High heat-resistant hydrophobic adhesive tape and preparation method thereof

Abstract

The application discloses a high-heat-resistance and high-hydrophobicity adhesive tape and a preparation method thereof. The high-heat-resistance and high-hydrophobicity adhesive tape is obtained by coating a modified polyacrylate solution on a PET substrate, wherein the modified polyacrylate solution is obtained by mixing an organosilicon modified polyacrylate solution, tackifying resin and a composite crosslinking agent. The organosilicon modified polyacrylate solution is prepared by free radical solution polymerization of a mercapto-epoxy organosilicon oligomer, butyl acrylate, isooctyl acrylate, vinyl acetate, methacrylic acid, an initiator and a solution. The method can prepare a high-water-resistance and high-hydrophobicity polyacrylate pressure-sensitive adhesive by introducing the mercapto-epoxy organosilicon oligomer in the polyacrylate polymerization process, and can effectively improve the adhesion of the organosilicon segment to the PET substrate by introducing the epoxy group in the organosilicon segment, thereby solving the problems of low peeling strength and poor holding power of the organosilicon modified pressure-sensitive adhesive, and obtaining the high-heat-resistance and high-hydrophobicity adhesive tape with excellent performance.

Description

Technical Field

[0001] This invention relates to the field of adhesive tapes, and in particular to a high heat-resistant hydrophobic adhesive tape and its preparation method. Background Technology

[0002] In recent years, polyacrylate tapes have been increasingly widely used in 3C electronic products, new energy vehicles, and electrical protection. However, in practical applications, these products are often exposed to moisture, and the presence of ester groups and other polar groups in the polyacrylate molecular chain affects the water resistance of the tape, causing it to detach and lose its adhesive or protective properties during use. Therefore, there is an urgent need to improve the water resistance of polyacrylate pressure-sensitive tapes.

[0003] Chinese invention patent (CN 120059624 A) discloses a waterproof pressure-sensitive adhesive tape and its manufacturing process. This patent introduces a curing agent with fluorinated segments into traditional acrylate adhesives, utilizing the hydrophobicity of the fluorinated segments to prepare a high-peel hydrophobic tape. However, the introduction of fluorinated compounds not only increases costs but also poses environmental problems. Chinese invention patent (CN101899274 A) improves the hydrophobicity of the tape by optimizing the polymerization process and formulation of polyacrylate pressure-sensitive adhesive, especially optimizing the tackifying resin and leveling agent, and introducing various additives. However, the polyacrylate tape obtained by this method is mainly for flexible circuit boards, with a narrow applicability. Furthermore, the use of a large number of additives affects the long-term stability of the hydrophobic tape. Therefore, it is particularly important to develop polyacrylate tapes with strong applicability, stability, and good water resistance and peel performance. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing hydrophobic tapes by providing a hydrophobic tape with high water resistance, high peel strength, high heat resistance, and stability, as well as a method for its preparation.

[0005] To achieve the above objectives, the technical solution adopted in this invention is: a method for preparing a high heat-resistant hydrophobic tape, comprising mixing 50-65 parts by weight of an organosilicon-modified polyacrylate solution, 3-8 parts by weight of a tackifying resin, and 0.5-1.0 parts by weight of a composite crosslinking agent to obtain a mixed adhesive, allowing it to stand, and then uniformly coating the mixed adhesive onto a corona-treated PET film and drying it. The thickness of the dried adhesive layer is 24-26 mm. Finally, the tape is transferred to an oven to cure and obtain the final product.

[0006] The organosilicon-modified polyacrylate solution is prepared through the following steps:

[0007] S1.1 Mix 5-8 parts by weight of isooctyl acrylate, 15-22 parts by weight of butyl acrylate, 25-40 parts by weight of ethyl acetate, 0.24-0.48 parts by weight of azobisisobutyronitrile, and 0.1-0.6 parts by weight of methacrylic acid, stir for 20-30 minutes, and then heat to [temperature missing]. Afterwards, the reaction proceeds for 1.5 to 2.5 hours;

[0008] S1.2 Mix 3-8 parts by weight of vinyl acetate, 1.5-4.5 parts by weight of mercaptoepoxy silicone oligomer, 0.04-0.08 parts by weight of azobisisobutyronitrile, and 3-5 parts by weight of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 1.5-2.5 hours. After the addition is complete, continue the reaction for 1-2 hours, and then heat to [temperature missing]. After reacting for 1 to 1.5 hours, the mixture was cooled to room temperature to obtain an organosilicon-modified polyacrylate solution.

[0009] The aforementioned mercaptoepoxy organosilicon oligomer is prepared by the following steps:

[0010] S2.1 Mix 20-30 parts by weight of mercaptosilane coupling agent, 5-10 parts by weight of epoxysilane coupling agent, and 80-100 parts by weight of ethanol evenly, then heat to... Stir for 0.5 to 1 hour;

[0011] S2.2 After mixing deionized water and acid catalyst evenly to form a mixture, control the pH to 2-3, then gradually add 6-10 parts by mass of the mixture to the above solution, control the adding time to 2-3 hours, and continue the reaction for 1-2 hours after the addition is completed;

[0012] After the S2.3 reaction is complete, cool to room temperature and let stand for 6-8 hours. Then, use vacuum distillation to remove residual ethanol, water and other impurities from the system. After filtration, obtain mercapto-epoxy organosilicon oligomer.

[0013] In a further technical solution, the tackifying resin is a mixture of hydrogenated modified terpene resin and hydrogenated modified rosin resin, wherein the softening point of the hydrogenated modified terpene resin is [missing information]. Acid value of 2~5 The softening point of hydrogenated modified rosin resin is Acid value of 80~120 The mass ratio of the hydrogenated modified terpene resin to the hydrogenated modified rosin resin is 1:3 to 3:1. Both the hydrogenated modified terpene resin and the hydrogenated modified rosin resin meet the softening point and acid value requirements, thus achieving the technical effects of this solution.

[0014] In a further technical solution, the composite crosslinking agent is composed of isophorone diisocyanate and aluminum acetylacetonate in a mass ratio of 5:1 to 2:1.

[0015] In a further technical solution, the mercaptosilane coupling agent in step S2.1 is one of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, or 3-mercaptopropylmethyldimethoxysilane; the epoxysilane coupling agent is one of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltriethoxysilane, or 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane.

[0016] In a further technical solution, the acid catalyst mentioned in step S2.1 is one of hydrochloric acid, sulfuric acid, acetic acid, formic acid, and nitric acid.

[0017] A high heat-resistant hydrophobic tape is prepared using any one of the above-described methods for preparing a high heat-resistant hydrophobic tape.

[0018] Introducing silicone segments into polyacrylate effectively improves the hydrophobicity of the tape. Compared to copolymerization, the grafting of silicone segments onto the polyacrylate molecular chain via a mercapto-vinyl click reaction improves grafting efficiency and compatibility, while reducing silicone segment migration and phase separation. Furthermore, introducing epoxy groups into silicone oligomers enhances the adhesion of pressure-sensitive adhesives to different substrates and reduces the negative impact of silicone oligomer introduction on the peel strength of the pressure-sensitive adhesive.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The prepared tape has both excellent hydrophobicity and good peel strength;

[0021] The prepared hydrophobic tape has good thermal stability and hydrophobic stability. Attached Figure Description

[0022] Figure 1 The infrared spectrum of the surface of the tape prepared in Example 1 is shown.

[0023] Figure 2 The image shows a scanning electron microscope (SEM) image of the surface of the tape prepared in Example 1.

[0024] Figure 3 Elemental analysis of the surface of the tape prepared in Example 1.

[0025] Figure 4 Photographs showing the contact angle of the tape surface prepared in Example 1. Detailed Implementation

[0026] Example 1

[0027] Preparation of mercaptoepoxy organosilicon oligomers:

[0028] (1) Add 24 parts by mass of 3-mercaptopropyltrimethoxysilane, 8 parts by mass of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 90 parts by mass of anhydrous ethanol to the reaction vessel. After mechanically stirring until homogeneous, raise the reaction temperature to [temperature missing]. Then continue stirring for 0.5 hours;

[0029] (2) Mix deionized water and hydrochloric acid evenly to form a mixture, control the pH of the mixture to be 2.5, and then gradually add 8 parts by mass of the mixture to the above solution, controlling the addition time to be 2 hours. After the addition is completed, continue the reaction for 1.5 hours.

[0030] (3) After the reaction is complete, cool to room temperature and stand for 6 hours. Then, use a rotary evaporator to evaporate under vacuum at 60°C to remove ethanol and water. After filtration, obtain mercapto-epoxy organosilicon oligomer.

[0031] Preparation of organosilicon-modified polyacrylate solution:

[0032] (1) Add 6 parts by mass of isooctyl acrylate, 16 parts by mass of butyl acrylate, 32 parts by mass of ethyl acetate, 0.36 parts by mass of azobisisobutyronitrile and 0.4 parts by mass of methacrylic acid to the reactor, stir for 30 min, and then heat to Then, the reaction was carried out for 2 hours;

[0033] (2) Mix 6 parts by mass of vinyl acetate, 3.0 parts by mass of mercaptoepoxy silicone oligomer, 0.06 parts by mass of azobisisobutyronitrile, and 4.5 parts by mass of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 2 hours. After the addition is complete, continue the reaction for another 2 hours, and then raise the temperature to [temperature missing]. After continuing the reaction for 1.5 hours, the reactor was cooled to room temperature and filtered to obtain an organosilicon-modified polyacrylate solution.

[0034] Preparation of high heat-resistant and hydrophobic adhesive tape:

[0035] 55 parts by weight of organosilicon-modified polyacrylate solution and 1.5 parts by weight of hydrogenated modified terpene resin (softening point: The acid value is 3. 4.5 parts by weight of hydrogenated modified rosin resin (softening point: The acid value is 88. 0.6 parts by weight of isophorone diisocyanate and 0.2 parts by weight of aluminum acetylacetonate are mixed evenly and allowed to stand until no bubbles are generated. Then, the mixture is coated onto a corona-treated PET film and placed in an oven to dry and cure, controlling the dry adhesive thickness to be 25 mm. Finally, the obtained tape is transferred to an oven for curing to obtain a high heat-resistant hydrophobic tape.

[0036] Figure 1 The image shows the infrared spectrum of the surface of the tape prepared in Example 1. As can be seen from the figure, 2985-2950... It is the absorption peak of the stretching vibration of methyl and methylene groups, 1727. It is the vibrational absorption peak of carbon-based C=O, and at the same time, it appears in 1050-1150 cm⁻¹. The vibration absorption peak is in the range of 2400-2600. No information was found. The vibrational absorption peak indicates that the thiol group participates in the polymerization reaction. At the same time, organosilicon oligomers were introduced, and organosilicon-modified polyacrylate was successfully prepared.

[0037] Figure 2 and Figure 3 The image shows scanning electron microscopy and elemental analysis of the surface of the tape prepared in Example 1. As can be seen from the figure, the prepared tape has a relatively smooth and uniform surface without obvious defects, and is mainly composed of three elements: C, O, and Si, indicating that the organosilicon-modified acrylate pressure-sensitive adhesive was successfully prepared.

[0038] Figure 4 This is a photograph of the contact angle of the tape surface prepared in Example 1. As can be seen from the figure, the contact angle of the prepared tape is approximately... The good hydrophobic effect indicates that the introduction of organosilicon improves the hydrophobicity of polyacrylate tape.

[0039] Example 2

[0040] Preparation of mercaptoepoxy organosilicon oligomers:

[0041] (1) Add 20 parts by mass of 3-mercaptopropyltriethoxysilane, 10 parts by mass of 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, and 80 parts by mass of anhydrous ethanol to the reaction vessel. After mechanically stirring until homogeneous, raise the reaction temperature to [temperature missing]. Then continue stirring for 0.5 hours;

[0042] (2) Mix deionized water and sulfuric acid evenly to form a mixture, control the pH of the mixture to be 2, and then gradually add 10 parts by mass of the mixture to the above solution, controlling the addition time to be 3h, and continue the reaction for 1h after the addition is completed;

[0043] (3) After the reaction is complete, cool to room temperature and let stand for 8 hours, then use a rotary evaporator to... The ethanol and water were removed by rotary evaporation under vacuum, and then filtered to obtain mercapto-epoxy organosilicon oligomers.

[0044] Preparation of organosilicon-modified polyacrylate solution:

[0045] (1) Add 5 parts by mass of isooctyl acrylate, 22 parts by mass of butyl acrylate, 40 parts by mass of ethyl acetate, 0.24 parts by mass of azobisisobutyronitrile and 0.1 parts by mass of methacrylic acid to the reactor, stir for 20 min, and then heat to Then, the reaction proceeded for 2.5 hours;

[0046] (2) Mix 3 parts by mass of vinyl acetate, 1.5 parts by mass of mercaptoepoxy silicone oligomer, 0.04 parts by mass of azobisisobutyronitrile, and 3 parts by mass of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 1.5 hours. After the addition is complete, continue the reaction for 1 hour, and then raise the temperature to [temperature missing]. After continuing the reaction for 1 hour, the reactor was cooled to room temperature and filtered to obtain an organosilicon-modified polyacrylate solution.

[0047] Preparation of high heat-resistant and hydrophobic adhesive tape:

[0048] Mix 50 parts by weight of organosilicon-modified polyacrylate solution and 1 part by weight of hydrogenated modified terpene resin (softening point: Acid value 2 ), 2 parts by weight of hydrogenated modified rosin resin (softening point is The acid value is 120. After mixing 0.5 parts by weight of isophorone diisocyanate and 0.1 parts by weight of aluminum acetylacetonate evenly, let it stand until no bubbles are generated. Then, coat it onto a corona-treated PET film and place it in an oven to dry and cure, controlling the dry adhesive thickness to 24 mm. Finally, the obtained tape is transferred to an oven for curing to obtain a high heat-resistant hydrophobic tape.

[0049] Example 3

[0050] Preparation of mercaptoepoxy organosilicon oligomers:

[0051] (1) Add 30 parts by weight of 3-mercaptopropylmethyldimethoxysilane, 5 parts by weight of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, and 100 parts by weight of anhydrous ethanol to the reaction vessel. After mechanically stirring until homogeneous, raise the reaction temperature to [temperature missing]. Then continue stirring for 1 hour;

[0052] (2) Mix deionized water and acetic acid evenly to form a mixture, control the pH of the mixture to 3, and then gradually add 6 parts by mass of the mixture to the above solution, controlling the addition time to 2 hours. After the addition is completed, continue the reaction for 2 hours.

[0053] (3) After the reaction is complete, cool to room temperature and let stand for 6 hours, then use a rotary evaporator to... The ethanol and water were removed by rotary evaporation under vacuum, and then filtered to obtain mercapto-epoxy organosilicon oligomers.

[0054] Preparation of organosilicon-modified polyacrylate solution:

[0055] (1) Add 8 parts by mass of isooctyl acrylate, 15 parts by mass of butyl acrylate, 25 parts by mass of ethyl acetate, 0.48 parts by mass of azobisisobutyronitrile and 0.6 parts by mass of methacrylic acid to the reactor, stir for 30 min, and then heat to Then, the reaction proceeded for 1.5 hours;

[0056] (2) Mix 8 parts by mass of vinyl acetate, 4.5 parts by mass of mercaptoepoxy silicone oligomer, 0.08 parts by mass of azobisisobutyronitrile, and 5 parts by mass of ethyl acetate evenly, and then add the mixture dropwise to the above solution over a period of 2.5 hours. After the addition is complete, continue the reaction for 2 hours, and then raise the temperature to [temperature missing]. After continuing the reaction for 1.5 hours, the reactor was cooled to room temperature and filtered to obtain an organosilicon-modified polyacrylate solution.

[0057] Preparation of high heat-resistant and hydrophobic adhesive tape:

[0058] 65 parts by weight of organosilicon-modified polyacrylate solution and 2 parts by weight of hydrogenated modified terpene resin (softening point: (Acid value 5 mgKOH / g), 6 parts by weight of hydrogenated modified rosin resin (softening point is...) After mixing 0.4 parts by weight of isophorone diisocyanate and 0.2 parts by weight of aluminum acetylacetonate evenly, the mixture was allowed to stand until no bubbles were generated. Then, it was coated onto a corona-treated PET film and placed in an oven to dry and cure, controlling the dry adhesive thickness to 26 μm. Finally, the obtained tape was transferred to an oven for curing to obtain a high heat-resistant hydrophobic tape.

[0059] Example 4

[0060] Preparation of mercaptoepoxy organosilicon oligomers:

[0061] (1) Add 28 parts by mass of 3-mercaptopropyltriethoxysilane, 7 parts by mass of 3-(2,3-epoxypropoxy)propyltriethoxysilane, and 95 parts by mass of anhydrous ethanol to the reaction vessel. After mechanically stirring until homogeneous, raise the reaction temperature to [temperature missing]. Then continue stirring for 1 hour;

[0062] (2) Mix deionized water and formic acid evenly to form a mixture, control the pH of the mixture to be 2.5, and then gradually add 8 parts by mass of the mixture to the above solution, controlling the addition time to be 2.5h, and continue the reaction for 1.5h after the addition is completed;

[0063] (3) After the reaction is complete, cool to room temperature and stand for 7 hours. Then, use a rotary evaporator to evaporate under vacuum at 80°C to remove ethanol and water. After filtration, obtain mercapto-epoxy organosilicon oligomer.

[0064] Preparation of organosilicon-modified polyacrylate solution:

[0065] (1) Add 6 parts by mass of isooctyl acrylate, 18 parts by mass of butyl acrylate, 32 parts by mass of ethyl acetate, 0.36 parts by mass of azobisisobutyronitrile and 0.4 parts by mass of methacrylic acid to the reactor, stir for 20 min, and then heat to Then, the reaction was carried out for 2 hours;

[0066] (2) Mix 6 parts by mass of vinyl acetate, 3.6 parts by mass of mercaptoepoxy silicone oligomer, 0.06 parts by mass of azobisisobutyronitrile, and 4 parts by mass of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 2 hours. After the addition is complete, continue the reaction for another 2 hours, and then raise the temperature to [temperature missing]. After continuing the reaction for 1.5 hours, the reactor was cooled to room temperature and filtered to obtain an organosilicon-modified polyacrylate solution.

[0067] Preparation of high heat-resistant and hydrophobic adhesive tape:

[0068] 55 parts by weight of organosilicon-modified polyacrylate solution and 3 parts by weight of hydrogenated modified terpene resin (softening point: Acid value ), 1 part by weight of hydrogenated modified rosin resin (softening point is Acid value 0.4 parts by weight of isophorone diisocyanate and 0.1 parts by weight of aluminum acetylacetonate are mixed evenly and allowed to stand until no bubbles are generated. Then, the mixture is coated onto a corona-treated PET film and placed in an oven to dry and cure, controlling the dry adhesive thickness to be [missing information]. Finally, the obtained tape is transferred to an oven for curing to obtain a high heat-resistant hydrophobic tape.

[0069] Example 5

[0070] Preparation of mercaptoepoxy organosilicon oligomers:

[0071] (1) Add 24 parts by mass of 3-mercaptopropyltrimethoxysilane, 9 parts by mass of 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane, and 86 parts by mass of anhydrous ethanol to the reactor. After mechanically stirring until homogeneous, raise the reaction temperature to [temperature missing]. Then continue stirring for 0.5 hours;

[0072] (2) Mix deionized water and nitric acid evenly to form a mixture, control the pH of the mixture to be 2, and then gradually add 8 parts by mass of the mixture to the above solution, controlling the addition time to be 2 hours. After the addition is completed, continue the reaction for 2 hours.

[0073] (3) After the reaction is complete, cool to room temperature and let stand for 8 hours, then use a rotary evaporator to... The ethanol and water were removed by rotary evaporation under vacuum, and then filtered to obtain mercapto-epoxy organosilicon oligomers.

[0074] Preparation of organosilicon-modified polyacrylate solution:

[0075] (1) Add 6 parts by mass of isooctyl acrylate, 20 parts by mass of butyl acrylate, 36 parts by mass of ethyl acetate, 0.32 parts by mass of azobisisobutyronitrile and 0.2 parts by mass of methacrylic acid to the reactor, stir for 30 min, and then heat to Then, the reaction proceeded for 1.5 hours;

[0076] (2) Mix 5 parts by mass of vinyl acetate, 3.6 parts by mass of mercaptoepoxy silicone oligomer, 0.06 parts by mass of azobisisobutyronitrile, and 5 parts by mass of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 2 hours. After the addition is complete, continue the reaction for 1.5 hours, and then heat to [temperature missing]. After continuing the reaction for 1 hour, the reactor was cooled to room temperature and filtered to obtain an organosilicon-modified polyacrylate solution.

[0077] Preparation of high heat-resistant and hydrophobic adhesive tape:

[0078] 62 parts by weight of organosilicon-modified polyacrylate solution and 3 parts by weight of hydrogenated modified terpene resin (softening point: Acid value ), 3 parts by weight of hydrogenated modified rosin resin (softening point is Acid value 0.8 parts by weight of isophorone diisocyanate and 0.2 parts by weight of aluminum acetylacetonate are mixed evenly and allowed to stand until no bubbles are generated. Then, the mixture is coated onto a corona-treated PET film and placed in an oven to dry and cure, controlling the dry adhesive thickness to be [missing information]. Finally, the obtained tape is transferred to an oven for curing to obtain a high heat-resistant hydrophobic tape.

[0079] Comparative Example 1 (without silicone)

[0080] Preparation of organosilicon-modified polyacrylate solution:

[0081] (1) Add 6 parts by mass of isooctyl acrylate, 16 parts by mass of butyl acrylate, 32 parts by mass of ethyl acetate, 0.36 parts by mass of azobisisobutyronitrile and 0.4 parts by mass of methacrylic acid to the reactor, stir for 30 min, and then heat to Then, the reaction was carried out for 2 hours;

[0082] (2) Mix 6 parts by mass of vinyl acetate, 0.06 parts by mass of azobisisobutyronitrile, and 4.5 parts by mass of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 2 hours. After the addition is complete, continue the reaction for another 2 hours, and then raise the temperature to [temperature missing]. After continuing the reaction for 1.5 hours, the reactor was cooled to room temperature and filtered to obtain an organosilicon-modified polyacrylate solution.

[0083] Preparation of high heat-resistant and hydrophobic adhesive tape:

[0084] Mix 55 parts by weight of polyacrylate solution and 1.5 parts by weight of hydrogenated modified terpene resin (softening point: 4.5 parts by weight of hydrogenated modified rosin resin (acid value of 3 mg KOH / g, softening point of 4.5 mg KOH / g) After mixing 0.6 parts by weight of isophorone diisocyanate and 0.2 parts by weight of aluminum acetylacetonate with an acid value of 88 mg KOH / g, the mixture was allowed to stand until no bubbles were generated. Then, it was coated onto a corona-treated PET film and placed in an oven to dry and cure, controlling the dry adhesive thickness to 25 μm. Finally, the obtained tape was transferred to an oven for curing to obtain a high heat-resistant hydrophobic tape.

[0085] Comparative Example 2 (single curing agent)

[0086] Preparation of mercaptoepoxy organosilicon oligomers:

[0087] (1) Add 24 parts by mass of 3-mercaptopropyltrimethoxysilane, 8 parts by mass of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 90 parts by mass of anhydrous ethanol to the reaction vessel. After mechanically stirring until homogeneous, raise the reaction temperature to [temperature missing]. Then continue stirring for 0.5 hours;

[0088] (2) Mix deionized water and hydrochloric acid evenly to form a mixture, control the pH of the mixture to be 2.5, and then gradually add 8 parts by mass of the mixture to the above solution, controlling the addition time to be 2 hours. After the addition is completed, continue the reaction for 1.5 hours.

[0089] (3) After the reaction is complete, cool to room temperature and stand for 6 hours. Then, use a rotary evaporator to evaporate under vacuum at 60°C to remove ethanol and water. After filtration, obtain mercapto-epoxy organosilicon oligomer.

[0090] Preparation of organosilicon-modified polyacrylate solution:

[0091] (1) Add 6 parts by mass of isooctyl acrylate, 16 parts by mass of butyl acrylate, 32 parts by mass of ethyl acetate, 0.36 parts by mass of azobisisobutyronitrile and 0.4 parts by mass of methacrylic acid to the reactor, stir for 30 min, and then heat to Then, the reaction was carried out for 2 hours;

[0092] (2) Mix 6 parts by mass of vinyl acetate, 3.0 parts by mass of mercaptoepoxy silicone oligomer, 0.06 parts by mass of azobisisobutyronitrile, and 4.5 parts by mass of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 2 hours. After the addition is complete, continue the reaction for another 2 hours, and then raise the temperature to [temperature missing]. After continuing the reaction for 1.5 hours, the reactor was cooled to room temperature and filtered to obtain an organosilicon-modified polyacrylate solution.

[0093] Preparation of high heat-resistant and hydrophobic adhesive tape:

[0094] 55 parts by weight of organosilicon-modified polyacrylate solution and 1.5 parts by weight of hydrogenated modified terpene resin (softening point: 4.5 parts by weight of hydrogenated modified rosin resin (acid value of 3 mg KOH / g, softening point of 4.5 mg KOH / g) After mixing 0.8 parts by weight of isophorone diisocyanate (acid value 88 mg KOH / g) evenly, let it stand until no bubbles are generated, then coat it onto a corona-treated PET film, and place it in an oven to dry and cure, controlling the dry adhesive thickness to 25 μm. Finally, transfer the obtained tape to an oven for curing to obtain a high heat-resistant hydrophobic tape.

[0095] Comparative Example 3 (single tackifying resin)

[0096] Preparation of mercaptoepoxy organosilicon oligomers:

[0097] (1) Add 24 parts by mass of 3-mercaptopropyltrimethoxysilane, 8 parts by mass of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 90 parts by mass of anhydrous ethanol to the reaction vessel. After mechanically stirring until homogeneous, raise the reaction temperature to [temperature missing]. Then continue stirring for 0.5 hours;

[0098] (2) Mix deionized water and hydrochloric acid evenly to form a mixture, control the pH of the mixture to be 2.5, and then gradually add 8 parts by mass of the mixture to the above solution, controlling the addition time to be 2 hours. After the addition is completed, continue the reaction for 1.5 hours.

[0099] (3) After the reaction is complete, cool to room temperature and stand for 6 hours. Then, use a rotary evaporator to evaporate under vacuum at 60°C to remove ethanol and water. After filtration, obtain mercapto-epoxy organosilicon oligomer.

[0100] Preparation of organosilicon-modified polyacrylate solution:

[0101] (1) Add 6 parts by mass of isooctyl acrylate, 16 parts by mass of butyl acrylate, 32 parts by mass of ethyl acetate, 0.36 parts by mass of azobisisobutyronitrile and 0.4 parts by mass of methacrylic acid to the reactor, stir for 30 min, and then heat to Then, the reaction was carried out for 2 hours;

[0102] (2) Mix 6 parts by mass of vinyl acetate, 3.0 parts by mass of mercaptoepoxy silicone oligomer, 0.06 parts by mass of azobisisobutyronitrile, and 4.5 parts by mass of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 2 hours. After the addition is complete, continue the reaction for another 2 hours, and then raise the temperature to [temperature missing]. After continuing the reaction for 1.5 hours, the reactor was cooled to room temperature and filtered to obtain an organosilicon-modified polyacrylate solution.

[0103] Preparation of high heat-resistant and hydrophobic adhesive tape:

[0104] 55 parts by weight of organosilicon-modified polyacrylate solution and 6 parts by weight of hydrogenated modified terpene resin (softening point: After mixing 0.6 parts by weight of isophorone diisocyanate and 0.2 parts by weight of aluminum acetylacetonate with an acid value of 3 mg KOH / g, the mixture was allowed to stand until no bubbles were generated. Then, it was coated onto a corona-treated PET film and placed in an oven to dry and cure, controlling the dry adhesive thickness to 25 μm. Finally, the obtained tape was transferred to an oven for curing to obtain a high heat-resistant hydrophobic tape.

[0105] Test methods

[0106] Peel strength test: The test was conducted in accordance with GB / T2792-1998 (Test method for 180° peel strength of adhesive tape). A specially treated SUS304 stainless steel plate was used as the substrate. The obtained tape was adhered to the stainless steel plate according to the standard requirements, and its 180° peel strength was tested.

[0107] Holding power test: The holding power test of the tape is determined in accordance with GB / T 4851-2014, which tests the failure time of the tape under load.

[0108] Initial tack test: The initial tack performance of the tape is tested using the rolling ball method (J.DOW method), and is determined in accordance with GB / T4852-2002 (Test method for initial tack of pressure-sensitive adhesive tape). The test result is expressed as the ball number of the largest steel ball that the pressure-sensitive adhesive tape can adhere to.

[0109] Hydrophobicity test: The tape was attached to a stainless steel plate and soaked in water for 72 hours, and then its 180° peel strength was tested.

[0110] Heat resistance test: According to GB / T 4851-2014 standard, the tape under 1kg load was placed in an oven at 85℃ and 85% humidity to test its failure time.

[0111] Contact angle test: Use a pipette to draw 5 μL of water and drop it onto the tape surface, then test the contact angle of the water droplet on the tape surface.

[0112]

[0113] As can be seen from the performance test results of the examples and comparative examples in Table 1, the high heat-resistant hydrophobic tapes obtained in Examples 1-5 not only have good peel strength and holding power, but also high initial tack, while also having good hydrophobicity and heat resistance.

[0114] Compared to Example 1, Comparative Example 1 does not contain silicone oligomers. Because Comparative Example 1 does not contain silicone, it exhibits higher peel strength (1416 gf) and better holding power at room temperature (greater than 240 h). Furthermore, its initial tack also reaches that of a 10# steel ball. However, hydrophobicity testing shows that the tape has poor hydrophobicity, only 542 gf, far lower than the 1023 gf of Example 1. In addition, its heat resistance is also poor, lasting only 73 h, while Example 1 lasts for more than 240 h. Therefore, the introduction of silicone oligomers can effectively improve the water resistance and heat resistance of the tape.

[0115] Compared to Example 1, Comparative Example 2 used a single curing agent. Because Comparative Example 2 used a single curing agent, isophorone diisocyanate, and did not contain the faster-reacting aluminum acetylacetonate curing agent, the degree of curing was reduced during the curing process, resulting in a lower peel strength of 1135 gf and a holding power of only 187 h at room temperature. However, the initial tack was higher, reaching 12# steel balls. Hydrophobicity testing showed that the tape had poor hydrophobicity, only 738 gf, lower than the 1023 gf of Example 1. Furthermore, its heat resistance was also poor, lasting only 128 h, while Example 1 lasted more than 240 h. It is evident that the use of a single curing agent after introducing silicone oligomers leads to a reduced degree of curing, thereby affecting the tape's peel strength, hydrophobicity, and heat resistance.

[0116] Compared to Example 1, Comparative Example 3 used a single tackifying resin. Because Comparative Example 3 used a single high-softening-point hydrogenated modified terpene resin as its tackifying resin, without the presence of a lower-softening-point hydrogenated modified rosin resin, the high-softening-point tackifying resin could improve the tape's heat resistance to some extent. However, the lack of a low-softening-point tackifying resin resulted in a decrease in initial tack and peel strength compared to Example 1, with a holding power of only 136 hours at room temperature. Hydrophobicity and heat resistance tests showed that the tape exhibited poor hydrophobicity and heat resistance, with values ​​of only 822 gf and 114 hours, respectively. In contrast, Example 1 showed a peel strength of 1023 gf and a heat resistance greater than 240 hours. Therefore, only by combining high-softening-point and low-softening-point tackifying resins can the tackifying resin's function be better utilized to obtain a high-peel-strength, heat-resistant, and hydrophobic tape.

[0117] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and variations without departing from the concept of the present invention, and these modifications all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for preparing a high heat-resistant hydrophobic tape, characterized in that, A mixed adhesive is prepared by thoroughly mixing 50-65 parts by weight of silicone-modified polyacrylate solution, 3-8 parts by weight of tackifying resin, and 0.5-1.0 parts by weight of composite crosslinking agent. After standing, the mixed adhesive is evenly coated onto a corona-treated PET film and dried. The thickness of the dried adhesive layer is 24-26 mm. Finally, the tape is transferred to an oven to cure and obtain the final product. The organosilicon-modified polyacrylate solution is prepared through the following steps: S1.1 Mix 5-8 parts by weight of isooctyl acrylate, 15-22 parts by weight of butyl acrylate, 25-40 parts by weight of ethyl acetate, 0.24-0.48 parts by weight of azobisisobutyronitrile, and 0.1-0.6 parts by weight of methacrylic acid, stir for 20-30 minutes, and then heat to [temperature missing]. Afterwards, the reaction proceeds for 1.5 to 2.5 hours; S1.2 Mix 3-8 parts by weight of vinyl acetate, 1.5-4.5 parts by weight of mercaptoepoxy silicone oligomer, 0.04-0.08 parts by weight of azobisisobutyronitrile, and 3-5 parts by weight of ethyl acetate thoroughly, and then add the mixture dropwise to the above solution over a period of 1.5-2.5 hours. After the addition is complete, continue the reaction for 1-2 hours, and then heat to [temperature missing]. After reacting for 1 to 1.5 hours, the mixture was cooled to room temperature to obtain an organosilicon-modified polyacrylate solution. The aforementioned mercaptoepoxy organosilicon oligomer is prepared by the following steps: S2.1 Mix 20-30 parts by weight of mercaptosilane coupling agent, 5-10 parts by weight of epoxysilane coupling agent, and 80-100 parts by weight of ethanol evenly, then heat to... Stir for 0.5 to 1 hour; S2.2 After mixing deionized water and acid catalyst evenly to form a mixture, control the pH to 2-3, then gradually add 6-10 parts by mass of the mixture to the above solution, control the adding time to 2-3 hours, and continue the reaction for 1-2 hours after the addition is completed; After the S2.3 reaction is complete, cool to room temperature and let stand for 6-8 hours. Then, use vacuum distillation to remove residual ethanol, water and other impurities from the system. After filtration, obtain mercapto-epoxy organosilicon oligomer.

2. The method for preparing a high heat-resistant hydrophobic tape according to claim 1, characterized in that: The tackifying resin is a mixture of hydrogenated modified terpene resin and hydrogenated modified rosin resin, wherein the softening point of the hydrogenated modified terpene resin is [missing information]. Acid value of 2~5 The softening point of hydrogenated modified rosin resin is Acid value of 80~120 The mass ratio of the hydrogenated modified terpene resin to the hydrogenated modified rosin resin is 1:3 to 3:

1.

3. The method for preparing a high heat-resistant hydrophobic tape according to claim 1, characterized in that: The composite crosslinking agent is composed of isophorone diisocyanate and aluminum acetylacetonate in a mass ratio of 5:1 to 2:

1.

4. The method for preparing a high heat-resistant hydrophobic tape according to claim 1, characterized in that: The mercaptosilane coupling agent mentioned in step S2.1 is one of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, or 3-mercaptopropylmethyldimethoxysilane; the epoxysilane coupling agent is one of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltriethoxysilane, or 3-(2,3-epoxypropoxy)propylmethyldiethoxysilane.

5. The method for preparing a high heat-resistant hydrophobic tape according to claim 1, characterized in that: The acid catalyst mentioned in step S2.1 is one of hydrochloric acid, sulfuric acid, acetic acid, formic acid and nitric acid.

6. A high heat-resistant and hydrophobic tape, characterized in that: It is prepared using the preparation method of the high heat-resistant hydrophobic tape according to any one of claims 1 to 5.

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