Foaming adhesive tape and preparation method thereof

Abstract

The invention relates to the technical field of foamed adhesive tapes, in particular to a foamed adhesive tape and a preparation method thereof. The foaming adhesive tape comprises an acrylic foaming base material, an adhesive layer coated on the surface of the acrylic foaming base material and a release film attached to the outer side of the adhesive layer, the adhesive layer is prepared from the following raw materials in parts by mass: 20 to 50 parts of butyl methacrylate, 10 to 30 parts of methyl acrylate, 5 to 15 parts of vinyl acetate, 20 to 60 parts of ethyl acetate, 5 to 10 parts of methanol, 1.1 to 3 parts of benzoyl peroxide, 5 to 15 parts of 2-hydroxypropyl acrylate, 5 to 10 parts of polystyrene microspheres, 10 to 20 parts of tetraethoxysilane, 1 to 5 parts of dopamine hydrochloride and 0.1 to 1 part of hexamethylenetetramine. 5-10 parts of hollow glass beads and 1-5 parts of a cross-linking agent. The cable is simple in structure, super-strong in impact resistance, good in thermal aging resistance and excellent in mechanical performance and stripping performance.

Description

Technical Field

[0001] The present invention relates to the technical field of foaming tapes, and in particular to a foaming tape and a preparation method thereof. Background Art

[0002] With the rapid development of technology, people's lives are increasingly inseparable from various tapes. At present, foaming tapes are widely used in products such as mobile phones, tablet computers, automobiles, air conditioners, washing machines, etc., mainly for short-term or permanent fixation of products. Now, higher standards are put forward for the adhesion and peeling performance of foaming tapes.

[0003] Foaming tapes can be bonded firmly to the adherend by heating or other means with a slight pressure. The most commonly used acrylic tapes are widely used at present because they have good fluidity and are easy to detach.

[0004] Although acrylic foaming tapes are easy to detach, they have poor initial adhesion and poor anti-aging performance. Therefore, with the passage of time and the change of environmental conditions, the peeling performance and mechanical properties of foaming tapes will decline and cannot meet the requirements of high performance for current electronic products.

[0005] In view of the above technical problems, it is necessary to provide a new foaming tape to improve its anti-aging performance on the basis of ensuring initial adhesion, and enhance its mechanical properties and peeling performance, which has become a technical problem to be solved at present. Summary of the Invention

[0006] The purpose of the present invention is to solve the deficiencies in the prior art and provide a foaming tape and a preparation method thereof.

[0007] A foaming tape includes: an acrylic foaming substrate, an adhesive layer coated on the surface of the acrylic foaming substrate, and a release film attached to the outside of the adhesive layer; the raw materials of the adhesive layer include, by mass: 20-50 parts of butyl methacrylate, 10-30 parts of methyl acrylate, 5-15 parts of vinyl acetate, 20-60 parts of ethyl acetate, 5-10 parts of methanol, 1.1-3 parts of benzoyl peroxide, 5-15 parts of 2-hydroxypropyl acrylate, 5-10 parts of polystyrene microspheres, 10-20 parts of tetraethyl orthosilicate, 1-5 parts of dopamine hydrochloride, 0.1-1 part of hexamethylenetetramine, 5-10 parts of hollow glass microspheres, and 1-5 parts of a crosslinking agent.

[0008] Preferably, the thickness of the acrylic foaming substrate is 50-150 μm, and the density is 0.5-0.65 g / cm 3 .

[0009] Preferably, the particle size of the polystyrene microspheres is 40-100 μm.

[0010] Preferably, the crosslinking agent is toluene diisocyanate-trimethylolpropane adduct (TMP-TDI adduct).

[0011] The preparation method of the above foaming tape comprises the following steps:

[0012] S1. Add butyl methacrylate, methyl acrylate, and vinyl acetate to ethyl acetate and stir evenly. Add methanol thereto and perform ultrasonic treatment for 1 - 2 h. Add benzoyl peroxide thereto and stir at 70 - 80 °C for 10 - 20 min. Add 2-hydroxypropyl acrylate and benzoyl peroxide thereto and stir at 85 - 92 °C for 5 - 10 h. Cool and filter to obtain an acrylate adhesive solution.

[0013] S2. Add polystyrene microspheres to an ethanol aqueous solution and perform ultrasonic dispersion for 10 - 20 min. Add tetraethyl orthosilicate thereto, add saturated ammonia water, perform ultrasonic treatment at 40 - 50 °C for 1 - 2 h, centrifuge, wash, dry in vacuum, calcine at 400 - 500 °C for 1 - 2 h, transfer to water, then add dopamine hydrochloride and perform ultrasonic treatment for 10 - 20 min. Add hexamethylenetetramine thereto and continue ultrasonic treatment for 5 - 15 min. Let stand at 70 - 80 °C for 1 - 2 h, filter, wash, and dry in vacuum to obtain hollow microsphere-loaded particles.

[0014] S3. Add hollow glass microspheres and hollow microsphere-loaded particles to the acrylate adhesive solution and stir for 10 - 20 min. Add the crosslinking agent thereto and continue stirring for 1 - 2 h to obtain an adhesive mucus.

[0015] S4. Coat the adhesive mucus on the surface of the acrylic foaming substrate, bake at 50 - 60 °C for 20 - 30 min to form an adhesive layer, and laminate a release film on the outside of the adhesive layer for curing.

[0016] Preferably, in S1, the ultrasonic frequency is 5 - 12 kHz.

[0017] Preferably, in S1, the mass ratio of benzoyl peroxide added after ultrasonic treatment to benzoyl peroxide added after stirring at 70 - 80 °C is 0.1 - 1:1 - 2.

[0018] Preferably, in S2, the ultrasonic dispersion frequency is 5 - 12 kHz.

[0019] Preferably, in S2, the ultrasonic treatment frequency is 5 - 12 kHz.

[0020] Preferably, in S4, the curing temperature is 60 - 70 °C and the curing time is 20 - 40 h.

[0021] Beneficial effects:

[0022] The foaming tape obtained by the present invention not only has good waterproof performance, but also has high temperature resistance and excellent anti-aging performance. Among them, the acrylate adhesive solution is combined with hollow glass microspheres and loaded hollow microspheres. After cross-linking, this special structure endows the tape with overall viscoelasticity, does not cause stress concentration, and can effectively bond with the substrate, with excellent impact resistance. The hollow glass microspheres and loaded hollow microspheres are closed-cell structures, with excellent air and water barrier properties and excellent waterproof performance.

[0023] The present invention uses polystyrene microspheres as a template, deposits a layer of silica shell on its surface, and forms hollow microspheres after calcination. However, it is very easy to generate strong air pressure, resulting in pores on the surface of the microspheres. The present invention further combines a layer of polydopamine organic layer on its surface, which can not only ensure the sealing effect of the microspheres, but also ensure the dispersibility in the acrylate adhesive solution. Even after thermal aging, it still maintains excellent holding adhesiveness, has less residual glue when peeled off after aging, and also has an excellent cushioning rate.

[0024] The structure of the present invention is simple, and it has excellent impact resistance, good heat aging resistance, excellent mechanical properties and peeling properties. The preparation method of the present invention is simple and easy to prepare, meeting industrial production requirements and can be used for large-scale production. Description of the Drawings

[0025] Figure 1 It is a comparison chart of the initial adhesiveness and holding adhesiveness of the foaming tapes obtained in Example 5 and Comparative Examples 1-2.

[0026] Figure 2 It is a comparison chart of the peel adhesiveness and water absorption rate of the adhesive layer of the foaming tapes obtained in Example 5 and Comparative Examples 1-2.

[0027] Figure 3 It is a comparison chart of the holding adhesiveness and residual glue area of the foaming tapes obtained in Example 5 and Comparative Examples 1-2 after thermal aging. Detailed Embodiments

[0028] The present invention will be further explained below with reference to specific embodiments.

[0029] The following acrylic foam substrate used was purchased from a certain Cheng Electronic Materials Co., Ltd. in Shenzhen, with a thickness of 0.1 mm and a density of 0.61 g / cm 3 . The following polystyrene microspheres used were purchased from a certain Ke Keyou Technology Co., Ltd. in Beijing, with a particle size of 50 μm. The following hollow glass microspheres used were purchased from a certain Bin Mineral Products Trading Co., Ltd. in Lingshou County, with a particle size of 80 μm. The following TMP-TDI adduct used was purchased from a certain Da Chemical Co., Ltd. in Gansu.

[0030] Example 1

[0031] A foaming tape, comprising: an acrylic foaming substrate, an adhesive layer coated on the surface of the acrylic foaming substrate, and a PET release film adhered to the outside of the adhesive layer.

[0032] The raw materials of the adhesive layer include: 200 g of butyl methacrylate, 100 g of methyl acrylate, 50 g of vinyl acetate, 200 g of ethyl acetate, 50 g of methanol, 11 g of benzoyl peroxide, 50 g of 2-hydroxypropyl acrylate, 50 g of polystyrene microspheres, 100 g of tetraethyl orthosilicate, 10 g of dopamine hydrochloride, 1 g of hexamethylenetetramine, 50 g of hollow glass microspheres, and 10 g of TMP-TDI adduct.

[0033] The preparation method of the above-mentioned foaming tape includes the following steps:

[0034] S1. Add butyl methacrylate, methyl acrylate, and vinyl acetate to ethyl acetate and stir evenly. Add methanol thereto and perform ultrasonic treatment for 1 h at an ultrasonic frequency of 5 kHz. Add 1 g of benzoyl peroxide thereto and stir at a temperature of 70 °C for 10 min. Add 2-hydroxypropyl acrylate and 10 g of benzoyl peroxide thereto and stir at a temperature of 85 °C for 5 h. Cool and filter through a 200-mesh sieve to obtain an acrylate adhesive solution.

[0035] S2. Add polystyrene microspheres to 500 g of an ethanol aqueous solution with a mass fraction of 40% and perform ultrasonic dispersion for 10 min at an ultrasonic frequency of 5 kHz. Add tetraethyl orthosilicate thereto, add 50 g of saturated ammonia water, and perform ultrasonic treatment at a temperature of 40 °C for 1 h at an ultrasonic frequency of 5 kHz. Centrifuge, wash, dry in vacuum, send it into a muffle furnace, calcine at a temperature of 400 °C for 1 h, send it into 500 g of deionized water, add dopamine hydrochloride and perform ultrasonic treatment for 10 min at an ultrasonic frequency of 5 kHz. Add hexamethylenetetramine thereto and continue ultrasonic treatment for 5 min. Let it stand at a temperature of 70 °C for 1 h, filter, wash, and dry in vacuum to obtain hollow microsphere-loaded particles.

[0036] S3. Add hollow glass microspheres and hollow microsphere-loaded particles to the acrylate adhesive solution, stir at a speed of 100 r / min for 10 min, add the TMP-TDI adduct thereto and continue stirring for 1 h to obtain an adhesive mucus.

[0037] S4. Place the acrylic foaming substrate on the unwind unit of a coater, coat the adhesive mucus on the surface of the acrylic foaming substrate with a coating thickness of 45 μm; bake at a temperature of 50 °C for 20 min to form an adhesive layer, adhere a PET release film to the outside of the adhesive layer, and cure at a temperature of 60 °C for 20 h.

[0038] Example 2

[0039] A foaming tape, comprising: an acrylic foaming substrate, an adhesive layer coated on the surface of the acrylic foaming substrate, and a PET release film adhered to the outside of the adhesive layer.

[0040] The raw materials of the adhesive layer include: 500 g of butyl methacrylate, 300 g of methyl acrylate, 150 g of vinyl acetate, 600 g of ethyl acetate, 100 g of methanol, 30 g of benzoyl peroxide, 150 g of 2-hydroxypropyl acrylate, 100 g of polystyrene microspheres, 200 g of tetraethyl orthosilicate, 50 g of dopamine hydrochloride, 10 g of hexamethylenetetramine, 100 g of hollow glass microspheres, and 50 g of TMP-TDI adduct.

[0041] The preparation method of the above foaming tape comprises the following steps:

[0042] S1. Add butyl methacrylate, methyl acrylate, and vinyl acetate to ethyl acetate and stir evenly. Add methanol thereto and perform ultrasonic treatment for 2 h at an ultrasonic frequency of 12 kHz. Add 10 g of benzoyl peroxide thereto and stir at 80°C for 20 min. Add 2-hydroxypropyl acrylate and 20 g of benzoyl peroxide thereto and stir at 92°C for 10 h. Cool and filter through a 200-mesh sieve to obtain an acrylate glue solution.

[0043] S2. Add polystyrene microspheres to 1000 g of an ethanol aqueous solution with a mass fraction of 60% and perform ultrasonic dispersion for 20 min at an ultrasonic frequency of 12 kHz. Add tetraethyl orthosilicate thereto, add 100 g of saturated ammonia water, perform ultrasonic treatment at 50°C for 2 h at an ultrasonic frequency of 12 kHz, centrifuge, wash, dry in vacuum, send it into a muffle furnace, calcine at 500°C for 2 h, send it into 1000 g of deionized water, add dopamine hydrochloride and perform ultrasonic treatment for 20 min at an ultrasonic frequency of 12 kHz. Add hexamethylenetetramine thereto and continue ultrasonic treatment for 15 min. Let it stand at 80°C for 2 h, filter, wash, and dry in vacuum to obtain hollow microsphere-loaded particles.

[0044] S3. Add hollow glass microspheres and hollow microsphere-loaded particles to the acrylate glue solution, stir at a speed of 300 r / min for 20 min, add TMP-TDI adduct thereto and continue stirring for 2 h to obtain a glue mucus.

[0045] S4. Place the acrylic foaming substrate on the unwinding unit of a coater, coat the glue mucus on the surface of the acrylic foaming substrate with a coating thickness of 55 μm; bake at 60°C for 30 min to form an adhesive layer, adhere a PET release film to the outside of the adhesive layer, and cure at 70°C for 40 h.

[0046] Example 3

[0047] A foaming tape, comprising: an acrylic foaming substrate, an adhesive layer coated on the surface of the acrylic foaming substrate, and a PET release film adhered to the outside of the adhesive layer.

[0048] The raw materials of the adhesive layer include: 300 g of butyl methacrylate, 250 g of methyl acrylate, 80 g of vinyl acetate, 500 g of ethyl acetate, 70 g of methanol, 20 g of benzoyl peroxide, 120 g of 2-hydroxypropyl acrylate, 70 g of polystyrene microspheres, 180 g of tetraethyl orthosilicate, 20 g of dopamine hydrochloride, 7 g of hexamethylenetetramine, 70 g of hollow glass microspheres, and 40 g of TMP-TDI adduct.

[0049] The preparation method of the above foaming tape comprises the following steps:

[0050] S1. Add butyl methacrylate, methyl acrylate, and vinyl acetate to ethyl acetate, stir evenly, add methanol thereto, perform ultrasonic treatment for 80 min at an ultrasonic frequency of 9 kHz, add 3 g of benzoyl peroxide thereto, stir at a temperature of 77 °C for 12 min, add 2-hydroxypropyl acrylate and 17 g of benzoyl peroxide thereto, stir at a temperature of 86 °C for 9 h, cool, and filter through a 200-mesh sieve to obtain an acrylate adhesive solution.

[0051] S2. Add polystyrene microspheres to 700 g of an ethanol aqueous solution with a mass fraction of 55%, perform ultrasonic dispersion for 13 min at an ultrasonic frequency of 9 kHz, add tetraethyl orthosilicate thereto, add 60 g of saturated ammonia water, perform ultrasonic treatment for 100 min at a temperature of 42 °C and an ultrasonic frequency of 6 kHz, centrifuge, wash, dry in vacuum, send it into a muffle furnace, calcine at a temperature of 480 °C for 80 min, send it into 900 g of deionized water, add dopamine hydrochloride, perform ultrasonic treatment for 12 min at an ultrasonic frequency of 9 kHz, add hexamethylenetetramine thereto, continue ultrasonic treatment for 8 min, stand at a temperature of 77 °C for 80 min, filter, wash, and dry in vacuum to obtain hollow microsphere-loaded particles.

[0052] S3. Add hollow glass microspheres and hollow microsphere-loaded particles to the acrylate adhesive solution, stir at a speed of 260 r / min for 13 min, add the TMP-TDI adduct thereto, and continue stirring for 100 min to obtain an adhesive mucus.

[0053] S4. Place the acrylic foaming substrate on the unwind unit of a coater, coat the adhesive mucus on the surface of the acrylic foaming substrate with a coating thickness of 50 μm; bake at a temperature of 52 °C for 28 min to form an adhesive layer, adhere a PET release film to the outside of the adhesive layer, and cure at a temperature of 62 °C for 35 h.

[0054] Example 4

[0055] A foaming tape, comprising: an acrylic foaming substrate, an adhesive layer coated on the surface of the acrylic foaming substrate, and a PET release film adhered to the outside of the adhesive layer.

[0056] The raw materials of the adhesive layer include: 400 g of butyl methacrylate, 150 g of methyl acrylate, 120 g of vinyl acetate, 300 g of ethyl acetate, 90 g of methanol, 20 g of benzoyl peroxide, 80 g of 2-hydroxypropyl acrylate, 90 g of polystyrene microspheres, 120 g of tetraethyl orthosilicate, 40 g of dopamine hydrochloride, 3 g of hexamethylenetetramine, 90 g of hollow glass microspheres, and 20 g of TMP-TDI adduct.

[0057] The preparation method of the above foaming tape comprises the following steps:

[0058] S1. Add butyl methacrylate, methyl acrylate, and vinyl acetate to ethyl acetate and stir evenly. Add methanol thereto and perform ultrasonic treatment for 100 min at an ultrasonic frequency of 6 kHz. Add 7 g of benzoyl peroxide thereto and stir at a temperature of 73 °C for 18 min. Add 2-hydroxypropyl acrylate and 13 g of benzoyl peroxide thereto and stir at a temperature of 90 °C for 7 h. Cool and filter through a 200-mesh sieve to obtain an acrylate adhesive solution.

[0059] S2. Add polystyrene microspheres to 900 g of an ethanol aqueous solution with a mass fraction of 45% and perform ultrasonic dispersion for 17 min at an ultrasonic frequency of 6 kHz. Add tetraethyl orthosilicate thereto, add 90 g of saturated ammonia water, and perform ultrasonic treatment at a temperature of 48 °C for 80 min at an ultrasonic frequency of 9 kHz. Centrifuge, wash, dry in vacuum, send into a muffle furnace, calcine at a temperature of 420 °C for 100 min, send into 700 g of deionized water, add dopamine hydrochloride and perform ultrasonic treatment for 18 min at an ultrasonic frequency of 6 kHz. Add hexamethylenetetramine thereto and continue ultrasonic treatment for 12 min. Let stand at a temperature of 73 °C for 100 min, filter, wash, and dry in vacuum to obtain hollow microsphere-loaded particles.

[0060] S3. Add hollow glass microspheres and hollow microsphere-loaded particles to the acrylate adhesive solution, stir at a speed of 150 r / min for 17 min, add the TMP-TDI adduct thereto and continue stirring for 80 min to obtain an adhesive mucus.

[0061] S4. Place the acrylic foaming substrate on the unwinding unit of a coater, coat the adhesive mucus on the surface of the acrylic foaming substrate with a coating thickness of 50 μm; bake at a temperature of 58 °C for 22 min to form an adhesive layer, adhere a PET release film to the outside of the adhesive layer, and cure at a temperature of 68 °C for 25 h.

[0062] Example 5

[0063] A foaming tape, comprising: an acrylic foaming substrate, an adhesive layer coated on the surface of the acrylic foaming substrate, and a PET release film adhered to the outside of the adhesive layer.

[0064] The raw materials of the adhesive layer include: 350 g of butyl methacrylate, 200 g of methyl acrylate, 100 g of vinyl acetate, 400 g of ethyl acetate, 80 g of methanol, 20 g of benzoyl peroxide, 100 g of 2-hydroxypropyl acrylate, 80 g of polystyrene microspheres, 150 g of tetraethyl orthosilicate, 30 g of dopamine hydrochloride, 5 g of hexamethylenetetramine, 80 g of hollow glass microspheres, and 30 g of TMP-TDI adduct.

[0065] The preparation method of the above-mentioned foaming tape comprises the following steps:

[0066] S1. Add butyl methacrylate, methyl acrylate, and vinyl acetate to ethyl acetate, stir evenly, add methanol thereto, perform ultrasonic treatment for 90 min at an ultrasonic frequency of 7.5 kHz, add 5 g of benzoyl peroxide thereto, stir at a temperature of 75 °C for 15 min, add 2-hydroxypropyl acrylate and 15 g of benzoyl peroxide thereto, stir at a temperature of 88 °C for 8 h, cool, and pass through a 200-mesh filter screen to obtain an acrylate glue solution;

[0067] S2. Add polystyrene microspheres to 800 g of an ethanol aqueous solution with a mass fraction of 50%, perform ultrasonic dispersion for 15 min at an ultrasonic frequency of 7.5 kHz, add tetraethyl orthosilicate thereto, add 80 g of saturated ammonia water, perform ultrasonic treatment for 90 min at a temperature of 45 °C and an ultrasonic frequency of 7.5 kHz, centrifuge, wash, dry in vacuum, send it into a muffle furnace, calcine at a temperature of 450 °C for 90 min, send it into 800 g of deionized water, add dopamine hydrochloride, perform ultrasonic treatment for 15 min at an ultrasonic frequency of 7.5 kHz, add hexamethylenetetramine thereto, continue ultrasonic treatment for 10 min, stand at a temperature of 75 °C for 90 min, filter, wash, and dry in vacuum to obtain hollow microsphere-loaded particles;

[0068] S3. Add hollow glass microspheres and hollow microsphere-loaded particles to the acrylate glue solution, stir at a speed of 200 r / min for 15 min, add TMP-TDI adduct thereto, and continue stirring for 90 min to obtain a glue mucus;

[0069] S4. Place the acrylic foaming substrate on the unwind unit of a coater, coat the glue mucus on the surface of the acrylic foaming substrate, with a coating thickness of 50 μm; bake at a temperature of 55 °C for 25 min to form an adhesive layer, adhere a PET release film to the outside of the adhesive layer, and cure at a temperature of 65 °C for 30 h.

[0070] Comparative Example 1

[0071] A foaming tape, comprising: an acrylic foaming substrate, an adhesive layer coated on the surface of the acrylic foaming substrate, and a PET release film adhered to the outside of the adhesive layer.

[0072] The raw materials of the adhesive layer include: 350 g of butyl methacrylate, 200 g of methyl acrylate, 100 g of vinyl acetate, 400 g of ethyl acetate, 80 g of methanol, 20 g of benzoyl peroxide, 100 g of 2-hydroxypropyl acrylate, 150 g of tetraethyl orthosilicate, 30 g of dopamine hydrochloride, 5 g of hexamethylenetetramine, 80 g of hollow glass microspheres, and 30 g of TMP-TDI adduct.

[0073] The preparation method of the above-mentioned foaming tape comprises the following steps:

[0074] S1. Add butyl methacrylate, methyl acrylate, and vinyl acetate to ethyl acetate, stir evenly, add methanol thereto, perform ultrasonic treatment for 90 min at an ultrasonic frequency of 7.5 kHz, add 5 g of benzoyl peroxide thereto, stir at a temperature of 75 °C for 15 min, add 2-hydroxypropyl acrylate and 15 g of benzoyl peroxide thereto, stir at a temperature of 88 °C for 8 h, cool, and pass through a 200-mesh filter screen to obtain an acrylate glue solution.

[0075] S2. Add tetraethyl orthosilicate to 800 g of an ethanol aqueous solution with a mass fraction of 50%, perform ultrasonic dispersion for 15 min at an ultrasonic frequency of 7.5 kHz, add 80 g of saturated ammonia water, perform ultrasonic treatment for 90 min at a temperature of 45 °C and an ultrasonic frequency of 7.5 kHz, centrifuge, wash, dry in vacuum, send it into a muffle furnace, calcine at a temperature of 450 °C for 90 min, send it into 800 g of deionized water, add dopamine hydrochloride, perform ultrasonic treatment for 15 min at an ultrasonic frequency of 7.5 kHz, add hexamethylenetetramine thereto, continue ultrasonic treatment for 10 min, stand at a temperature of 75 °C for 90 min, filter, wash, and dry in vacuum to obtain hollow microsphere-loaded particles.

[0076] S3. Add hollow glass microspheres and hollow microsphere-loaded particles to the acrylate glue solution, stir at a speed of 200 r / min for 15 min, add TMP-TDI adduct thereto, and continue stirring for 90 min to obtain a glue mucus.

[0077] S4. Place the acrylic foaming substrate on the unwinding unit of a coater, coat the glue mucus on the surface of the acrylic foaming substrate, with a coating thickness of 50 μm; bake at a temperature of 55 °C for 25 min to form an adhesive layer, adhere a PET release film to the outside of the adhesive layer, and cure at a temperature of 65 °C for 30 h.

[0078] Comparative Example 2

[0079] A foaming tape, comprising: an acrylic foaming substrate, an adhesive layer coated on the surface of the acrylic foaming substrate, and a PET release film adhered to the outside of the adhesive layer.

[0080] The raw materials of the adhesive layer include: 350 g of butyl methacrylate, 200 g of methyl acrylate, 100 g of vinyl acetate, 400 g of ethyl acetate, 80 g of methanol, 20 g of benzoyl peroxide, 100 g of 2-hydroxypropyl acrylate, 80 g of polystyrene microspheres, 150 g of tetraethyl orthosilicate, 80 g of hollow glass microspheres, and 30 g of TMP-TDI adduct.

[0081] The preparation method of the above-mentioned foaming tape comprises the following steps:

[0082] S1. Add butyl methacrylate, methyl acrylate, and vinyl acetate to ethyl acetate and stir evenly. Add methanol thereto and perform ultrasonic treatment for 90 min at an ultrasonic frequency of 7.5 kHz. Add 5 g of benzoyl peroxide thereto and stir at a temperature of 75 °C for 15 min. Add 2-hydroxypropyl acrylate and 15 g of benzoyl peroxide thereto and stir at a temperature of 88 °C for 8 h. Cool and pass through a 200-mesh filter screen to obtain an acrylate adhesive solution.

[0083] S2. Add polystyrene microspheres to 800 g of an ethanol aqueous solution with a mass fraction of 50% and perform ultrasonic dispersion for 15 min at an ultrasonic frequency of 7.5 kHz. Add tetraethyl orthosilicate thereto, add 80 g of saturated ammonia water, and perform ultrasonic treatment at a temperature of 45 °C for 90 min at an ultrasonic frequency of 7.5 kHz. Centrifuge, wash, dry in vacuum, send it into a muffle furnace, and calcine at a temperature of 450 °C for 90 min to obtain hollow microsphere-supported particles.

[0084] S3. Add hollow glass microspheres and hollow microsphere-supported particles to the acrylate adhesive solution, stir at a speed of 200 r / min for 15 min, add the TMP-TDI adduct thereto and continue stirring for 90 min to obtain an adhesive mucus.

[0085] S4. Place the acrylic foaming substrate on the unwind unit of a coater, coat the adhesive mucus on the surface of the acrylic foaming substrate with a coating thickness of 50 μm; bake at a temperature of 55 °C for 25 min to form an adhesive layer, adhere a PET release film to the outside of the adhesive layer, and cure at a temperature of 65 °C for 30 h.

[0086] Refer to GB / T 31125-2014 "Test Method for Initial Adhesion of Adhesive Tapes - Ring Method" to test the initial adhesion of the foaming tapes obtained in Example 5 and Comparative Examples 1-2.

[0087] Refer to GB / T 4851-2014 "Test Method for Holding Power of Adhesive Tapes" to test the holding power of the foaming tapes obtained in Example 5 and Comparative Examples 1-2.

[0088] As Figure 1 shown, the initial tack and holding tack of the foamed tape obtained in Example 5 were both the highest, superior to those of Comparative Examples 1-2 (P < 0.05).

[0089] The foamed tapes obtained in Example 5 and Comparative Examples 1-2 were pasted onto a stainless steel plate with a flat surface and gently finger-pressed; the standard test roller was rolled back and forth on each specimen 5 times at a speed of about 10 mm / min to promote full contact between the specimen and the surface of the stainless steel plate. After standing for 20 min, the specimen and the stainless steel plate were fixed on the testing machine with a peeling angle of 180°; the separation speed of the testing machine fixture was set to 5 - 500 mm / min. During the test, a reading was taken every 10 mm at the middle part of each spline, and at least 5 readings were taken. The average value of the five numbers was the peeling force of the specimen.

[0090] Acrylic foamed substrates of the same specification were baked at 55 °C for 25 min and then cured at 65 °C for 30 h as the blank group. After standing for 24 h, they were weighed, then completely immersed in water for 48 h, taken out, drained, and weighed; the foamed tapes obtained in Example 5 and Comparative Examples 1-2 were pasted onto a stainless steel plate with a flat surface and gently finger-pressed; the standard test roller was rolled back and forth on each specimen 5 times at a speed of about 10 mm / min to promote full contact between the specimen and the surface of the stainless steel plate. After standing for 24 h, they were weighed, then completely immersed in water for 48 h, taken out, drained, and weighed to calculate the water absorption rate of the adhesive layer.

[0091] Water absorption rate of the adhesive layer = (mass of each group after water absorption - mass of each group before water absorption - mass of the blank group after water absorption + mass of the blank group before water absorption) ÷ (mass of each group before water absorption - mass of the blank group before water absorption - mass of the stainless steel plate) × 100%

[0092] As Figure 2 shown, the peeling tack of the foamed tape obtained in Example 5 was higher than that of Comparative Examples 1-2 (P < 0.05), while the water absorption rate of the adhesive layer of the foamed tape obtained in Example 5 was lower than that of Comparative Examples 1-2 (P < 0.05).

[0093] The foamed tapes obtained in Example 5 and Comparative Examples 1-2 were aged in an environment of 110 °C and 80% RH for 72 h, and then the holding tack of the aged foamed tapes of each group was tested again with reference to GB / T 4851-2014 "Test Method for Holding Tack of Adhesive Tapes".

[0094] After aging the foamed tapes obtained in Example 5 and Comparative Examples 1-2 in an environment of 110°C and 80% RH for 30 days, they were pasted onto a stainless steel plate with a flat surface and gently pressed with fingers; a standard test roller was rolled back and forth on each specimen 5 times at a speed of about 10 mm / min to promote complete contact between the specimen and the surface of the stainless steel plate. After 20 min, the foamed tapes of each group were peeled off, and the area of the region with residual glue on the surface of the stainless steel plate was counted, and the percentage of the residual glue area in the total pasted area was calculated.

[0095] As Figure 3 shown, the foamed tape obtained in Example 5 still had higher tackiness than Comparative Examples 1-2 (P < 0.05) after heat aging, and the residual glue area was the smallest, being superior to Comparative Examples 1-2 (P < 0.05).

[0096] The applicant believes that this is because the present invention uses an acrylate adhesive solution in combination with hollow glass microspheres and loaded hollow microspheres. After cross-linking, this special structure endows the tape with overall viscoelasticity, does not cause stress concentration, and effectively bonds with the substrate. The hollow glass microspheres and loaded hollow microspheres have a closed-cell structure and excellent air and water barrier properties, and excellent waterproof performance. At the same time, the present invention uses polystyrene microspheres as a template, deposits a layer of silica shell on its surface, forms hollow microspheres through calcination, and further combines a layer of polydopamine organic layer on its surface, which can not only ensure the sealing effect of the microspheres but also ensure the dispersibility in the acrylate adhesive solution. Even after heat aging, it still maintains excellent tackiness, and at the same time, there is less residual glue when peeled off after aging.

[0097] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A foam tape, characterized in that: It includes: an acrylic foam substrate, an adhesive layer coated on the surface of the acrylic foam substrate, and a release film attached to the outside of the adhesive layer; The raw materials of the adhesive layer include, by mass, 20-50 parts of butyl methacrylate, 10-30 parts of methyl acrylate, 5-15 parts of vinyl acetate, 20-60 parts of ethyl acetate, 5-10 parts of methanol, 1.1-3 parts of benzoyl peroxide, 5-15 parts of 2-hydroxypropyl acrylate, 5-10 parts of polystyrene microspheres, 10-20 parts of tetraethyl orthosilicate, 1-5 parts of dopamine hydrochloride, 0.1-1 parts of hexamethylenetetramine, 5-10 parts of hollow glass microspheres, and 1-5 parts of a cross-linking agent.

2. The foam tape according to claim 1, characterized in that: The thickness of the acrylic foam substrate is 50-150μm and the density is 0.5-0.65g / cm 3 .

3. The foam tape according to claim 1, characterized in that: The particle size of polystyrene microspheres is 40-100 μm.

4. The foam tape according to claim 1, characterized in that: The crosslinking agent is toluene diisocyanate-trimethylolpropane adduct.

5. A method for preparing a foam tape as claimed in any one of claims 1 to 4, characterized in that: The steps include: S1. Add butyl methacrylate, methyl acrylate and vinyl acetate to ethyl acetate and stir evenly, add methanol thereto and ultrasonicate for 1-2h, add benzoyl peroxide thereto, stir at 70-80°C for 10-20min, add 2-hydroxypropyl acrylate and benzoyl peroxide thereto, stir at 85-92°C for 5-10h, cool, and filter to obtain acrylate glue; S2, adding polystyrene microspheres to ethanol aqueous solution and ultrasonically dispersing for 10-20 minutes, adding tetraethyl orthosilicate thereto, adding saturated ammonia water, ultrasonically treating at 40-50° C. for 1-2 hours, centrifuging, washing, vacuum drying, calcining at 400-500° C. for 1-2 hours, sending to water, adding dopamine hydrochloride and ultrasonically treating for 10-20 minutes, adding hexamethylenetetramine thereto and ultrasonically treating for 5-15 minutes, standing at 70-80° C. for 1-2 hours, filtering, washing, and vacuum drying to obtain loaded hollow microspheres; S3, adding the hollow glass microspheres and the loaded hollow microspheres to the acrylic adhesive solution and stirring for 10-20 minutes, adding a crosslinking agent and continuing to stir for 1-2 hours to obtain an adhesive solution; S4. Apply adhesive liquid to the surface of the acrylic foam substrate, bake at 50-60°C for 20-30 minutes to form an adhesive layer, and attach a release film to the outside of the adhesive layer and mature it.

6. The method for preparing the foam tape according to claim 5, characterized in that: In S1, the ultrasound frequency is 5-12kHz.

7. The method for preparing the foam tape according to claim 5, characterized in that: In S1, the mass ratio of the benzoyl peroxide added after ultrasonic treatment to the benzoyl peroxide added after stirring at 70-80°C is 0.1-1:1-2.

8. The method for preparing the foam tape according to claim 5, characterized in that: In S2, the frequency of ultrasonic dispersion is 5-12 kHz.

9. The method for preparing the foam tape according to claim 5, characterized in that: In S2, the frequency of ultrasonic treatment was 5-12 kHz.

10. The method for preparing the foam tape according to claim 5, characterized in that: In S4, the aging temperature is 60-70°C and the aging time is 20-40h.

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