Thermal viscosity-reducing adhesive, thermal viscosity-reducing adhesive tape and preparation method of thermal viscosity-reducing adhesive tape

Abstract

The invention discloses a thermal viscosity-reducing adhesive, a thermal viscosity-reducing adhesive tape and a preparation method of the thermal viscosity-reducing adhesive tape. The soft monomer is composed of one or more of isononyl acrylate, heptyl acrylate, polycaprolactone acrylate, polyethylene oxide-based acrylate, siloxane modified acrylate, vinyl octanoate and isododecyl acrylate; the hard monomer is prepared from one or more of dicyclopentadiene acrylic ester, poly (p-phenylene terephthamide), hexafluoropropylene oxide and polyaryletherketone; the functional monomer is composed of one or more of epoxy propyl acrylate, sulfo acrylate, mercapto acrylate and methoxyl acrylate. According to the scheme, by optimizing the ratio of the soft monomer to the hard monomer, the stripping force of the adhesive can be accurately controlled under the high-temperature process condition, so that the stable bonding force is kept, excessive stripping or bonding strength reduction is avoided, and the stripping requirement after the high-temperature process is met.

Description

Technical Field

[0001] The invention relates to the field of heat-reducing adhesive tapes, in particular to a heat-reducing adhesive, a heat-reducing adhesive tape and a preparation method thereof. Background Art

[0002] According to the need to use tape to fix the raw materials in the processing of some products for processing, and the product needs to be easily removed after the processing is completed without affecting the product quality. For example, in the processing of semiconductor chips, the wafer material needs to be bonded and fixed to protect it during cutting and grinding; after the processing is completed, the wafer slices need to be easily and completely removed from the fixed position without affecting the wafer itself. At the same time, when processing tiny components such as plastic parts, glass, metal plates, etc., it is usually necessary to use tape to fix them to avoid damage caused by the movement of components during the cutting process. This kind of tape used for fixing can provide good bonding strength at room temperature, and can be easily removed when the processing is completed, without causing damage to the processed parts. The prior art generally uses a low-viscosity double-sided tape for processing. The tape maintains high viscosity during fixing to ensure that the object is fixed firmly. After the processing is completed, the adhesiveness of the tape is reduced by heating or UV, so that the fixed object can be easily removed.

[0003] Based on the above problems, someone invented a reversible heat-reducing pressure-sensitive adhesive, a double-sided tape and a preparation method thereof. The Chinese invention patent No. 2023118060716 is used to solve the above problems. After testing, the solution has the following defects:

[0004] 1. The adhesive implemented in the above scheme cannot achieve precise control of the peeling force under high temperature process conditions, so the stability of the adhesion is poor, resulting in excessive peeling or decreased bonding strength.

[0005] 2. It is not peeled cleanly under high temperature conditions, resulting in adhesive residue, which cannot ensure the cleanliness of the surface of the workpiece and affects the subsequent process treatment. Summary of the invention

[0006] The purpose of this application is to provide a technical solution to solve the problems raised in the above background technology.

[0007] To achieve the above objectives, this application provides the following technical solutions:

[0008] A heat-reducing adhesive, comprising, by weight:

[0009]

[0010] The soft monomer is one or more of isononyl acrylate, heptyl acrylate, polycaprolactone acrylate, polyethylene oxide acrylate, silicone modified acrylate, vinyl octanoate, and isododecyl acrylate;

[0011] The hard monomer is one or more of dicyclopentadienyl acrylate, poly(p-phenylene terephthalamide), hexafluoropropylene oxide, and poly(aryletherketone);

[0012] The functional monomer is composed of one or more of epoxypropyl acrylate, sulfonic acid acrylate, mercapto acrylate and methoxy acrylate.

[0013] Preferably, the initial expansion temperature of the thermosensitive expandable microspheres is 85-105 degrees, the maximum expansion temperature is 120-140 degrees, the expansion particle size is 10-35um, and the expansion ratio is 2-6 times.

[0014] Preferably, the curing agent is one or more of antelope acrylate-terminated isocyanate, fluorinated isocyanate, vinyl polysiloxane, polyether-terminated isocyanate, epoxyaziridine, cyanate curing agent, carbene crosslinking agent, thiol acrylate crosslinking agent, polyurea crosslinking agent, and bifunctional polyamide curing agent.

[0015] Preferably, the solvent is one or more of methylcyclohexane, butyl glycol ether, methyl propylene glycol ether, tert-butyl alcohol, trifluoroethanol, isobutyl alcohol, isoamyl acetate, diethylene glycol ethyl ether acetate, cyclohexanone, and diisopropyl ether.

[0016] A method for preparing a heat-reducing adhesive comprises the following steps:

[0017] In a reaction kettle, add 40-60 parts of soft monomer, 20-40 parts of hard monomer, 5-10 parts of functional monomer and 50-150 parts of solvent in sequence, stir evenly, then add 0.5-2 parts of curing agent and continue to stir evenly to form a prepolymer; the reaction time at this time is 6-15 hours, and the reaction temperature is 80-100 degrees; after stirring, cool to 50-60 degrees, add 3-10 parts of thermosensitive expandable microspheres, stir evenly, and vacuum degassing to obtain a heat-reducing viscosity adhesive.

[0018] A heat-reducing adhesive tape comprises a substrate layer, an adhesive layer and a release layer stacked in sequence, wherein the adhesive layer is formed by thermally curing the heat-reducing adhesive described in any one of claims 1 to 4.

[0019] A method for preparing a heat-reducing adhesive tape comprises the following steps: coating a layer of heat-reducing adhesive on the surface of a substrate layer with a coating thickness of 20-80 microns, and obtaining the heat-reducing adhesive tape after thermal curing.

[0020] Preferably, the substrate layer is a polyester film.

[0021] In summary, the technical effects and advantages of the present invention are as follows:

[0022] 1. This scheme optimizes the ratio of soft monomers to hard monomers to achieve adhesives that can precisely control peeling force under high-temperature process conditions, thereby maintaining stable bonding force, avoiding excessive peeling or decreased bonding strength, and meeting the peeling requirements after high-temperature processes.

[0023] 2. The combination of the curing agent and the monomer in this solution can ensure clean peeling at high temperature, avoid adhesive residue, and ensure the surface of the workpiece is clean without affecting subsequent process treatment.

[0024] 3. The adhesive achieved by this solution through the ratio of soft monomers and hard monomers ensures high flexibility and high transparency while maintaining high-temperature peeling performance. It is suitable for applications such as folding screens and optical protective films, and can still maintain good optical properties and bending tolerance under high temperature conditions.

[0025] 4. This solution uses low-VOC solvents such as methyl cyclohexane, isoamyl acetate and environmentally friendly curing agents, which can reduce the emission of harmful gases in high-temperature processes and improve the environmental protection and safety of the production process. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Embodiment 1:

[0028] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0029] Soft monomer: 50 parts of isononyl acrylate,

[0030] Hard monomer: 30 parts of dicyclopentadienyl acrylate,

[0031] Functional monomer: 7 parts of epoxypropane acrylate,

[0032] Curing agent: 1.5 parts of hydroxy acrylate-terminated isocyanate,

[0033] Solvent: 100 parts of methylcyclohexane,

[0034] Thermal expandable microspheres: 5 parts.

[0035] Preparation method:

[0036] (1) In a light-shielded reactor, first add the following in order by weight:

[0037] 50 parts of isononyl acrylate (Evonik Industries), 30 parts of dicyclopentadienyl acrylate (Sigma-Aldrich). Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0038] (2) After ultrasonic dispersion, add by weight:

[0039] 7 parts of epoxypropane acrylate (BASF), continue stirring for 5-10 minutes, keep the speed at 500-800rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30℃.

[0040] (3) Add by weight:

[0041] 100 parts of methylcyclohexane (Tokyo Chemical Industry TCI Chemicals), 1.5 parts of hydroxy acrylate-terminated isocyanate (Covestro), continue stirring, keep the speed at 500-800rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and the temperature is controlled at 25-30℃.

[0042] (4) Add by weight:

[0043] 5 parts of thermosensitive expandable microspheres (AkzoNobel) were stirred evenly, the speed was set to 300-500 rpm, the time was 10-20 minutes, and the expandable microspheres were ensured to be fully mixed with the base material, and the temperature was maintained at 25-30°C.

[0044] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0045] Embodiment 2:

[0046] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0047] Soft monomer: 45 parts of heptyl acrylate,

[0048] Hard monomer: 35 parts of poly(p-phenylene terephthalamide),

[0049] Functional monomer: 6 parts of sulfate acrylate,

[0050] Curing agent: 1.8 parts of polyether blocked isocyanate,

[0051] Solvent: 90 parts of tert-butyl alcohol,

[0052] Thermosensitive expandable microspheres: 4.5 parts.

[0053] Preparation method:

[0054] (1) In a light-shielded reactor, first add 45 parts of heptyl acrylate (Evonik) and 35 parts of poly(p-phenylene terephthalamide) (Sigma-Aldrich) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0055] (2) After ultrasonic dispersion, add 6 parts of sulfated acrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the rotation speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0056] (3) Add 90 parts of tert-butyl alcohol (Eastman Chemical) and 1.8 parts of polyether blocked isocyanate (Covestro) by weight, continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30°C.

[0057] (4) Add 4.5 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres are fully mixed with the base material. Keep the temperature at 25-30°C.

[0058] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0059] Embodiment 3:

[0060] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0061] Soft monomer: 50 parts of polycaprolactone acrylate,

[0062] Hard monomer: 30 parts of polyether aryl ketone,

[0063] Functional monomer: 8 parts of sulfonic acid acrylate,

[0064] Curing agent: 1.5 parts of cyanate curing agent,

[0065] Solvent: 110 parts of propylene glycol methyl ether acetate,

[0066] Thermal expandable microspheres: 6 parts.

[0067] Preparation method:

[0068] (1) In a light-shielded reactor, first add 50 parts of polycaprolactone acrylate (Evonik) and 30 parts of polyether aryl ketone (Dow Chemical) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0069] (2) After ultrasonic dispersion, add 8 parts of sulfonic acid acrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0070] (3) Add by weight: 110 parts of propylene glycol methyl ether acetate (Eastman Chemical) and 1.5 parts of cyanate curing agent (Bayer), continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30°C.

[0071] (4) Add 6 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres and the base material are fully mixed. Keep the temperature at 25-30°C.

[0072] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0073] Embodiment 4:

[0074] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0075] Soft monomer: 50 parts of vinyl octanoate,

[0076] Hard monomer: 35 parts of dicyclopentadienyl acrylate,

[0077] Functional monomer: 6 parts of methoxyacrylate,

[0078] Curing agent: 1.5 parts of epoxyaziridine,

[0079] Solvent: 90 parts of cyclohexanone,

[0080] Thermal expansion microspheres: 5.5 parts

[0081] Preparation method:

[0082] (1) In a light-shielded reactor, first add 50 parts of vinyl octanoate (Evonik) and 35 parts of dicyclopentadienyl acrylate (Sigma-Aldrich) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0083] (2) After ultrasonic dispersion, add 6 parts of methoxyacrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0084] (3) Add by weight: 90 parts of cyclohexanone (TCI Chemicals, Tokyo Chemical Industry) and 1.5 parts of epoxyaziridine (Bayer), continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30°C.

[0085] (4) Add 5.5 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres are fully mixed with the base material. Keep the temperature at 25-30°C.

[0086] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0087] Embodiment 5:

[0088] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0089] Soft monomer: 45 parts of isododecyl acrylate,

[0090] Hard monomer: 30 parts of hexafluoropropylene oxide,

[0091] Functional monomer: 8 parts of mercapto acrylate,

[0092] Curing agent: 1.2 parts of fluorinated isocyanate,

[0093] Solvent: 100 parts of ethyl acetate,

[0094] Thermosensitive expandable microspheres: 4.8 parts.

[0095] Preparation method:

[0096] (1) In a light-shielded reactor, first add 45 parts of isododecyl acrylate (Evonik) and 30 parts of hexafluoropropylene oxide (Arkema) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0097] (2) After ultrasonic dispersion, add 8 parts of mercapto acrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0098] (3) Add by weight: 100 parts of ethyl acetate (Eastman Chemical) and 1.2 parts of fluorinated isocyanate (Covestro), continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30°C.

[0099] (4) Add 4.8 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres and the base material are fully mixed. Keep the temperature at 25-30°C.

[0100] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0101] Embodiment 6:

[0102] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0103] Soft monomer: 50 parts of siloxane-modified acrylate,

[0104] Hard monomer: 30 parts of hexafluoropropylene oxide,

[0105] Functional monomer: 7 parts of epoxypropane acrylate,

[0106] Curing agent: 1.5 parts of hydroxy acrylate-terminated isocyanate,

[0107] Solvent: 110 parts of ethyl acetate,

[0108] Thermal expandable microspheres: 5 parts.

[0109] Preparation method:

[0110] (1) In a light-shielded reactor, first add 50 parts of siloxane-modified acrylate (Evonik) and 30 parts of hexafluoropropylene oxide (DuPont) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0111] (2) After ultrasonic dispersion, add 7 parts of epoxypropane acrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0112] (3) Add by weight: 110 parts of ethyl acetate (Eastman Chemical) and 1.5 parts of hydroxy acrylate-terminated isocyanate (Covestro), continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is properly adjusted, and control the temperature at 25-30°C.

[0113] (4) Add 5 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres are fully mixed with the base material. Keep the temperature at 25-30°C.

[0114] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0115] Embodiment 7:

[0116] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0117] Soft monomer: 48 parts of isononyl acrylate,

[0118] Hard monomer: 32 parts of dicyclopentadienyl acrylate,

[0119] Functional monomer: 8 parts of sulfonic acid acrylate,

[0120] Curing agent: 1.5 parts of polyether blocked isocyanate,

[0121] Solvent: 90 parts of diethylene glycol ethyl ether acetate,

[0122] Thermal expandable microspheres: 6 parts.

[0123] Preparation method:

[0124] (1) In a light-shielded reactor, add 48 parts of isononyl acrylate (Evonik) and 32 parts of dicyclopentadienyl acrylate (Sigma-Aldrich) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0125] (2) After ultrasonic dispersion, add 8 parts of sulfonic acid acrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0126] (3) Add by weight: 90 parts of diethylene glycol ethyl ether acetate (Eastman Chemical) and 1.5 parts of polyether blocked isocyanate (Covestro), continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30°C.

[0127] (4) Add 6 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres and the base material are fully mixed. Keep the temperature at 25-30°C.

[0128] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0129] Embodiment 8:

[0130] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0131] Soft monomer: 45 parts of vinyl octanoate,

[0132] Hard monomer: 35 parts of polycaprolactone acrylate,

[0133] Functional monomer: 7 parts of methoxyacrylate,

[0134] Curing agent: 1.5 parts of bifunctional polyamide curing agent,

[0135] Solvent: 95 parts of isoamyl acetate,

[0136] Thermal expansion microspheres: 5 parts

[0137] Preparation method:

[0138] (1) In a light-shielded reactor, add 45 parts of vinyl octanoate (Evonik) and 35 parts of polycaprolactone acrylate (Arkema) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0139] (2) After ultrasonic dispersion, add 7 parts of methoxyacrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0140] (3) Add by weight: 95 parts of isoamyl acetate (Eastman Chemical) and 1.5 parts of difunctional polyamide curing agent (Huntsman), continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is reasonably adjusted, and control the temperature at 25-30°C.

[0141] (4) Add 5 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres are fully mixed with the base material. Keep the temperature at 25-30°C.

[0142] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0143] Embodiment 9:

[0144] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0145] Soft monomer: 50 parts of isododecyl acrylate,

[0146] Hard monomer: 25 parts of dicyclopentadienyl acrylate,

[0147] Functional monomer: 10 parts of sulfonic acid acrylate,

[0148] Curing agent: 1.2 parts of hydroxy acrylate-terminated isocyanate,

[0149] Solvent: 120 parts of isopropanol,

[0150] Thermosensitive expandable microspheres: 4.5 parts.

[0151] Preparation method:

[0152] (1) In a light-shielded reactor, add 50 parts of isododecyl acrylate (Evonik) and 25 parts of dicyclopentadienyl acrylate (Sigma-Aldrich) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0153] (2) After ultrasonic dispersion, add 10 parts of sulfonic acid acrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0154] (3) Add by weight: 120 parts of isopropyl alcohol (Eastman Chemical) and 1.2 parts of hydroxy acrylate-terminated isocyanate (Covestro), continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is properly adjusted, and control the temperature at 25-30°C.

[0155] (4) Add 4.5 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres are fully mixed with the base material. Keep the temperature at 25-30°C.

[0156] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0157] Embodiment 10:

[0158] A heat-reducing adhesive is prepared from the following raw materials in parts by weight:

[0159] Soft monomer: 55 parts of isononyl acrylate,

[0160] Hard monomer: 25 parts of dicyclopentadienyl acrylate,

[0161] Functional monomer: 6 parts of methoxyacrylate,

[0162] Curing agent: 1.7 parts of hydroxy acrylate-terminated isocyanate,

[0163] Solvent: 110 parts of propylene glycol methyl ether acetate,

[0164] Thermal expandable microspheres: 5 parts.

[0165] Preparation method:

[0166] (1) In a light-shielded reactor, add 55 parts of isononyl acrylate (Evonik) and 25 parts of dicyclopentadienyl acrylate (Sigma-Aldrich) in order by weight. Ultrasonic dispersion and stirring are performed uniformly, the speed is set to 800-1200 rpm, the time is set to 10-20 minutes, and the temperature is controlled at 25-30°C. The viscosity is measured by a rotational viscometer to ensure the initial dispersion effect.

[0167] (2) After ultrasonic dispersion, add 6 parts of methoxyacrylate (BASF) by weight, continue stirring for 5-10 minutes, keep the speed at 500-800 rpm, ensure that the functional monomer is fully mixed with other components, and keep the temperature at 25-30°C.

[0168] (3) Add by weight: 110 parts of propylene glycol methyl ether acetate (Eastman Chemical) and 1.7 parts of hydroxy acrylate-terminated isocyanate (Covestro), continue stirring, keep the speed at 500-800 rpm, set the time to 5-10 minutes, ensure that the viscosity is properly adjusted, and control the temperature at 25-30°C.

[0169] (4) Add 5 parts of thermosensitive expandable microspheres (AkzoNobel) by weight, stir evenly, set the speed to 300-500 rpm, and stir for 10-20 minutes to ensure that the expandable microspheres are fully mixed with the base material. Keep the temperature at 25-30°C.

[0170] (5) After all stirring and mixing steps are completed, vacuum degassing is performed to ensure that the bubbles in the glue are completely discharged. Finally, the material is discharged to obtain a heat-reduced viscosity adhesive.

[0171] Test method: According to the test method of GB / T 2792-2014_Peel strength of adhesive tape, the peel strength of the test adhesive tape was tested before and after being attached to a standard stainless steel plate and heated at 180°C for 1 hour. The thermal growth rate was calculated according to the following formula: Thermal growth rate of adhesive tape = (peel strength after heating at 180°C - peel strength before heating at 180°C) * 100% / peel strength before heating at 180°C. The test results are shown in Table 1 below:

[0172] Example Peel strength before heating at 180℃(N / 25mm) Peel strength after heating at 180℃(N / 25mm) Thermal growth rate (%) 1 2.4 2.88 20％ 2 2.52 3.28 30.16％ 3 2.44 3.05 25％ 4 2.36 2.77 17.37％ 5 2.48 3.22 29.84％ 6 2.60 3.64 40％ 7 2.56 3.2 25％ 8 2.46 2.95 19.92％ 9 2.42 2.9 19.83％ 10 2.50 3.50 40％

[0173] The above-listed heat-reducing adhesive is coated and cured to form a film to obtain a heat-reducing adhesive tape, which is placed in an oven at 85°C and taken out for observation after 48 hours. Its properties are shown in Table 2:

[0174] Example Viscosity test (g) Peel force test (N / 25mm) transparency(%) Flexibility (folding times) Observations 1 820 2.78 92 5000 No significant changes 2 850 3.20 90 4800 Slightly discolored 3 830 3.05 91 5100 No significant changes 4 810 2.67 93 5300 Slightly bubbling 5 840 3.10 89 4700 Slight yellowing 6 880 3.64 88 4500 No significant changes 7 860 3.15 90 4900 Slightly warped edge 8 830 2.95 91 5200 No significant changes 9 810 2.85 92 5050 Slightly bubbling 10 850 3.50 89 4600 No significant changes

[0175] The adhesion test standard is GB / T 4852-2002 (test method for initial adhesion of pressure-sensitive adhesive tapes).

[0176] The peel force test standard is GB / T 2792-2014 (test method for 180° peel strength of pressure-sensitive adhesive tape).

[0177] The transparency test standard is ASTM D1003-2013 (Test method for light transmittance and haze of plastics).

[0178] The flexibility test standard is GB / T 7125-2014 (Adhesive tape flexibility test standard).

[0179] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A heat-reducing adhesive, characterized in that: In parts by weight: The soft monomer is one or more of isononyl acrylate, heptyl acrylate, polycaprolactone acrylate, polyethylene oxide acrylate, silicone modified acrylate, vinyl octanoate, and isododecyl acrylate; The hard monomer is one or more of dicyclopentadienyl acrylate, poly(p-phenylene terephthalamide), hexafluoropropylene oxide, and poly(aryletherketone); The functional monomer is composed of one or more of epoxypropyl acrylate, sulfonic acid acrylate, mercapto acrylate and methoxy acrylate.

2. The heat-reducing adhesive according to claim 1, characterized in that: The initial expansion temperature of the thermosensitive expandable microspheres is 85-105 degrees, the maximum expansion temperature is 120-140 degrees, the expansion particle size is 10-35um, and the expansion ratio is 2-6 times.

3. The heat-reducing adhesive according to claim 1, characterized in that: The curing agent is one or more of antelope acrylate-terminated isocyanate, fluorinated isocyanate, vinyl polysiloxane, polyether-terminated isocyanate, epoxyaziridine, cyanate curing agent, carbene crosslinking agent, thiol acrylate crosslinking agent, polyurea crosslinking agent, and bifunctional polyamide curing agent.

4. The heat-reducing adhesive according to claim 1, characterized in that: The solvent is one or more of methylcyclohexane, butyl glycol ether, methyl propylene glycol ether, tert-butyl alcohol, trifluoroethanol, isobutyl alcohol, isoamyl acetate, diethylene glycol ethyl ether acetate, cyclohexanone and diisopropyl ether.

5. A method for preparing a heat-reducing adhesive according to claims 1-4, characterized in that: The steps include: In a reaction kettle, add 40-60 parts of soft monomer, 20-40 parts of hard monomer, 5-10 parts of functional monomer and 50-150 parts of solvent in sequence, stir evenly, then add 0.5-2 parts of curing agent and continue to stir evenly to form a prepolymer; the reaction time at this time is 6-15 hours, and the reaction temperature is 80-100 degrees; after stirring, cool to 50-60 degrees, add 3-10 parts of thermosensitive expandable microspheres, stir evenly, and vacuum degassing to obtain a heat-reducing viscosity adhesive.

6. A heat-reducing adhesive tape, characterized in that: The invention comprises a substrate layer, an adhesive layer and a release layer which are stacked in sequence, wherein the adhesive layer is formed by thermally curing the heat-reducing adhesive as described in any one of claims 1 to 4.

7. A method for preparing a heat-reducing adhesive tape according to claim 6, characterized in that: The method comprises the following steps: coating a layer of heat-reducing adhesive on the surface of the substrate layer with a coating thickness of 20-80 microns, and obtaining the heat-reducing adhesive tape after heat curing.

8. The heat-reducing adhesive tape according to claim 6, characterized in that: The substrate layer is a polyester film.

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