High-buffering die-mark-extrusion-resistant silica gel pressure-sensitive adhesive and preparation method thereof

Abstract

The invention discloses a high-buffer mold mark extrusion resistant silica gel pressure-sensitive adhesive and a preparation method thereof. The high-buffer mold mark extrusion resistant silica gel pressure-sensitive adhesive comprises a first release layer, an adhesive layer and a second release layer, the adhesive layer is prepared from the following components in parts by weight: 0.5 to 3.5 parts of carbon black powder, 0.5 to 1.5 parts of dispersing agent, 0.5 to 1.5 parts of flatting agent, 10 to 40 parts of methylbenzene, 100 parts of silica gel pressure-sensitive adhesive, 8 to 12 parts of nano silicon dioxide, 13 to 18 parts of foaming microsphere, 0.8 to 1.2 parts of curing agent and 0.8 to 1.2 parts of platinum catalyst. According to the invention, a nano silicon dioxide / foaming microsphere synergistic enhancement system is added into the glue, so that the mold mark resistance and extrusion resistance of the product are improved; the colloid has excellent tensile strength and high buffering performance, and the curing agent and the catalyst are added to crosslink the silica gel pressure-sensitive adhesive, so that a complex macromolecular chain crosslinked net structure is constructed.

Description

Technical Field

[0001] The invention relates to the technical field of adhesive preparation, in particular to a high-buffering anti-mold extrusion silicone pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of the electronics market, demand for adhesive tape materials has also grown. OLED, as a third-generation display technology, offers advantages such as lighter weight, lower energy consumption, higher brightness, better luminous efficiency, and flexibility. Major international manufacturers are scrambling to increase their R&D investment in OLED technology, and are placing new demands on the anti-buffering performance of display modules.

[0003] Currently, the majority of screen manufacturers utilize a cushioning method that primarily involves inserting a cushioning foam between the panel and the mounting layer to protect the panel from drops or impacts. However, this foam is relatively thick and its cushioning properties fall short of high-performance requirements. Consequently, a few manufacturers are using silicone pressure-sensitive adhesives as a cushioning layer. While this cushioning performance is significantly improved compared to previous technologies, its resistance to mold and extrusion is inferior to that of foam. In summary, existing silicone pressure-sensitive adhesive technology cannot simultaneously meet the requirements for high cushioning and high resistance to mold and extrusion. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-buffering anti-mold imprint and extrusion silicone pressure-sensitive adhesive and a preparation method thereof, so as to solve the problem that the organic silicone pressure-sensitive adhesive technology in the prior art cannot simultaneously meet the requirements of high buffering and high anti-mold imprint and anti-extrusion.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: a high-buffering anti-mold extrusion silicone pressure-sensitive adhesive, comprising a first release layer, an adhesive layer and a second release layer, wherein the adhesive layer comprises the following components by weight: 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of a dispersant, 0.5-1.5 parts of a leveling agent, 10-40 parts of toluene, 100 parts of a silicone pressure-sensitive adhesive, 8-12 parts of nano-silica, 13-18 parts of foamed microspheres, 0.8-1.2 parts of a curing agent, and 0.8-1.2 parts of a platinum catalyst.

[0006] Preferably, the first release layer is a PET fluoroplastic release film, the color of the first release layer is blue, and the thickness of the first release layer is 75 μm.

[0007] Preferably, the thickness of the adhesive layer is 120 μm.

[0008] Preferably, the second release layer is a PET fluoroplastic release film, the second release layer is colorless and transparent, and the thickness of the second release layer is 50 μm.

[0009] Preferably, the adhesive layer comprises the following components by weight: 100 parts of silicone pressure-sensitive adhesive, 10 parts of nano-silica, 15 parts of foamed microspheres, 3 parts of carbon black powder, 1 part of dispersant, 1 part of leveling agent, 1 part of curing agent, 1 part of platinum water catalyst, and 70 parts of toluene.

[0010] A method for preparing a high-buffering, mold-resistant, extrusion-resistant silicone pressure-sensitive adhesive comprises the following steps:

[0011] S1. Prepare the following raw materials: 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of leveling agent, 10-40 parts of toluene, 100 parts of silicone pressure-sensitive adhesive, 8-12 parts of nano-silica, 13-18 parts of foamed microspheres, 0.8-1.2 parts of curing agent, and 0.8-1.2 parts of platinum catalyst;

[0012] S2, pre-disperse 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of leveling agent, and 10-40 parts of toluene in a disperser in advance;

[0013] S3, adding 100 parts of silicone pressure-sensitive adhesive, 8-12 parts of nano-silicon dioxide, 13-18 parts of foamed microspheres, and 0.8-1.2 parts of curing agent, and mixing the materials at 20-25° C. to form a composite material;

[0014] S4, add 0.8-1.2 parts of platinum catalyst and stir;

[0015] S5. After the stirring is completed, vacuuming the obtained adhesive layer stock solution;

[0016] S6. Apply glue on the release film, adjust the coating thickness to obtain a dry glue thickness of 50-220 μm, and dry.

[0017] Preferably, the stirring is carried out using a 500L vertical double-shaft scraping disperser.

[0018] Preferably, the drying temperature in S6 is 130° C., and the drying time is 8-40 minutes.

[0019] Preferably, the thickness of the bottom release film is 50 μm-200 μm, and the thickness of the top release film is 25 μm-50 μm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. Adding nano-silica / foamed microspheres synergistic reinforcement system into the glue improves the product's anti-mold and anti-extrusion properties.

[0022] 2. The colloid has excellent tensile strength and high cushioning properties. The addition of curing agent and catalyst makes the silicone pressure-sensitive adhesive cross-linked, thereby achieving the construction of a complex macromolecular chain cross-linked network structure.

[0023] 3. During use, customers can intuitively and quickly determine the difference between the upper and lower release films on both sides of the tape through color recognition, and then quickly and accurately determine which side is the removal side, avoiding the mistakes and time waste caused by the previous method of trial peeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 It is a structural schematic diagram of the present invention.

[0026] In the figure: 1, first release layer; 2, adhesive layer; 3, second release layer. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0028] Example 1

[0029] See also Figure 1 In an embodiment of the present invention, a high-buffering, mold-resistant, extrusion-resistant silicone pressure-sensitive adhesive comprises a first release layer 1, an adhesive layer 2, and a second release layer 3. The adhesive layer 2 comprises the following components by weight: 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of a dispersant, 0.5-1.5 parts of a leveling agent, 10-40 parts of toluene, 100 parts of a silicone pressure-sensitive adhesive, 8-12 parts of nano-silicon dioxide, 13-18 parts of foamed microspheres, 0.8-1.2 parts of a curing agent, and 0.8-1.2 parts of a platinum catalyst.

[0030] The first release layer 1 is a PET fluoroplastic release film, the color of the first release layer 1 is blue, and the thickness of the first release layer 1 is 75 μm.

[0031] The thickness of the adhesive layer 2 is 120 μm.

[0032] The second release layer 3 is a PET fluoroplastic release film, is colorless and transparent, and has a thickness of 50 μm.

[0033] The adhesive layer 2 includes the following components by weight: 100 parts of silicone pressure-sensitive adhesive, 10 parts of nano-silicon dioxide, 15 parts of foamed microspheres, 3 parts of carbon black powder, 1 part of dispersant, 1 part of leveling agent, 1 part of curing agent, 1 part of platinum water catalyst, and 70 parts of toluene.

[0034] A method for preparing a high-buffering, mold-resistant, extrusion-resistant silicone pressure-sensitive adhesive comprises the following steps:

[0035] S1. Prepare the following raw materials: 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of leveling agent, 10-40 parts of toluene, 100 parts of silicone pressure-sensitive adhesive, 8-12 parts of nano-silica, 13-18 parts of foamed microspheres, 0.8-1.2 parts of curing agent, and 0.8-1.2 parts of platinum catalyst;

[0036] S2. Pre-disperse 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of leveling agent, and 10-40 parts of toluene in a disperser in advance; adding the dispersant to disperse the carbon black powder in advance can make the carbon black more evenly dispersed in the system, enhance the UV shielding effect of the tape, and avoid the grainy appearance of the tape;

[0037] S3. Add 100 parts of silicone pressure-sensitive adhesive, 8-12 parts of nano-silica, 13-18 parts of foamed microspheres, and 0.8-1.2 parts of curing agent, mix and stir the materials at 20-25°C to form a composite material; add the nano-silica / foamed microsphere synergistic reinforcement system to the adhesive to improve the product's anti-mold and anti-extrusion properties; ensure that the adhesive has excellent tensile strength and high cushioning properties, add curing agent and catalyst to cross-link the silicone pressure-sensitive adhesive, thereby achieving the construction of a complex macromolecular chain cross-linked network structure;

[0038] S4, add 0.8-1.2 parts of platinum catalyst and stir;

[0039] S5. After the stirring is completed, vacuuming the obtained adhesive layer stock solution to reduce the generation of bubbles inside the adhesive layer, thereby improving its flexibility during subsequent use, making it less likely to break, and improving its mechanical properties;

[0040] S6. Apply glue on the release film, adjust the coating thickness to obtain a dry glue thickness of 50-220 μm, and dry it; the drying temperature is 130° C., and the drying time is 8-40 minutes (preferably 15 minutes).

[0041] The stirring adopts a 500L vertical double-shaft scraping side and bottom disperser, which is suitable for stirring and dispersing chemicals and paints and coatings. It has the characteristics of efficient mixing and uniform dispersion, and is more suitable for large-scale production. It can also be used with chemical stirrers, stirred reactors and other equipment.

[0042] The thickness of the bottom release film (first release layer) is 50μm-200μm, and the thickness of the top release film (second release layer) is 25μm-50μm.

[0043] Example 2

[0044] This embodiment provides a method for preparing a high-buffered anti-mold extrusion silicone pressure-sensitive adhesive, which differs from Example 1 only in that the drying time is 10 min, and the rest is the same as Example 1.

[0045] Example 3

[0046] This embodiment provides a method for preparing a high-buffering, mold-resistant, extrusion-resistant silicone pressure-sensitive adhesive. The only difference between this method and Example 1 is that the drying time is 30 minutes, and the rest is the same as Example 1.

[0047] Example 4

[0048] This embodiment provides a method for preparing a high-buffering, mold-resistant, extrusion-resistant silicone pressure-sensitive adhesive. The only difference between this method and Example 1 is that the carbon black pre-dispersion is eliminated, S2 and S3 are combined together, and the rest is the same as Example 1.

[0049] Example 5

[0050] The embodiment provides a method for preparing a high-buffering mold-imprinting and extrusion-resistant silicone pressure-sensitive adhesive. The difference between the embodiment and the embodiment 1 is that silicon dioxide and foamed microspheres are not added, and the rest is the same as the embodiment 1.

[0051] Example 6

[0052] This embodiment provides a method for preparing a high-buffering, mold-imprint-resistant, extrusion-resistant silicone pressure-sensitive adhesive. The only difference between this method and Example 1 is that silicon dioxide is not added, and the rest is the same as Example 1.

[0053] Example 7

[0054] This embodiment provides a method for preparing a high-buffering, mold-printing and extrusion-resistant silicone pressure-sensitive adhesive. The only difference between this method and Example 1 is that foamed microspheres are not added, and the rest is the same as Example 1.

[0055] Example 8

[0056] This embodiment provides a preparation method of high-buffering anti-mold extrusion silicone pressure-sensitive adhesive. The only difference between the embodiment and embodiment 1 is that the silicone pressure-sensitive adhesive is 100 parts, nano-silica is 8 parts, foamed microspheres are 13 parts, carbon black powder is 0.5 parts, dispersant is 0.5 parts, leveling agent is 0.5 parts, curing agent is 0.8 parts, platinum water catalyst is 0.8 parts, and toluene is 70 parts. The remaining steps are the same as those in embodiment 1.

[0057] Example 9

[0058] The embodiment provides a preparation method of high-buffering anti-mold extrusion silicone pressure-sensitive adhesive, which differs from Example 1 only in that: 100 parts of silicone pressure-sensitive adhesive, 12 parts of nano-silica, 18 parts of foamed microspheres, 3.5 parts of carbon black powder, 1.5 parts of dispersant, 1.5 parts of leveling agent, 1.2 parts of curing agent, 1.2 parts of platinum water catalyst, and 70 parts of toluene. The remaining steps are the same as Example 1.

[0059] The adhesive tapes provided in Examples 1-9 were subjected to the following tests.

[0060] (1) Peel strength: According to GB / T 2792-2014 "Test method for peel strength of adhesive tapes", the sample was moved and bonded to a SUS304 steel plate. The peel strength at 180° at 23°C was recorded.

[0061] (2) Cushioning absorption rate: Cut the sample to be tested into 30mm*30mm pieces; turn on the test equipment, set the height (height = drop height + thickness of the sample to be tested + diameter of the test steel ball), adsorb the test steel ball on the instrument, and press the test button to test. Test three times without load (without placing cushioning material), and take the average value X0. Test three times with material and take the average value X1. Impact absorption rate = (X0-X1) / X0;

[0062] (3) Module extrusion: manually attach the test sample to the back of the module, then use a φ3 (3mm diameter) flat head to extrude the material at a speed of 1mm / min, and record the force when the mold appears on the screen surface;

[0063] (4) The test sample is manually attached to the module, and then squeezed with a φ3 ball head die at a speed of 1 mm / min. The force when the screen shows broken bright spots is recorded.

[0064] Peel force (gf / inch) Buffer absorption rate (%) Die extrusion (N) Module stamping (N) Appearance Example 1 3365 72 61 58 OK Example 2 3920 73 33 25 OK Example 3 2163 68 62 60 OK Example 4 1962 64 38 34 NG Example 5 4216 72 28 22 OK Example 6 3651 73 30 24 OK Example 7 3599 70 58 50 OK Example 8 4053 72 43 35 OK Example 9 2769 69 62 58 OK

[0065] Compared with Examples 1, 2, and 3, reducing the baking time will lead to a decrease in the degree of glue crosslinking and a smaller modulus. Although the cushioning performance of the colloid is improved, the module effect is greatly reduced because the colloid is too soft. On the contrary, increasing the baking time increases the degree of colloid crosslinking, significantly reduces the peeling, reduces its cushioning performance, and reduces the mold extrusion benefit.

[0066] Compared with Examples 1 and 4, the carbon black pre-dispersion is cancelled and the carbon black is directly added to the glue for stirring. The carbon black cannot be dispersed evenly and the carbon black agglomerates. The feedback on the surface of the tape will have a granular feel. The surface of the tape is uneven, has color difference, and has poor adhesion.

[0067] Compared with Example 1, Example 5 does not add silicon dioxide and foamed microspheres, and its cushioning performance is the same, but the anti-mold and anti-extrusion performance is worse than that of Example 1.

[0068] Compared with Examples 1 and 6, without adding silicon dioxide, the colloid is still soft and there is no significant difference in cushioning, but the anti-mold and anti-extrusion properties are poor.

[0069] Compared with Example 1 and Example 7, no foamed microspheres are added. Since silicon dioxide is a hard substance, if silicon dioxide is added alone, the colloid will be too hard. Moreover, since the additive is too simple, the cushioning and mold extrusion will be reduced to varying degrees.

[0070] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A high-buffered anti-mold extrusion silicone pressure-sensitive adhesive, characterized in that: The invention comprises a first release layer, an adhesive layer and a second release layer, wherein the adhesive layer comprises the following components in parts by weight: 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of a dispersant, 0.5-1.5 parts of a leveling agent, 10-40 parts of toluene, 100 parts of a silicone pressure-sensitive adhesive, 8-12 parts of nano-silicon dioxide, 13-18 parts of foamed microspheres, 0.8-1.2 parts of a curing agent and 0.8-1.2 parts of a platinum catalyst.

2. The high-buffering anti-mold extrusion silicone pressure-sensitive adhesive according to claim 1, characterized in that: The first release layer is a PET fluoroplastic release film, the color of the first release layer is blue, and the thickness of the first release layer is 75 μm.

3. The high-buffering anti-mold extrusion silicone pressure-sensitive adhesive according to claim 1, characterized in that: The thickness of the adhesive layer is 120 μm.

4. The high-buffering anti-mold extrusion silicone pressure-sensitive adhesive according to claim 1, characterized in that: The second release layer is a PET fluoroplastic release film, is colorless and transparent, and has a thickness of 50 μm.

5. The high-buffering anti-mold extrusion silicone pressure-sensitive adhesive according to claim 1, characterized in that: The adhesive layer includes the following components by weight: 100 parts of silicone pressure-sensitive adhesive, 10 parts of nano-silicon dioxide, 15 parts of foamed microspheres, 3 parts of carbon black powder, 1 part of dispersant, 1 part of leveling agent, 1 part of curing agent, 1 part of platinum water catalyst, and 70 parts of toluene.

6. A method for preparing a high-buffering anti-mold extrusion silicone pressure-sensitive adhesive, characterized in that: The following steps are involved: S1. Prepare the following raw materials: 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of leveling agent, 10-40 parts of toluene, 100 parts of silicone pressure-sensitive adhesive, 8-12 parts of nano-silica, 13-18 parts of foamed microspheres, 0.8-1.2 parts of curing agent, and 0.8-1.2 parts of platinum catalyst; S2, pre-disperse 0.5-3.5 parts of carbon black powder, 0.5-1.5 parts of dispersant, 0.5-1.5 parts of leveling agent, and 10-40 parts of toluene in a disperser in advance; S3, adding 100 parts of silicone pressure-sensitive adhesive, 8-12 parts of nano-silicon dioxide, 13-18 parts of foamed microspheres, and 0.8-1.2 parts of curing agent, and mixing the materials at 20-25° C. to form a composite material; S4, add 0.8-1.2 parts of platinum catalyst and stir; S5. After the stirring is completed, vacuuming the obtained adhesive layer stock solution; S6. Apply glue on the release film, adjust the coating thickness to obtain a dry glue thickness of 50-220 μm, and dry.

7. The high-buffering anti-mold extrusion silicone pressure-sensitive adhesive and its preparation method according to claim 6, characterized in that: The stirring was carried out using a 500L vertical double-shaft scraping disperser.

8. The high-buffering anti-mold extrusion silicone pressure-sensitive adhesive and the preparation method thereof according to claim 6, characterized in that: The drying temperature in S6 is 130° C., and the drying time is 8-40 minutes.

9. The high-buffering anti-mold extrusion silicone pressure-sensitive adhesive and the preparation method thereof according to claim 6, characterized in that: The thickness of the bottom release film is 50μm-200μm, and the thickness of the top release film is 25μm-50μm.

Images