Recyclable water-based polyacrylate adhesive as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of adhesive preparation, and particularly relates to a recyclable water-based polyacrylate adhesive as well as a preparation method and application thereof. The adhesive is prepared from the following raw materials in parts by weight: 40 to 50 parts of acrylic monomers, 10 to 15 parts of peroxide solution, 5 to 15 parts of bicarbonate solution, 1 to 20 parts of diaminodienamine ester, 50 to 60 parts of water and 1 to 5 parts of alkylphenol polyoxyethylene ether. According to the recyclable adhesive provided by the invention, the water-based polyacrylate is used as a matrix, and the diaminodienamine ester and the diacetone acrylamide are added to generate dynamic bonds, so that the network density of a polymer is improved, the content of hydrogen bonds is increased, and the deformation resistance of the adhesive is improved; the problem of low bonding strength of a water-based polyacrylate adhesive in the prior art is solved.

Description

Technical Field

[0001] The present application belongs to the technical field of adhesive preparation, and specifically relates to a recyclable water-based polyacrylate adhesive and a preparation method and application thereof. Background Art

[0002] Traditional solvent-based adhesives are being gradually replaced by water-based adhesives due to their high volatile organic compound (VOC) emissions and severe environmental pollution. As an environmentally friendly adhesive, water-based polyacrylate adhesives are widely used in packaging, textiles, wood processing, and other fields due to their non-toxic, pollution-free, and safe properties. However, traditional water-based polyacrylate adhesives form a three-dimensional cross-linked network structure after curing, making them difficult to dissolve or melt, making them difficult to recycle and reuse, resulting in resource waste and environmental pollution.

[0003] Prior art discloses a modified water-based polyacrylate emulsion adhesive, which is prepared by adding a hydrolyzable silane and a penetrant to a water-based polyacrylate emulsion to form a composite adhesive. While this method can improve adhesion, heat resistance, and peel strength, the material uses a composite structure and is complex to prepare. The adhesive has low tensile strength and is disposable, making it non-recyclable. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and provide a recyclable water-based polyacrylate adhesive and a preparation method and application thereof, specifically adopting the following technical solutions: In a first aspect, the present invention provides a recyclable water-based polyacrylate adhesive, the raw materials of which include, in parts by weight: 40-50 parts by weight of acrylic monomer, 10-15 parts by weight of peroxide solution, 5-15 parts by weight of bicarbonate solution, 1-20 parts by weight of diaminodienamine ester, 50-60 parts by weight of water, and 1-5 parts by weight of alkylphenol polyoxyethylene ether; The structure of the diaminodienamine ester is as follows: ; The structure of the recyclable water-based polyacrylate adhesive is as follows: , where m, n, o, p, and q are all greater than 100.

[0005] As can be seen from the above structure, the present invention incorporates an acrylic monomer containing a large number of nitrogen, oxygen and fluorine atoms, and these nitrogen, oxygen and fluorine atoms can form a large number of hydrogen bonds, which can greatly improve the tensile strength of the adhesive. In addition, due to the existence of dynamic bonds, the old adhesive can be simply shredded and then simply re-applied to achieve the same performance as the original adhesive, which has good recyclability.

[0006] As a further preferred embodiment, the acrylic monomers are trifluoropropylene, acrylbenzene, acrylic acid, diacetone acrylamide and butyl acrylate.

[0007] As a further preferred embodiment, the ratio of trifluoropropylene, acrylbenzene, acrylic acid, diacetone acrylamide, and butyl acrylate is 20-50: 25-55: 25-40: 15-55: 40-75.

[0008] As a further preferred embodiment, the peroxide is potassium persulfate and sodium persulfate; and the bicarbonate solution is sodium bicarbonate solution.

[0009] As a further preferred embodiment, the alkylphenol polyoxyethylene ether is octylphenol polyoxyethylene ether-10.

[0010] In a second aspect, the present invention provides a method for preparing the above-mentioned recyclable water-based polyacrylate adhesive, comprising the following steps: Mix trifluoropropylene, allylbenzene, acrylic acid, diacetone acrylamide, butyl acrylate, water, and octylphenol polyoxyethylene ether-10 to obtain an acrylate monomer mixed solution; The sodium bicarbonate solution with a pH of 8 was heated to 80° C., and then the acrylic acid ester monomer mixed solution and potassium persulfate solution were added dropwise for reaction. After the reaction was completed, the mixture was cooled to room temperature to obtain a polyacrylate emulsion; Adding diaminodienamine ester to the polyacrylate emulsion, stirring evenly, and drying to obtain the recyclable water-based polyacrylate adhesive.

[0011] The invention uses potassium persulfate to initiate polymerization of acrylic acid ester monomers to generate a polyacrylate emulsion containing a carbon group (diacetone acrylamide) capable of generating a Schiff base dynamic bond, which then forms a Schiff base dynamic bond with the amino group of diaminodienamine ester.

[0012] As a further preferred embodiment, the diaminodienamine ester is prepared by the following steps: 1,12-diester acetylene and 1,3-propylenediamine are reacted in an ice bath. After the reaction is completed, the mixture is washed and dried to obtain the product.

[0013] As a further preferred embodiment, the molar ratio of the diaminodienamine ester to diacetone acrylamide is 1:1.

[0014] In a third aspect, the present invention provides the use of the above-mentioned recyclable water-based polyacrylate adhesive in metal interface bonding.

[0015] In a fourth aspect, the present invention provides a method for bonding a metal interface using the above-mentioned recyclable water-based polyacrylate adhesive, comprising the following steps: The recyclable water-based polyacrylate adhesive is applied between metal substrates and hot-pressed at a temperature of 100° C. to 150° C. and a pressure of 5 MPa to 15 MPa to form the adhesive.

[0016] The beneficial effects of the present invention are: (1) The recyclable adhesive provided by the present invention is based on water-based polyacrylate, and diaminodienamine ester and diacetone acrylamide are added to generate dynamic bonds, thereby increasing the network density of the polymer, increasing the content of hydrogen bonds, and improving the deformation resistance of the adhesive, thereby solving the problem of low bonding strength of water-based polyacrylate adhesives in the prior art.

[0017] (2) The present invention uses water-based polyacrylate as the matrix of the adhesive, which fundamentally solves the problem of volatile organic compound (VOC) emissions caused by traditional solvent-based adhesives. In addition, when the water-based polyacrylate itself is heated, the molecular chain migrates and has a certain thermal processing ability, which provides conditions for the subsequent recycling of the adhesive. On the original basis, functional groups that can generate dynamic bonds are introduced and polymerized on the polyacrylate skeleton. This not only greatly increases the recyclability but also eliminates the need for subsequent complicated compounding processes.

[0018] (3) In the method for preparing the recyclable adhesive of the present invention, diacetone acrylamide and diamino dienamine ester are used to generate dynamic bonds. Since the amino group of diamino dienamine ester and diacetone acrylamide generate Schiff base dynamic bonds, in the subsequent treatment of the old adhesive, the dynamic bonds are reorganized by breaking the adhesive in a high temperature environment, so that the adhesive can be efficiently recycled.

[0019] (4) In the preparation method of the present invention, diaminodienamine ester is used as the long chain, which provides a soft end structure for the adhesive, increases the fluidity of the molecular chain, makes it easier to form hydrogen bonds, and thus improves the strength of the adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 Shown is a schematic diagram of the adhesive sample attached to tinplate. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] Example 1 A recyclable water-based polyacrylate adhesive, the preparation method of which specifically comprises the following steps: (1) Preparation of diaminodienamine esters: 1 mol of 1,12-diester alkyne was slowly added dropwise to 2.05 mol of 1,3-propylenediamine solution at a flow rate of 0.2 ml / s. After the addition was complete, the reaction was continued in an ice bath at 5°C for 8 h. The product was then washed with deionized water to remove excess 1,3-propylenediamine and dried to obtain a diaminodienamine ester, the structure of which is as follows: .

[0024] (2) Preparation of recyclable water-based polyacrylate adhesive: Step 1: 7 g of trifluoropropylene, 8 g of allylbenzene, 6.5 g of acrylic acid, 3.5 g of diacetone acrylamide, 15 g of butyl acrylate, 40 g of deionized water and 2.1 g of octylphenol polyoxyethylene ether-10 were stirred in a stirrer at a speed of 200 r / min for 5 min to obtain a mixed solution of acrylic ester monomers; Step 2: Add 20 ml of sodium bicarbonate solution with a pH of 8 into the reaction apparatus and heat it to 80°C. Then, add 30 g of deionized water, the mixed solution of acrylic acid ester monomers obtained in step 1, and 15 g of potassium persulfate solution dropwise within 2 h. After cooling to room temperature, a polyacrylate emulsion is obtained. Then, add 9.4 g of the diaminodienamine ester prepared in step 1, and dry at 85°C to obtain an adhesive.

[0025] Example 2 A recyclable water-based polyacrylate adhesive, the preparation method of which specifically comprises the following steps: (1) Preparation of diaminodienamine esters: 1 mol of 1,12-diester alkyne was slowly added dropwise to 2.05 mol of 1,3-propylenediamine solution at a flow rate of 0.2 ml / s. After the addition was completed, the reaction was continued in an ice bath at 5°C for 8 h. The product was then washed with deionized water to remove excess 1,3-propylenediamine and dried to obtain diaminodienamine ester.

[0026] (2) Preparation of recyclable water-based polyacrylate adhesive: Step 1: 7 g of trifluoropropylene, 8 g of allylbenzene, 6.5 g of acrylic acid, 7 g of diacetone acrylamide, 15 g of butyl acrylate, 40 g of deionized water and 2.1 g of octylphenol polyoxyethylene ether-10 were stirred in a stirrer at a speed of 200 r / min for 5 min to obtain a mixed solution of acrylic ester monomers; Step 2: Add 20 ml of sodium bicarbonate solution with a pH of 8 into the reaction apparatus and heat it to 80°C. Then, add 30 g of deionized water, the mixed solution of acrylic acid ester monomers obtained in step 1, and 15 g of potassium persulfate solution dropwise within 2 h. After cooling to room temperature, a polyacrylate emulsion is obtained. Then, 18.8 g of the diaminodienamine ester prepared in step 1 is added, and the mixture is dried at 85°C to obtain an adhesive.

[0027] Example 3 A recyclable water-based polyacrylate adhesive, the preparation method of which specifically comprises the following steps: (1) Preparation of diaminodienamine esters: 1 mol of 1,12-diester alkyne was slowly added dropwise to 2.05 mol of 1,3-propylenediamine solution at a flow rate of 0.2 ml / s. After the addition was completed, the reaction was continued in an ice bath at 5°C for 8 h. The product was then washed with deionized water to remove excess 1,3-propylenediamine and dried to obtain diaminodienamine ester.

[0028] (2) Preparation of recyclable water-based polyacrylate adhesive: Step 1: 7 g of trifluoropropylene, 8 g of allylbenzene, 6.5 g of acrylic acid, 10.5 g of diacetone acrylamide, 15 g of butyl acrylate, 40 g of deionized water and 2.1 g of octylphenol polyoxyethylene ether-10 were stirred in a stirrer at a speed of 200 r / min for 5 min to obtain a mixed solution of acrylic acid ester monomers; Step 2: Add 20 ml of sodium bicarbonate solution with a pH of 8 into the reaction apparatus and heat it to 80°C. Then, add 30 g of deionized water, the mixed solution of acrylic acid ester monomers obtained in step 1, and 15 g of potassium persulfate solution dropwise within 2 h. After cooling to room temperature, a polyacrylate emulsion is obtained. Then, add 28.2 g of the diaminodienamine ester prepared in step 1, and dry at 85°C to obtain an adhesive.

[0029] Comparative Example 1 A recyclable water-based polyacrylate adhesive is prepared by a method similar to that of Example 1, except that diacetone acrylamide (DAAM) is replaced with 14 g and diaminodienamine ester is replaced with 37.4 g. The rest of the process remains unchanged.

[0030] Comparative Example 2 A recyclable water-based polyacrylate adhesive, the preparation method of which is similar to that of Example 1, the only difference being that diaminodienamine ester is not added in step 2 of (2), and the rest of the process remains unchanged.

[0031] Example 4 The adhesive prepared above was subjected to shear strength test and recycling ability test, and the specific process was as follows: Place the adhesive between the polished tinplates (see diagram for details). Figure 1 The adhesive was hot pressed at 100-150°C and 5-15 MPa for 1-2 h, and then the metal substrate containing the adhesive was placed under a tensile testing machine to test the tensile strength of the adhesive (all adhesives were applied to the bonding area of 1 cm 2 The results are shown in Table 1: Table 1 Adhesive tensile strength test and its tensile strength test after recycling The 5% mol DAAM in the table means that diacetone acrylamide accounts for 5% of the total molar amount of trifluoropropylene, acrylbenzene, acrylic acid, diacetone acrylamide and butyl acrylate.

[0032] As can be seen from Table 1 above, when comparing Example 1, Example 2, and Example 3, the tensile strength of the adhesive increases and then decreases when adjusting the monomer of diacetone acrylamide. The reason is that at this specific ratio, the number of nitrogen, oxygen, and fluorine atoms in the adhesive reaches the extreme value of the normal distribution. Therefore, overall, Example 2 has better overall performance.

[0033] Among them, Example 3 has the highest content of diacetone acrylamide (DAAM), the most dynamic bonds in the adhesive, and the highest adhesive recovery rate (Example 3), which can reach the highest recovery rate of 98.50%. This is because the proportion of diacetone acrylamide in Example 3 is higher than that in Examples 1 and 2, and the dynamic bonds formed in the adhesive also increase, which improves the recovery efficiency. However, due to the greatly increased cross-linking density of the adhesive, the internal cohesive force of the adhesive increases, making it difficult for the adhesive to form effective and strong hydrogen bonds with the surface of the substrate when heating and bonding the board.

[0034] However, when the amount of diacetone acrylamide is too large (Comparative Example 1), the amount of diaminodienamine ester is also increased, the dynamic bonds in the adhesive increase, and the cross-linked network density of the adhesive is too high, resulting in increased cohesion of the adhesive. The increased cohesion of the adhesive greatly reduces the wettability of the adhesive when in contact with the substrate, resulting in the adhesive performance of Comparative Example 1 being far inferior to that of Examples 1, 2, and 3.

[0035] Comparative Example 2 tested the performance of the adhesive without adding diaminodienamine ester. It can be seen that the adhesive strength of the adhesive is improved, but the recycling ability of the adhesive is greatly reduced when the dynamic bond is lost. The reason is that acrylic polymers do undergo molecular chain migration under heat and pressure, allowing the material to be recycled by hot pressing. However, in the absence of dynamic bonds, it is difficult for the material to withstand multiple hot pressing recycling, and the material eventually loses its adhesiveness.

[0036] The embodiments of the present application are described above in conjunction with the accompanying drawings. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the core idea of the present application, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present application and the claims, all of which are within the protection of the present application.

Claims

1. A recyclable water-based polyacrylate adhesive, characterized in that: The raw materials include, by weight: 40-50 parts by weight of acrylic monomer, 10-15 parts by weight of peroxide solution, 5-15 parts by weight of bicarbonate solution, 1-20 parts by weight of diaminodienamine ester, 50-60 parts by weight of water, and 1-5 parts by weight of alkylphenol polyoxyethylene ether; The structure of the diaminodienamine ester is as follows: ； The structure of the recyclable water-based polyacrylate adhesive is as follows: , where m, n, o, p, and q are all greater than 100.

2. The recyclable water-based polyacrylate adhesive according to claim 1, characterized in that: The acrylic monomers are trifluoropropylene, acrylbenzene, acrylic acid, diacetone acrylamide and butyl acrylate.

3. The recyclable water-based polyacrylate adhesive according to claim 2, characterized in that: The mass ratio of trifluoropropylene, acrylbenzene, acrylic acid, diacetone acrylamide and butyl acrylate is 20-50: 25-55: 25-40: 15-55: 40-75.

4. The recyclable water-based polyacrylate adhesive according to claim 1, characterized in that: The peroxide is potassium persulfate or sodium persulfate; the bicarbonate solution is sodium bicarbonate solution.

5. The recyclable water-based polyacrylate adhesive according to claim 1, characterized in that: The alkylphenol polyoxyethylene ether is octylphenol polyoxyethylene ether-10.

6. The method for preparing the recyclable water-based polyacrylate adhesive according to any one of claims 1 to 5, characterized in that: The following steps are involved: Mix trifluoropropylene, allylbenzene, acrylic acid, diacetone acrylamide, butyl acrylate, water, and octylphenol polyoxyethylene ether-10 to obtain an acrylate monomer mixed solution; The sodium bicarbonate solution with a pH of 8 was heated to 80° C., and then the acrylic acid ester monomer mixed solution and potassium persulfate solution were added dropwise for reaction. After the reaction was completed, the mixture was cooled to room temperature to obtain a polyacrylate emulsion; Adding diaminodienamine ester to the polyacrylate emulsion, stirring evenly, and drying to obtain the recyclable water-based polyacrylate adhesive.

7. The preparation method according to claim 6, characterized in that The diaminodienamine ester is prepared by the following steps: 1,12-diester acetylene and 1,3-propylenediamine are reacted in an ice bath. After the reaction is completed, the mixture is washed and dried to obtain the product.

8. The preparation method according to claim 6, characterized in that The molar ratio of the diaminodienamine ester to diacetone acrylamide is 1:

1.

9. Use of the recyclable water-based polyacrylate adhesive according to any one of claims 1 to 5 in metal interface bonding.

10. The method for bonding metal interfaces with a recyclable water-based polyacrylate adhesive according to any one of claims 1 to 5, characterized in that: The following steps are involved: The recyclable water-based polyacrylate adhesive is applied between metal substrates and hot-pressed at a temperature of 100° C. to 150° C. and a pressure of 5 MPa to 15 MPa to form the adhesive.

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