Adhesive, preparation method thereof and adhesive tape

Abstract

The invention discloses an adhesive, a preparation method thereof and an adhesive tape. The adhesive comprises the following components: water-based resin, a curing agent, a plasticizer, a cross-linking agent, a hydrophilic auxiliary agent and deionized water. The water-based resin comprises water-based polyamide resin, water-based polyurethane-acrylic acid copolymer resin and water-based fluororesin; the cross-linking agent comprises an isocyanate cross-linking agent, an epoxy resin cross-linking agent and an ethylene cross-linking agent, and the hydrophilic auxiliary agent comprises polyvinyl alcohol and polyvinylpyrrolidone; according to the adhesive, the preparation method thereof and the adhesive tape, the technical problems of adhesive power, stability, flexibility, processability, environmental protection property, wettability and the like of the adhesive are solved by optimizing the formula of the adhesive, especially the combination of the water-based resin, the cross-linking agent, the plasticizer and the hydrophilic aid, and the requirements on high-performance adhesives in industrial application are met.

Description

Technical Field

[0001] The invention relates to an adhesive and a preparation method thereof and an adhesive tape. Background Art

[0002] As an important industrial material, adhesives are widely used in many industries such as electronics, automobiles, packaging, and construction. With the increasing requirements for environmental protection and the demand for high-performance products, the performance, environmental friendliness, and scope of application of adhesives have become key research and development directions. At present, most common adhesives on the market use solvent-based or water-based resins as base materials. Although these adhesives meet basic needs to a certain extent, there are still many shortcomings, which are mainly reflected in the following aspects:

[0003] Traditional adhesives will experience decreased adhesion and peel strength after long-term use or in extreme environments (such as high humidity, high temperature, etc.). In particular, for some specific substrates (such as metals, plastics, etc.), the adhesive effect of the adhesive cannot be maintained for a long time, resulting in aging and failure of the adhesive layer. Therefore, the existing technology has not yet provided a durable and widely applicable solution to the adhesion and stability of adhesives.

[0004] Many traditional adhesives use solvent-based formulas, which contain a large amount of volatile organic compounds (VOCs). These chemicals not only pollute the environment, but also pose potential hazards to the health of operators. With increasingly stringent environmental regulations, how to reduce VOCs emissions and produce low-toxic, pollution-free adhesives has become an urgent problem to be solved in the adhesive field.

[0005] The fluidity, coating performance and flexibility of the adhesive after curing are the key factors affecting the use effect of the adhesive. In the existing technology, although some water-based adhesives have improved environmental performance, they have poor performance in flexibility, fluidity and processability, especially in large-area coating or complex-shaped substrates, resulting in low production efficiency and insufficient mechanical strength and durability of the product.

[0006] For some adhesives used in humid environments or in contact with water, the wettability and hydrophilicity of the adhesive directly affect its service life and performance. In the prior art, many water-based adhesives will fall off and become ineffective when in contact with water or in a humid environment, resulting in the inability to achieve good bonding effects in some special environments.

[0007] The curing speed of adhesives directly affects production efficiency, especially in large-scale industrial applications. Too slow a curing speed may lead to a long production cycle, which in turn affects overall output and benefits. At the same time, the effect of cross-linking during the curing process is crucial to the mechanical properties of the adhesive. In the curing process of existing adhesives, the cross-linking reaction is often difficult to control uniformly, resulting in differences in the strength and durability of the adhesive layer after curing. Summary of the invention

[0008] The object of the present invention is to provide an adhesive and a preparation method thereof and an adhesive tape. By optimizing the formula of the adhesive, especially the combination of a water-based resin, a cross-linking agent, a plasticizer and a hydrophilic additive, many technical problems in terms of adhesion, stability, flexibility, processability, environmental protection and wettability of the adhesive are solved, thereby meeting the demand for high-performance adhesives in industrial applications.

[0009] The technical solution adopted by the present invention to solve its technical problem is:

[0010] An adhesive comprises the following components: water-based resin, curing agent, plasticizer, cross-linking agent, hydrophilic auxiliary agent and deionized water; the water-based resin comprises water-based polyamide resin, water-based polyurethane-acrylic copolymer resin and water-based fluororesin; the cross-linking agent comprises isocyanate, epoxy resin and ethylene cross-linking agent, and the hydrophilic auxiliary agent comprises polyvinyl alcohol and polyvinyl pyrrolidine.

[0011] Preferably, the composition comprises the following components in weight percentage: water-based resin: 30-50%, curing agent: 5-20%, plasticizer: 5-15%, cross-linking agent: 0.5-5%, hydrophilic additive: 0.1-3%, and the balance is deionized water.

[0012] Preferably, the weight percentages of the various components in the water-based resin are: water-based polyamide resin: 30-50%, water-based polyurethane-acrylic copolymer resin 20-40%, water-based fluororesin 10-20%, the weight percentages of the various components in the cross-linking agent are: isocyanate cross-linking agent 40-60%, epoxy resin cross-linking agent 20-30%, ethylene cross-linking agent 10-20%; the weight percentages of the various components in the hydrophilic additive are: polyvinyl alcohol 40-70%, polyvinyl pyrrolidine 30-60%.

[0013] Preferably, the curing agent is selected from one or more of a polyurethane curing agent, an epoxy resin curing agent or a polyisocyanate curing agent.

[0014] Preferably, the plasticizer is one or more of phthalate esters, fatty acid esters or phosphate esters.

[0015] Another technical problem to be solved by the present invention is to provide a method for preparing an adhesive, comprising the following steps:

[0016] Mixing a water-based polyamide resin, a water-based polyurethane-acrylic copolymer resin and a water-based fluororesin in a predetermined ratio to obtain a water-based resin mixture;

[0017] Add polyvinyl alcohol and polyvinyl pyrrolidine to the aqueous resin mixture and continue stirring until completely dissolved and evenly dispersed;

[0018] Add isocyanate, epoxy resin and vinyl crosslinking agent, and stir until evenly dispersed;

[0019] Add plasticizer and continue stirring;

[0020] Add curing agent and stir until complete reaction;

[0021] Use deionized water to adjust the viscosity and pH value of the adhesive and stir evenly;

[0022] Filter to remove impurities and obtain the finished adhesive product.

[0023] Preferably, the temperature is controlled at 20-50°C during the stirring process.

[0024] Another technical problem to be solved by the present invention is to provide a tape, the adhesive surface of which is coated with an adhesive as described in any of the above items, the base material of the tape is one or more of polyester film, polyethylene film, polypropylene film, non-woven fabric, paper or metal foil, and the layer thickness of the adhesive is 5-50μm.

[0025] Another technical problem to be solved by the present invention is to provide the adhesive tape so as to coat the adhesive on the surface of the substrate by spraying, dipping or coating.

[0026] Another technical problem to be solved by the present invention is to provide a method for preparing an adhesive tape, comprising the following steps:

[0027] The prepared adhesive is evenly coated on the surface of the selected substrate;

[0028] Through the curing treatment, the adhesive is completely cured to obtain a tape with stable adhesion;

[0029] The cured tape is cut to the required size and packaged.

[0030] The beneficial effects of the present invention are:

[0031] By using a variety of water-based resins such as water-based polyamide resin, water-based polyurethane-acrylic copolymer resin and water-based fluororesin, this solution can improve the adhesion of adhesives on various substrates while ensuring long-term stability and reliability under different environmental conditions; the use of water-based adhesives solves the environmental pollution and health hazards caused by volatile organic compounds (VOCs) contained in traditional solvent-based adhesives. This solution uses water-based resins to reduce VOC emissions and meet green environmental protection requirements.

[0032] The addition of plasticizers (such as phenyl phosphates or fatty acid esters) and cross-linking agents (such as isocyanates, epoxy resins, and ethylene cross-linking agents) in this solution can effectively improve the fluidity, flexibility, and processing properties of the adhesive, and at the same time form an adhesive layer with excellent mechanical properties after curing; the addition of hydrophilic additives (such as polyvinyl alcohol and polyvinyl pyrrolidine) helps to improve the wettability and hydrophilicity of the adhesive, so that it can still maintain good bonding properties when in contact with water or a humid environment, thereby solving the problem of performance degradation of traditional adhesives in a humid environment.

[0033] In the application of adhesives, the curing speed and cross-linking effect directly affect the performance and production efficiency of the final adhesive. This solution can effectively increase the cross-linking density of the adhesive, optimize the curing rate, and thus improve the production efficiency and mechanical properties of the product after curing by combining isocyanate, epoxy resin and ethylene cross-linking agents; the addition of silica improves the mechanical strength of the tape and enhances its tear and tensile resistance. The addition of aluminum powder not only improves the thermal reflectivity of the tape, but also helps to improve the overall hardness and durability of the tape, further solving the problem of the tape being easily deformed or damaged under high temperature and mechanical stress. Specific implementation methods

[0035] The principles and features of the present invention are described below, and the examples given are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described more specifically by way of examples in the following paragraphs.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0037] Example 1

[0038] An adhesive comprising the following components:

[0039]

[0040] A method for preparing an adhesive comprises the following steps:

[0041] Mixing water-based polyamide resin, water-based polyurethane-acrylic copolymer resin and water-based fluororesin in proportion to obtain a water-based resin mixture;

[0042] Add polyvinyl alcohol and polyvinyl pyrrolidine and continue stirring until completely dissolved and evenly dispersed;

[0043] Add isocyanate, epoxy resin and vinyl crosslinking agent and stir evenly;

[0044] Add plasticizer and continue stirring;

[0045] Add curing agent and stir until complete reaction;

[0046] Adjust the viscosity and pH value with deionized water and stir evenly;

[0047] Filter to remove impurities and obtain the finished adhesive product.

[0048] A method for preparing an adhesive tape comprises the following steps:

[0049] The prepared adhesive is evenly coated on the surface of the polyester film;

[0050] Through the curing treatment, the adhesive is completely cured to obtain a tape with stable adhesion;

[0051] The cured tape is cut to the required size and packaged.

[0052] Example 2

[0053] An adhesive comprising the following components:

[0054]

[0055] A method for preparing an adhesive comprises the following steps:

[0056] Mixing water-based polyamide resin, water-based polyurethane-acrylic copolymer resin and water-based fluororesin in proportion to obtain a water-based resin mixture;

[0057] Add polyvinyl alcohol and polyvinyl pyrrolidine and continue stirring until completely dissolved and evenly dispersed;

[0058] Add isocyanate, epoxy resin and vinyl crosslinking agent and stir evenly;

[0059] Add phosphate plasticizer and continue stirring evenly;

[0060] Add curing agent and stir until complete reaction;

[0061] Adjust the viscosity and pH value with deionized water and stir evenly;

[0062] Filter to remove impurities and obtain the finished adhesive product.

[0063] A method for preparing an adhesive tape comprises the following steps:

[0064] The prepared adhesive is evenly coated on the surface of the polypropylene film;

[0065] Through the curing treatment, the adhesive is completely cured to obtain a tape with stable adhesion;

[0066] The cured tape is cut to the required size and packaged.

[0067] Example 3

[0068] An adhesive comprising the following components:

[0069]

[0070] A method for preparing an adhesive comprises the following steps:

[0071] Mixing water-based polyamide resin, water-based polyurethane-acrylic copolymer resin and water-based fluororesin in proportion to obtain a water-based resin mixture;

[0072] Add polyvinyl alcohol and polyvinyl pyrrolidine and continue stirring until completely dissolved and evenly dispersed;

[0073] Add isocyanate, epoxy resin and vinyl crosslinking agent and stir evenly;

[0074] Add plasticizer and continue stirring;

[0075] Add curing agent and stir until complete reaction;

[0076] Adjust the viscosity and pH value with deionized water and stir evenly;

[0077] Filter to remove impurities and obtain the finished adhesive product.

[0078] A method for preparing an adhesive tape comprises the following steps:

[0079] Evenly apply the prepared adhesive on the surface of the non-woven fabric;

[0080] Through the curing treatment, the adhesive is completely cured to obtain a tape with stable adhesion;

[0081] The cured tape is cut to the required size and packaged.

[0082] Experimental example

[0083] Experimental Materials:

[0084] Adhesive samples: Example 1, Example 2, Example 3

[0085] Control sample: conventional adhesive on the market (polyurethane-based adhesive)

[0086] Test substrates: stainless steel, aluminum alloy, PVC, wood (different surface types are used to verify the suitability of the adhesive)

[0087] Laboratory equipment: electronic dynamometer, humidity chamber, vibration test bench, constant temperature and humidity chamber, microscope, etc.

[0088] Experimental methods:

[0089] Adhesion test

[0090] Purpose: To evaluate the adhesion of different adhesives.

[0091] method:

[0092] Stainless steel and PVC surfaces were selected as test substrates.

[0093] Apply different adhesives on the surface of the substrate and wait for them to fully cure.

[0094] The peel test was performed using an electronic tensile tester, and the peel strength (unit: N / mm) was recorded.

[0095] Compare the performance of Example 1, Example 2, Example 3 and the existing adhesive on different substrates.

[0096] Table 1 Adhesion test record

[0097] sample Substrate Peel strength (N / mm) Remark Example 1 Stainless steel 3.2 24 hours after curing, room temperature Example 1 PVC 2.8 24 hours after curing, room temperature Example 2 Stainless steel 3.5 24 hours after curing, room temperature Example 2 PVC 3.0 24 hours after curing, room temperature Example 3 Stainless steel 4.0 24 hours after curing, room temperature Example 3 PVC 3.3 24 hours after curing, room temperature Existing adhesives Stainless steel 2.5 24 hours after curing, room temperature Existing adhesives PVC 2.0 24 hours after curing, room temperature

[0098] The adhesion of Example 1, Example 2, and Example 3 is significantly higher than that of the existing adhesive, especially on metal and plastic substrates. Example 3 has the strongest adhesion on aluminum alloy and PVC, reaching 1.5 times that of the existing adhesive.

[0099] Stability test

[0100] Purpose: To evaluate the stability of adhesives under different environmental conditions.

[0101] method:

[0102] Each adhesive sample was coated on the surface of aluminum alloy and wood, and after curing, was placed in a constant temperature and humidity test box set at high temperature (70°C) and low temperature (-20°C) environments.

[0103] Check the change of adhesion regularly and test the bond strength by tensile test or peel test.

[0104] The stability performance of each adhesive was recorded and compared with existing adhesives.

[0105] Table 2 Stability test record

[0106]

[0107] In high and low temperature environments, the adhesion of Example 1, Example 2 and Example 3 changes little, indicating that they have good thermal stability and low temperature stability. In contrast, the existing adhesive shows a large decrease in adhesion in a high temperature environment.

[0108] Flexibility test

[0109] Purpose: To evaluate the flexibility of adhesives.

[0110] method:

[0111] Apply different adhesive samples on the surface of aluminum foil or film and wait for them to cure.

[0112] Bend the cured adhesive sample to 90 degrees and hold for 10 seconds.

[0113] Observe the adhesive for cracks or peeling.

[0114] The flexibility behavior of the adhesive was recorded on a scale of 0 (brittle) to 5 (extremely flexible).

[0115] Table 3 Flexibility test record

[0116]

[0117]

[0118] In the bending test, no obvious cracks or falling off occurred in Example 1, Example 2 and Example 3, showing good flexibility. The existing adhesive had slight cracks under the same test conditions, and had poor flexibility.

[0119] Processability test

[0120] Purpose: To evaluate the processability of adhesives, including coating properties, curing speed and processing temperature range.

[0121] method:

[0122] The coating rheology and working time of each adhesive were tested at laboratory temperature (20°C).

[0123] Record the coating effect of the adhesive, whether there is sagging, bubbles, etc.

[0124] Evaluate the cure time (e.g., the difference between cure time at room temperature and under accelerated cure conditions).

[0125] Analyze the processing temperature range and applicability of each adhesive.

[0126] Table 4 Processability test record

[0127]

[0128] The adhesives of all the examples showed excellent processability, smooth coating, and no obvious sagging. The curing time of Example 3 was relatively short, which was suitable for rapid processing requirements. Existing adhesives cured too slowly in high temperature environments, affecting production efficiency.

[0129] Environmental testing

[0130] Purpose: To verify whether the adhesive meets environmental protection requirements.

[0131] method:

[0132] The volatile organic compound (VOC) content of each adhesive is tested and analyzed by gas chromatography (GC) or other appropriate methods.

[0133] Evaluate the difficulty of waste disposal and potential harm to the environment of the adhesive after curing.

[0134] The VOC emissions of each adhesive were recorded and compared with conventional adhesives on the market.

[0135] Table 5 Environmental protection test record

[0136]

[0137] The VOC content of Example 1, Example 2 and Example 3 is low, all meet environmental protection standards, and the solidified waste is easy to handle. The VOC content of existing adhesives is high, and the solidified waste is difficult to handle.

[0138] 6. Wettability test

[0139] Purpose: To evaluate the wetting properties of adhesives on different substrate surfaces.

[0140] method:

[0141] Apply different adhesives to smooth surfaces (such as glass, metal, plastic, etc.).

[0142] The contact angle of the adhesive on the surfaces of different substrates was measured by a contact angle goniometer.

[0143] The contact angle is recorded, with lower contact angles generally indicating better wettability.

[0144] The wettability of Example 1, Example 2, Example 3 and the existing adhesive were compared.

[0145] Table 6 Wettability Test Record

[0146]

[0147] The contact angles of Examples 1, 2 and 3 on different substrate surfaces are significantly lower than those of existing adhesives, showing better wettability. In particular, Example 2 has the best wettability on metal and plastic surfaces.

[0148] Through the above experiments, Examples 1, 2 and 3 all outperform existing adhesives in terms of adhesion, stability, flexibility, processability, environmental protection and wettability. In particular, the three examples show significant advantages in terms of adhesion and stability, especially Example 3, which has the strongest adhesion and good thermal stability. At the same time, these examples also have obvious advantages in terms of environmental protection and wettability, which meet the environmental protection requirements and practical application needs of modern adhesives.

[0149] The above embodiments of the present invention are not intended to limit the protection scope of the present invention, and the implementation modes of the present invention are not limited thereto. All other modifications, replacements or changes made to the above structures of the present invention based on the above contents of the present invention, in accordance with common technical knowledge and customary means in the art, without departing from the above basic technical ideas of the present invention, should fall within the protection scope of the present invention.

Claims

1. An adhesive, characterized in that: The invention comprises the following components: water-based resin, curing agent, plasticizer, cross-linking agent, hydrophilic auxiliary agent and deionized water; the water-based resin comprises water-based polyamide resin, water-based polyurethane-acrylic copolymer resin and water-based fluororesin; the cross-linking agent comprises isocyanate, epoxy resin and ethylene cross-linking agent, and the hydrophilic auxiliary agent comprises polyvinyl alcohol and polyvinyl pyrrolidine.

2. The adhesive according to claim 1, characterized in that The invention comprises the following components in weight percentage: water-based resin: 30-50%, curing agent: 5-20%, plasticizer: 5-15%, cross-linking agent: 0.5-5%, hydrophilic auxiliary agent: 0.1-3%, and the balance is deionized water.

3. The adhesive according to claim 1, characterized in that The weight percentages of the various components in the water-based resin are: water-based polyamide resin: 30-50%, water-based polyurethane-acrylic copolymer resin 20-40%, water-based fluororesin 10-20%, the weight percentages of the various components in the cross-linking agent are: isocyanate cross-linking agent 40-60%, epoxy resin cross-linking agent 20-30%, ethylene cross-linking agent 10-20%; the weight percentages of the various components in the hydrophilic additive are: polyvinyl alcohol 40-70%, polyvinyl pyrrolidine 30-60%.

4. The adhesive according to claim 1, characterized in that The curing agent is selected from one or more of a polyurethane curing agent, an epoxy resin curing agent or a polyisocyanate curing agent.

5. The adhesive according to claim 1, characterized in that: The plasticizer is one or more of phthalate esters, fatty acid esters or phosphate esters.

6. A method for preparing an adhesive, characterized in that: The following steps are involved: Mixing a water-based polyamide resin, a water-based polyurethane-acrylic copolymer resin and a water-based fluororesin in a predetermined ratio to obtain a water-based resin mixture; Add polyvinyl alcohol and polyvinyl pyrrolidine to the aqueous resin mixture and continue stirring until completely dissolved and evenly dispersed; Add isocyanate, epoxy resin and vinyl crosslinking agent, and stir until evenly dispersed; Add plasticizer and continue stirring; Add curing agent and stir until complete reaction; Use deionized water to adjust the viscosity and pH value of the adhesive and stir evenly; Filter to remove impurities and obtain the finished adhesive product.

7. The method for preparing the adhesive according to claim 6, characterized in that: The temperature was controlled at 20-50°C during the stirring process.

8. An adhesive tape, characterized in that: The adhesive side of the tape is coated with An adhesive according to any one of claims 1-7, wherein the substrate of the adhesive tape is one or more of polyester film, polyethylene film, polypropylene film, non-woven fabric, paper or metal foil, and the layer thickness of the adhesive is 5-50 μm.

9. The high temperature resistant pressure sensitive adhesive tape according to claim 8, characterized in that: The adhesive tape is applied to the surface of the substrate by spraying, dipping or coating.

10. A method for preparing an adhesive tape, characterized in that: The following steps are involved: Evenly coating the prepared adhesive on the surface of the selected substrate; Through the curing treatment, the adhesive is completely cured to obtain a tape with stable adhesion; The cured tape is cut to the required size and packaged.

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