 mm (i.e., the long side of the rectangle);

[0123] 3) The distance between adjacent bonding units 100 in the extension direction X is 5-20 mm (ie, the distance between the adjacent long sides of two spaced rectangles).

[0124] The non-adhesive areas between the spaced adhesive units 100 have no adhesive structure and retain a non-adhesive function, that is, after bonding, the non-adhesive carrier layer 10 is peeled off to leave a distance space. The size of the die-cut slices of different sizes is determined according to the production line process requirements. That is, the cross-sectional shape, size and spacing of the adhesive unit 100 have multiple settings and combinations, which need to be determined and die-cut according to the application scenario.

[0125] Also optionally, a cover film 50 is attached to the outer side of the hot pressing layer 40 of the adhesive unit 100 away from the base film layer 30 . In this case, a plurality of adhesive units 100 are arranged at intervals between the carrier film layer 10 and the cover film 50 .

[0126] The coating liquid for the non-sticky layer 20 and the coating liquid for the hot pressing layer 40 may be a solvent-based coating liquid or an aqueous coating liquid.

[0127] Taking the room temperature non-adhesive double-sided tape in the aforementioned embodiment as an example, the use thereof includes but is not limited to the following steps:

[0128] (1) Remove the cover film 50 and attach the hot pressing layer 40 to the adherend;

[0129] (2) hot pressing, so that the hot pressing layer 40 is heated and excited to bond with the adherend;

[0130] (3) Removing the carrier film layer 10. Since the carrier film layer 10 is non-sticky, the electrode active layer material will not be sticked away during the removal process.

[0131] The specific grades and corresponding physical and chemical parameters of the main raw materials of each embodiment of the present invention are shown in Table 1:

[0132] Table 1:

[0133]

[0134]

[0135] Example 1

[0136] The room temperature non-adhesive double-sided tape of Example 1 comprises a carrier film layer 10, a non-adhesive layer 20, a base film layer 30, a heat-pressing layer 40 and a cover film 50 stacked in sequence, as shown in the attached drawings. Figure 1 , specifically:

[0137] (1) a carrier film layer 10, having a thickness of 50 μm and being a PET-based silicon release film;

[0138] (2) a non-stick layer 20 having a thickness of 2 μm and comprising, by weight:

[0139] The first polyolefin resin comprises:

[0140]

[0141] (3) The base film layer 30 is a PET film with a thickness of 5 μm;

[0142] (4) A hot pressing layer 40 having a thickness of 5 μm and comprising, by weight:

[0143] The second polyolefin resin comprises:

[0144] 20 parts of α-polyolefin 3588FL,

[0145] 20 parts of modified polyolefin QF551;

[0146] 46 parts of petroleum resin P125;

[0147] SIS rubber D1114 8 parts;

[0148] 6 parts of viscosity regulator LP130;

[0149] (5) Cover film 50, 25 μm thick, made of PET-based silicon release film;

[0150] The room temperature non-adhesive double-sided tape of Example 1 was prepared by the following method:

[0151] Step 1: Apply a non-sticky layer 20 coating solution on one side of the carrier film 10, dry it, and then heat-press and laminate it to one side of the base film 30;

[0152] Step 2: Coat the hot pressing layer 40 coating liquid on the other side of the base film layer 30 and dry it to obtain the room temperature non-stick double-sided tape.

[0153] Step 3: Attach the cover film 50 to the outer side of the heat-pressed layer 40 away from the base film layer.

[0154] The coating liquid for the non-adhesive layer 20 and the coating liquid for the hot pressing layer 40 are solvent-based coating liquids.

[0155] Specifically, the non-sticky layer coating liquid is prepared by the following steps:

[0156] A. Add organic solvent (aromatic hydrocarbon solvent) into the reactor and start stirring at a speed of 20 rpm;

[0157] B. Weigh and add SEBS rubber, petroleum resin, and the first polyolefin resin in order, start the reactor and heat it to 150±10℃;

[0158] C. Increase the stirring speed to 60 rpm and stir for 60 minutes to fully dissolve;

[0159] D. The solid content is set at 10-15wt%. After the test is qualified, the temperature is lowered. When the temperature is ≤60℃, the material is filtered through a metal filter and treated with a demagnetizer to obtain a solvent-based non-stick coating liquid.

[0160] The hot pressing layer coating solution is prepared by the following steps:

[0161] A. Add organic solvent (aromatic hydrocarbon solvent) into the reactor and start stirring at a speed of 20 rpm;

[0162] B. Weigh and add the materials, add SIS rubber, petroleum resin, second polyolefin resin and viscosity regulator in order, start the reactor and heat it to 150±10℃;

[0163] C. Increase the stirring speed to 60 rpm and stir for 60 minutes to fully dissolve;

[0164] D. The solid content is set at 20-25wt%. After the test is qualified, the temperature is lowered. When the temperature is ≤60°C, the material is filtered through a metal filter and treated with a demagnetizer to obtain a solvent-based hot pressing layer coating liquid.

[0165] Application Example 1

[0166] The order and composition of the layers of the room temperature non-adhesive double-sided tape of Application Example 1 are the same as those of Example 1, except that a die-cutting step is further included after step 2:

[0167] Die cutting is performed in a direction perpendicular to the carrier film layer 10 to remove the stacked non-adhesive layer 20, base film layer 30 and hot pressing layer 40 from the carrier film layer 10 as a whole, thereby forming a plurality of spaced adhesive units 100 on the carrier film layer 10. Each adhesive unit 100 has a bonding structure including the non-adhesive layer 20, the base film layer 30 and the hot pressing layer 40, as shown in FIG. Figure 2 As shown. With the extension direction X of the double-sided tape and the perpendicular direction Y of the tape extension direction as reference, the adhesive unit 100 is die-cut into rectangular cross-sectional shapes arranged at intervals:

[0168] The length of the bonding unit 100 in the extension direction X is 2.5 mm;

[0169] The length of the bonding unit 100 in the vertical direction Y is 11 mm;

[0170] The distance between adjacent bonding units 100 in the extension direction X is 8 mm.

[0171] Application Example 2

[0172] Application Example 2 has the same basic structure and composition as Application Example 1, see Figure 2 As shown, the difference is that the adhesive unit 100 of the room temperature non-adhesive double-sided tape has different specifications and sizes. The specific differences are as follows:

[0173] The length of the bonding unit 100 in the extension direction X is 2.2 mm;

[0174] The length of the bonding unit 100 in the vertical direction Y is 5.5 mm;

[0175] The distance between adjacent bonding units 100 in the extension direction X is 13 mm.

[0176] Example 2

[0177] The difference between this embodiment and embodiment 1 is that the structural composition of each layer is slightly different, as follows:

[0178] (1) The thickness of the carrier film layer 10 is 50 μm, and the material is a PET-based silicon release film;

[0179] (2) The thickness of the non-stick layer 20 is 1 μm, and the composition is the same as that of Example 1;

[0180] (3) The base film layer 30 is a BOPP film with a thickness of 8 μm;

[0181] (4) The thickness of the hot pressing layer 40 is 3 μm, and the composition is the same as that of Example 1;

[0182] (5) The thickness of the cover film 50 is 25 μm and the material is a PET-based silicon release film.

[0183] Example 3

[0184] The difference between this embodiment and embodiment 1 is that the structural composition of each layer is slightly different, as follows:

[0185] (1) The thickness of the carrier film layer 10 is 50 μm, and the material is a PET-based silicon release film;

[0186] (2) The thickness of the non-stick layer 20 is 5 μm and the composition is the same as that of Example 1;

[0187] (3) The base film layer 30 is a PI film with a thickness of 5.5 μm;

[0188] (4) The thickness of the hot pressing layer 40 is 8 μm, and the composition is the same as that of Example 1;

[0189] (5) The thickness of the cover film 50 is 25 μm and the material is a PET-based silicon release film.

[0190] Example 4

[0191] The room temperature non-stick double-sided tape of Example 4 has the same structure and composition as that of Example 1, except that, during the preparation process, the non-stick layer coating liquid and the hot pressing layer coating liquid of Example 4 are aqueous coating liquids, and the non-stick layer coating liquid is prepared by the following steps:

[0192] A. Weighing and adding materials: Add the solvent cyclohexane, the elastic material, the optional tackifying resin, and the first polyolefin resin into a reaction kettle and start stirring at a speed of about 45 rpm and a temperature of 70±10°C until a clear mixture A without solid particles is obtained;

[0193] B. In another new reactor, deionized water and emulsifier were weighed and added in sequence, and the temperature was set to 40° C., the stirring speed was 30 rpm, and the stirring time was 60 min to obtain a mixture B;

[0194] C. Add mixture B to the above mixture A, set the temperature to 45±2°C, stir at a speed of 70 rpm, and stir for 30 min to obtain mixture C;

[0195] D. homogenizing the mixture C twice using a homogenizer;

[0196] E. Distill the solvent off the homogenized mixture C, control the temperature at 85±2° C., and stir at 45 rpm to obtain an aqueous coating solution for a non-sticky layer.

[0197] The hot pressing layer coating solution is prepared by the following steps:

[0198] A. Weighing and adding materials: Add the solvent cyclohexane and the optional elastic material, tackifying resin, second polyolefin resin, and optional viscosity modifier into a reaction kettle and start stirring at a speed of 45 rpm and a temperature of 70±10°C until a clear mixture A without solid particles is obtained;

[0199] B. In another new reactor, deionized water and emulsifier were weighed and added in sequence, and the temperature was set to 40° C., the stirring speed was 30 rpm, and the stirring time was 60 min to obtain a mixture B;

[0200] C. Add mixture B to the above mixture A, set the temperature to 45±2°C, stir at a speed of 75 rpm, and stir for 30 min to obtain mixture C;

[0201] D. homogenizing the mixture C twice using a homogenizer;

[0202] E. Distilling the homogenized mixture C to remove the solvent, controlling the temperature at 85±2° C. and stirring at 45 rpm to obtain an aqueous coating solution for the hot pressing layer.

[0203] The differences between Example 1 to Example 4 are shown in Table 2:

[0204] Table 2:

[0205]

[0206] Examples 5-9 and Comparative Examples 1-2

[0207] The difference between Examples 5-9 and Comparative Examples 1-2 and Example 1 is that the raw material ratios in the non-adhesive layer and the hot pressing layer are different. The specific differences are shown in Table 3:

[0208] Table 3 Raw material composition of non-adhesive layer and hot pressing layer of Examples 1, 5-9 and Comparative Examples 1-2

[0209]

[0210]

[0211] Comparative Example 3

[0212] The difference between Comparative Example 3 and Example 1 is that the non-adhesive layer and the hot pressing layer in the non-adhesive double-sided adhesive tape of Comparative Example 3 are both acrylic adhesive (acrylic resin).

[0213] Test methods and results

[0214] Samples were prepared for performance testing according to the composition parameters of each layer of Examples 1-9 and the comparative example: a non-sticky layer coating liquid was applied to one side of the carrier film layer, and after drying, the non-sticky layer coating liquid was bonded to the base film layer by hot pressing; a hot pressing layer coating liquid was applied to the other side of the base film layer, and after drying, the non-sticky layer was cut to a size of 20 mm × 100 mm; a cover film was attached to the surface of the hot pressing layer away from the base film layer to obtain the corresponding tape samples. Each tape sample was tested, and the results are shown in Table 4.

[0215] (1) Carrier film peeling force test: Remove the cover film of the tape sample and laminate it on a steel plate by hot pressing. The 180° peeling force between the carrier film and the non-adhesive layer is the carrier film peeling force. The peeling speed is 300 mm / min.

[0216] (2) Hot pressing initial adhesion @ Al foil test: Remove the cover film of the tape sample and laminate it on the aluminum foil by hot pressing. Then, use double-sided tape to stick the aluminum foil on the steel plate. Remove the carrier film layer and test the 180° peel strength between the hot pressing layer and the aluminum foil at a peel speed of 300 mm / min.

[0217] (3) Bubble liquid adhesion test: remove the cover film of the tape sample, laminate it on aluminum foil by hot pressing, remove the carrier film layer, immerse it in electrolyte, and age it in an oven at 85°C for 4 hours. Take it out and wipe it dry, then test the adhesion according to the above method (2), which is the bubble liquid adhesion.

[0218] (4) Swelling rate test: Take 2±0.1g of rubber blocks from the non-adhesive layer and the hot-pressed layer, respectively, with the mass recorded as M1, soak them in 50g of electrolyte, place them in an 85℃ oven, age them for 24 hours, take out the rubber blocks, wipe off the electrolyte on their surface, and weigh them to obtain M2. The swelling rate is calculated according to the formula (M2-M1)×100% / M1.

[0219] (5) Dissolution rate test: Take 1.4±0.1g of the rubber block of the non-sticky layer and the hot-pressed layer respectively, record the mass as M1, soak it in 7±0.5g of electrolyte, record the mass as M2, then seal it with a syringe bottle and place it in an 85℃ oven. After aging for 24 hours, take 20±5mg of the clear liquid, heat it to 300℃ at a rate of 10℃ / min using a thermogravimetric analyzer (TGA), and read the weight percentage of the residual material, record it as A. The dissolution rate is calculated according to the formula A×M2 / M1.

[0220] Table 4 Test results of Examples 1-9 and Comparative Examples 1-3

[0221]

[0222] The test results show that the room-temperature peeling force between the non-adhesive layer and the carrier film in the above-mentioned samples (preferably 10-40 g / inch, more preferably 12-25 g / inch) is greater than the room-temperature peeling force between the hot-pressed layer and the cover film (preferably 0.1-5 g / inch, more preferably 0.5-2.5 g / inch). Removing the cover film before applying the tape has little impact on the structure of the carrier film and adhesive layer. Furthermore, after hot pressing, the adhesion force between the hot-pressed layer and the adherend (e.g., aluminum foil) (above 190 N / m) is much greater than the peeling force between the non-adhesive layer and the carrier film. Therefore, the carrier film can be easily peeled off from the non-adhesive layer without significantly affecting the structure of the adhesive layer. Furthermore, due to the non-adhesive nature of the carrier film, the electrode active layer material will not be removed when the cover film is peeled off after hot pressing, thus having no negative impact on the battery. Furthermore, swelling and dissolution tests of the non-adhesive layer and the hot-pressed layer in electrolyte show that the non-adhesive layer of the tape has a swelling rate of less than 5%, preferably less than 3%, and a dissolution rate of less than 5%, more preferably less than 3%. The hot-pressed layer has a swelling rate of less than 8%, more preferably less than 6%, and a dissolution rate of less than 5%, preferably less than 3%, demonstrating strong electrolyte resistance. Furthermore, after soaking, the hot-pressed layer's soaking adhesion is increased to greater than 250 N / m, preferably greater than 300 N / m. The hot-pressed layer undergoes a high-temperature and high-pressure activation treatment before being immersed in the electrolyte. With increased soaking time, the colloid in the hot-pressed layer fully infiltrates the surface of the bonded substrate, forming a stable "riveting effect," while preventing the electrolyte from eroding the interior of the tape. Consequently, the present invention demonstrates that the hot-pressed layer's hot-pressed adhesion increases after soaking, surpassing the initial adhesion strength exhibited by the hot-pressed layer after brief initial soaking. This makes it particularly suitable for lithium battery applications, such as tab weld mark protection. In contrast, in Comparative Example 1, the composition of the non-adhesive layer is not within the material composition range, resulting in a room temperature peeling force between the non-adhesive layer and the carrier film layer that is too low, only 3g / inch (less than 5g / inch), which is similar to the peeling force of the cover film. When the cover film is removed, the adhesive layer is easily taken away. In Comparative Example 2, the composition of the hot pressing layer is not within the material composition range, resulting in the inability to perform good heat activation in a very short time when measuring the initial hot pressing adhesion. The adhesive layer and the Al foil do not achieve good infiltration, the initial adhesion is low, and the dissolution rate of the adhesive layer in the electrolyte is high. The adhesion of the adhesive layer decreases significantly after soaking. In addition, the comprehensive properties of the adhesive unit in Application Examples 1 and 2 of the present invention, such as the bonding performance and electrolyte resistance, are similar to those in Example 1, demonstrating a variety of designs and applications of the adhesive unit.

[0223] In summary, the present invention designs the structure of each layer, bonding unit, and bonding force of the room temperature non-adhesive double-sided tape, so that the room temperature non-adhesive double-sided tape can better meet the construction process and effectively protect the lug weld marks.

[0224] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A room temperature non-adhesive double-sided tape, characterized in that: It includes a carrier film layer, a non-adhesive layer, a base film layer and a hot pressing layer stacked in sequence; In parts by weight, the non-stick layer comprises: 60-90 parts of the first polyolefin resin, 5-30 parts of elastic material; In parts by weight, the hot pressing layer comprises: 20-60 parts of the second polyolefin resin, 30-70 parts of tackifying resin; The first polyolefin resin and the second polyolefin resin respectively include at least one of an α-olefin polymer resin and a modified polyolefin resin; The elastic material has a melt index of 1-100 g / 10 min at a temperature of 190-230° C. and a load of 5.00 kg; The room temperature peeling force between the non-adhesive layer and the carrier film layer is greater than the room temperature peeling force of the hot pressing layer, but less than the hot pressing bonding force of the hot pressing layer.

2. The room temperature non-adhesive double-sided tape according to claim 1, wherein: Room temperature non-adhesive double-sided tape meets at least one of the following requirements: 1) The carrier film layer is a single-sided release film or a double-sided release film with a thickness of 15-100 μm; 2) The thickness of the non-adhesive layer is 0.5-12 μm; 3) The thickness of the hot pressing layer is 2-15 μm; 4) The base film layer has a thickness of 1-25 μm and includes at least one of a PP film layer, a PI film layer, a PE film layer, a PET film layer, a PPS film layer, and a BOPP film layer.

3. The room temperature non-adhesive double-sided tape according to claim 1 or 2, characterized in that: A cover film is laminated on the outer side of the hot pressing layer away from the base film layer. The thickness of the cover film is 10-40 μm. The room temperature peeling force between the hot pressing layer and the cover film is 0.1-10 g / inch, which is smaller than the room temperature peeling force between the non-adhesive layer and the carrier film layer.

4. The room temperature non-adhesive double-sided tape according to claim 1 or 2, wherein: The α-olefin polymer resin includes at least one of polyethylene resin (PE), polypropylene resin (PP), ethylene and octene copolymer resin (POE), and amorphous polyα-olefin resin (APAO); The modified polyolefin resin includes at least one of maleic anhydride modified polyolefin resin, (meth)acrylic acid modified polyolefin resin, and copolymer modified polyolefin resin.

5. The room temperature non-adhesive double-sided tape according to claim 4, wherein: In the first polyolefin resin, the mass ratio of the α-olefin polymer resin to the modified polyolefin resin is (5-65):(15-70), and the peeling force of the non-adhesive layer and the carrier layer at room temperature is 5-60 g / inch; In the second polyolefin resin, the mass ratio of α-olefin polymer resin to modified polyolefin resin is (5-30):(10-35), the room temperature peeling force of the hot pressing layer is below 10g / inch, and the hot pressing bonding force is above 100N / m.

6. The room temperature non-adhesive double-sided tape according to claim 5, wherein: The non-sticky layer further comprises 5-10 parts of the tackifying resin in parts by weight; In parts by weight, the hot pressing layer further comprises 1-20 parts of the elastic material and 1-20 parts of a viscosity regulator.

7. The room temperature non-adhesive double-sided tape according to claim 6, wherein: The tackifying resin includes at least one of rosin resin, terpene resin, and petroleum resin; The elastic material includes at least one of SBS, SIS, and SEBS rubber materials; The viscosity modifier includes at least one of paraffin wax, microcrystalline wax, synthetic wax, polyethylene wax, polypropylene wax, and sasol wax.

8. The method for preparing a room temperature non-adhesive double-sided tape according to any one of claims 1 to 7, wherein: The steps include: Step 1: Apply non-stick coating liquid on one side of the carrier film layer, dry it, and then heat-press it onto one side of the base film layer; Step 2: coating the hot pressing layer coating liquid on the other side of the base film layer, and drying to obtain the room temperature non-stick double-sided adhesive tape.

9. The preparation method according to claim 8, wherein After step 2, the following steps are also included: Die cutting in a direction perpendicular to the carrier film layer to remove a portion of the laminated non-adhesive layer, base film layer and heat-pressed layer from the carrier film layer, thereby forming a plurality of spaced adhesive units on the carrier film layer; Optionally, a cover film is attached to the outer side of the heat pressing layer away from the base film layer.

10. Use of the room temperature non-stick double-sided tape according to any one of claims 1 to 7 in tab protection, pole piece protection, pole piece edge insulation protection, and finishing tape.

Images