Acrylic foam tape as well as preparation method and application thereof

Abstract

The invention relates to an acrylic foam tape as well as a preparation method and application thereof. The acrylic foam adhesive tape comprises an acrylic foam adhesive layer and a release layer which are stacked in sequence, the acrylic foam adhesive layer is prepared from the following raw materials in parts by weight: 70 to 90 parts of acrylic prepolymer, 10 to 30 parts of acrylate monomer, 0.1 to 1.0 part of photoinitiator and 0.05 to 0.2 part of cross-linking agent. According to the invention, the preparation raw materials of the acrylic foam adhesive layer are designed, so that the acrylic foam adhesive tape has higher initial viscosity and low-temperature resistance, can keep higher initial viscosity in actual low-temperature application, is not easy to separate after being adhered, and is formed by one-step coating, simple in process and lower in cost.

Description

Technical Field

[0001] This invention relates to the field of foam tape technology, and more particularly to an acrylic foam tape, its preparation method, and its application. Background Technology

[0002] Today, the new energy vehicle sector is developing rapidly, and high-performance acrylic foam tape is gradually replacing traditional adhesives for interior and exterior vehicle trim, as well as for bonding around battery pack housings. Acrylic foam tape, made entirely of acrylic ester materials, possesses high cohesive strength and adhesion, while also exhibiting sealing, waterproofing, shock absorption, and pressure resistance. It is widely used in automobiles, home appliances, electronic equipment, and construction.

[0003] CN114752013A discloses a high-temperature resistant acrylic foam tape with high tensile strength, flexibility, and high-temperature resistance. CN111072847A discloses an acrylic foam tape that is soft, has good adhesion, and possesses weak adhesiveness and adsorption properties, enabling temporary fixation and repeated application to smooth surfaces. CN113444469A discloses an acrylic foam tape with high adhesion, high elasticity, and high tensile strain.

[0004] However, with industry development and rising performance standards, conventional acrylic foam tapes can no longer meet the requirements of low-temperature or ultra-low-temperature applications. Specifically, conventional acrylic foam tapes exhibit low initial tack in low-temperature applications, making them difficult to apply or prone to peeling after application. Therefore, developing a low-temperature, high-initial-tack acrylic foam tape will effectively solve the practical application problems in low-temperature environments. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide an acrylic foam tape, its preparation method, and its applications. By designing the raw materials for preparing the acrylic foam adhesive layer, the acrylic foam tape possesses high initial tack and low-temperature resistance. It maintains high initial tack under actual low-temperature applications, preventing easy detachment during bonding. Furthermore, the tape is formed through a single coating process, resulting in a simple process and low cost.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides an acrylic foam tape, the acrylic foam tape comprising an acrylic foam adhesive layer and a release layer stacked sequentially; the raw materials for preparing the acrylic foam adhesive layer comprise the following components in parts by weight: 70-90 parts of acrylic prepolymer, 10-30 parts of acrylate monomers, 0.1-1.0 parts of photoinitiator and 0.05-0.2 parts of crosslinking agent.

[0008] The weight parts of the acrylic prepolymer can be, for example, 73 parts, 75 parts, 80 parts, 85 parts, or 88 parts.

[0009] The weight parts of the acrylate monomers may be, for example, 12 parts, 15 parts, 20 parts, 25 parts, or 27 parts.

[0010] The photoinitiator may be present in parts by weight of, for example, 0.2 parts, 0.4 parts, 0.5 parts, 0.6 parts, or 0.8 parts.

[0011] The weight percentage of the crosslinking agent can be, for example, 0.08 parts, 0.1 parts, 0.12 parts, 0.15 parts, or 0.18 parts.

[0012] In this invention, acrylic prepolymer is copolymerized with acrylate monomers. Under the action of a photoinitiator (UV curing), the system generates free radicals, which induce the opening of carbon-carbon double bonds and link them into long chains, forming a regular polymer network. The functional groups of the prepolymer and the reactive functional groups of the acrylate monomers can further react and crosslink, further enhancing the network structure. This not only optimizes the mechanical properties of the product but also efficiently controls the glass transition temperature (Tg) and crosslinking density. At the same time, it can reduce the reaction viscosity and increase the reaction activity, giving the product flexibility, adhesion, and impact strength. This method can improve the curing speed, facilitate processing, and thus reduce costs.

[0013] Preferably, the release layer is a red PE release film or glassine release paper.

[0014] Preferably, the thickness of the acrylic foam adhesive layer is 0.3-1.1 mm, for example, it can be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm or 1.0 mm.

[0015] Preferably, the thickness of the release layer is 0.1-0.15 mm, for example, it can be 0.125 mm.

[0016] Preferably, the raw materials for preparing the acrylic acid prepolymer include the following components: polymeric monomers, photoinitiators, and chain transfer agents.

[0017] Preferably, the polymeric monomer includes any one or a combination of at least two of soft monomers, hard monomers, or functional monomers.

[0018] Preferably, the soft monomer comprises any one or a combination of at least two of isobornyl acrylate, isooctyl acrylate, or cyclohexyl acrylate.

[0019] Preferably, the hard monomer comprises methyl acrylate and / or methyl methacrylate.

[0020] Preferably, the functional monomer includes acrylic acid and / or methacrylic acid.

[0021] Preferably, the photoinitiator comprises 2-hydroxy-2-methyl-1-phenyl-1-propanone and / or 1-hydroxycyclohexylphenyl ketone.

[0022] Preferably, the chain transfer agent comprises dodecyl mercaptan.

[0023] Preferably, the acrylate monomers include isooctyl acrylate and / or cyclohexyl acrylate.

[0024] Preferably, the photoinitiator comprises 1-hydroxycyclohexylphenyl ketone and / or diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride.

[0025] Preferably, the crosslinking agent comprises 1,6-hexanediol diacrylate and / or trimethylolpropane triacrylate.

[0026] Preferably, the raw materials for preparing the acrylic foam adhesive layer also include 2-9 parts of hollow glass microspheres, for example, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts or 8 parts, etc.

[0027] Preferably, the raw materials for preparing the acrylic foam adhesive layer also include 1-3 parts of fumed silica, for example, 1.2 parts, 1.5 parts, 2 parts, 2.5 parts, or 2.7 parts.

[0028] Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 0.05-0.2 parts of chain transfer agent, such as 0.08 parts, 0.1 parts, 0.12 parts, 0.15 parts, or 0.18 parts.

[0029] Preferably, the chain transfer agent comprises dodecyl mercaptan.

[0030] Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 0.05-0.2 parts of silane coupling agent, such as 0.08 parts, 0.1 parts, 0.12 parts, 0.15 parts, or 0.18 parts.

[0031] Preferably, the silane coupling agent comprises 3-glycidyl etheroxypropyltrimethoxysilane and / or siloxane wetting and leveling agents.

[0032] Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 0.03-0.5 parts of nano pigment, such as 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, or 0.4 parts.

[0033] Preferably, the nano-color paste comprises K-ITUV and / or K3-ITUV.

[0034] Preferably, the raw materials for preparing the acrylic foam adhesive layer also include 2-8 parts of tackifying resin, for example, 3 parts, 4 parts, 5 parts, 6 parts or 7 parts, etc.

[0035] Preferably, the tackifying resin comprises TP7042 and / or C5 petroleum resin.

[0036] Preferably, the raw materials for preparing the acrylic foam adhesive layer also include 2-10 parts of an active diluent, such as 3 parts, 5 parts, 7 parts, 8 parts, or 9 parts.

[0037] Preferably, the reactive diluent comprises β-acryloyloxypropionic acid.

[0038] In this invention, the tackifying resin TP7042 and / or C5 petroleum resin, due to their good compatibility and interaction with the prepolymer, have a good small molecule filling effect, effectively increasing the free volume, reducing surface tension and wetting effect, thereby enhancing the initial tack, adhesion and cohesive strength of the product; the reactive diluent β-acryloyloxypropionic acid, through its small molecule structure and active groups, reduces the crosslinking density, imparts flexibility and adhesion to the product, and can also reduce viscosity and regulate the reaction rate.

[0039] Preferably, the raw materials for preparing the acrylic acid prepolymer include the following components by weight: 80-90 parts of soft monomer, 1-10 parts of functional monomer, 0.01-0.1 parts of photoinitiator and 0.001-0.01 parts of chain transfer agent.

[0040] The weight percentage of the soft monomer can be, for example, 82 parts, 84 parts, 85 parts, 86 parts, or 88 parts.

[0041] The number of weight parts of the functional unit can be, for example, 2 parts, 4 parts, 5 parts, 6 parts, or 8 parts.

[0042] The weight percentage of the photoinitiator can be, for example, 0.02 parts, 0.04 parts, 0.05 parts, 0.06 parts, or 0.08 parts.

[0043] The weight percentage of the chain transfer agent may be, for example, 0.002 parts, 0.004 parts, 0.005 parts, 0.006 parts, or 0.008 parts.

[0044] Preferably, the raw materials for preparing the acrylic acid prepolymer also include 1-10 parts of hard monomers, for example, 2 parts, 4 parts, 5 parts, 6 parts or 8 parts, etc.

[0045] Preferably, the preparation method of the acrylic prepolymer includes the following steps: mixing soft monomers, hard monomers and functional monomers, then adding a photoinitiator and a chain transfer agent, and carrying out a polymerization reaction under light irradiation to obtain the acrylic prepolymer.

[0046] Preferably, the preparation method of the acrylic acid prepolymer includes the following steps: mixing the polymerizable monomers, adding a photoinitiator and a chain transfer agent, stirring for 10-30 min (e.g., 12 min, 15 min, 20 min, 25 min or 28 min, etc.), and carrying out a polymerization reaction under ultraviolet light irradiation to obtain the acrylic acid prepolymer.

[0047] Preferably, the stirring is carried out under nitrogen protection.

[0048] Preferably, the polymerization reaction is carried out under nitrogen protection.

[0049] Preferably, the ultraviolet light source is a high-pressure mercury lamp or an LED light source.

[0050] Preferably, the wavelength of the ultraviolet light source is 350-370 nm, for example, it can be 353 nm, 355 nm, 360 nm or 368 nm, etc.

[0051] Preferably, the energy of the ultraviolet light source is 1100-1300 mJ / cm². 2 For example, it could be 1150 mJ / cm 2 1180mJ / cm 2 1200 mJ / cm 2 1250 mJ / cm 2 Or 1280 mJ / cm 2 wait.

[0052] Preferably, the polymerization reaction stops when the viscosity of the reaction system at 25°C is 3000-6000 cps (e.g., 3500 cps, 4000 cps, 4500 cps, 5000 cps or 5500 cps, etc.).

[0053] Preferably, the polymerization reaction time is 5-10 min, for example, it can be 6 min, 7 min, 7.5 min, 8 min or 9 min.

[0054] Preferably, the reaction temperature of the polymerization reaction is 21-25°C, for example, it can be 22°C, 22.5°C, 23°C, 23.5°C or 24°C.

[0055] In a second aspect, the present invention provides a method for preparing acrylic foam tape as described in the first aspect, the method comprising the following steps:

[0056] (1) Mix and stir the acrylic prepolymer and acrylate monomers:

[0057] (2) Add photoinitiator, crosslinking agent, optional chain transfer agent, optional silane coupling agent, optional nano pigment, optional tackifying resin and optional reactive diluent and mix.

[0058] (3) Add optional hollow glass microspheres and optional fumed silica and mix and stir to obtain the adhesive for acrylic foam layer;

[0059] (4) Apply the adhesive of the acrylic foam adhesive layer to the transparent PET release film, cure it by ultraviolet irradiation, and transfer the adhesive layer to the release layer after curing to obtain the acrylic foam tape.

[0060] Preferably, the stirring time in step (1) is 1.5-2.5 h, for example, it can be 1.6 h, 1.8 h, 2 h, 2.2 h or 2.4 h.

[0061] Preferably, the stirring time in step (2) is 0.5-1.5 h, for example, it can be 0.6 h, 0.8 h, 1 h, 1.2 h or 1.4 h.

[0062] Preferably, the stirring time in step (3) is 1.5-2.5 h, for example, it can be 1.6 h, 1.8 h, 2 h, 2.2 h or 2.4 h.

[0063] Thirdly, the present invention provides an application of the acrylic foam tape as described in the first aspect in the bonding and fixing of battery casings, bonding of battery cells, edge bonding of new energy vehicle battery pack housings, or bonding of automotive exterior parts.

[0064] Compared with the prior art, the present invention has at least the following beneficial effects:

[0065] This invention designs the raw materials for preparing acrylic foam adhesive layers, enabling acrylic foam tape to possess high initial tack and low-temperature resistance. It can maintain high initial tack under actual low-temperature applications, making it difficult for the tape to detach. Furthermore, the tape is formed by one-time coating, which is simple and cost-effective. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the structure of the acrylic foam tape described in this invention. Wherein, 1 is the release layer, and 2 is the acrylic foam adhesive layer. Detailed Implementation

[0067] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0068] Example 1

[0069] This embodiment provides an acrylic foam tape, which includes an acrylic foam adhesive layer and a release layer stacked sequentially. The thickness of the acrylic foam adhesive layer is 0.4 mm, and the release layer is a red PE release film with a thickness of 0.125 mm.

[0070] The preparation method of the acrylic foam tape includes the following steps:

[0071] (1) Mix 450 g of isooctyl acrylate and 50 g of acrylic acid to form a mixed monomer solution, add it to the reactor, add 0.5 g of 1-hydroxycyclohexylphenyl ketone (184) and 0.05 g of dodecyl mercaptan (NDM) to the reactor, stir for 20 min under nitrogen protection, and after thorough stirring, carry out the polymerization reaction under LED light source with a wavelength of 365 nm. The polymerization reaction temperature is 25℃. When the dynamic viscosity of the reaction system reaches 5000 cps, turn off the UV lamp to obtain acrylic acid prepolymer;

[0072] (2) Weigh 90 parts of acrylic prepolymer and 10 parts of isooctyl acrylate, stir for 2 h to make the acrylic prepolymer and isooctyl acrylate completely and evenly mixed.

[0073] (3) Based on step (2), add 0.3 parts of 1-hydroxycyclohexylphenyl ketone, 0.1 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride, 0.1 parts of 1,6-hexanediol diacrylate, 0.1 parts of n-dodecyl mercaptan, 0.2 parts of KBM-403 (purchased from Shin-Etsu Chemical Co., Ltd., Japan), 0.1 parts of K-ITUV (purchased from Index Pigment Technology Co., Ltd.), and 2 parts of TP7042 (purchased from Corten, USA), and stir for 1 h to ensure that all additives are fully mixed and uniform.

[0074] (4) Based on step (3), add 9 parts of hollow glass microspheres (purchased from Potters Industries) and 3 parts of fumed silica (purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.), stir for 2 h to make the filler fully mixed and uniform, and obtain the adhesive for acrylic foam layer;

[0075] (5) The adhesive obtained in step (4) is degassed under vacuum negative pressure and coated onto a transparent PET release film through a double roller coating head. The film is then subjected to a light intensity of 1200 mJ / cm at a wavelength of 360 nm. 2 After curing by ultraviolet light, the adhesive layer is transferred to the release layer to obtain the acrylic foam tape.

[0076] Example 2

[0077] This embodiment provides an acrylic foam tape, which includes an acrylic foam adhesive layer and a release layer stacked sequentially. The thickness of the acrylic foam adhesive layer is 0.4 mm, and the release layer is a red PE release film with a thickness of 0.125 mm.

[0078] The preparation method of the acrylic foam tape includes the following steps:

[0079] (1) Mix 450 g of isooctyl acrylate and 50 g of acrylic acid to form a mixed monomer solution, add it to the reactor, add 0.5 g of 1-hydroxycyclohexylphenyl ketone (184) and 0.05 g of dodecyl mercaptan (NDM) to the reactor, stir for 20 min under nitrogen protection, and after thorough stirring, carry out the polymerization reaction under LED light source with a wavelength of 365 nm. The polymerization reaction temperature is 25℃. When the dynamic viscosity of the reaction system reaches 5000 cps, turn off the UV lamp to obtain acrylic acid prepolymer;

[0080] (2) Weigh 80 parts of acrylic prepolymer and 20 parts of isooctyl acrylate, stir for 2 h to make the acrylic prepolymer and isooctyl acrylate completely and evenly mixed.

[0081] (3) Based on step (2), add 0.3 parts of 1-hydroxycyclohexylphenyl ketone, 0.1 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine, 0.12 parts of 1,6-hexanediol diacrylate, 0.1 parts of n-dodecyl mercaptan, 0.2 parts of KBM-403, 0.1 parts of K-ITUV, and 2 parts of TP7042, and stir for 1 h to ensure that all additives are fully mixed.

[0082] (4) Based on step (3), add 9 parts hollow glass microspheres and 3 parts fumed silica, stir for 2 h to make the filler fully mixed and uniform, and obtain the adhesive for acrylic foam layer;

[0083] (5) The adhesive obtained in step (4) is degassed under vacuum negative pressure and coated onto a transparent PET release film through a double roller coating head. The film is then subjected to a light intensity of 1200 mJ / cm at a wavelength of 360 nm. 2 After curing by ultraviolet light, the adhesive layer is transferred to the release layer to obtain the acrylic foam tape.

[0084] Example 3

[0085] This embodiment provides an acrylic foam tape, which includes an acrylic foam adhesive layer and a release layer stacked sequentially. The thickness of the acrylic foam adhesive layer is 0.4 mm, and the release layer is a red PE release film with a thickness of 0.125 mm.

[0086] The preparation method of the acrylic foam tape includes the following steps:

[0087] (1) Mix 450 g of isooctyl acrylate and 50 g of acrylic acid to form a mixed monomer solution, add it to the reactor, add 0.5 g of 1-hydroxycyclohexylphenyl ketone (184) and 0.05 g of dodecyl mercaptan (NDM) to the reactor, stir for 20 min under nitrogen protection, and after thorough stirring, carry out the polymerization reaction under LED light source with a wavelength of 365 nm. The polymerization reaction temperature is 25℃. When the dynamic viscosity of the reaction system reaches 5000 cps, turn off the UV lamp to obtain acrylic acid prepolymer;

[0088] (2) Weigh 70 parts of acrylic prepolymer and 30 parts of isooctyl acrylate, stir for 2 h to make the acrylic prepolymer and isooctyl acrylate completely and evenly mixed.

[0089] (3) Based on step (2), add 0.3 parts of 1-hydroxycyclohexylphenyl ketone, 0.1 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine, 0.15 parts of 1,6-hexanediol diacrylate, 0.05 parts of n-dodecyl mercaptan, 0.2 parts of KBM-403, 0.1 parts of K-ITUV, 2 parts of TP7042, and 3 parts of β-acryloyloxypropionic acid, and stir for 1 h to ensure that all additives are fully mixed.

[0090] (4) Based on step (3), add 9 parts hollow glass microspheres and 3 parts fumed silica, stir for 2 h to make the filler fully mixed and uniform, and obtain the adhesive for acrylic foam layer;

[0091] (5) The adhesive obtained in step (4) is degassed under vacuum negative pressure and coated onto a transparent PET release film through a double roller coating head. The film is then subjected to a light intensity of 1200 mJ / cm at a wavelength of 360 nm. 2 After curing by ultraviolet light, the adhesive layer is transferred to the release layer to obtain the acrylic foam tape.

[0092] Example 4

[0093] This embodiment provides an acrylic foam tape, which differs from Embodiment 1 only in that TP7042 is not added in step (3), and the thickness of the acrylic foam tape layer is 0.4 mm.

[0094] Example 5

[0095] This embodiment provides an acrylic foam tape, which differs from Embodiment 3 only in that β-acryloyloxypropionic acid is not added in step (3), and the thickness of the acrylic foam tape layer is 0.4 mm.

[0096] Comparative Example 1

[0097] This comparative example provides an acrylic foam tape, which differs from Example 1 only in that all monomers are directly polymerized, omitting the step of preparing the prepolymer.

[0098] Specifically, the acrylic foam tape comprises an acrylic foam adhesive layer and a release layer stacked sequentially. The thickness of the acrylic foam adhesive layer is 0.4 mm, and the release layer is a red PE release film with a thickness of 0.125 mm.

[0099] The preparation method of the acrylic foam tape includes the following steps:

[0100] (1) Mix 506 g of isooctyl acrylate and 50 g of acrylic acid to form a mixed monomer solution, add it to a reaction vessel, add 0.5 g of 1-hydroxycyclohexylphenyl ketone (184) and 0.05 g of dodecyl mercaptan (NDM) to the reaction vessel, stir for 20 min under nitrogen protection, and after thorough stirring, carry out the initiation polymerization reaction under the irradiation of an LED light source with a wavelength of 365 nm. The polymerization reaction temperature is 25℃. When the dynamic viscosity of the reaction system reaches 5000 cps, turn off the UV lamp to obtain acrylic acid prepolymer;

[0101] (2) Based on step (1), add 0.3 parts of 1-hydroxycyclohexylphenyl ketone, 0.1 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine, 0.1 parts of 1,6-hexanediol diacrylate, 0.1 parts of n-dodecyl mercaptan, 0.2 parts of KBM-403, 0.1 parts of K-ITUV, and 2 parts of TP7042, and stir for 1 h to ensure that all additives are fully mixed.

[0102] (3) Based on step (2), add 9 parts hollow glass microspheres and 3 parts fumed silica, stir for 2 h to make the filler fully mixed and uniform, and obtain the adhesive for acrylic foam layer;

[0103] (4) The adhesive obtained in step (3) is degassed under vacuum negative pressure and coated onto a transparent PET release film through a double roller coating head. The film is then subjected to a light intensity of 1200 mJ / cm at a wavelength of 360 nm. 2 After curing by ultraviolet light, the adhesive layer is transferred to the release layer to obtain the acrylic foam tape.

[0104] Comparative Example 2

[0105] This comparative example provides an acrylic foam tape, which differs from Example 2 only in that all monomers are directly polymerized, omitting the step of preparing the prepolymer.

[0106] Specifically, the acrylic foam tape comprises an acrylic foam adhesive layer and a release layer stacked sequentially. The thickness of the acrylic foam adhesive layer is 0.4 mm, and the release layer is a red PE release film with a thickness of 0.125 mm.

[0107] The preparation method of the acrylic foam tape includes the following steps:

[0108] (1) Mix 575 g of isooctyl acrylate and 50 g of acrylic acid to form a mixed monomer solution, add it to a reaction vessel, add 0.5 g of 1-hydroxycyclohexylphenyl ketone (184) and 0.05 g of dodecyl mercaptan (NDM) to the reaction vessel, stir for 20 min under nitrogen protection, and after thorough stirring, carry out the polymerization reaction under the irradiation of an LED light source with a wavelength of 365 nm. The polymerization reaction temperature is 25℃. When the dynamic viscosity of the reaction system reaches 5000 cps, turn off the UV lamp to obtain acrylic acid prepolymer;

[0109] (2) Based on step (1), add 0.3 parts of 1-hydroxycyclohexylphenyl ketone, 0.1 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine, 0.12 parts of 1,6-hexanediol diacrylate, 0.1 parts of n-dodecyl mercaptan, 0.2 parts of KBM-403, 0.1 parts of K-ITUV, and 2 parts of TP7042, and stir for 1 h to ensure that all additives are fully mixed.

[0110] (3) Based on step (2), add 9 parts hollow glass microspheres and 3 parts fumed silica, stir for 2 h to make the filler fully mixed and uniform, and obtain the adhesive for acrylic foam layer;

[0111] (4) The adhesive obtained in step (3) is degassed under vacuum negative pressure and coated onto a transparent PET release film through a double roller coating head. The film is then subjected to a light intensity of 1200 mJ / cm at a wavelength of 360 nm. 2 After curing by ultraviolet light, the adhesive layer is transferred onto the thermal layer to obtain the acrylic foam tape.

[0112] Test methods

[0113] Hardness: GB / T 531.1-2008 "Test Method for Indentation Hardness of Vulcanized Rubber or Thermoplastic Rubber - Part 1: Shore Hardness Test (Shore Hardness)"

[0114] Initial tack of ball rolling: GB / T 4852-2002 (Ball Rolling Method)

[0115] Ring-shaped initial tack: GB / T 31125-2014 (Ring-shaped method)

[0116] Dynamic shear strength: GB / T 33332-2016 "Test method for dynamic shear strength of adhesive tapes"

[0117] Peel strength at different temperatures: GB / T 2792-2014 "Test Method for Peel Strength of Adhesive Tapes"

[0118] Thickness: GB / T 7125-2014 "Test Method for Thickness of Adhesive Tape"

[0119] The test results are shown in Table 1.

[0120] Table 1

[0121]

[0122] The test results show that:

[0123] (1) As can be seen from Examples 1-5, the present invention designs the raw materials for preparing acrylic foam tape and uses acrylic prepolymer and acrylate monomers to copolymerize and prepare acrylic foam tape. The resulting foam tape has high initial tack and peel strength. By increasing the proportion of acrylate monomers, tackifying resins and reactive diluents, the initial tack and peel performance of the product can be effectively improved. At the same time, it can maintain good performance without degradation in low temperature environment, which solves the difficulties of actual operation in low temperature environment and meets the application needs in low temperature environment.

[0124] (2) By comparing Example 1 with Examples 4-5, it can be seen that the present invention improves the performance of acrylic foam tape by further adding tackifying resin and active diluent to the raw materials.

[0125] (3) By comparing Example 1 with Comparative Examples 1-2, it can be seen that if the polymer monomer is directly polymerized without preparing a prepolymer, the performance of the acrylic foam tape will decrease.

[0126] In summary, this invention, through the design of the raw materials for preparing the acrylic foam adhesive layer, enables the acrylic foam tape to possess high initial tack and low-temperature resistance. It maintains high initial tack under actual low-temperature applications, making it less prone to detachment. The acrylic foam tape of this invention has a hardness of 41-45, a ball tack of 20-32#, a ring tack of 51-62 N / inch, a dynamic shear strength of 889-1154 Kpa, a peel strength at 25°C and 90°C of 46-52 N / inch, a peel strength at 5°C and 90°C of 44-58 N / inch, and a peel strength at -30°C and 90°C of 45-65 N / inch.

[0127] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An acrylic foam tape, characterized in that, The acrylic foam tape comprises an acrylic foam adhesive layer and a release layer stacked sequentially. The raw materials for preparing the acrylic foam adhesive layer include the following components in parts by weight: 70-90 parts of acrylic prepolymer, 10-30 parts of acrylate monomers, 0.1-1.0 parts of photoinitiator, and 0.05-0.2 parts of crosslinking agent.

2. The acrylic foam tape according to claim 1, characterized in that, The release layer is a red PE release film or glassine release paper.

3. The acrylic foam tape according to claim 1 or 2, characterized in that, The raw materials for preparing the acrylic prepolymer include the following components: polymeric monomers, photoinitiators, and chain transfer agents; Preferably, the polymeric monomer includes any one or a combination of at least two of soft monomers, hard monomers, or functional monomers; Preferably, the soft monomer comprises any one or a combination of at least two of isobornyl acrylate, isooctyl acrylate, or cyclohexyl acrylate; Preferably, the hard monomer comprises methyl acrylate and / or methyl methacrylate; Preferably, the functional monomer includes acrylic acid and / or methacrylic acid; Preferably, the photoinitiator comprises 2-hydroxy-2-methyl-1-phenyl-1-propanone and / or 1-hydroxycyclohexylphenyl ketone; Preferably, the chain transfer agent comprises dodecyl mercaptan.

4. The acrylic foam tape according to any one of claims 1-3, characterized in that, The acrylate monomers include isooctyl acrylate and / or cyclohexyl acrylate; Preferably, the photoinitiator comprises 1-hydroxycyclohexylphenyl ketone and / or diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride; Preferably, the crosslinking agent comprises 1,6-hexanediol diacrylate and / or trimethylolpropane triacrylate.

5. The acrylic foam tape according to any one of claims 1-4, characterized in that, The raw materials for preparing the acrylic foam adhesive layer also include 2-9 parts of hollow glass microspheres; Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 1-3 parts of fumed silica; Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 0.05-0.2 parts of chain transfer agent; Preferably, the chain transfer agent comprises dodecyl mercaptan; Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 0.05-0.2 parts of silane coupling agent; Preferably, the silane coupling agent comprises 3-glycidyl etheroxypropyltrimethoxysilane and / or a siloxane wetting and leveling agent; Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 0.03-0.5 parts of nano-color paste; Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 2-8 parts of tackifying resin; Preferably, the raw materials for preparing the acrylic foam adhesive layer further include 2-10 parts of an active diluent; Preferably, the reactive diluent comprises β-acryloyloxypropionic acid.

6. The acrylic foam tape according to any one of claims 1-5, characterized in that, The raw materials for preparing the acrylic prepolymer include the following components by weight: 80-90 parts of soft monomer, 1-10 parts of functional monomer, 0.01-0.1 parts of photoinitiator, and 0.001-0.01 parts of chain transfer agent; Preferably, the raw materials for preparing the acrylic acid prepolymer further include 1-10 parts of hard monomer.

7. The acrylic foam tape according to any one of claims 1-6, characterized in that, The preparation method of the acrylic acid prepolymer includes the following steps: The monomers are mixed, and then a photoinitiator and a chain transfer agent are added. The polymerization reaction is carried out under light irradiation to obtain the acrylic acid prepolymer.

8. A method for preparing acrylic foam tape as described in any one of claims 1-7, characterized in that, The preparation method includes the following steps: (1) Mix and stir the acrylic prepolymer and acrylate monomers: (2) Add photoinitiator, crosslinking agent, optional chain transfer agent, optional silane coupling agent, optional nano pigment, optional tackifying resin and optional reactive diluent and mix. (3) Add optional hollow glass microspheres and optional fumed silica and mix and stir to obtain the adhesive for acrylic foam layer; (4) Apply the adhesive of the acrylic foam adhesive layer to the transparent PET release film, cure it by ultraviolet irradiation, and transfer the adhesive layer to the release layer after curing to obtain the acrylic foam tape.

9. The preparation method according to claim 8, characterized in that, The stirring time in step (1) is 1.5-2.5 hours; Preferably, the stirring time in step (2) is 0.5-1.5 h; Preferably, the stirring time in step (3) is 1.5-2.5 h.

10. The application of an acrylic foam tape as described in any one of claims 1-7 in the bonding and fixing of battery casings, bonding of battery cells, edge bonding of new energy vehicle battery pack housings, or bonding of automotive exterior parts.

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