Low-foam low-glass transition temperature water-based adhesive and preparation method thereof
By adopting low-foam and low-glass transition temperature aqueous adhesive formulas, the problems of high cost, high foam and unstable performance of traditional adhesives are solved, and better flexibility, low-temperature performance and adhesion are achieved, and production efficiency and user experience are improved.
Patent Information
- Application Number
- CN202411731616.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-03-07
AI Technical Summary
Traditionally, pure acrylic emulsion aqueous adhesives have high production costs, frequent foam generation and unstable performance, resulting in increased peeling force and affecting user experience and production efficiency.
The aqueous adhesive formula with low foam type and low glass transition temperature is adopted, including 33-40 parts butyl acrylate, 0.1-0.6 parts acrylic acid, 1-4 parts glycolic acid, 1 part ammonium persulfate, 1 part composite emulsifier, 1 part wetting agent, 1 part defoaming agent, 1 part pH value regulator and 23 parts deionized water. Through fine emulsification and reaction control, foam generation and glass transition temperature are reduced.
The water-based adhesive with low foam type and low glass transition temperature has better flexibility, low temperature performance and adhesion, reduces the impact of foam, and ensures the performance stability and user experience of the adhesive.
Smart Images
Figure CN119570401A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of water-based adhesives, and in particular to a low-foaming, low-glass-transition-temperature water-based adhesive and a preparation method thereof. Background Art
[0002] Water-based adhesives are widely used in packaging, construction, automobiles and other fields. Their main advantages are environmental protection, solvent-free, and low VOC (volatile organic compound) emissions. However, traditional medium-viscosity pure acrylic emulsion water-based adhesives have a series of challenges, especially in terms of cost, performance stability and production process control. First of all, the production cost of pure acrylic emulsion is relatively high, and the difficulty in foam generation and reaction control often leads to unstable product quality. Especially during the lamination reaction, the generation of foam will affect the performance of the adhesive and the appearance of the final product. In addition, N-hydroxymethyl acrylamide (HMA), as a common cross-linking agent, can effectively improve the cohesive strength of the adhesive, but it is easy to cause chain termination reaction during the polymerization reaction, affecting the control of chain growth and molecular weight. This reaction not only affects the bonding performance of the adhesive, but may also reduce its temperature resistance and stability, limiting its use in some high-demand applications. Another technical bottleneck is the hard monomer used in traditional medium-viscosity water-based adhesives. Taking PE (polyethylene) protective film adhesive as an example, the traditional hard monomer system will have the problem of increased adhesion over time after the adhesive product is applied, which will cause difficulties in peeling, affecting the user experience and production efficiency. Summary of the invention
[0003] In order to solve the problems of high production cost, high foam generation and unstable performance of existing water-based adhesives in the prior art, which leads to increased peeling force, the present application provides a low-foam, low glass transition temperature water-based adhesive and a preparation method to solve the above problems.
[0004] In order to achieve the above purpose, the technical solution adopted in this application is:
[0005] A low-foaming, low-glass-transition-temperature water-based adhesive comprises the following raw materials: 33-40 parts of butyl acrylate, 0.1-0.6 parts of acrylic acid, 1-4 parts of glycolic acid, 1 part of ammonium persulfate, 1 part of composite emulsifier, 1 part of wetting agent, 1 part of defoamer, 1 part of pH value regulator and 23 parts of deionized water.
[0006] A method for preparing a low-foaming, low-glass transition temperature water-based adhesive, the preparation steps are as follows:
[0007] S1. Prepare the reaction environment: Take 23 parts of deionized water and put them into the prepared three-necked flask and four-necked flask to obtain a pure reaction environment.
[0008] S2. Obtaining an ammonium persulfate solution: taking 0.4-0.6 parts of pure water, adding ammonium persulfate to the pure water, and shaking well to obtain an ammonium persulfate solution.
[0009] S3, obtaining a reaction emulsion: firstly add 40% ammonium persulfate solution and 60% ammonium persulfate solution into a three-necked flask and a four-necked flask respectively, then add a composite emulsifier into the three-necked flask, and after emulsification for 0.5h-1.5h, obtain a reaction emulsion.
[0010] S4. Obtain seed emulsion: take 33-40 parts of butyl acrylate, 0.1-0.6 parts of acrylic acid, and 1-4 parts of glycolic acid, and put them into a three-necked flask in sequence, and stir and emulsify for 1h-3h. After the emulsification is completed, take 1 part of the initiator solution, add 0.4 parts of the initiator solution to the three-necked flask, and keep the remaining 0.6 parts of the initiator solution for use. After shaking, the seed emulsion is obtained.
[0011] S5. First reaction: Heat the four-necked flask. After heating, add part of the seed emulsion and 0.6 parts of the initiator solution. Continue to heat the four-necked flask until the temperature is 79° C.-83° C., then dropwise add the remaining seed emulsion to complete the first reaction and obtain a reaction mixture.
[0012] S6. Second reaction: After the reaction mixture in the four-necked flask is stationary for 0.5h-1.5h and cooled to 53°C-57°C, 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are added to the reaction mixture in sequence. After the temperature drops below 50°C, the reaction process is completed to obtain an adhesive.
[0013] As a further improvement of the present invention, a thermometer, a condenser and a water bath are installed inside the four-necked flask in step S1.
[0014] As a further improvement of the present invention, in step S2, 0.4 parts of pure water are taken and 4.1% ammonium persulfate is added.
[0015] As a further improvement of the present invention, in step S3, 6.9% of the composite emulsifier is added into the three-necked flask.
[0016] As a further improvement of the present invention, in step S4, 36-37 parts of butyl acrylate, 0.3-0.4 parts of acrylic acid, and 1-2 parts of glycolic acid are put into a three-necked flask in sequence and stirred and emulsified for 1.5 hours.
[0017] As a further improvement of the present invention, in step S5, the pure water in the four-necked bottle is first heated to above 75°C using a water washing pot, 0.7 parts of the seed emulsion is added to the four-necked bottle, and the remaining 0.3 parts of the seed emulsion is added dropwise when the temperature is 79°C-83°C.
[0018] As a further improvement of the present invention, in step S5, the temperature during the overall dropwise addition of the seed emulsion is controlled at 85°C±2, and the overall dropwise addition time is 3.25h.
[0019] As a further improvement of the present invention, in step S6, the reaction mixture is kept at 85°C ± 2°C, then allowed to react for 1 hour, and when the temperature is lowered to 55°C, 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are added in sequence.
[0020] Compared with the prior art, the technical solution provided by the present invention has the following advantages and effects:
[0021] 1. The preparation method of the water-based adhesive in the present application is compared with the preparation method of the existing water-based adhesive. The water-based adhesive prepared by the preparation method of the present application has a lower polymer glass transition temperature (Tg), the mobility of the polymer molecular chain is stronger, the flexibility and low-temperature performance of the adhesive are better, and the adhesion is also better. Specifically, the defoamer and wetting agent in the adhesive formula play a significant low-foaming role. By adding an appropriate amount of defoamer during the preparation process, the generation of foam can be effectively reduced, ensuring that the adhesive will not be affected by foam problems during the application process. Its bonding effect and use experience.
[0022] 2. The adhesive in this application has a low glass transition temperature (Tg), which means that the adhesive can remain flexible at a lower temperature and is not easy to become brittle or harden. The low glass transition temperature allows the water-based adhesive to be used in a wider temperature range, and is suitable for use in environments with large temperature changes, maintaining excellent bonding properties. By precisely controlling the addition ratio of the emulsifier and ammonium persulfate solution and the reaction steps, the stability of the adhesive emulsion is ensured, and the uniformity and performance stability can be maintained for a long time. The use of a composite emulsifier improves the emulsification effect, reduces the unevenness of the liquid phase, and avoids the phenomenon of particles being too large or too small. Among them, the ratio design of butyl acrylate and acrylic acid enhances the adhesion performance of the adhesive. Butyl acrylate is the main polymerization monomer, which can effectively improve the flexibility and adhesion strength of the adhesive, while acrylic acid helps to enhance the cross-linking and stability of the adhesive layer and improve durability.
[0023] 3. The adhesive in this application does not contain solvents, meets environmental protection requirements, does not produce volatile organic compounds (VOCs), reduces pollution to the environment, and controls details during the emulsification process (such as emulsification time, temperature, type of emulsifier, etc.) to ensure the stability and fineness of the emulsion, avoid common emulsion stratification or precipitation problems, and enhance the service life of the final adhesive. Due to its low foaming, low glass transition temperature and good emulsification effect, this water-based adhesive can be used for bonding a variety of materials, such as effective adhesion to substrates. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.
[0025] Figure 1 It is a flow chart of the preparation method of the present invention. DETAILED DESCRIPTION
[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0027] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0028] A low-foaming, low-glass-transition-temperature water-based adhesive comprises the following raw materials: 33-40 parts of butyl acrylate, 0.1-0.6 parts of acrylic acid, 1-4 parts of glycolic acid, 1 part of ammonium persulfate, 1 part of composite emulsifier, 1 part of wetting agent, 1 part of defoamer, 1 part of pH value regulator and 23 parts of deionized water.
[0029] The present invention is further described in detail below in conjunction with examples:
[0030] Embodiment 1:
[0031] The raw materials are: 33 parts of butyl acrylate, 0.1 parts of acrylic acid, 1 part of glycolic acid, 1 part of ammonium persulfate, 1 part of composite emulsifier, 1 part of wetting agent, 1 part of defoaming agent, 1 part of pH regulator and 23 parts of deionized water.
[0032] Preparation steps:
[0033] S1. Take 23 portions of deionized water and put them into the prepared three-necked flask and the four-necked flask equipped with a thermometer, a condenser and a water bath to obtain a pure reaction environment.
[0034] S2. Take 0.4 parts of pure water, add 4.1% ammonium persulfate, and shake well to obtain an ammonium persulfate solution.
[0035] S3. First, add 40% ammonium persulfate solution and 60% ammonium persulfate solution to the three-necked flask and the four-necked flask respectively, then add 6.9% composite emulsifier to the three-necked flask, and emulsify for 0.5h to obtain a reaction emulsion.
[0036] S4. Take 33 parts of butyl acrylate, 0.1 parts of acrylic acid and 1 part of glycolic acid, and put them into a three-necked flask in sequence, stirring and emulsifying for 1 hour. After the emulsification is completed, take 1 part of the initiator solution, add 0.4 parts of the initiator solution into the three-necked flask, and keep the remaining 0.6 parts of the initiator solution for use. After shaking, a seed emulsion is obtained.
[0037] S5. First use a water washing pot to heat the pure water in the four-necked bottle to above 75°C. After heating is completed, add 0.7 parts of seed emulsion and 0.6 parts of initiator solution, and continue to heat the four-necked bottle until the temperature reaches 79°C, then add the remaining 0.3 parts of seed emulsion to complete the first reaction and obtain a reaction mixture. The temperature during the entire dropwise addition of the seed emulsion is controlled at 85°C±2, and the overall dropwise addition time is 3.25h.
[0038] S6. After the reaction mixture in the four-necked bottle has been stationary for 0.5 h and cooled to 53° C., 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are added to the reaction mixture in sequence. After the temperature drops below 50° C., the reaction process is completed to obtain an adhesive.
[0039] Embodiment 2:
[0040] The raw materials are: 40 parts of butyl acrylate, 0.6 parts of acrylic acid, 4 parts of glycolic acid, 1 part of ammonium persulfate, 1 part of composite emulsifier, 1 part of wetting agent, 1 part of defoaming agent, 1 part of pH regulator and 23 parts of deionized water.
[0041] Preparation steps:
[0042] S1. Take 23 portions of deionized water and put them into the prepared three-necked flask and the four-necked flask equipped with a thermometer, a condenser and a water bath to obtain a pure reaction environment.
[0043] S2. Take 0.6 parts of pure water, add 4.1% ammonium persulfate, and shake well to obtain an ammonium persulfate solution.
[0044] S3. First, add 40% ammonium persulfate solution and 60% ammonium persulfate solution to the three-necked flask and the four-necked flask respectively, then add 6.9% composite emulsifier to the three-necked flask, and after emulsification for 1.5 hours, obtain a reaction emulsion.
[0045] S4. Take 40 parts of butyl acrylate, 0.6 parts of acrylic acid and 4 parts of glycolic acid, and put them into a three-necked flask in sequence, stirring and emulsifying for 3 hours. After the emulsification is completed, take 1 part of the initiator solution, add 0.4 parts of the initiator solution into the three-necked flask, and keep the remaining 0.6 parts of the initiator solution for use. After shaking, a seed emulsion is obtained.
[0046] S5. First use a water washing pot to heat the pure water in the four-necked bottle to above 75°C. After heating is completed, add 0.7 parts of seed emulsion and 0.6 parts of initiator solution, and continue to heat the four-necked bottle until the temperature reaches 83°C, then add the remaining 0.3 parts of seed emulsion to complete the first reaction and obtain a reaction mixture. The temperature during the entire dropwise addition of the seed emulsion is controlled at 85°C ± 2, and the overall dropwise addition time is 3.25h.
[0047] S6. After the reaction mixture in the four-necked bottle has been stationary for 1.5 hours and cooled to 57°C, 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are taken and added to the reaction mixture in sequence. After the temperature drops below 50°C, the reaction process is completed to obtain an adhesive.
[0048] Embodiment 3:
[0049] Raw material selection: including the following raw materials: 36.9 parts of butyl acrylate, 0.4 parts of acrylic acid, 1.56 parts of glycolic acid, 1 part of ammonium persulfate, 1 part of composite emulsifier, 1 part of wetting agent, 1 part of defoaming agent, 1 part of pH regulator and 23 parts of deionized water.
[0050] Preparation steps:
[0051] S1. Take 23 portions of deionized water and put them into the prepared three-necked flask and the four-necked flask equipped with a thermometer, a condenser and a water bath to obtain a pure reaction environment.
[0052] S2. Take 0.4 parts of pure water, add 4.1% ammonium persulfate, and shake well to obtain an ammonium persulfate solution.
[0053] S3. First, add 40% ammonium persulfate solution and 60% ammonium persulfate solution to the three-necked flask and the four-necked flask respectively, and then add 6.9% composite emulsifier to the three-necked flask. After emulsification for 1 hour, a reaction emulsion is obtained.
[0054] S4. Take 36.9 parts of butyl acrylate, 0.4 parts of acrylic acid and 1.56 parts of glycolic acid, and put them into a three-necked flask in sequence, stirring and emulsifying for 1.5 hours. After the emulsification is completed, take 1 part of the initiator solution, add 0.4 parts of the initiator solution to the three-necked flask, and keep the remaining 0.6 parts of the initiator solution for use. After shaking, a seed emulsion is obtained.
[0055] S5. First use a water washing pot to heat the pure water in the four-necked bottle to above 75°C. After heating is completed, add 0.7 parts of seed emulsion and 0.6 parts of initiator solution, and continue to heat the four-necked bottle until the temperature reaches 81±2°C, then add the remaining 0.3 parts of seed emulsion to complete the first reaction and obtain a reaction mixture. The temperature during the entire dropwise addition of the seed emulsion is controlled at 85°C±2, and the overall dropwise addition time is 3.25h.
[0056] S6. After the reaction mixture in the four-necked bottle has been stationary for 1 hour and cooled to 55°C, 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are added to the reaction mixture in sequence. After the temperature drops below 50°C, the reaction process is completed to obtain an adhesive.
[0057] Embodiment 4:
[0058] Raw material selection: including the following raw materials: 37 parts of butyl acrylate, 0.4 parts of acrylic acid, 1 part of glycolic acid, 1 part of ammonium persulfate, 1 part of composite emulsifier, 1 part of wetting agent, 1 part of defoaming agent, 1 part of pH regulator and 23 parts of deionized water.
[0059] Preparation steps:
[0060] S1. Take 23 portions of deionized water and put them into the prepared three-necked flask and the four-necked flask equipped with a thermometer, a condenser and a water bath to obtain a pure reaction environment.
[0061] S2. Take 0.4 parts of pure water, add 4.1% ammonium persulfate, and shake well to obtain an ammonium persulfate solution.
[0062] S3. First, add 40% ammonium persulfate solution and 60% ammonium persulfate solution to the three-necked flask and the four-necked flask respectively, then add 6.9% composite emulsifier to the three-necked flask, and after emulsification for 1.5 hours, obtain a reaction emulsion.
[0063] S4. Take 37 parts of butyl acrylate, 0.4 parts of acrylic acid and 1 part of glycolic acid, and put them into a three-necked flask in sequence, and stir and emulsify for 2 hours. After the emulsification is completed, take 1 part of the initiator solution, add 0.4 parts of the initiator solution into the three-necked flask, and keep the remaining 0.6 parts of the initiator solution for use. After shaking, a seed emulsion is obtained.
[0064] S5. First use a water washing pot to heat the pure water in the four-necked bottle to above 75°C. After heating is completed, add 0.7 parts of seed emulsion and 0.6 parts of initiator solution, and continue to heat the four-necked bottle until the temperature reaches 81°C, then add the remaining 0.3 parts of seed emulsion to complete the first reaction and obtain a reaction mixture. The temperature during the entire dropwise addition of the seed emulsion is controlled at 85°C±2, and the overall dropwise addition time is 3.25h.
[0065] S6. After the reaction mixture in the four-necked bottle has been stationary for 1 hour and cooled to 55°C, 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are added to the reaction mixture in sequence. After the temperature drops below 50°C, the reaction process is completed to obtain an adhesive.
[0066] Embodiment 5:
[0067] Raw material selection: including the following raw materials: 38 parts of butyl acrylate, 0.5 parts of acrylic acid, 3 parts of glycolic acid, 1 part of ammonium persulfate, 1 part of composite emulsifier, 1 part of wetting agent, 1 part of defoaming agent, 1 part of pH regulator and 23 parts of deionized water.
[0068] Preparation steps:
[0069] S1. Take 23 portions of deionized water and put them into the prepared three-necked flask and the four-necked flask equipped with a thermometer, a condenser and a water bath to obtain a pure reaction environment.
[0070] S2. Take 0.5 parts of pure water, add 4.1% ammonium persulfate, and shake well to obtain an ammonium persulfate solution.
[0071] S3. First, add 40% ammonium persulfate solution and 60% ammonium persulfate solution to the three-necked flask and the four-necked flask respectively, and then add 6.9% composite emulsifier to the three-necked flask. After emulsification for 1 hour, a reaction emulsion is obtained.
[0072] S4. Take 38 parts of butyl acrylate, 0.5 parts of acrylic acid and 3 parts of glycolic acid, and put them into a three-necked flask in sequence, stirring and emulsifying for 1.5 hours. After the emulsification is completed, take 1 part of the initiator solution, add 0.4 parts of the initiator solution into the three-necked flask, and keep the remaining 0.6 parts of the initiator solution for use. After shaking, a seed emulsion is obtained.
[0073] S5. First use a water washing pot to heat the pure water in the four-necked bottle to above 75°C. After heating is completed, add 0.7 parts of seed emulsion and 0.6 parts of initiator solution, and continue to heat the four-necked bottle until the temperature reaches 81°C, then add the remaining 0.3 parts of seed emulsion to complete the first reaction and obtain a reaction mixture. The temperature during the entire dropwise addition of the seed emulsion is controlled at 85°C±2, and the overall dropwise addition time is 3.25h.
[0074] S6. After the reaction mixture in the four-necked bottle has been stationary for 1 hour and cooled to 55°C, 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are added to the reaction mixture in sequence. After the temperature drops below 50°C, the reaction process is completed to obtain an adhesive.
[0075] Comparative Example:
[0076] Original preparation method: add 20-25 parts of deionized soft water into a three-necked bottle, add 7‰ emulsifier and stand for one hour; add 0.4-0.5 parts of AA, 0.7-0.8 parts of HEA, 2-3 parts of MMA, 2-3 parts of EHA respectively, and continue emulsification for 1.5 hours; add 20-25 parts of deionized water into a four-necked bottle equipped with a thermometer, condenser, and water bath, add 0.7‰ of the bottom emulsifier A-50 into the four-necked bottle, and add 0.04 parts of the buffer sodium hydrogen phosphate ; Prepare ammonium persulfate solution by adding 5‰ ammonium persulfate + 0.4 parts of pure water; when the temperature rises to 75°C, add 40% of the ammonium persulfate solution into a four-necked bottle and 60% into a three-necked bottle, continue to raise the temperature to 81°C±1°C and start dripping the emulsion in the three-necked bottle; control the temperature at 85°C±2°C (there is a problem) and drip it in about 3 hours; after dripping, keep warm at 86°C-87°C for 1-1.5 hours, cool down to about 55°C, add wetting agent, defoaming agent, and ammonia regulator respectively, continue to cool down to below 50°C and filter out the material.
[0077] according to
[0078] The glass transition temperature of the homopolymer obtained by the original preparation method is: Tg=5.62.
[0079] The glass transition temperature of the homopolymer obtained by the current preparation method is: Tg=5.69.
[0080] By comparing the glass transition temperature of the homopolymer of the original preparation method with the glass transition temperature of the homopolymer of the current preparation method, it can be seen that a lower Tg means that the adhesive can maintain flexibility at a lower temperature, reducing brittleness or failure caused by temperature changes.
[0081] Specifically, in the application of water-based adhesives, the glass transition temperature (Tg) of homopolymers is a very important indicator. Tg refers to the temperature at which a polymer changes from a glassy state to a rubbery state, reflecting the hardness, toughness and application performance of the polymer. A lower glass transition temperature (Tg) means that the polymer becomes softer at a lower temperature and has better fluidity and ductility, which is very important for the performance of the adhesive.
[0082] It is worth noting that the low-foam type, low-glass transition temperature water-based adhesive in this application has better softness and adhesion at low temperatures than the water-based adhesive prepared by the original preparation method, which is particularly important for adhesives used in low-temperature environments. For example, when the low-Tg water-based adhesive is used in winter or cold areas, it can ensure that the adhesive can still effectively adhere to the substrate surface, will not lose adhesion due to temperature reduction, and is relatively soft and ductile at room temperature, which makes the adhesive in this application have better toughness and impact resistance. For some applications that require high flexibility (such as flexible packaging, flexible electronic products, etc.), low Tg can improve the adaptability of the adhesive, avoid bonding failure due to hardness and brittleness, and the adhesive in this application can be easier to flow and unfold when applied, especially in the process of coating, brushing or spraying, low Tg can help the adhesive to evenly cover and quickly penetrate into the substrate surface, thereby improving the adhesion effect.
[0083] It is further worth noting that the low-foaming, low-glass-transition-temperature water-based adhesive in this application has better ductility and stretchability. In the application of adhesives, this means that low-Tg polymers can provide better bonding strength, especially less prone to cracking in environments with greater external forces, and also have better wetting properties, can better adapt to humid environments, and enhance adhesion to materials in humid or water-immersed environments. In addition, the adhesive in this application can effectively reduce the generation of foam, ensuring that the adhesive will not affect its bonding effect and use experience due to foam problems during application.
[0084] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A low-foaming, low-glass-transition-temperature water-based adhesive, characterized in that: Including the following ingredients: 33-40 parts of butyl acrylate, 0.1-0.6 parts of acrylic acid, 1-4 parts of glycolic acid, 1 part of ammonium persulfate, 1 part of composite emulsifier, 1 part of wetting agent, 1 part of defoaming agent, 1 part of pH regulator and 23 parts of deionized water.
2. A method for preparing a low-foaming, low-glass transition temperature water-based adhesive, comprising the raw materials of claim 1, characterized in that: The preparation steps are as follows: S1. Prepare the reaction environment: Take 23 parts of deionized water and put them into the prepared three-necked flask and four-necked flask to obtain a pure reaction environment. S2. Obtaining an ammonium persulfate solution: taking 0.4-0.6 parts of pure water, adding ammonium persulfate to the pure water, and shaking well to obtain an ammonium persulfate solution. S3, obtaining a reaction emulsion: firstly add 40% ammonium persulfate solution and 60% ammonium persulfate solution into a three-necked flask and a four-necked flask respectively, then add a composite emulsifier into the three-necked flask, and after emulsification for 0.5h-1.5h, obtain a reaction emulsion. S4. Obtain seed emulsion: take 33-40 parts of butyl acrylate, 0.1-0.6 parts of acrylic acid, and 1-4 parts of glycolic acid, and put them into a three-necked flask in sequence, and stir and emulsify for 1h-3h. After the emulsification is completed, take 1 part of the initiator solution, add 0.4 parts of the initiator solution to the three-necked flask, and keep the remaining 0.6 parts of the initiator solution for use. After shaking, the seed emulsion is obtained. S5. First reaction: Heat the four-necked flask. After heating, add part of the seed emulsion and 0.6 parts of the initiator solution. Continue to heat the four-necked flask until the temperature is 79° C.-83° C., then dropwise add the remaining seed emulsion to complete the first reaction and obtain a reaction mixture. S6. Second reaction: After the reaction mixture in the four-necked flask is stationary for 0.5h-1.5h and cooled to 53°C-57°C, 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are added to the reaction mixture in sequence. After the temperature drops below 50°C, the reaction process is completed to obtain an adhesive.
3. The method for preparing a low-foaming, low-glass transition temperature water-based adhesive according to claim 2, characterized in that: The four-necked flask in step S1 is equipped with a thermometer, a condenser and a water bath.
4. The method for preparing a low-foaming, low-glass transition temperature water-based adhesive according to claim 3, characterized in that: In step S2, 0.4 parts of pure water are taken and 4.1% ammonium persulfate is added.
5. The method for preparing a low-foaming, low-glass transition temperature water-based adhesive according to claim 4, characterized in that: In the step S3, 6.9% of the composite emulsifier is added into a three-necked flask.
6. The method for preparing a low-foaming, low-glass-transition-temperature water-based adhesive according to claim 5, characterized in that: In step S4, 36-37 parts of butyl acrylate, 0.3-0.4 parts of acrylic acid, and 1-2 parts of glycolic acid are put into a three-necked flask in sequence and stirred and emulsified for 1.5 hours.
7. The method for preparing a low-foaming, low-glass transition temperature water-based adhesive according to claim 6, characterized in that: In step S5, firstly, the pure water in the four-necked bottle is heated to above 75° C. by using a water washing pot, 0.7 parts of the seed emulsion is added to the four-necked bottle, and the remaining 0.3 parts of the seed emulsion is added dropwise when the temperature is 79° C.-83° C.
8. The method for preparing a low-foaming, low-glass-transition-temperature water-based adhesive according to claim 7, characterized in that: In the step S5, the temperature during the entire dropwise addition of the seed emulsion is controlled at 85°C±2°C, and the entire dropwise addition time is 3.25 hours.
9. The method for preparing a low-foaming, low-glass-transition-temperature water-based adhesive according to claim 8, characterized in that: In step S6, the reaction mixture is kept at 85°C ± 2°C, then allowed to react for 1 hour, and when the temperature is lowered to 55°C, 1 part of a wetting agent, 1 part of a defoaming agent and 1 part of a pH regulator are added in sequence.