High-performance rubber pressure-sensitive adhesive and preparation method thereof

Abstract

The invention relates to a high-performance rubber pressure-sensitive adhesive and a preparation method thereof, and belongs to the technical field of hot-melt pressure-sensitive adhesives, and the high-performance rubber pressure-sensitive adhesive comprises the following components by weight: 40-60 parts of natural rubber or synthetic rubber; 20 to 40 parts of tackifying resin; 5-15 parts of a plasticizer; 1-5 parts of an antioxidant; 1-3 parts of an ultraviolet light absorber; 5 to 10 parts of filler; 0.5 to 2 parts of a cross-linking agent; and 300 to 400 parts of a solvent. The pressure-sensitive adhesive is suitable for the fields of labels, adhesive tapes, medical patches and the like, and has three specific functions of excellent adhesion, weather resistance and aging resistance.

Description

Technical Field

[0001] The present application belongs to the technical field of hot melt pressure sensitive adhesives, and in particular relates to a high performance rubber pressure sensitive adhesive and a preparation method thereof. Background Art

[0002] Pressure-sensitive adhesive (PSA) is an adhesive that can generate adhesion under slight pressure and is widely used in industries such as packaging, electronics, and medical treatment. Traditional pressure-sensitive adhesives are mainly based on materials such as acrylates, silicone rubber, or natural rubber. Among them, rubber-based pressure-sensitive adhesives have attracted much attention due to their good initial adhesion, long-lasting adhesion, and weather resistance. However, existing rubber pressure-sensitive adhesives are prone to aging under high temperature and high humidity environments, resulting in a decrease in adhesion performance, which limits their scope of application. Therefore, it is of great significance to develop a rubber pressure-sensitive adhesive with excellent weather resistance, aging resistance, and adhesion performance.

[0003] In the prior art 1 of hot-melt pressure-sensitive adhesive, preparation method thereof and label product with publication number CN119490817A, among the core components TPE (styrene elastomer, 15-20%), tackifying resin (50-55%), softener (25-35%) and heat-resistant agent (nano-alumina), emphasis is placed on the synergistic effect of excess tackifying resin and softener on heat / humidity resistance; this enables the adhesive to have functions such as heat resistance, moisture resistance and flexibility, and is widely used in the field of diapers.

[0004] In the second prior art application, a hot-melt pressure-sensitive adhesive for cotton packing tape and its preparation method, published under publication number CN119684946A, the tape emphasizes UV resistance, high and low temperature resistance, aging resistance, and frost resistance, targeting the harsh climates of Xinjiang and other regions. Its core components are a thermoplastic elastomer + rubber (butyl rubber and polyisobutylene), rubber filler oil, monomer resin, additives (antioxidant, UV absorber), and petroleum resin; the UV absorber is added to achieve aging resistance.

[0005] As can be seen from the above-mentioned prior art, any specific application requires specific functions. Achieving these functions requires adjusting the core components and their ratios, as well as refining the preparation methods. For example, prior art one employs a solvent-free process, with softeners added stepwise, stirring in a high-temperature oil bath at 120°C-180°C, and then vacuuming. Prior art two utilizes premixed butyl rubber, followed by heating and mixing, and finally vacuuming; this involves temperature control at 80°C-120°C and specific process conditions. Summary of the Invention

[0006] The purpose of the present invention is to address the existing problem that pressure-sensitive adhesives suitable for use in the fields of labels, tapes, medical patches, etc. require three specific functions: excellent adhesion, weather resistance and aging resistance. The present invention provides a rubber pressure-sensitive adhesive with excellent adhesion, weather resistance and aging resistance and a preparation method thereof.

[0007] In order to achieve the above technical objectives, the following technical solutions are now provided. In the first aspect, a high-performance rubber pressure-sensitive adhesive comprises, by weight, the following components:

[0008] Natural rubber or synthetic rubber: 40-60 parts;

[0009] Tackifying resin: 20-40 parts;

[0010] Plasticizer: 5-15 parts;

[0011] Antioxidants: 1-5 parts;

[0012] Ultraviolet absorber: 1-3 parts;

[0013] Filler: 5-10 parts;

[0014] Cross-linking agent: 0.5-2 parts;

[0015] Solvent: 300-400 parts.

[0016] In an operative embodiment, the natural rubber is smoked sheet rubber or standard rubber, and the synthetic rubber is styrene-butadiene rubber or butyl rubber.

[0017] In an practicable embodiment, the tackifying resin is one of rosin resin, terpene resin or petroleum resin.

[0018] In an operative embodiment, the plasticizer is phthalate esters or epoxidized vegetable oil.

[0019] In an operative embodiment, the antioxidant is a phenolic or aminic antioxidant.

[0020] In an operative embodiment, the ultraviolet absorber is a benzotriazole or a benzophenone.

[0021] In an practicable manner, the filler is one of calcium carbonate, talc or silicon dioxide.

[0022] In an operative embodiment, the cross-linking agent is sulfur or peroxide.

[0023] In an operative embodiment, the solvent is one of toluene, ethyl acetate or acetone.

[0024] In a second aspect, a method for preparing the high-performance rubber pressure-sensitive adhesive according to any one of the first aspects comprises the following steps:

[0025] Step 1: masticating the natural rubber or synthetic rubber on an open mill for 10-15 minutes at a temperature of 58-65° C. to reduce the molecular weight to a suitable range of 100,000-200,000 to form a natural rubber matrix or a synthetic rubber matrix;

[0026] Step 2: Mix the natural rubber matrix or synthetic rubber matrix formed in step 1 with a tackifying resin, a plasticizer, an antioxidant, an ultraviolet absorber, a filler, and a crosslinking agent using a high-speed disperser at a speed of 800 rpm to 1200 rpm for 30 min to 45 min until the mixture is uniform and free of particles;

[0027] Step 3: Dissolve the mixture in step 2 in an appropriate amount of solvent, the amount of solvent is 2-4 times the amount of the mixture, and the dissolution temperature is controlled at 55°C to form a uniform glue solution;

[0028] Step 4: Apply the adhesive solution in step 3 on the substrate, wherein the wet film thickness after coating is 60 μm-150 μm;

[0029] Step 5: Dry the wet film in step 4. In the first stage, dry it at 58°C-65°C for 5-10 minutes. Then enter the second stage and dry it at 80°C-100°C for 10-15 minutes. After cross-linking and curing, the rubber pressure-sensitive adhesive product is obtained.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] By optimizing the ratio of rubber to tackifying resin, the initial tack and sustained tack of the pressure-sensitive adhesive are significantly improved. The addition of antioxidants and UV absorbers significantly enhances the weathering and aging resistance of the pressure-sensitive adhesive. The use of environmentally friendly plasticizers and solvents reduces environmental pollution. The preparation process is simple and amenable to industrial production. DETAILED DESCRIPTION

[0032] Example 1, a high-performance rubber pressure-sensitive adhesive, comprising, by weight, 40-60 parts of natural rubber or synthetic rubber; 20-40 parts of tackifying resin; 5-15 parts of plasticizer; 1-5 parts of antioxidant; 1-3 parts of ultraviolet absorber; 5-10 parts of filler; 0.5-2 parts of cross-linking agent; and 300-400 parts of solvent.

[0033] In this embodiment, the natural rubber is smoked rubber or standard rubber, and the synthetic rubber is styrene-butadiene rubber or butyl rubber.

[0034] In this embodiment, the tackifying resin is one of rosin resin, terpene resin or petroleum resin.

[0035] In this embodiment, the plasticizer is phthalate esters or epoxidized vegetable oil.

[0036] In this embodiment, the antioxidant is a phenolic or amine antioxidant.

[0037] In this embodiment, the ultraviolet absorber is a benzotriazole or benzophenone type.

[0038] In this embodiment, the filler is one of calcium carbonate, talc or silicon dioxide.

[0039] In this embodiment, the cross-linking agent is sulfur or peroxide.

[0040] In this embodiment, the solvent is one of toluene, ethyl acetate or acetone.

[0041] Example 2, a method for preparing the high-performance rubber pressure-sensitive adhesive described in the example, comprising the following steps:

[0042] Step 1: masticating the natural rubber or synthetic rubber on an open mill for 10-15 minutes at a temperature of 58-65° C. to reduce the molecular weight to a suitable range of 100,000-200,000 to form a natural rubber matrix or a synthetic rubber matrix;

[0043] Step 2: Mix the natural rubber matrix or synthetic rubber matrix formed in step 1 with a tackifying resin, a plasticizer, an antioxidant, an ultraviolet absorber, a filler, and a crosslinking agent using a high-speed disperser at a speed of 800 rpm to 1200 rpm for 30 min to 45 min until the mixture is uniform and free of particles;

[0044] Step 3: Dissolve the mixture in step 2 in an appropriate amount of solvent, the amount of solvent is 2-4 times the amount of the mixture, and the dissolution temperature is controlled at 55°C to form a uniform glue solution;

[0045] Step 4: Apply the adhesive solution in step 3 on the substrate, wherein the wet film thickness after coating is 60 μm-150 μm;

[0046] Step 5: Dry the wet film in step 4. In the first stage, dry it at 58°C-65°C for 5-10 minutes. Then enter the second stage and dry it at 80°C-100°C for 10-15 minutes. After cross-linking and curing, the rubber pressure-sensitive adhesive product is obtained.

[0047] The following specific examples are given in combination with the above-mentioned embodiment 1 and embodiment 2:

[0048] In Example 1, 50 parts of natural rubber were masticated on an open mill for 10 minutes at a temperature of 60° C. to form a natural rubber matrix for later use.

[0049] Then add 30 parts of rosin resin, 10 parts of dioctyl phthalate, 2 parts of phenolic antioxidant, 1 part of benzotriazole ultraviolet absorber, 5 parts of calcium carbonate and 1 part of sulfur, use a high-speed disperser at a speed of 800 rpm, and mix for 30 minutes until uniform and free of particles.

[0050] The mixture was dissolved in toluene, the amount of toluene solvent was twice that of the mixture, and the dissolution temperature was controlled at 55°C to form a uniform glue solution.

[0051] The adhesive solution is coated on a PET film, wherein the wet film thickness after coating is 60 μm. The wet film is dried, and in the first stage, a temperature of 60° C. is used for drying for 5 minutes; then in the second stage, a temperature of 80° C. is used for drying for 10 minutes. After cross-linking and curing, a rubber pressure-sensitive adhesive product is obtained.

[0052] In Example 2, 60 parts of styrene-butadiene rubber were masticated on an open mill for 15 minutes at a temperature of 60° C. to form a synthetic rubber matrix for later use.

[0053] Add 40 parts of terpene resin, 15 parts of epoxidized vegetable oil, 3 parts of amine antioxidant, 2 parts of benzophenone ultraviolet absorber, 10 parts of talc and 2 parts of peroxide, use a high-speed disperser at a speed of 1200 rpm, and mix for 45 minutes until uniform and free of particles.

[0054] The mixture was dissolved in ethyl acetate, the amount of ethyl acetate solvent was 3 times that of the mixture, and the dissolution temperature was controlled at 55°C to form a uniform glue solution.

[0055] The adhesive solution is coated on the non-woven fabric, wherein the wet film thickness after coating is 150 μm, and the wet film is dried. In the first stage, the temperature is 60° C. for 10 minutes; then the second stage is carried out, and the temperature is 100° C. for 15 minutes. After cross-linking and curing, the rubber pressure-sensitive adhesive product is obtained.

[0056] Perform performance tests on Example 1 and Example 2, including:

[0057] Peel strength test: Referring to the standard GB / T2792-2014, the test specimen width is 24mm, reinforced with 75μm PET, attached to a standard mirror steel plate and a copper foil plate, and left to stand at room temperature for 72 hours. The 180° peel strength is tested at a test rate of 300mm / min.

[0058] High-temperature constant load test: The test specimen is 24mm wide and 100mm long. It is reinforced with 75μm PET and attached to a standard mirror steel plate. It is left to stand for 20 minutes. The test specimen is placed in a 100℃ oven with the tail end of the tape at a 90° angle to the steel plate and a 50g weight hung on the tail end. It is placed in a 100℃ environment for 12 hours. The displacement of the tape is observed and recorded.

[0059] Hardness test: The test specimen is 24mm wide, the adhesive layer is superimposed to 2mm, and it is attached to a standard glass plate. The hardness is tested using a hardness tester.

[0060] Holding force test: The test specimen is 24mm wide and 24mm long, reinforced with 75μm PET, attached to a mirror steel plate used for standard holding force test, and left to stand for 30 minutes. The test specimen is placed in an 85℃ oven with a 1kg weight hung on the end. It is left at 85℃ for 24 hours, and the displacement of the tape is observed and recorded.

[0061] Aging resistance test: Cut the test sample into the same size as the tempered glass of the mobile phone and stick it on the glass plate of the mobile phone. Place it in an oven with a high temperature of 85℃ and a relative humidity of 85 for 24 hours. Take out the sample and observe whether the adhesive layer contaminates the glass.

[0062] The test results are shown in Table 1:

[0063]

[0064] Table 1

[0065] Test results show that Example 1, prepared using Example 2, exhibits excellent adhesion, heat resistance, and aging resistance. Excellent adhesion to steel plates and copper foil is demonstrated, while high-temperature retention and lack of displacement under a constant load demonstrate excellent heat resistance. Its long-term pollution-free performance in high-temperature and high-humidity environments demonstrates its aging resistance. The product is particularly suitable for applications such as labels, tapes, and medical patches, and has broad market prospects.

[0066] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0067] In the description of this specification, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships, which are only for the convenience of describing the technical solution of this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this patent application.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this patent application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0069] In this specification, unless otherwise specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this specification based on specific circumstances.

[0070] In this specification, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it can mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it can mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0071] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0072] Although embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A high performance rubber pressure-sensitive adhesive, characterized in that: By weight, the components include: Natural rubber or synthetic rubber: 40-60 parts; Tackifying resin: 20-40 parts; Plasticizer: 5-15 parts; Antioxidants: 1-5 parts; Ultraviolet absorber: 1-3 parts; Filler: 5-10 parts; Cross-linking agent: 0.5-2 parts; Solvent: 300-400 parts.

2. The high performance rubber pressure sensitive adhesive according to claim 1, characterized in that The natural rubber is smoked sheet rubber or standard rubber, and the synthetic rubber is styrene-butadiene rubber or butyl rubber.

3. The high performance rubber pressure sensitive adhesive according to claim 1, characterized in that: The tackifying resin is one of rosin resin, terpene resin or petroleum resin.

4. The high performance rubber pressure sensitive adhesive according to claim 1, characterized in that: The plasticizer is phthalate or epoxidized vegetable oil.

5. The high performance rubber pressure sensitive adhesive according to claim 1, characterized in that: The antioxidant is a phenolic antioxidant or an amine antioxidant.

6. The high performance rubber pressure sensitive adhesive according to claim 1, characterized in that: The ultraviolet absorber is a benzotriazole or a benzophenone.

7. The high performance rubber pressure sensitive adhesive according to claim 1, characterized in that: The filler is one of calcium carbonate, talc or silicon dioxide.

8. The high performance rubber pressure sensitive adhesive according to claim 1, characterized in that: The cross-linking agent is sulfur or peroxide.

9. The high performance rubber pressure sensitive adhesive according to claim 1, characterized in that: The solvent is one of toluene, ethyl acetate or acetone.

10. A method for preparing the high-performance rubber pressure-sensitive adhesive according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: masticating the natural rubber or synthetic rubber on an open mill for 10-15 minutes at a temperature of 58-65° C. to reduce the molecular weight to a suitable range of 100,000-200,000 to form a natural rubber matrix or a synthetic rubber matrix; Step 2: Mix the natural rubber matrix or synthetic rubber matrix formed in step 1 with a tackifying resin, a plasticizer, an antioxidant, an ultraviolet absorber, a filler, and a crosslinking agent using a high-speed disperser at a speed of 800 rpm to 1200 rpm for 30 min to 45 min until the mixture is uniform and free of particles; Step 3: Dissolve the mixture in step 2 in an appropriate amount of solvent, the amount of solvent is 2-4 times the amount of the mixture, and the dissolution temperature is controlled at 55°C to form a uniform glue solution; Step 4: Apply the adhesive solution in step 3 on the substrate, wherein the wet film thickness after coating is 60 μm-150 μm; Step 5: Dry the wet film in step 4. In the first stage, dry it at 58°C-65°C for 5-10 minutes. Then enter the second stage and dry it at 80°C-100°C for 10-15 minutes. After cross-linking and curing, the rubber pressure-sensitive adhesive product is obtained.

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