Elastic adhesive tape for splicing and method for manufacturing the same

Abstract

The application discloses a kind of elastic adhesive tapes for winding and preparation method thereof, the elastic adhesive tape includes at least one release layer, one substrate layer and one adhesive layer from outside to inside;Release layer is formed by curing release layer composition, release layer composition includes by weight parts: silicone release complex 90-100, hydrogen-containing silicone oil 3-6, isocyanate 3-8, refined diatomite 5-20;Silicone release complex includes dimethyl hydroxy silicone oil and hydroxyl-terminated vinyl methyl polysiloxane homologues.The elastic adhesive tape disclosed in the application can effectively solve the problem of easy to cause impression in the application of flexible coating containing roll product winding, and the elastic release layer is firm and not easy to fall off, and the release layer will not be adhered to the roll, and most of the problems existing in the prior art can be solved.

Description

Technical Field

[0001] This invention relates to the manufacture of encapsulation materials for solar cell modules, and more particularly to an elastic tape for splicing and its preparation method. Background Technology

[0002] Splicing rolls is a standard procedure for packaging and shipping roll products. Currently, adhesive tape is commonly used for splicing rolls. These tapes often use PET / PVC / cloth-based / masking tape as the base material.

[0003] In the field of photovoltaic encapsulation materials, to avoid fiber / micro-particle contamination introduced by cloth backing, masking tape, etc., and to meet high tensile strength requirements, PET / PVC and other plastic tapes are often used. For products that are not pressure resistant, such as transparent mesh backsheets, black encapsulation backsheets, and adhesive films, the inherent thickness of the tape at the splicing and bonding points causes a significant height difference between the roll surface and the tape surface. After winding, the interlayer tension causes strong interlayer compression between the roll surface and the tape surface, resulting in obvious tape marks and visual differences from the surrounding area on the soft roll surface, leading to a decrease in product yield. Researchers have tried to reduce the marks by selecting thinner tapes, reducing the height of the protrusions, using tapes of different thicknesses, or creating beveled transitions. However, since the tape substrate is a rigid material, the mark problem still exists, and significant thinning leads to a significant decrease in the tensile strength of the tape, making it prone to breakage during winding or unwinding. Beveled transition solutions are complex and not suitable for mass production. In these cases, elastic tape is generally chosen as a solution.

[0004] However, existing elastic tape solutions have many problems, such as poor high-temperature resistance, poor solvent resistance, and low tensile strength. EB (electron beam) curing does not require high temperatures, but the resulting release layer is brittle and cannot be used to prepare elastic tapes for flexible substrates. Silicone-based release materials have low surface energy and excellent release effect, making them particularly suitable for use under high-extrusion conditions in rolls. Combined with UV curing, they can avoid high-temperature baking, and the resulting release layer is flexible, thus becoming an important choice for matching flexible substrates. However, UV light penetration depth is limited, resulting in low curing depth. Uncrosslinked silicone release agents can easily seep out onto the surface under extrusion, contaminating the product. UV curing of the release surface generally results in slow crosslinking speeds and incomplete curing, leading to stickiness and product contamination.

[0005] Meanwhile, the release layer is a low-polarity material with low surface energy, resulting in poor adhesion to the substrate. This problem is not obvious on rigid substrates but is easily exposed on flexible substrates. On the one hand, the shrinkage and expansion of the tape due to compression, stretching, or temperature changes do not match the deformation of the release layer, easily leading to localized detachment or curling of the release layer. On the other hand, as disclosed in CN104085139B, the silicone oil surface of the lightweight release film generally uses a release agent, resulting in a loosely bonded internal molecular structure and a rough surface. Under compression conditions, the contact area with the adhesive surface is large, increasing the adhesion force and causing easy detachment, leading to adhesion problems during use. Furthermore, the high shrinkage rate of free radical UV curing results in high internal stress in the prepared coating, generally leading to poor adhesion. The traditional solution is to introduce a base coating, but for elastic substrates, their inability to withstand high temperatures and solvents makes the preparation of the base coating difficult and the process complex. Therefore, the market urgently needs to develop new elastic tape solutions that can be applied to the splicing of roll products. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide an elastic adhesive tape for splicing and a method for preparing the same.

[0007] To achieve the above objectives, the present invention provides, in a first aspect, an elastic tape for splicing, the elastic tape comprising, from the outside in, at least a release layer, a substrate layer and an adhesive layer; The release layer is formed by curing a release layer composition, which comprises, by weight: 90-100 parts of organosilicon release compound, 3-6 parts of hydrogen-containing silicone oil, 3-8 parts of isocyanate, and 5-20 parts of refined diatomaceous earth; Organosilicon release compounds include dimethyl hydroxy silicone oil and hydroxyl-terminated vinylmethyl polysiloxane homologues.

[0008] Preferably, the dimethyl hydroxyl silicone oil has a hydroxyl content of 0.9% to 6% and a number average molecular weight of 500 to 8000.

[0009] Preferably, the viscosity of the hydroxyl-terminated vinylmethyl polysiloxane homologue is 500~30000 mPa·s, and its vinyl segments are located in the side chain position.

[0010] Preferably, the hydrogen-containing silicone oil includes dimethyl polysiloxane with an end-hydrogen structure and a hydrogen content of 0.2% to 1.0%.

[0011] Preferably, the isocyanate includes one or a combination of several of TDI (toluene diisocyanate), MDI (diphenylmethane-4,4'-diisocyanate), IPDI (isoflurone diisocyanate), and H6XDI (hydrogenated diphenylmethylene diisocyanate).

[0012] Preferably, the release layer composition further includes 0.01 to 0.3 parts of a catalyst, which includes one or more of a thermal crosslinking catalyst and an ultraviolet crosslinking catalyst.

[0013] Preferably, the thermal crosslinking catalyst is a low-temperature thermal crosslinking catalyst that can achieve a highly efficient catalytic reaction at a lower temperature. The low-temperature thermal crosslinking catalyst is an organotin compound, which includes one or more of di(dodecyl sulfide)dibutyltin, dibutyltin diacetate, stannous octoate, and dibutyltin dilaurate.

[0014] Preferably, the ultraviolet crosslinking catalyst is a platinum complex catalyst, including the Karstedt catalyst.

[0015] Preferably, the refined diatomaceous earth is acid-treated diatomaceous earth, and the diatomaceous earth is non-clay diatomaceous earth or non-clay diatomaceous earth with a fineness of 500 mesh or greater.

[0016] Preferably, the release layer composition further includes 0.2 to 0.7 parts of a dispersant, which is a polymer copolymer containing multiple pigment-affinity anchoring groups, and includes one or more of acrylic copolymers and pigment-affinity polymer block copolymers.

[0017] Preferably, the substrate layer is made of a substrate layer composition, the components of which, by weight, include: 100 parts of main resin, 0.1 to 0.3 parts of coupling agent, and 10 to 25 parts of refined diatomaceous earth; The surface of the substrate layer is treated with corona or plasma.

[0018] Preferably, the main resin includes TPU, POE or EVA, and the VA content of EVA does not exceed 35%.

[0019] Preferably, the adhesive layer is formed by curing an adhesive layer composition, the components of which, by weight, include: 20-55 parts of polyurethane acrylate, 10-30 parts of reactive diluent, 5-20 parts of tackifying resin, 1-5 parts of photoinitiator, and 0.1-1.5 parts of other additives.

[0020] Preferably, the polyurethane acrylate is a prepolymer synthesized from aliphatic isocyanate, polyester resin, and hydroxy acrylate; The reactive diluent is an acrylic acid derivative monomer; Reactive diluents include one or more of the following: tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, and trimethylolpropane triacrylate; The tackifying resin is a terpene resin, which includes one or more of α-terpene resin, β-terpene resin, and terpene phenolic resin. The photoinitiator is a pyrolysis-type photoinitiator; Other additives include one or more of defoamers, leveling agents, and stabilizers.

[0021] Preferably, the viscosity of the polyurethane acrylate at room temperature is 5000~40000 cps; Acrylic acid derivative monomers contain two or three functional groups; Cleavage photoinitiators include one or more of the following: benzoin dimethyl ether, benzoin ethyl ether, benzoin butyl ether, 2-hydroxy-2-methyl-1-phenyl ketone, 1-hydroxy-cyclohexyl-phenyl ketone, benzopyrene, and acetophenone; Defoamers include one or more of phosphate ester defoamers and fatty acid ester defoamers; Leveling agents include one or more of polyacrylate leveling agents and nitrocellulose; Stabilizers include one or more of hydroquinone, p-methoxyphenol, 2,6-di-tert-butylcresol, anthraquinone, and phenothiazines.

[0022] Preferably, the thickness of the release layer is 5μm~60μm, the thickness of the substrate layer is 50μm~500μm, and the thickness of the adhesive layer is 10μm~40μm.

[0023] In a second aspect, the present invention provides a method for preparing an elastic adhesive tape, comprising the following steps: The refined diatomaceous earth is treated with a coupling agent, mixed with the main resin, melt-extruded, cooled and shaped to obtain the substrate layer. Surface treatment of the substrate layer; After the release layer composition is mixed evenly, a release layer slurry is prepared. The release layer slurry is then evenly coated onto one side of the surface-treated substrate layer. The side of the substrate layer coated with release slurry is first cured by UV lamp irradiation, then cured by infrared lamp irradiation, and finally cooled and rolled up. After the adhesive layer composition is mixed evenly, an adhesive layer slurry is prepared, and the adhesive layer slurry is evenly coated on the other side of the surface-treated substrate layer. The side of the substrate layer coated with adhesive paste is irradiated and cured with a UV lamp to obtain an elastic tape; The elastic tape is wound onto the core, with the adhesive layer facing inward and in contact with the core. The outer surface is then wrapped with a plastic film for transportation or storage.

[0024] The present invention has the following beneficial effects: (1) The elastic tape provided by the present invention uses an elastic combination of elastic substrate / elastic release layer to transform the deformation that extends in the direction of the roll surface during extrusion into the extension in the direction of the tape, while the deformation is released step by step, thereby eliminating the generation of imprints on the roll surface.

[0025] (2) In this invention, the release layer is formed by UV crosslinking of dimethyl hydroxy silicone oil and hydroxyl-terminated vinylmethyl polysiloxane homologues and low-temperature crosslinking of isocyanate. The release layer introduces loose and porous diatomaceous earth, which does not affect the release effect and reduces the shrinkage caused by the crosslinking process. The substrate layer also introduces loose and porous diatomaceous earth, which improves the surface roughness and increases the anchor points for the connection between the release layer and the substrate layer. The introduced dimethyl hydroxy silicone oil has low surface tension and is non-polar, with strong permeability, and can penetrate into the cavities of diatomaceous earth at the interface (including the solid-liquid interface of the release layer and the adjacent interface between the release layer and the substrate layer). In particular, the use of purified and processed diatomaceous earth has higher light transmittance, specific surface area, better hygroscopicity and surface acidity, which is conducive to promoting the dissolution of the low-viscosity hydroxysiloxanes that penetrate into it, accelerating hydrolytic crosslinking and condensation with hydroxyl groups on the surface of the diatomaceous earth cavity, and constructing a riveted connection. In conjunction with the cross-linking reaction between isocyanate and hydroxyl groups, the diatomaceous earth in the release layer is firmly locked, preventing loosening and "powdering" phenomena, and also enhancing the interfacial adhesion of the release layer to the substrate layer.

[0026] (3) The release layer of the present invention has a fast UV crosslinking speed. With the addition of isocyanate, it can react with the hydroxyl groups in the matrix components to connect the matrix components such as hydroxyl silicone oil and hydroxyl-terminated vinyl methyl polysiloxane together. This can reduce or eliminate the oiling caused by the inability of the internal UV crosslinking and improve the problem of slow curing and easy sticking of the release layer surface.

[0027] (4) In this invention, by introducing hydroxyl-terminated vinylmethyl polysiloxane homologues of different molecular weights into the release layer, the problem of the compatibility deteriorating sharply due to the large difference in crosslinking speed between various macromolecular and small molecule release materials can be avoided. This helps to improve the internal density and surface smoothness of the release layer, thereby reducing the pulling of the release layer from the adhesive layer. Attached Figure Description

[0028] The accompanying drawings illustrate exemplary embodiments of the invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0029] Figure 1 This is a schematic diagram of the structure of an elastic tape for splicing in this invention; Figure 2 This is a schematic flowchart of a method for preparing elastic adhesive tape according to the present invention.

[0030] In the diagram: 1. Release layer; 2. Substrate layer; 3. Adhesive layer. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings.

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] Example 1 A type of elastic tape for splicing rolls, see [link to relevant documentation] Figure 1 The elastic tape consists of a release layer 1, a substrate layer 2, and an adhesive layer 3 from the outside in.

[0034] See Figure 2 The steps for preparing this elastic tape are as follows: S1: Refined diatomaceous earth is treated with a coupling agent, mixed with the main resin, melt-extruded, cooled and shaped to obtain substrate layer 2.

[0035] S2: Perform surface treatment on substrate layer 2.

[0036] S3: After uniformly mixing the release layer 1 composition, a release layer 1 slurry is prepared, and the release layer 1 slurry is uniformly coated on one side of the surface-treated substrate layer 2.

[0037] S4: The side of the substrate layer 2 coated with the release layer 1 slurry is first cured by UV lamp irradiation, then cured by infrared lamp irradiation, and finally cooled and rolled up.

[0038] S5: After the adhesive layer 3 composition is mixed evenly, an adhesive layer 3 slurry is prepared, and the adhesive layer 3 slurry is evenly coated on the other side of the surface-treated substrate layer 2.

[0039] S6: UV lamp irradiation and curing are performed on one side of the substrate layer 2 coated with adhesive layer 3 slurry to obtain elastic tape.

[0040] S7: Wrap the elastic tape around the core, with the adhesive layer 3 facing inward and in contact with the core, and wrap the outer surface with a plastic film for transportation or storage.

[0041] Specifically, in this embodiment, the substrate layer 2 is an EVA hot-melt resin layer with a thickness of 0.3 mm. The components of the substrate layer 2 include the following raw materials in parts by weight: EVA particles: 100 units Coupling agent: 0.15 parts Refined diatomaceous earth: 15 parts The EVA particles used are UE654-04 from Taiwan Polymer, with a VA content of 33%. The coupling agent used is KH590 (γ-mercaptopropyltrimethoxysilane) from Nantong Runfeng Petrochemical. The refined diatomaceous earth is 500 mesh fine, and is non-clay diatomaceous earth or non-clay diatomaceous earth refined by acid treatment.

[0042] Based on the above-mentioned composition formula of substrate layer 2, the specific steps of the preparation method of substrate layer 2 are as follows: (1) Add KH-590 diluted with ethanol to deionized water with pH=4 and stir for 30 minutes to hydrolyze.

[0043] (2) Spray the hydrolysate evenly onto the surface of diatomaceous earth and mix it under high-speed shear force.

[0044] (3) Dry the treated diatomaceous earth at 115 degrees Celsius and stir for 25 minutes.

[0045] (4) EVA particles and treated diatomaceous earth are introduced into a single-screw extruder and melt-mixed. The viscous melt is extruded and cooled to form an EVA hot-melt substrate layer 2 of a specified thickness.

[0046] In this embodiment, the release layer 1 comprises the following raw materials in parts by weight: 50 mPa·s hydroxyl silicone oil: 20 parts 500 mPa·s low viscosity hydroxyl-terminated vinylmethyl polysiloxane: 15 parts Hydroxyl-terminated vinylmethyl polysiloxane with a viscosity of 5000 mPa·s: 40 parts High viscosity hydroxyl-terminated vinylmethyl polysiloxane (18000 mPa·s): 25 parts Polydimethylsiloxane containing active hydrogen: 4 parts Acrylic copolymer: 0.4 parts Isocyanate: 6 parts Refined diatomaceous earth: 15 parts Organotin catalyst: 0.04 parts Platinum complex catalyst: 0.06 parts The hydroxyl-terminated silicone oil has a molecular weight of 1200 and a hydroxyl content of 2.5%. The low-viscosity additive in the hydroxyl-terminated vinylmethyl polysiloxane homologues has a vinyl content of 5.2%, the medium-viscosity additive has a vinyl content of 3.5%, and the high-viscosity additive has a vinyl content of 1.4%. The active hydrogen content in the hydrogen-containing polydimethylsiloxane is 0.5%. The acrylic copolymer dispersant is BYK-2009. The isocyanate curing agent is Covestro Z4470. The refined diatomaceous earth is acid-treated, 500-mesh non-clay-containing diatomaceous earth or non-clay-based diatomaceous earth. The organotin catalyst is stannous octoate T-9 from Yake Technology. The platinum complex catalyst is PT-3000 from Guangzhou Xiyi Chemical.

[0047] Based on the above composition formula of release layer 1, the specific steps of the preparation method of release layer 1 are as follows: (1) Add the raw materials of release layer 1, excluding the platinum complex catalyst, to the dispersion tank and mix evenly. Then add 0.06 parts of platinum complex catalyst, stir evenly, degas under vacuum, and pack into a barrel.

[0048] (2) Use a slot extrusion coating machine to coat the release layer 1 on the corona-treated substrate layer 2, and control the coating thickness to be 25μm. The UVLED curing machine uses a 365nm wavelength high-pressure mercury lamp with a light intensity of 120w / cm. The roll coating speed is controlled to be 10m / min.

[0049] (3) Then, use an infrared tunnel oven to control the film temperature at 70±5 degrees Celsius and the rolling speed at 10m / min.

[0050] In this embodiment, the adhesive layer 3 comprises the following raw materials in parts by weight: Polyurethane acrylate: 40 parts Reactive diluent: 20 parts Tackifying resin: 10 parts Photoinitiator: 3 parts Defoamer: 0.2 parts Leveling agent: 0.5 parts Stabilizer: 0.2 parts Among them, the photoinitiator is BASF's 2-hydroxy-2-methyl-1-phenyl ketone, the reactive diluent is 1,6-hexanediol diacrylate (HDDA) from Aite (Shandong) New Materials, the polyurethane acrylate is Agisyn271 from Youming (Shanghai) Chemical, the tackifying resin is α-terpene resin T80 from Zhengzhou Cyber ​​Chemical, the defoamer is tributyl phosphate from Jiangsu Suoaifu Environmental Protection Technology, the leveling agent is Flow300 from Digo, and the stabilizer is p-methoxyphenol from Nantong Yunheng New Materials.

[0051] Based on the above composition of adhesive layer 3, the specific steps of the preparation method of adhesive layer 3 are as follows: (1) Stir 3 parts photoinitiator and 20 parts reactive diluent at room temperature for 15 minutes. Then add 40 parts polyurethane acrylate, 10 parts tackifying resin, 0.2 parts defoamer, 0.5 parts leveling agent and 0.2 parts stabilizer in sequence, and stir at room temperature for 60 minutes. Vacuum degassing, filter and pack into barrels.

[0052] (2) Apply adhesive layer 3 to the corona-treated substrate layer 2 using a slot extrusion coating machine, controlling the coating thickness to be 20 μm. The UVLED curing machine uses a 365 nm wavelength high-pressure mercury lamp with a light intensity of 100 W / cm. Nitrogen atmosphere. The roll coating speed is controlled at 10 m / min.

[0053] Example 2 In this embodiment, the substrate layer 2 is a TPU hot-melt resin layer with a thickness of 0.3 mm. The substrate layer 2 comprises the following raw materials in parts by weight: TPU particles: 100 parts Coupling agent: 0.20 parts Diatomaceous earth: 20 parts The TPU particles used were Covestro's TexinRxT70A. The coupling agent used was Nantong Runfeng Petrochemical KH590 (γ-mercaptopropyltrimethoxysilane silane). The diatomaceous earth was 500 mesh fine and purified by acid treatment.

[0054] Based on the above-mentioned composition formula of substrate layer 2, the specific steps of the preparation method of substrate layer 2 are as follows: (1) Add KH-590 diluted with ethanol to deionized water with pH=4 and stir for 30 minutes to hydrolyze.

[0055] (2) Spray the hydrolysate evenly onto the surface of diatomaceous earth and mix it under high-speed shear force.

[0056] (3) Dry the treated diatomaceous earth at 115 degrees Celsius and stir for 25 minutes.

[0057] (4) TPU particles and treated diatomaceous earth are introduced into a single-screw extruder and melt-mixed. The viscous melt is extruded, cooled, and molded to prepare a TPU hot-melt substrate layer 2 of a specified thickness.

[0058] In this embodiment, the release layer 1 comprises the following raw materials in parts by weight: 100 mPa·s hydroxyl silicone oil: 13 parts Low viscosity hydroxyl-terminated vinylmethyl polysiloxane (1000 mPa·s): 27 parts High viscosity hydroxyl-terminated vinylmethyl polysiloxane (15000 mPa·s): 51 parts Polydimethylsiloxane containing active hydrogen: 5 parts Acrylic copolymer: 0.4 parts, Isocyanate: 5 parts Refined diatomaceous earth: 15 parts Organotin catalyst: 0.04 parts Platinum complex catalyst: 0.06 parts The hydroxyl silicone oil has a molecular weight of 3600 and a hydroxyl content of 0.90%. The low-viscosity vinyl content of the hydroxyl-terminated vinylmethyl polysiloxane homologue is 5.0%, and the high-viscosity vinyl content is 1.7%. The active hydrogen content of the hydrogen-containing polydimethylsiloxane is 0.5%. The acrylic copolymer dispersant is BYK-2009. The isocyanate curing agent is Mitsui Chemicals D120N. The diatomaceous earth has a fineness of 500 mesh and is purified by acid treatment. The organotin catalyst is stannous octoate T-9 from Yake Technology. The platinum complex catalyst is PT-3000 from Guangzhou Xiyi Chemical.

[0059] Based on the above composition formula of release layer 1, the specific steps of the preparation method of release layer 1 are as follows: (1) Add the release layer component 1 raw materials, excluding the platinum complex catalyst, to the dispersion tank and mix evenly. Then add 0.06 parts of platinum complex catalyst, stir evenly, degas under vacuum, and pack into a barrel.

[0060] (2) Use a slot extrusion coating machine to coat the release layer 1 on the corona-treated substrate layer 2, and control the coating thickness to be 25μm. The UVLED curing machine uses a 365nm wavelength high-pressure mercury lamp with a light intensity of 120w / cm. The roll coating speed is controlled to be 10m / min.

[0061] (3) Then, use an infrared tunnel oven to control the film temperature at 70±5 degrees Celsius and the rolling speed at 10m / min.

[0062] In this embodiment, the adhesive layer 3 comprises the following raw materials in parts by weight: Polyurethane acrylate: 40 parts Reactive diluent: 25 parts Tackifying resin: 10 parts Photoinitiator: 3 parts Defoamer: 0.2 parts Leveling agent: 0.5 parts Stabilizer: 0.2 parts Among them, the photoinitiator is benzoin dimethyl ether from Hubei Shineng Chemical Technology, the reactive diluent is dipropylene glycol diacrylate (DPGDA) from Guangdong Yuhe New Materials, the polyurethane acrylate is Agisyn271 from Youming (Shanghai) Chemical, the tackifying resin is Dercolyte M115α,β-copolyterpene from DRT France, the defoamer is tributyl phosphate from Jiangsu Suoaifu Environmental Protection Technology, the leveling agent is Flow300 from DIG, and the stabilizer is p-methoxyphenol from Nantong Yunheng New Materials.

[0063] Based on the above composition of adhesive layer 3, the specific steps of the preparation method of adhesive layer 3 are as follows: (1) Stir 3 parts photoinitiator and 25 parts reactive diluent at room temperature for 15 minutes. Then add 40 parts polyurethane acrylate, 10 parts tackifying resin, 0.2 parts defoamer, 0.5 parts leveling agent and 0.2 parts stabilizer in sequence, and stir at room temperature for 60 minutes. Vacuum degassing, filter and pack into barrels.

[0064] (2) Apply adhesive layer 3 to the corona-treated substrate layer 2 using a slot extrusion coating machine, controlling the coating thickness to be 20 μm. The UVLED curing machine uses a 365 nm wavelength high-pressure mercury lamp with a light intensity of 100 W / cm. Nitrogen atmosphere. The roll coating speed is controlled at 10 m / min.

[0065] Example 3 In this embodiment, the substrate layer 2 and the adhesive layer 3 are the same as in Example 1.

[0066] The difference lies in the fact that the release layer 1 comprises the following raw materials in parts by weight: 100 mPa·s hydroxyl silicone oil: 20 parts Hydroxyl-terminated vinylmethyl polysiloxane with a viscosity of 2500 mPa·s: 30 parts High viscosity hydroxyl-terminated vinylmethyl polysiloxane with a viscosity of 12000 mPa·s: 45 parts Polydimethylsiloxane containing active hydrogen: 4 parts Acrylic copolymer: 0.4 parts Isocyanate: 6 parts Refined diatomaceous earth: 15 parts Organotin catalyst: 0.04 parts Platinum complex catalyst: 0.06 parts The hydroxyl-terminated silicone oil has a molecular weight of 3600 and a hydroxyl content of 0.90%. The medium-viscosity additive in the hydroxyl-terminated vinylmethyl polysiloxane homologue has a vinyl content of 4.1%, and the high-viscosity additive has a vinyl content of 2.2%. The active hydrogen content in the hydrogen-containing polydimethylsiloxane is 0.5%. The acrylic copolymer dispersant is BYK-2009. The isocyanate curing agent is Mitsui Chemicals D120N. The refined diatomaceous earth has a fineness of 500 mesh and is acid-treated. The organotin catalyst is stannous octoate T-9 from Yake Technology. The platinum complex catalyst is PT-3000 from Guangzhou Xiyi Chemical.

[0067] Based on the above composition formula of release layer 1, the specific steps of the preparation method of release layer 1 are as follows: (1) Add the raw materials of release layer 1, excluding the platinum complex catalyst, to the dispersion tank and mix evenly. Then add 0.06 parts of platinum complex catalyst, stir evenly, degas under vacuum, and pack into a barrel.

[0068] (2) Use a slot extrusion coating machine to coat the release layer 1 on the corona-treated substrate layer 2, and control the coating thickness to be 25μm. The UVLED curing machine uses a 365nm wavelength high-pressure mercury lamp with a light intensity of 120w / cm. The roll coating speed is controlled to be 10m / min.

[0069] (3) Then, use an infrared tunnel oven to control the film temperature at 60±5 degrees Celsius and the rolling speed at 10m / min.

[0070] Example 4 Compared with Example 1, the refined diatomaceous earth in release layer 1 was changed to 20 parts, while all other parts remained the same.

[0071] Example 5 Compared with Example 1, the refined diatomaceous earth in release layer 1 was changed to 5 parts, while all other parts remained the same.

[0072] Example 6 Compared with Example 1, the release layer 1 containing active hydrogen polydimethylsiloxane was changed to 3 parts, while all other parts remained the same.

[0073] Example 7 Compared with Example 1, the release layer 1 containing active hydrogen polydimethylsiloxane was changed to 6 parts, while all other parts remained the same.

[0074] Example 8 Compared with Example 1, the isocyanate in release layer 1 was changed to 3 parts, while all other parts remained the same.

[0075] Example 9 Compared to Example 1, the isocyanate in release layer 1 was changed to 8 parts, while all other parts remained the same.

[0076] Comparative Example 1 Release layer 1 uses the same materials and amounts as in Example 1, except that the UV curing conditions are removed.

[0077] Comparative Example 2 Release layer 1 uses the same materials and amounts as in Example 1, except that the infrared curing condition is removed.

[0078] Comparative Example 3 Release layer 1 only removes isocyanate; the other added materials and amounts are the same as in Example 1.

[0079] Comparative Example 4 Release layer 1 contains only low-viscosity hydroxyl-terminated vinylmethyl polysiloxane, while medium-viscosity and high-viscosity hydroxyl-terminated vinylmethyl polysiloxane are removed. Other materials and dosages are the same as in Example 1.

[0080] Comparative Example 5 Release layer 1 removes refined diatomaceous earth; other added materials and amounts are the same as in Example 1.

[0081] Comparative Example 6 The substrate layer 2 was changed to 0.1mm thick PE, while the release layer 1 and adhesive layer 3 were the same as in Example 1.

[0082] Experimental Example To compare and illustrate the elastic tapes prepared in Examples 1-9 and Comparative Examples 1-6 of this technical solution, the comprehensive performance of the samples was tested.

[0083] 1. Tape tensile property test The tensile strength of the specimens was examined using a DLS-05 thin film electronic tensile testing machine, following the testing method specified in GB / T 1040.3-2006. The specimen width was 25 mm, the specimen length was 15 cm, and the tensile speed was 100 m / min.

[0084] 2. Surface dryness test Cover the surface of release layer 1 with a single layer of tissue paper, press a 1 kg weight on it for 5 minutes, remove the tissue paper, and observe whether there is any release material stuck to the tissue paper or any oil stains on the surface of the tissue paper.

[0085] 3. Release force test This test strip is used to evaluate the adhesion between release layer 1 and adhesive layer 3. Two pieces of elastic tape, each 150 mm long and 25 mm wide, are used. The adhesive layer 3 of one strip is bonded to the release layer 1 of the other strip, with the edges aligned. A 2 kg standard roller is used to roll the strip back and forth three times. The sample adhesion must ensure no air bubbles between the layers. After applying and treating the tape, the strip is allowed to stand for 20 minutes at an ambient temperature of 25±2℃ and humidity of 50±10%. The test strip is then fixed to a steel plate, clamps are installed, and a tensile testing machine is used to separate the two pieces of tape at a 180-degree angle.

[0086] 4. Adhesion test This test strip is used to evaluate the adhesion between the tape and the backing plate. Two pieces of elastic tape, each 150 mm long and 25 mm wide, are used. The adhesive layer 3 of one strip is bonded to the EVA side of the backing plate, with the edges aligned. A 5 kg standard roller is used to roll the strip back and forth three times. The sample adhesion must be free of air bubbles between layers. After applying and treating the tape, it should be allowed to stand for 20 minutes at an ambient temperature of 25±2℃ and humidity of 50±10%. The test strip is then fixed to a steel plate, a clamp is installed, and a tensile testing machine is used to separate the tape from the backing plate at a 180-degree angle.

[0087] The test results are shown in the table below: Table 1. Performance test results of Examples 1-3 and Comparative Examples 1-6 The above analysis of experimental results shows that: 1. As can be seen from the comparison of Examples 1, 2, and 3, the use of trifunctional crosslinking monomers in adhesive layer 3 can improve the hardness of adhesive layer 3, which helps to reduce the degree of penetration and contact between adhesive layer 3 and release layer 1 under extrusion conditions, thereby reducing the adhesion between the two. As the proportion of medium and high viscosity release agents increases, the density of release layer 1 increases, its tensile strength gradually deteriorates, and it is easy to partially peel off from the substrate.

[0088] 2. As can be seen from Examples 1, 2, 3 and Comparative Example 4, the increased proportion of medium and high viscosity hydroxyl-terminated vinyl methyl polysiloxane used in release layer 1 can accelerate the UV curing speed of release layer 1, increase the density of the surface layer, effectively block internal oil seepage, and at the same time reduce the penetration of the adhesive layer agent, which can reduce the degree of adhesion to the bonding layer.

[0089] 3. As can be seen from Examples 1, 2, 3 and 5, the introduction of isocyanate and diatomaceous earth into release layer 1 can improve the oiling problem of release layer 1 to varying degrees. The former improves the crosslinking of small molecule silicon materials, and the latter promotes the adsorption and bonding of small molecule silicon materials.

[0090] 4. Comparative Examples 1, 2, and 3 show that the poor curing and cross-linking of release layer 1 can improve the anti-peeling ability of release layer 1 during the stretching process, but release layer 1 is sticky and oily overall, which also significantly increases the release force between adhesive layer 3 and release layer 1 to a certain extent.

[0091] Comparative Examples 5, 6, and 7 show that although PE as a substrate also has good elasticity, the release layer 1 has poor adhesion to its surface, and the release layer 1 peels off from the surface at a relatively small elongation.

[0092] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above invention, and these changes or modifications still fall within the scope of the present invention.

Claims

1. An elastic adhesive tape for splicing rolls, characterized in that, The elastic tape comprises at least one release layer, one substrate layer and one adhesive layer from the outside to the inside; The release layer is formed by curing a release layer composition, which comprises, by weight: 90-100 parts of organosilicon release compound, 3-6 parts of hydrogen-containing silicone oil, 3-8 parts of isocyanate, and 5-20 parts of refined diatomaceous earth. The release layer composition also comprises 0.01-0.3 parts of catalyst, which includes one or more of thermal crosslinking catalyst and ultraviolet crosslinking catalyst. The isocyanate curing agent is either Covestro Z4470 or Mitsui Chemicals D120N. The release layer composition is cured by first being cured by UV lamp irradiation and then by infrared lamp irradiation. The substrate layer is made of a substrate layer composition, the components of which, by weight, include: 100 parts of main resin, 0.1 to 0.3 parts of coupling agent, and 10 to 25 parts of refined diatomaceous earth. The main resin includes TPU, POE, or EVA, and the VA content of EVA does not exceed 35%. The organosilicon release complex comprises dimethyl hydroxy silicone oil and hydroxyl-terminated vinylmethyl polysiloxane homologues.

2. The elastic tape according to claim 1, characterized in that, The dimethyl hydroxyl silicone oil has a hydroxyl content of 0.9% to 6% and a number average molecular weight of 500 to 8000.

3. The elastic tape according to claim 1, characterized in that, The viscosity of the hydroxyl-terminated vinylmethyl polysiloxane homologue is 500~30000 mPa·s, and its vinyl segments are located in the side chain position.

4. The elastic tape according to claim 1, characterized in that, The hydrogen-containing silicone oil includes dimethyl polysiloxane with an end-hydrogen structure and a hydrogen content of 0.2% to 1.0%.

5. The elastic tape according to claim 1, characterized in that, The thermal crosslinking catalyst is an organotin compound, which includes one or more of di(dodecyl sulfide)dibutyltin, dibutyltin diacetate, stannous octoate, and dibutyltin dilaurate.

6. The elastic tape according to claim 1, characterized in that, The ultraviolet crosslinking catalyst is a platinum complex catalyst, which includes a Karstedt catalyst.

7. The elastic tape according to claim 1, characterized in that, The refined diatomaceous earth is acid-treated diatomaceous earth, and the diatomaceous earth is non-clay diatomaceous earth or non-clay diatomaceous earth with a fineness greater than or equal to 500 mesh.

8. The elastic tape according to claim 1, characterized in that, The release layer composition further includes 0.2 to 0.7 parts of a dispersant, wherein the dispersant is a polymer copolymer containing multiple pigment-loving anchoring groups, and the dispersant includes one or more of acrylic copolymers and pigment-loving polymer block copolymers.

9. A method for preparing an elastic adhesive tape, used to prepare the elastic adhesive tape according to any one of claims 1-8, characterized in that, Includes the following steps: The refined diatomaceous earth is treated with a coupling agent and mixed with the main resin of the substrate layer composition. The mixture is then melt-extruded, cooled, and shaped to obtain the substrate layer. Surface treatment of the substrate layer; After the release layer composition is mixed evenly, a release layer slurry is prepared. The release layer slurry is then evenly coated onto one side of the surface-treated substrate layer. The side of the substrate layer coated with release slurry is first cured by UV lamp irradiation, then cured by infrared lamp irradiation, and finally cooled and rolled up. After the adhesive layer composition is mixed evenly, an adhesive layer slurry is prepared, and the adhesive layer slurry is evenly coated on the other side of the surface-treated substrate layer. The elastic tape is obtained by UV-curing the side of the substrate layer coated with adhesive paste. The elastic tape is wound onto the core, with the adhesive layer facing inward and in contact with the core, and the outer surface is wrapped with a plastic film.

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