An aqueous acrylic resin-based emulsion composition and a method for preparing the same

Abstract

The application relates to the technical field of adhesives, and discloses an emulsion composition based on water-based acrylic resin and a preparation method thereof.The adhesive is formed by mixing acrylic ester emulsion polymer as a base material and auxiliary materials such as sodium hydroxyethyl cellulose and inorganic fillers, wherein the acrylic ester emulsion polymer is prepared by first using an emulsifier to emulsify acrylic ester monomers and a crosslinking agent, and then using an initiator to initiate a free radical polymerization reaction.The presence of the crosslinking agent enables the prepared acrylic emulsion polymer to have a three-dimensional crosslinking network structure, and the crosslinking agent structure contains a large number of strong polar sulfonic acid hydrophilic groups, ether bonds and benzene rings, etc., which can effectively improve the bonding performance and heat resistance of the adhesive.

Description

Technical Field

[0001] This invention relates to the field of adhesive technology, and more specifically to an emulsion composition based on water-based acrylic resin and its preparation method. Background Technology

[0002] Adhesives are ubiquitous in daily work and life. Currently, adhesives are mainly divided into water-based adhesives and solvent-based adhesives. Solvent-based adhesives contain a large amount of volatile organic solvents, which are harmful to the environment and do not conform to the current concept of green and sustainable development. Therefore, they will gradually be eliminated from the market. Water-based adhesives use water as a solvent or dispersant and do not release organic solvents during use, so they have a significant advantage in terms of environmental protection.

[0003] Currently, waterborne adhesives mainly include waterborne polyurethane adhesives, waterborne epoxy resin adhesives, and waterborne acrylic adhesives. Among them, waterborne acrylic adhesives have excellent film-forming properties and weather resistance, while also possessing good bonding performance, enabling effective bonding to various substrates such as metals, wood, plastics, and ceramics. Therefore, they have a wide range of applications, especially in industrial manufacturing, building decoration, and packaging materials. However, acrylic adhesives have poor heat resistance and will experience aging and loss of adhesion when working in continuous high-temperature environments. In addition, the bonding performance of conventional acrylic adhesives is insufficient to meet requirements, leading to a gradual limitation of their application range. Based on this, the present invention provides a waterborne acrylic resin emulsion composition with good comprehensive performance, which can solve the problems existing in the prior art. Summary of the Invention

[0004] In order to solve the problems mentioned in the background art, the present invention aims to provide an emulsion composition based on water-based acrylic resin and a method for preparing the same.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An emulsion composition based on an aqueous acrylic resin, comprising the following raw materials in parts by weight:

[0007] The composition consists of 65-80 parts acrylate emulsion polymer, 1-3 parts sodium hydroxyethyl cellulose, 4-10 parts inorganic filler, and 0.5-1 part defoamer.

[0008] As a further aspect of the present invention, the preparation method of the acrylate emulsion polymer includes the following steps:

[0009] Step 1: Add butyl acrylate, butyl methacrylate, crosslinking agent, sodium dodecylbenzenesulfonate and deionized water to the polymerization reactor. After the addition is complete, start stirring and mix evenly. Then raise the temperature to 50-55℃ and emulsify for 30-60 minutes to obtain the emulsion.

[0010] The second step is to continue adding azobisisobutyronitrile to the polymerization reactor. After the addition is complete, the temperature in the polymerization reactor is further increased to 80-82℃, and the polymerization is continued to be stirred for 3-6 hours. Then, the heating is stopped, the material is cooled down and discharged to obtain the acrylate emulsion polymer.

[0011] As a further embodiment of the present invention, the mass ratio of butyl acrylate, butyl methacrylate, crosslinking agent, sodium dodecylbenzenesulfonate, deionized water and azobisisobutyronitrile is 1-2:0.5-1:0.1-0.2:0.05-0.1:10-15:0.01-0.03.

[0012] As a further aspect of the present invention, the method for preparing the crosslinking agent includes the following steps:

[0013] Step 1: Add sodium benzenesulfonate derivative and N,N-dimethylformamide to the reaction vessel. After the addition is complete, purge with nitrogen for protection and start stirring. After a homogeneous solution is formed, add 3,6-dioxanoic acid and phase transfer catalyst to the reaction vessel. After the addition is complete, start heating and control the heating rate at 2-4℃ / min. Raise the temperature to 80-90℃ and keep it at this temperature for 6-9 hours with continuous stirring. Then evaporate the solvent, cool down and collect the product. After purification, the crosslinking agent intermediate is obtained.

[0014] Step 2: Add the crosslinking agent intermediate to tetrahydrofuran, stir evenly, place in an ice bath environment, then add the unsaturated modifier and acid-binding agent to the formed homogeneous solution. After the addition is complete, remove from the ice bath and stir at a temperature of 30-40℃ for 2-4 hours. Evaporate to remove the solvent, collect the product, and the crosslinking agent can be obtained.

[0015] As a further aspect of the present invention, the method for preparing the sodium benzenesulfonate derivative is as follows:

[0016] Sodium benzoate-3,5-disulfonate and acetone were added to a reaction vessel and stirred until homogeneous. Then, a composite catalyst was added. After the addition was complete, the temperature was raised to 40-50°C and stirred for 20-40 minutes. The mixture was then cooled to room temperature, and 1,3-diepoxyglycerol ether was added to the reaction vessel. The mixture was kept warm and stirred for 3-6 hours. The solvent was then evaporated to remove the solvent, and the material was collected. After purification, the sodium benzenesulfonate derivative was obtained.

[0017] As a further aspect of the present invention, the molar ratio of sodium benzoate-3,5-disulfonate and 1,3-diepoxyglycerol ether is 1:1.

[0018] As a further embodiment of the present invention, the composite catalyst is a mixture of N-hydroxysuccinimide and dicyclohexylcarbodiimide in a mass ratio of 1:2-3.

[0019] As a further embodiment of the present invention, the phase transfer catalyst is any one of tetrabutylammonium hydrogen sulfate, tetramethylammonium bromide, or tetrabutylammonium bromide.

[0020] As a further embodiment of the present invention, the unsaturated modifier is acryloyl chloride or methacryloyl chloride; the acid-binding agent is triethylamine.

[0021] Specifically, under the catalysis of a phase transfer catalyst, the two equivalent epoxy substituents in the sodium benzenesulfonate derivative structure can undergo a continuous esterification ring-opening reaction with the two equivalent carboxyl substituents in the 3,6-dioxaoctanoic acid structure to obtain a crosslinking agent intermediate. Since a large number of active hydroxyl groups are generated during the ring-opening reaction, an unsaturated modifier is used to functionalize the crosslinking agent intermediate under the action of an acid-binding agent to obtain a polymeric substance with ester bond linkage, alternating benzenesulfonic acid-dioxa block linkage, and a large number of unsaturated alkenyl substituents, i.e., a crosslinking agent.

[0022] Among them, sodium benzenesulfonate derivatives are prepared by using sodium benzoate-3,5-disulfonate and 1,3-diepoxyglycerol ether as raw materials, and by using a composite catalyst to catalyze the esterification reaction between the active carboxyl substituents and hydroxyl substituents in their structures.

[0023] A method for preparing an emulsion composition based on an aqueous acrylic resin includes the following steps:

[0024] Step A: Weigh each raw material according to the specified weight proportions to complete the material preparation;

[0025] Step B: Add the acrylate emulsion polymer, sodium hydroxyethyl cellulose and inorganic filler into the mixing tank, control the rotation speed to 1000-1500 r / min, and mechanically stir for 10-20 min to form a mixture;

[0026] Step C: Adjust the rotation speed to 500-800 r / min, add the defoamer to the mixture, stir for 5-10 minutes, and let it stand to defoam.

[0027] As a further aspect of the present invention, the inorganic filler is any one of talc, calcium carbonate, or fumed silica.

[0028] The beneficial effects of this invention are:

[0029] This invention utilizes a crosslinking agent with a unique structure to participate in the preparation of acrylate emulsion polymers. Firstly, the crosslinking agent structure contains numerous highly polar sulfonic acid hydrophilic groups and ether bonds, exhibiting strong hydrophilicity and giving the adhesive a water-based characteristic. Secondly, during polymerization, multiple unsaturated alkenyl substituents in the crosslinking agent structure can undergo free radical polymerization with acrylic monomers, resulting in a three-dimensional crosslinked network structure in the prepared acrylate emulsion polymer. This network structure significantly hinders the movement of acrylate molecular chains, exhibiting higher stability under high-temperature conditions. Furthermore, the crosslinking agent structure contains abundant rigid benzene rings, further enhancing the stability of the acrylate molecular chains and thus contributing to the adhesive's excellent heat resistance. Finally, the presence of numerous sulfonic acid groups and ether bonds in the crosslinking agent structure enables hydrogen bonding with the adherend matrix, effectively enhancing the adhesive's bonding performance.

[0030] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is an infrared analysis test image of the crosslinking agent. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] An emulsion composition based on an aqueous acrylic resin, comprising the following raw materials in parts by weight:

[0036] 65 parts acrylate emulsion polymer, 1 part sodium hydroxyethyl cellulose, 4 parts talc, and 0.5 parts defoamer BYK-019;

[0037] The method for preparing the emulsion composition includes the following steps:

[0038] Step A: Weigh each raw material according to the specified weight proportions to complete the material preparation;

[0039] Step B: Add the acrylate emulsion polymer, sodium hydroxyethyl cellulose and talc to the mixing tank, control the rotation speed at 1000 r / min, and mechanically stir for 20 min to form a mixture;

[0040] Step C: Adjust the rotation speed to 500 r / min, add defoamer BYK-019 to the mixture, stir for 10 minutes, and let it stand to defoam.

[0041] The preparation method of the acrylate emulsion polymer includes the following steps:

[0042] Step 1: Add 8g butyl acrylate, 3g butyl methacrylate, 0.6g crosslinking agent, 0.3g sodium dodecylbenzenesulfonate and 60mL deionized water to the polymerization reactor. After the addition is complete, start stirring and mix evenly. Then raise the temperature to 50℃ and emulsify for 40 minutes to obtain the emulsion.

[0043] The second step is to continue adding 0.1g of azobisisobutyronitrile to the polymerization reactor. After the addition is complete, the temperature in the polymerization reactor is further increased to 82℃, and the polymerization is continued to be stirred for 4 hours. Then, the heating is stopped, the material is cooled down and discharged to obtain the acrylate emulsion polymer.

[0044] The preparation method of the crosslinking agent includes the following steps:

[0045] Step 1: Add 0.5g of sodium benzoate-3,5-disulfonate and acetone to the reaction vessel and stir until well mixed. Then add 0.1g of N-hydroxysuccinimide and 0.3g of dicyclohexylcarbodiimide. After the addition is complete, raise the temperature to 45℃ and stir for 30min. Then cool to room temperature and add 0.33g of 1,3-diepoxyglycerol ether glycerol to the reaction vessel. Keep warm and stir for 4h. Evaporate to remove the solvent, collect the material, and purify it to obtain sodium benzenesulfonate derivative.

[0046] Step 2: Add 0.6g of sodium benzenesulfonate derivative and N,N-dimethylformamide to the reaction vessel. After the addition is complete, purge with nitrogen for protection and start stirring. After a homogeneous solution is formed, add 0.2g of 3,6-dioxanoic acid and 0.01g of tetrabutylammonium bromide to the reaction vessel. After the addition is complete, start heating and control the heating rate at 3℃ / min. Raise the temperature to 90℃ and keep it at this temperature for 8 hours with continuous stirring. Then evaporate the solvent, cool down and collect the product. After purification, the crosslinking agent intermediate is obtained.

[0047] Step 3: Add 0.4g of crosslinking agent intermediate to tetrahydrofuran, stir well, place in an ice bath environment, then add 0.05g of acryloyl chloride and 0.02g of triethylamine to the formed homogeneous solution. After the addition is complete, remove from the ice bath, stir at 35℃ for 3h, evaporate to remove the solvent, collect the product, and the crosslinking agent can be obtained.

[0048] Figure 1 This is the infrared analysis test pattern of the crosslinking agent, where 3311 cm⁻¹ -1 The characteristic absorption peak appearing at 3084 cm⁻¹ is a characteristic absorption peak of hydroxyl groups generated by the ring-opening reaction and not involved in subsequent reactions. -1 and 3047cm -1 The characteristic absorption peak appearing at 3012 cm⁻¹ is the hydrocarbon absorption peak in the benzene ring skeleton. -1 The characteristic absorption peak appearing at 1747 cm⁻¹ is the hydrocarbon absorption peak in the unsaturated carbon-carbon double bond. -1 The characteristic absorption peak appearing at 1068 cm⁻¹ is the characteristic absorption peak of the carbon-oxygen double bond of the ester group. -1 The characteristic absorption peak appearing at this point is the characteristic absorption peak of the ether bond.

[0049] Example 2

[0050] An emulsion composition based on an aqueous acrylic resin, comprising the following raw materials in parts by weight:

[0051] 70 parts acrylate emulsion polymer, 2 parts sodium hydroxyethyl cellulose, 5 parts calcium carbonate, and 0.6 parts defoamer BYK-019;

[0052] The method for preparing the emulsion composition includes the following steps:

[0053] Step A: Weigh each raw material according to the specified weight proportions to complete the material preparation;

[0054] Step B: Add the acrylate emulsion polymer, sodium hydroxyethyl cellulose and calcium carbonate to the mixing tank, control the rotation speed at 1200 r / min, and mechanically stir for 15 min to form a mixture;

[0055] Step C: Adjust the rotation speed to 600 r / min, add defoamer BYK-019 to the mixture, stir for 10 minutes, and let it stand to defoam.

[0056] The preparation method of the acrylate emulsion polymer is the same as that in Example 1.

[0057] Example 3

[0058] An emulsion composition based on an aqueous acrylic resin, comprising the following raw materials in parts by weight:

[0059] 80 parts of acrylate emulsion polymer, 3 parts of sodium hydroxyethyl cellulose, 10 parts of fumed silica, and 1 part of defoamer BYK-019;

[0060] The method for preparing the emulsion composition includes the following steps:

[0061] Step A: Weigh each raw material according to the specified weight proportions to complete the material preparation;

[0062] Step B: Add the acrylate emulsion polymer, sodium hydroxyethyl cellulose and fumed silica to the mixing tank, control the rotation speed at 1500 r / min, and mechanically stir for 10 min to form a mixture;

[0063] Step C: Adjust the rotation speed to 800 r / min, add defoamer BYK-019 to the mixture, stir for 5 minutes, and let it stand to defoam.

[0064] The preparation method of the acrylate emulsion polymer is the same as that in Example 1.

[0065] Comparative Example 1

[0066] An emulsion composition based on an aqueous acrylic resin, comprising the following raw materials in parts by weight:

[0067] 70 parts acrylate emulsion polymer, 2 parts sodium hydroxyethyl cellulose, 5 parts calcium carbonate, and 0.6 parts defoamer BYK-019;

[0068] The method for preparing the emulsion composition includes the following steps:

[0069] Step A: Weigh each raw material according to the specified weight proportions to complete the material preparation;

[0070] Step B: Add the acrylate emulsion polymer, sodium hydroxyethyl cellulose and calcium carbonate to the mixing tank, control the rotation speed at 1200 r / min, and mechanically stir for 15 min to form a mixture;

[0071] Step C: Adjust the rotation speed to 600 r / min, add defoamer BYK-019 to the mixture, stir for 10 minutes, and let it stand to defoam.

[0072] The preparation method of the acrylate emulsion polymer differs from that in Example 1 in that the crosslinking agent is replaced with the conventional crosslinking agent N,N'-methylenebisacrylamide, while the rest are the same.

[0073] Comparative Example 2

[0074] An emulsion composition based on an aqueous acrylic resin, comprising the following raw materials in parts by weight:

[0075] 70 parts acrylate emulsion polymer, 2 parts sodium hydroxyethyl cellulose, 5 parts calcium carbonate, and 0.6 parts defoamer BYK-019;

[0076] The method for preparing the emulsion composition includes the following steps:

[0077] Step A: Weigh each raw material according to the specified weight proportions to complete the material preparation;

[0078] Step B: Add the acrylate emulsion polymer, sodium hydroxyethyl cellulose and calcium carbonate to the mixing tank, control the rotation speed at 1200 r / min, and mechanically stir for 15 min to form a mixture;

[0079] Step C: Adjust the rotation speed to 600 r / min, add defoamer BYK-019 to the mixture, stir for 10 minutes, and let it stand to defoam.

[0080] The preparation method of the acrylate emulsion polymer differs from that in Example 1 in that the crosslinking agent is removed, while the rest are the same.

[0081] Performance testing

[0082] The emulsion compositions from the examples and comparative examples were coated onto the surface of a PET film. After curing, a release film was applied over the coating, followed by a curing treatment to form test samples. A 180° peel strength test was performed according to standard GB / T 2792-1998. Another sample from the same batch was placed in a 120°C environment for one day and then subjected to the same 180° peel strength test to evaluate its heat resistance. The test results are shown in the table below:

[0083] Table 1 - Test Results

[0084]

[0085] Analysis of the test results shows that the emulsion composition prepared in the embodiments of the present invention exhibits significantly better adhesion and heat resistance.

[0086] The number of functional groups that can form hydrogen bonds with the substrate in the emulsion composition prepared by using acrylate emulsion polymers prepared by the conventional crosslinking agent N,N'-methylenebisacrylamide is greatly reduced, resulting in a decrease in bonding strength. In addition, the crosslinking density of the molecular chain is also reduced, and the structure does not contain rigid benzene rings, thus significantly reducing various properties.

[0087] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A waterborne acrylic resin-based emulsion composition, characterized in that, Includes the following raw materials by weight: Acrylic emulsion polymer 65-80 parts, sodium hydroxyethyl cellulose 1-3 parts, inorganic filler 4-10 parts, defoamer 0.5-1 part; The preparation method of the acrylate emulsion polymer includes the following steps: Step 1: Add butyl acrylate, butyl methacrylate, crosslinking agent, sodium dodecylbenzenesulfonate and deionized water to the polymerization reactor. After the addition is complete, start stirring and mix evenly. Then raise the temperature to 50-55℃ and emulsify for 30-60 minutes to obtain the emulsion. The second step is to continue adding azobisisobutyronitrile to the polymerization reactor. After the addition is complete, the temperature in the polymerization reactor is further increased to 80-82℃. The polymerization is continued to be stirred for 3-6 hours. Then, the heating is stopped, the material is cooled and discharged to obtain the acrylate emulsion polymer. The preparation method of the crosslinking agent includes the following steps: Step 1: Add sodium benzenesulfonate derivative and N,N-dimethylformamide to the reaction vessel. After the addition is complete, purge with nitrogen for protection and start stirring. After a homogeneous solution is formed, add 3,6-dioxanoic acid and phase transfer catalyst to the reaction vessel. After the addition is complete, start heating and control the heating rate at 2-4℃ / min. Raise the temperature to 80-90℃ and keep it at this temperature for 6-9 hours with continuous stirring. Then evaporate the solvent, cool down and collect the product. After purification, the crosslinking agent intermediate is obtained. Step 2: Add the crosslinking agent intermediate to tetrahydrofuran, stir evenly, place in an ice bath environment, then add unsaturated modifier and acid-binding agent to the formed homogeneous solution. After the addition is complete, remove from the ice bath and stir at 30-40℃ for 2-4 hours. Evaporate to remove the solvent, collect the product, and the crosslinking agent can be obtained. The unsaturated modifier is acryloyl chloride or methacryloyl chloride; The sodium benzenesulfonate derivative is prepared by esterification reaction using sodium benzoate-3,5-disulfonate and 1,3-diepoxyglycerol ether as raw materials under the action of a composite catalyst.

2. The emulsion composition based on aqueous acrylic resin according to claim 1, characterized in that, The mass ratio of butyl acrylate, butyl methacrylate, crosslinking agent, sodium dodecylbenzenesulfonate, deionized water and azobisisobutyronitrile is 1-2:0.5-1:0.1-0.2:0.05-0.1:10-15:0.01-0.

03.

3. The emulsion composition based on aqueous acrylic resin according to claim 1, characterized in that, The molar ratio of sodium benzoate-3,5-disulfonate and 1,3-diepoxyglycerol ether is 1:

1.

4. The emulsion composition based on aqueous acrylic resin according to claim 1, characterized in that, The composite catalyst is a mixture of N-hydroxysuccinimide and dicyclohexylcarbodiimide in a mass ratio of 1:2-3.

5. The emulsion composition based on aqueous acrylic resin according to claim 1, characterized in that, The phase transfer catalyst is any one of tetrabutylammonium hydrogen sulfate, tetramethylammonium bromide, or tetrabutylammonium bromide.

6. The emulsion composition based on aqueous acrylic resin according to claim 1, characterized in that, The acid-binding agent is triethylamine.

7. A method for preparing the emulsion composition based on aqueous acrylic resin as described in claim 1, characterized in that, Includes the following steps: Step A: Weigh each raw material according to the specified weight proportions to complete the material preparation; Step B: Add the acrylate emulsion polymer, sodium hydroxyethyl cellulose and inorganic filler to the mixing tank, control the rotation speed to 1000-1500 r / min, and mechanically stir for 10-20 min to form a mixture; Step C: Adjust the rotation speed to 500-800 r / min, add the defoamer to the mixture, stir for 5-10 minutes, and let it stand to defoam.

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