Supporting and protecting adhesive tape for four-curved-surface display screen and preparation method of supporting and protecting adhesive tape

Abstract

The invention discloses a supporting and protecting adhesive tape for a four-curved-surface display screen and a preparation method of the supporting and protecting adhesive tape. The supporting and protecting adhesive tape comprises a first base material PET (Polyethylene Terephthalate) film layer, an antistatic acrylic acid pressure-sensitive adhesive layer, a second base material PET film layer, a thermosetting base material layer, an acrylic acid pressure-sensitive adhesive layer and a double-sided antistatic PET release film layer which are sequentially laminated. The thermosetting base material layer is arranged in the supporting and protecting adhesive tape, and room-temperature reaction type isocyanate and saturated polyester resin react to form a cross-linked net-shaped structure to a certain degree, so that the risk of glue overflow in the hot pressing process can be avoided; the high-temperature deblocking isocyanate reacts with the saturated polyester resin in the deblocking process to form thermosetting net-shaped macromolecules, good shaping performance is achieved, the problem of stress concentration of the display module and the four-curved-surface glass cover plate is greatly solved, the problems of bubbles or wrinkles and the like in the attaching process are avoided, and the service life of the display module and the four-curved-surface glass cover plate is prolonged. And the problems of softening and repeated plasticizing of the mobile phone in the heating process can be avoided.

Description

Technical Field

[0001] The invention relates to the field of supporting and protecting adhesive tapes for display screens, and in particular to a supporting and protecting adhesive tape for a four-curved display screen and a preparation method thereof. Background Art

[0002] With the continuous development of display technology, personal wearables, 3D curved mobile phones and other electronic products, flexible OLED displays are becoming more and more widely used. At present, the manufacturing process of flexible OLED displays is to form a layer of PI film polymer flexible substrate on a rigid substrate glass substrate, prepare electrodes and light-emitting layers on the flexible substrate, and after completion, separate the rigid substrate from the flexible substrate, and finally attach the PET substrate support protective film tape on the other side of the flexible substrate.

[0003] The four-curved display is based on the double-sided curved screen, with curved design on the top and bottom, which makes the four-curved mobile phone have a large screen-to-body ratio and greatly optimizes the visual experience. However, during the hot pressing process of ordinary PET substrate supporting protective film tape, due to the 3D curved design of the four corners of the four sides, there may be folds or stress concentration points at the corners, which may easily cause problems such as bubbles and wrinkles.

[0004] Therefore, there is an urgent need to develop a supporting protective tape for four-curved display screens to solve the problem of stress concentration points generated after hot pressing of the corners, resulting in defects such as bubbles or wrinkles. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a supporting protective tape for a four-curved display screen and a preparation method thereof. A thermosetting substrate layer is arranged in the supporting protective tape, which has plasticity when heated and is fixed by a cross-linking reaction after heating, thereby greatly reducing the stress concentration problem between the display module and the four-curved glass cover plate, thereby avoiding problems such as bubbles or wrinkles during the bonding process.

[0006] In order to solve the above technical problems, the present invention provides a supporting protective tape for a four-curved display screen, comprising a first substrate PET film layer, an antistatic acrylic pressure-sensitive adhesive layer, a second substrate PET film layer, a thermosetting substrate layer, an acrylic pressure-sensitive adhesive layer and a double-sided antistatic PET release film layer stacked in sequence.

[0007] The present invention sets a thermosetting substrate layer in the supporting protective tape. The thermosetting substrate layer is plastic when heated and can be cross-linked and shaped after heating, which greatly reduces the stress concentration problem between the display module and the four-curved glass cover plate, thereby avoiding problems such as bubbles or wrinkles during the bonding process. In addition, the thermosetting substrate layer can also prevent problems such as softening and repeated plasticization of the mobile phone during the heating process.

[0008] Furthermore, the components of the thermosetting substrate layer include saturated polyester resin, room temperature reactive isocyanate and high temperature deblocking isocyanate.

[0009] Furthermore, the thermosetting substrate layer comprises the following components in parts by weight: 50-90 parts of saturated polyester resin A, 10-50 parts of saturated polyester resin B, 1-9 parts of room temperature reactive isocyanate, and 1-9 parts of high temperature deblocking isocyanate.

[0010] Specifically, the weight proportion of the saturated polyester resin A may be 50 parts, 60 parts, 70 parts, 80 parts, 90 parts, etc.

[0011] Specifically, the weight proportion of the saturated polyester resin B may be 10 parts, 20 parts, 30 parts, 40 parts, 50 parts, etc.

[0012] Specifically, the weight parts of the room temperature reactive isocyanate can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, etc. Preferably, the weight parts of the room temperature reactive isocyanate are 4-6 parts, such as 4 parts, 5 parts, 6 parts.

[0013] Specifically, the weight parts of the high temperature deblocking type isocyanate can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, etc. Preferably, the weight parts of the high temperature deblocking type isocyanate is 4-6 parts, such as 4 parts, 5 parts, 6 parts.

[0014] The saturated polyester resin A has a glass transition temperature (Tg) of 48-100°C, such as Toyobo GK360, with a Tg point of about 52°C. The saturated polyester resin B has a glass transition temperature of 0-47°C, such as Toyobo GK780, with a Tg point of about 36°C.

[0015] The thermosetting substrate layer of the present invention adopts saturated polyester resin, room temperature reactive isocyanate, and high temperature unblocking isocyanate, wherein the saturated polyester resin has excellent adhesion to the PET film, thereby avoiding the phenomenon of separation of the PET film and the thermosetting substrate layer during the film tearing process; saturated polyester resins with different Tg points are selected to control the hardness and softness of the material. If the Tg is too high, the material will have high hardness, low high temperature flow and filling properties, and will not be easy to fit; if the Tg is too low, the material will be too soft and will have weak support and protection for the OLED screen; the room temperature reactive isocyanate reacts with the saturated polyester resin to form a certain degree of cross-linked network structure, thereby avoiding the risk of glue overflow during the hot pressing process; the high temperature unblocking isocyanate fully reacts with the saturated polyester resin during the thermal unblocking process to form a thermosetting network macromolecule with good setting properties.

[0016] Furthermore, the saturated polyester resin A and the saturated polyester resin B are both prepared by condensation polymerization of polyols and polyacids.

[0017] Furthermore, the room temperature reactive isocyanate is one or more of toluene diisocyanate and its dimer and trimer, hexamethylene diisocyanate and its dimer and trimer, such as Bayer N3390.

[0018] Furthermore, the high temperature deblocking type isocyanate is synthesized from a blocking agent and a room temperature reactive type isocyanate, and the blocking agent is phenol and / or methyl ethyl ketone oxime, such as Bayer BL3175.

[0019] Furthermore, the thickness of the thermosetting substrate layer is 20-75 μm.

[0020] Specifically, the thickness of the thermosetting substrate layer may be 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, or 75 μm.

[0021] Furthermore, the thickness of the antistatic acrylic pressure-sensitive adhesive layer is 5-15 μm, and the thickness of the acrylic pressure-sensitive adhesive layer is 10-20 μm.

[0022] Specifically, the thickness of the antistatic acrylic pressure-sensitive adhesive layer can be 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, or 15 μm.

[0023] Specifically, the thickness of the antistatic acrylic pressure-sensitive adhesive layer may be 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm.

[0024] Furthermore, the thickness of the first substrate PET film layer is 30-60 μm, for example, 30 μm, 40 μm, 50 μm, or 60 μm.

[0025] Furthermore, the thickness of the second substrate PET film layer is 10-40 μm, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, or 40 μm.

[0026] Furthermore, the thickness of the double-sided antistatic PET release film layer is 30-60 μm, for example, 30 μm, 40 μm, 50 μm, or 60 μm.

[0027] The second aspect of the present invention provides a method for preparing the supporting protective tape for the four-curved display screen according to the first aspect, comprising the following steps:

[0028] S1, mixing saturated polyester resin A, saturated polyester resin B, room temperature reactive isocyanate, high temperature deblocking isocyanate and an organic solvent to obtain a mixed slurry, coating the mixed slurry on one side of the second substrate PET film layer, and forming a thermosetting substrate layer on one side of the second substrate PET film layer after drying;

[0029] S2, coating a layer of acrylic pressure-sensitive adhesive on the surface of the thermosetting substrate layer, and attaching a double-sided antistatic PET release film;

[0030] S3, coating a layer of antistatic acrylic pressure-sensitive adhesive on the first substrate PET film layer, and laminating it with the other side of the second substrate PET film layer in S1 to obtain the supporting protective tape for the four-curved display screen.

[0031] Furthermore, the solvent is one or more of ethyl acetate, butanone and toluene.

[0032] Furthermore, the solid content of the mixed slurry is 40wt%-60wt%.

[0033] Beneficial effects of the present invention:

[0034] The present invention sets a thermosetting substrate layer in the supporting protective tape. The thermosetting substrate layer is plastic when heated and can be cross-linked and shaped after heating, which greatly reduces the stress concentration problem between the display module and the four-curved glass cover plate, thereby avoiding problems such as bubbles or wrinkles during the bonding process. In addition, the thermosetting substrate layer can also prevent problems such as softening and repeated plasticization of the mobile phone during the heating process.

[0035] The thermosetting substrate layer of the present invention adopts saturated polyester resin, room temperature reactive isocyanate and high temperature unblocking isocyanate, wherein the saturated polyester resin has excellent adhesion to the PET film, thereby avoiding the phenomenon of separation of the PET film and the thermosetting substrate layer during the film tearing process; the room temperature reactive isocyanate reacts with the saturated polyester resin to form a certain degree of cross-linked network structure, thereby avoiding the risk of glue overflow during the hot pressing process; the high temperature unblocking isocyanate fully reacts with the saturated polyester resin during the thermal unblocking process to form a thermosetting network macromolecule with good setting property. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of the supporting protective tape for a four-curved display screen of the present invention;

[0037] Explanation of the numbers in the figure: 1. first substrate PET film layer, 2. antistatic acrylic pressure-sensitive adhesive layer, 3. second substrate PET film layer, 4. thermosetting substrate layer, 5. acrylic pressure-sensitive adhesive layer, 6. double-sided antistatic PET release film layer. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0039] This embodiment provides a support and protection tape for a four-curved display screen, such as Figure 1 As shown, it includes a first substrate PET film layer 1, an antistatic acrylic pressure-sensitive adhesive layer 2, a second substrate PET film layer 3, a thermosetting substrate layer 4, an acrylic pressure-sensitive adhesive layer 5 and a double-sided antistatic PET release film layer 6 which are sequentially stacked. The thermosetting substrate layer includes the following components in parts by weight: 50-90 parts of saturated polyester resin A, 10-50 parts of saturated polyester resin B, 2-8 parts of room temperature reactive isocyanate, and 2-8 parts of high temperature deblocking isocyanate; the saturated polyester resin A has a glass transition temperature of 48-100°C, and the saturated polyester resin B has a glass transition temperature of 0-47°C.

[0040] Preferably, the room temperature reactive isocyanate is one or more of toluene diisocyanate and its dimer and trimer, hexamethylene diisocyanate and its dimer and trimer, such as Bayer N3390. Preferably, the high temperature deblocking isocyanate is synthesized from a blocking agent and a room temperature reactive isocyanate, and the blocking agent is phenol and / or methyl ethyl ketone oxime, such as Bayer BL3175.

[0041] Preferably, the thickness of the thermosetting substrate layer is 20-75 μm, the thickness of the antistatic acrylic pressure-sensitive adhesive layer is 5-15 μm, and the thickness of the acrylic pressure-sensitive adhesive layer is 10-20 μm.

[0042] The method for preparing the supporting protective tape for the four-curved display screen comprises the following steps:

[0043] S1, mixing saturated polyester resin A, saturated polyester resin B, room temperature reactive isocyanate, high temperature deblocking isocyanate and organic solvent to obtain a mixed slurry, coating the mixed slurry on one side of the second substrate PET film layer 3, and forming a thermosetting substrate layer 4 on one side of the second substrate PET film layer 3 after drying;

[0044] S2, coating a layer of acrylic pressure-sensitive adhesive on the surface of the thermosetting substrate layer 4, and attaching a double-sided antistatic PET release film 6;

[0045] S3, coating a layer of antistatic acrylic pressure-sensitive adhesive on the first substrate PET film layer 1, and laminating it with the other side of the second substrate PET film layer 3 in S1 to obtain the supporting protective tape for the four-curved display screen.

[0046] Example 1

[0047] This embodiment relates to a support and protection tape for a four-curved display screen, comprising a sequentially stacked optical-grade first substrate PET film layer with a thickness of 50 μm, an antistatic acrylic pressure-sensitive adhesive layer with a thickness of 8 μm, an optical-grade second substrate PET film layer with a thickness of 25 μm, a thermosetting substrate layer with a thickness of 50 μm, an acrylic pressure-sensitive adhesive layer with a thickness of 13 μm, and a double-sided antistatic PET release film layer with a thickness of 50 μm, which is prepared according to the preparation method of the above embodiment. In parts by weight, the coating slurry of the thermosetting substrate layer includes the following components: 90 parts of saturated polyester resin A, 10 parts of saturated polyester resin B, 5 parts of room temperature reactive isocyanate, 5 parts of high temperature deblocking isocyanate, and 150 parts of ethyl acetate. Among them, the antistatic acrylic pressure-sensitive adhesive layer coating glue is selected from LT-0403A glue of Lutian New Materials Co., Ltd., the acrylic pressure-sensitive adhesive layer is selected from Anzu Chemical Y-1510 glue, the saturated polyester resin A is Toyobo GK360 with a Tg point of about 52°C, the saturated polyester resin B is Toyobo GK780 with a Tg point of about 36°C, the room temperature reactive isocyanate is Bayer N3390, and the high temperature deblocking isocyanate is Bayer BL3175.

[0048] Example 2

[0049] This embodiment relates to a support and protection tape for a four-curved display screen, comprising a sequentially stacked optical-grade first substrate PET film layer with a thickness of 50 μm, an antistatic acrylic pressure-sensitive adhesive layer with a thickness of 8 μm, an optical-grade second substrate PET film layer with a thickness of 25 μm, a thermosetting substrate layer with a thickness of 50 μm, an acrylic pressure-sensitive adhesive layer with a thickness of 13 μm, and a double-sided antistatic PET release film layer with a thickness of 50 μm, prepared according to the preparation method of the above embodiment. In parts by weight, the coating slurry of the thermosetting substrate layer comprises the following components: 50 parts of saturated polyester resin A, 50 parts of saturated polyester resin B, 5 parts of room temperature reactive isocyanate, 5 parts of high temperature deblocking isocyanate, and 150 parts of ethyl acetate. Among them, the antistatic acrylic pressure-sensitive adhesive layer coating glue is selected from LT-0403A glue of Lutian New Materials Co., Ltd., the acrylic pressure-sensitive adhesive layer is selected from Anzu Chemical Y-1510 glue, the saturated polyester resin A is Toyobo GK360 with a Tg point of about 52°C, the saturated polyester resin B is Toyobo GK780 with a Tg point of about 36°C, the room temperature reactive isocyanate is Bayer N3390, and the high temperature deblocking isocyanate is Bayer BL3175.

[0050] Example 3

[0051] This embodiment relates to a support and protection tape for a four-curved display screen, comprising a sequentially stacked optical-grade first substrate PET film layer with a thickness of 50 μm, an antistatic acrylic pressure-sensitive adhesive layer with a thickness of 8 μm, an optical-grade second substrate PET film layer with a thickness of 25 μm, a thermosetting substrate layer with a thickness of 50 μm, an acrylic pressure-sensitive adhesive layer with a thickness of 13 μm, and a double-sided antistatic PET release film layer with a thickness of 50 μm, prepared according to the preparation method of the above embodiment. In parts by weight, the coating slurry of the thermosetting substrate layer comprises the following components: 80 parts of saturated polyester resin A, 20 parts of saturated polyester resin B, 5 parts of room temperature reactive isocyanate, 5 parts of high temperature deblocking isocyanate, and 150 parts of ethyl acetate. Among them, the antistatic acrylic pressure-sensitive adhesive layer coating glue is selected from LT-0403A glue of Lutian New Materials Co., Ltd., the acrylic pressure-sensitive adhesive layer is selected from Anzu Chemical Y-1510 glue, the saturated polyester resin A is Toyobo GK360 with a Tg point of about 52°C, the saturated polyester resin B is Toyobo GK780 with a Tg point of about 36°C, the room temperature reactive isocyanate is Bayer N3390, and the high temperature deblocking isocyanate is Bayer BL3175.

[0052] Example 4

[0053] This embodiment relates to a support and protection tape for a four-curved display screen, comprising a sequentially stacked optical-grade first substrate PET film layer with a thickness of 50 μm, an antistatic acrylic pressure-sensitive adhesive layer with a thickness of 8 μm, an optical-grade second substrate PET film layer with a thickness of 25 μm, a thermosetting substrate layer with a thickness of 50 μm, an acrylic pressure-sensitive adhesive layer with a thickness of 13 μm, and a double-sided antistatic PET release film layer with a thickness of 50 μm, prepared according to the preparation method of the above embodiment. In parts by weight, the coating slurry of the thermosetting substrate layer comprises the following components: 90 parts of saturated polyester resin A, 10 parts of saturated polyester resin B, 9 parts of room temperature reactive isocyanate, 1 part of high temperature deblocking isocyanate, and 150 parts of ethyl acetate. Among them, the antistatic acrylic pressure-sensitive adhesive layer coating glue is selected from LT-0403A glue of Lutian New Materials Co., Ltd., the acrylic pressure-sensitive adhesive layer is selected from Anzu Chemical Y-1510 glue, the saturated polyester resin A is Toyobo GK360 with a Tg point of about 52°C, the saturated polyester resin B is Toyobo GK780 with a Tg point of about 36°C, the room temperature reactive isocyanate is Bayer N3390, and the high temperature deblocking isocyanate is Bayer BL3175.

[0054] Example 5

[0055] This embodiment relates to a support and protection tape for a four-curved display screen, comprising a sequentially stacked optical-grade first substrate PET film layer with a thickness of 50 μm, an antistatic acrylic pressure-sensitive adhesive layer with a thickness of 8 μm, an optical-grade second substrate PET film layer with a thickness of 25 μm, a thermosetting substrate layer with a thickness of 50 μm, an acrylic pressure-sensitive adhesive layer with a thickness of 13 μm, and a double-sided antistatic PET release film layer with a thickness of 50 μm, prepared according to the preparation method of the above embodiment. In parts by weight, the coating slurry of the thermosetting substrate layer comprises the following components: 90 parts of saturated polyester resin A, 10 parts of saturated polyester resin B, 1 part of room temperature reactive isocyanate, 10 parts of high temperature deblocking isocyanate, and 150 parts of ethyl acetate. Among them, the antistatic acrylic pressure-sensitive adhesive layer coating glue is selected from LT-0403A glue of Lutian New Materials Co., Ltd., the acrylic pressure-sensitive adhesive layer is selected from Anzu Chemical Y-1510 glue, the saturated polyester resin A is Toyobo GK360 with a Tg point of about 52°C, the saturated polyester resin B is Toyobo GK780 with a Tg point of about 36°C, the room temperature reactive isocyanate is Bayer N3390, and the high temperature deblocking isocyanate is Bayer BL3175.

[0056] Comparative Example 1

[0057] The difference between this comparative example and Example 1 is that it includes a sequentially stacked optical-grade first substrate PET film layer with a thickness of 50 μm, an antistatic acrylic pressure-sensitive adhesive layer with a thickness of 8 μm, an optical-grade second substrate PET film layer with a thickness of 75 μm, an acrylic pressure-sensitive adhesive layer with a thickness of 13 μm, and a double-sided antistatic PET release film layer with a thickness of 50 μm, and other parameters remain unchanged.

[0058] Test Case

[0059] Adhesion test: Test the second substrate PET film layer + thermosetting substrate layer + acrylic pressure-sensitive adhesive layer, cut the sample into a 25mm wide * 200mm long sample; stick it on the Glass board, use the pressing device to slowly reciprocate three times for rolling, and after 20 minutes, install the test board on the tensile tester, bend the lower part of the sample 180°, fix it on the upper chuck, and then peel it at a speed of 300mm / min. The peeling length is more than 100mm, and its strength is automatically recorded on the recording paper. The same sample is measured three times in parallel.

[0060] High temperature static shear test: carried out at 80°C with a 1000g hanging weight (test method refers to GB / T4851-2014).

[0061] Film tearing static voltage / surface resistance test: the test method refers to GB / T 33375-2016.

[0062] Whether rebound bubbles are generated: Place the display module in a four-sided hot pressing mold and keep it at 80℃*5min to fully solidify and fit. After taking out the sample, let it stand for 24h and observe whether there are bubbles at the four corners of the four curved surfaces.

[0063] The above test was performed on the supporting protective tapes of Examples 1-5 and the comparative example. The test results are shown in Table 1:

[0064] Table 1

[0065]

[0066]

[0067] As shown in Table 1, the supporting protective tape prepared in Example 1-3 has excellent performance, and there is no glue overflow and no bubble rebound during the hot pressing process. In Example 4, the room temperature reaction type isocyanate content is high, and there is no glue overflow during the hot pressing process, but there are obvious rebound bubbles after standing for 24 hours, mainly because the room temperature reaction type isocyanate content is high, the initial crosslinking density of the heat-curing substrate layer is high, and the plasticity is poor. It cannot fully flow during the hot pressing process, resulting in filling difficulties, and bubbles appear in the initial stage and standing for 24 hours. In Example 5, the room temperature reaction type isocyanate content is low, resulting in low initial crosslinking degree, strong plasticity, full flow during the hot pressing process, filling the curved surface, no bubbles at room temperature and after standing for 24 hours, but glue overflow is caused during the hot pressing process. Therefore, by controlling the room temperature reaction type isocyanate and the high temperature unblocking type isocyanate to control within a reasonable range, it is possible to avoid glue overflow during the hot pressing process and rebound bubbles after hot pressing. Comparative Example 1 has no thermosetting substrate layer, a large number of rebound bubbles appear, and the product performance is poor.

[0068] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A supporting protective tape for a four-curved display screen, characterized in that: It comprises a first substrate PET film layer, an antistatic acrylic pressure-sensitive adhesive layer, a second substrate PET film layer, a thermosetting substrate layer, an acrylic pressure-sensitive adhesive layer and a double-sided antistatic PET release film layer which are sequentially stacked.

2. The supporting protective tape for a four-curved display screen according to claim 1, characterized in that: The components of the thermosetting substrate layer include saturated polyester resin, room temperature reactive isocyanate and high temperature deblocking isocyanate.

3. The supporting protective tape for a four-curved display screen according to claim 2, characterized in that: The thermosetting substrate layer comprises the following components by weight: 50-90 parts of saturated polyester resin A, 10-50 parts of saturated polyester resin B, 1-9 parts of room temperature reactive isocyanate, and 1-9 parts of high temperature deblocking isocyanate; The glass transition temperature of the saturated polyester resin A is 48-100°C, and the glass transition temperature of the saturated polyester resin B is 0-47°C.

4. The supporting protective tape for a four-curved display screen according to claim 2, characterized in that: The room temperature reactive isocyanate is one or more of toluene diisocyanate and its dimer and trimer, hexamethylene diisocyanate and its dimer and trimer.

5. The supporting protective tape for a four-curved display screen according to claim 4, characterized in that: The high-temperature deblocking type isocyanate is synthesized from a blocking agent and a room-temperature reactive type isocyanate, and the blocking agent is phenol and / or methyl ethyl ketone oxime.

6. The supporting protective tape for a four-curved display screen according to claim 1, characterized in that: The thickness of the thermosetting substrate layer is 20-75 μm.

7. The supporting protective tape for a four-curved display screen according to claim 1, characterized in that: The thickness of the antistatic acrylic pressure-sensitive adhesive layer is 5-15 μm, and the thickness of the acrylic pressure-sensitive adhesive layer is 10-20 μm.

8. A method for preparing the supporting protective tape for a four-curved display screen according to any one of claims 1 to 7, characterized in that: The steps include: S1, mixing saturated polyester resin A, saturated polyester resin B, room temperature reactive isocyanate, high temperature deblocking isocyanate and an organic solvent to obtain a mixed slurry, coating the mixed slurry on one side of the second substrate PET film layer, and forming a thermosetting substrate layer on one side of the second substrate PET film layer after drying; S2, coating a layer of acrylic pressure-sensitive adhesive on the surface of the thermosetting substrate layer, and attaching a double-sided antistatic PET release film; S3, coating a layer of antistatic acrylic pressure-sensitive adhesive on the first substrate PET film layer, and laminating it with the other side of the second substrate PET film layer in S1 to obtain the supporting protective tape for the four-curved display screen.

9. The method for preparing the supporting protective tape for a four-curved display screen according to claim 8, characterized in that: The solvent is one or more of ethyl acetate, butanone and toluene.

10. The method for preparing the supporting protective tape for a four-curved display screen according to claim 8, characterized in that: The solid content of the mixed slurry is 40wt%-60wt%.

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