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

Abstract

The invention particularly relates to a high-performance acrylate pressure-sensitive adhesive and a preparation method thereof. The acrylate pressure-sensitive adhesive is prepared from the following raw materials in parts by weight: 80 to 100 parts of acrylate monomer, 2 to 8 parts of epoxy resin, 5 to 10 parts of functional monomer, 0.2 to 0.8 part of initiator and 40 to 60 parts of solvent. Wherein methyl methacrylate, n-butyl acrylate, ethyl acrylate and methoxyethyl acrylate are used as comonomers, acrylic acid, N-methoxyacrylamide and hydroxyethyl acrylate are used as functional monomers, and epoxy resin is matched to prepare the acrylate pressure-sensitive adhesive with an epoxy group. Good adhesive performance, high-temperature and high-humidity resistance and weather resistance are shown. The pressure-sensitive adhesive solution can be stably stored at room temperature, and when the acrylate pressure-sensitive adhesive solution is used for preparing an adhesive tape, a cross-linking agent does not need to be used, so that the operation is simple, and the application range is wide.

Description

Technical Field

[0001] The invention relates to the technical field of pressure-sensitive adhesives, and in particular to a high-performance acrylate pressure-sensitive adhesive and a preparation method thereof. Background Art

[0002] Acrylic pressure-sensitive adhesive has the advantages of high polymer molecular weight, wide range of emulsion viscosity and adjustable rheology, and its production process is simple, low cost and more environmentally friendly. Therefore, it has great development potential and a broad application market, and is used to gradually replace solvent-based polyacrylate pressure-sensitive adhesive. For synthetic acrylic pressure-sensitive adhesive, the monomers used are diverse, highlighting the complex characteristics of the macromolecular copolymer composition in the adhesive. However, the initial adhesion, peeling force and holding force of this type of pressure-sensitive adhesive restrict each other and it is difficult to achieve a balance.

[0003] In different application scenarios, more and more requirements are put forward for acrylic pressure-sensitive adhesives. For example, in environments with high humidity, pressure-sensitive adhesives are required to have high water resistance; pressure-sensitive adhesive materials with short service life are required to have low residual adhesive rate; and pressure-sensitive adhesives with long service life are required to have strong adhesion. At this stage, acrylic pressure-sensitive adhesives have poor water resistance and moisture and heat resistance, and there are also common problems such as uneven bonding performance and weather resistance, which makes it difficult to meet the diverse needs of the current market. Summary of the invention

[0004] In order to solve the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a high-performance acrylic pressure-sensitive adhesive and a preparation method thereof.

[0005] The purpose of the present invention is achieved through the following technical scheme: a high-performance acrylic pressure-sensitive adhesive comprises the following raw materials in parts by weight: 80-100 parts of acrylic monomers, 2-8 parts of epoxy resins, 5-10 parts of functional monomers, 0.2-0.8 parts of initiators, and 40-60 parts of solvents.

[0006] Furthermore, the acrylic acid ester monomer is at least one of methyl methacrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, ethyl acrylate, ethyl acetoacetate methacrylate, and methoxyethyl acrylate.

[0007] Furthermore, the acrylic ester monomer is a mixed monomer consisting of methyl methacrylate, n-butyl acrylate, ethyl acrylate and methoxyethyl acrylate in a mass ratio of 2-3:10-11:3-4:1-2.

[0008] Furthermore, the functional monomer is at least one of acrylic acid, N-methoxyacrylamide, β-carboxyethyl acrylate, and hydroxyethyl acrylate. As a preferred embodiment of the present invention, the functional monomer is compounded with acrylic acid, N-methoxyacrylamide, and hydroxyethyl acrylate in a mass ratio of 3:4-5:1.

[0009] Furthermore, the epoxy equivalent of the epoxy resin is 450-500 g / eq. In the present invention, the epoxy resin is preferably epoxy resin E20.

[0010] The present invention uses methyl methacrylate, n-butyl acrylate, ethyl acrylate and methoxyethyl acrylate as comonomers, acrylic acid, N-methoxyacrylamide and hydroxyethyl acrylate as functional monomers, and epoxy resin to prepare an acrylate pressure-sensitive adhesive with epoxy groups. The good adhesion, heat resistance and weather resistance of the epoxy resin can be used to significantly improve the mechanical properties, high temperature resistance and corrosion resistance of the acrylate pressure-sensitive adhesive after cross-linking with acrylate, and the adhesive properties of the pressure-sensitive adhesive are also guaranteed. Furthermore, the ingenious combination of the comonomer and the functional monomer has a significant effect on improving the high temperature and humidity resistance and oil resistance of the pressure-sensitive adhesive.

[0011] Further, the initiator is at least one of a metal persulfate initiator, benzoyl peroxide, and an azo initiator. Specifically, the metal persulfate initiator is potassium persulfate, ammonium persulfate, or sodium persulfate.

[0012] Furthermore, the solvent is at least one of ethyl acetate, xylene, toluene and butanone.

[0013] Furthermore, 8-12 parts of fluorine-containing acrylate monomers are included.

[0014] Furthermore, the fluorine-containing acrylate monomer is at least one of trifluoroethyl acrylate, perfluorooctyl ethyl methacrylate, perfluoroalkylpropyl methacrylate, and perfluorooctyl ethyl acrylate.

[0015] The present invention can significantly improve the peel strength and water resistance of the acrylic pressure-sensitive adhesive by adding fluorinated acrylic monomers. The hydrophobic segments in the fluorinated polymer segments can give the pressure-sensitive adhesive a certain hydrophobicity, so that the pressure-sensitive adhesive can delay water penetration, thereby improving its water resistance.

[0016] The present invention also provides a method for preparing the high-performance acrylic pressure-sensitive adhesive, comprising the following steps:

[0017] (1) dissolving an initiator in a portion of a solvent and stirring uniformly to obtain an initiating solution;

[0018] (2) Add acrylate monomer, functional monomer, epoxy resin and remaining solvent into the reactor, raise the reaction temperature to 75-85° C., add half of the total amount of the initiator solution dropwise therein, and then keep the temperature for 0.5-1 h;

[0019] (3) adding half of the remaining initiating solution to the system of step (2) and continuing to keep warm for 0.5-1h;

[0020] (4) Then, the remaining initiating solution is added to the reaction system of step (3), and the temperature is kept for 2-3 hours. When the adhesive solution is cooled to room temperature, the high-performance acrylic pressure-sensitive adhesive is obtained.

[0021] In the present invention, the high-performance acrylic pressure-sensitive adhesive obtained by the above preparation method has good storage stability, and when the acrylic pressure-sensitive adhesive is used to prepare a tape, there is no need to use a cross-linking agent, and the operation is simple. At the same time, the obtained tape has good adhesive properties, high temperature resistance, weather resistance and oil resistance.

[0022] The beneficial effects of the present invention are as follows: the high-performance acrylic pressure-sensitive adhesive obtained by the present invention through the combination of the comonomer, the functional monomer, the epoxy resin and the fluorinated acrylic monomer has good adhesive properties, high temperature and high humidity resistance and weather resistance, and can be applied to different scenarios. Furthermore, the acrylic pressure-sensitive adhesive liquid has excellent storage stability, and when the adhesive tape is prepared by using it, no additional cross-linking agent is required, the operation is simple, and the process is pollution-free. DETAILED DESCRIPTION

[0023] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0024] In an embodiment of the present invention, a high-performance acrylic pressure-sensitive adhesive comprises the following raw materials in parts by weight: 80-100 parts of acrylic monomers, 2-8 parts of epoxy resins, 5-10 parts of functional monomers, 0.2-0.8 parts of initiators, and 40-60 parts of solvents.

[0025] In some embodiments of the present invention, the acrylic acid ester monomer is at least one of methyl methacrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, ethyl acrylate, ethyl acetoacetate methacrylate, and methoxyethyl acrylate.

[0026] In some embodiments of the present invention, the acrylic ester monomer is a mixed monomer consisting of methyl methacrylate, n-butyl acrylate, ethyl acrylate and methoxyethyl acrylate in a mass ratio of 2-3:10-11:3-4:1-2.

[0027] In some embodiments of the present invention, the functional monomer is at least one of acrylic acid, N-methoxyacrylamide, β-carboxyethyl acrylate, and hydroxyethyl acrylate.

[0028] In some embodiments of the present invention, the epoxy equivalent of the epoxy resin is 450-500 g / eq. Wherein, the epoxy resin is preferably epoxy resin E20.

[0029] In some embodiments of the present invention, the initiator is at least one of metal persulfate, benzoyl peroxide, and azo initiators, wherein the azo initiator is preferably diisovaleronitrile.

[0030] In some embodiments of the present invention, the solvent is at least one of ethyl acetate, xylene, toluene, and butanone.

[0031] In some embodiments of the present invention, 8-12 parts of fluorine-containing acrylate monomers are further included.

[0032] In some embodiments of the present invention, the fluorine-containing acrylate monomer is at least one of trifluoroethyl acrylate, perfluorooctyl ethyl methacrylate, perfluoroalkylpropyl methacrylate, and perfluorooctyl ethyl acrylate.

[0033] In some embodiments of the present invention, a method for preparing a high-performance acrylic pressure-sensitive adhesive comprises the following steps:

[0034] (1) dissolving an initiator in a portion of a solvent and stirring uniformly to obtain an initiating solution;

[0035] (2) Add acrylate monomer, functional monomer, epoxy resin and remaining solvent into the reactor, raise the reaction temperature to 75-85° C., add half of the total amount of the initiator solution dropwise therein, and then keep the temperature for 0.5-1 h;

[0036] (3) adding half of the remaining initiating solution to the system of step (2) and continuing to keep warm for 0.5-1h;

[0037] (4) Then, the remaining initiating solution is added to the reaction system of step (3), and the temperature is kept for 2-3 hours. When the adhesive solution is cooled to room temperature, the high-performance acrylic pressure-sensitive adhesive is obtained.

[0038] Example 1

[0039] The present embodiment provides a high-performance acrylic pressure-sensitive adhesive, which includes the following raw materials in parts by weight: 80 parts of acrylic monomers, 3 parts of epoxy resins, 5 parts of functional monomers, 0.3 parts of initiators, and 42 parts of solvents.

[0040] Furthermore, the acrylic acid ester monomer is a mixed monomer consisting of methyl methacrylate, n-butyl acrylate, ethyl acrylate and methoxyethyl acrylate in a mass ratio of 2:10:3:2.

[0041] Furthermore, the functional monomer is compounded by acrylic acid, N-methoxyacrylamide and hydroxyethyl acrylate in a mass ratio of 3:4:1.

[0042] Furthermore, the epoxy resin is epoxy resin E20.

[0043] Furthermore, the initiator is ammonium persulfate.

[0044] Furthermore, the solvent is a mixture of ethyl acetate and toluene in a mass ratio of 5.5:1.

[0045] The method for preparing the high-performance acrylic pressure-sensitive adhesive described in this embodiment comprises the following steps:

[0046] (1) dissolving an initiator in a portion of a solvent and stirring uniformly to obtain an initiating solution;

[0047] (2) Add acrylate monomer, functional monomer, epoxy resin and remaining solvent into the reactor, raise the reaction temperature to 80° C., add half of the total amount of the initiator solution dropwise therein, and then keep the temperature for 1 hour;

[0048] (3) adding half of the remaining initiation solution to the system of step (2) and keeping warm for 1 hour;

[0049] (4) Then, the remaining initiating solution is added to the reaction system of step (3), and the temperature is kept for 2 hours. After the adhesive solution is cooled to room temperature, the high-performance acrylic pressure-sensitive adhesive is obtained.

[0050] Example 2

[0051] The present embodiment provides a high-performance acrylic pressure-sensitive adhesive, which includes the following raw materials in parts by weight: 90 parts of acrylic monomers, 4 parts of epoxy resins, 6 parts of functional monomers, 0.5 parts of initiators, and 50 parts of solvents.

[0052] Furthermore, the acrylic acid ester monomer is a mixed monomer consisting of methyl methacrylate, n-butyl acrylate, ethyl acrylate and methoxyethyl acrylate in a mass ratio of 2.5:10:4:1.

[0053] Furthermore, the functional monomer is compounded by acrylic acid, N-methoxyacrylamide and hydroxyethyl acrylate in a mass ratio of 3:4.5:1.

[0054] Furthermore, the epoxy resin is epoxy resin E20.

[0055] Furthermore, the initiator is benzoyl peroxide.

[0056] Furthermore, the solvent is a mixture of ethyl acetate and xylene in a mass ratio of 5.6:1.

[0057] Furthermore, 9 parts of fluorine-containing acrylate monomers are included.

[0058] Furthermore, the fluorine-containing acrylate monomer is composed of trifluoroethyl acrylate and perfluoroalkylpropyl methacrylate in a mass ratio of 2:3.

[0059] The method for preparing the high-performance acrylic pressure-sensitive adhesive described in this embodiment comprises the following steps:

[0060] (1) dissolving an initiator in a portion of a solvent and stirring uniformly to obtain an initiating solution;

[0061] (2) Add acrylate monomer, functional monomer, epoxy resin and remaining solvent into the reactor, raise the reaction temperature to 80° C., dropwise add half of the total amount of the initiator solution, and then keep the temperature for 0.8 h;

[0062] (3) adding half of the remaining initiation solution to the system of step (2) and keeping warm for 1 hour;

[0063] (4) Then, the remaining initiating solution is added to the reaction system of step (3), and the temperature is kept for 2.5 hours. After the adhesive solution is cooled to room temperature, the high-performance acrylic pressure-sensitive adhesive is obtained.

[0064] Example 3

[0065] The present embodiment provides a high-performance acrylic pressure-sensitive adhesive, comprising the following raw materials in parts by weight: 100 parts of acrylic monomers, 6 parts of epoxy resins, 8 parts of functional monomers, 0.7 parts of initiators, and 58 parts of solvents.

[0066] Furthermore, the acrylic acid ester monomer is a mixed monomer consisting of methyl methacrylate, n-butyl acrylate, ethyl acrylate and methoxyethyl acrylate in a mass ratio of 3:11:4:1.

[0067] Furthermore, the functional monomer is compounded by acrylic acid, N-methoxyacrylamide and hydroxyethyl acrylate in a mass ratio of 3:4:1.

[0068] Furthermore, the epoxy resin is epoxy resin E20.

[0069] Furthermore, the initiator is azobisisovaleronitrile.

[0070] Furthermore, the solvent is a mixture of ethyl acetate and butanone in a mass ratio of 6:1.

[0071] Furthermore, it also includes 10 parts of fluorine-containing acrylate monomers, wherein the fluorine-containing acrylate monomers are composed of trifluoroethyl acrylate and perfluoroalkylpropyl methacrylate in a mass ratio of 2:3.

[0072] The method for preparing the high-performance acrylic pressure-sensitive adhesive described in this embodiment comprises the following steps:

[0073] (1) dissolving an initiator in a portion of a solvent and stirring uniformly to obtain an initiating solution;

[0074] (2) Add acrylate monomer, functional monomer, epoxy resin and remaining solvent into the reactor, raise the reaction temperature to 80° C., add half of the total amount of the initiator solution dropwise therein, and then keep the temperature for 1 hour;

[0075] (3) adding half of the remaining initiation solution to the system of step (2) and keeping warm for 1 hour;

[0076] (4) Then, the remaining initiating solution is added to the reaction system of step (3), and the temperature is kept for 3 hours. After the adhesive solution is cooled to room temperature, the high-performance acrylic pressure-sensitive adhesive is obtained.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 2 is that the acrylic acid ester monomer is a mixed monomer consisting of methyl methacrylate, n-butyl acrylate and ethyl acrylate in a mass ratio of 2.5:10:4.

[0079] Comparative Example 2

[0080] The difference between this comparative example and Example 2 is that the functional monomer is composed of acrylic acid and ethyl acrylate in a mass ratio of 2:1.

[0081] Comparative Example 3

[0082] The difference between this comparative example and Example 2 is that: in this comparative example, no epoxy resin is added, and the remaining components are changed in equal proportions.

[0083] In the present invention, in order to test the performance of the high-performance acrylic pressure-sensitive adhesive, 5 mL of the pressure-sensitive adhesive solution prepared in Examples 1-3 or Comparative Examples 1-2 was evenly coated on a PET film to form a 50 μm thick adhesive layer, and then transferred to a 115-120°C oven for baking for 5-10 minutes. After taking it out, a release film was attached to the surface of the adhesive layer, and the release film was closely attached to the adhesive layer by rolling, and placed at room temperature for 24 hours to obtain a pressure-sensitive adhesive tape for testing. The specific test results are shown in Table 1 below:

[0084]

[0085] The initial adhesion is tested according to GB / T4582-2002 standard. The pressure-sensitive tape is cut into samples with a size of 100mm×100mm and attached to the inclined surface of the instrument. Steel balls with specified numbers and different diameters are freely released from the standard line of the 30° inclined surface in order from large to small, until a steel ball with a certain number completely stops on the adhesive layer. This steel ball number is used to represent the initial adhesion performance of the pressure-sensitive tape.

[0086] The 85℃ holding force adopts the GB / T4851-2014 test standard. The pressure-sensitive tape is cut into 100mm*25mm samples and attached to a stainless steel plate wiped clean with ethanol. The upper end is aligned with the standard line, and the excess part of the lower end is cut off. After rolling back and forth with a 2kg rubber roller for 3 times, it is placed for 20 minutes. The stainless steel plate with the sample is hung vertically on the test frame to prevent it from shaking. A 1kg weight is hung below. The time it takes for the sample to fall under a temperature environment of 85℃ represents the holding force of the pressure-sensitive adhesive layer of the protective film. Three test specimens are prepared for each pressure-sensitive tape sample, and the final result is the average of the three tests.

[0087] The 180° peel force test is carried out in accordance with GB / T 2792-2014 standard using a BLD-CH electronic peel tester. The pressure-sensitive tape is cut into 200mm*25mm strips, pasted on a stainless steel plate, rolled back and forth 3 times with a 2kg rubber roller, left for 20 minutes, and tested with a peel tester at a test speed of 300mm / min. The average value of three tests is taken for each sample.

[0088] The high temperature resistance test method of the pressure-sensitive tape is as follows: the pressure-sensitive tape is placed in a 150°C oven for 2 hours, and then placed at room temperature for 30 minutes before a 180° peeling force test. The average value of three tests is taken for each sample.

[0089] The aging resistance test method of the pressure-sensitive tape is as follows: the pressure-sensitive tape is cut into 150×25 mm sample strips, placed in a constant temperature and humidity aging box at 70°C and 95% humidity for 72 hours, and then the aged sample strips are tested for adhesion and 180° peel strength.

[0090] The high-performance acrylic pressure-sensitive adhesive prepared by the preparation method of the present invention has a relatively high initial adhesive force, and the pressure-sensitive adhesive has good holding force and 180° peeling force, which means that the adhesive performance of the acrylic pressure-sensitive adhesive is stable and balanced. Furthermore, it performs well in high temperature resistance and aging resistance tests, and the holding force and 180° peeling force of the pressure-sensitive adhesive after high temperature and high temperature and high humidity treatment respectively have a slight decrease trend, which means that it has good high temperature and high humidity stability.

[0091] The above specific embodiments are further explanations of the technical solutions and beneficial effects of the present invention, and are not limitations of the implementation methods. For those skilled in the art, any obvious replacements that do not depart from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A high-performance acrylic pressure-sensitive adhesive, characterized in that: The invention comprises the following raw materials in parts by weight: 80-100 parts of acrylate monomers, 2-8 parts of epoxy resins, 5-10 parts of functional monomers, 0.2-0.8 parts of initiators and 40-60 parts of solvents.

2. The high performance acrylic pressure sensitive adhesive according to claim 1, characterized in that: The acrylic acid ester monomer is at least one of methyl methacrylate, isobutyl acrylate, n-butyl acrylate, isooctyl acrylate, ethyl acrylate, ethyl acetoacetate methacrylate, and methoxyethyl acrylate.

3. The high performance acrylic pressure sensitive adhesive according to claim 2, characterized in that: The acrylic acid ester monomer is a mixed monomer consisting of methyl methacrylate, n-butyl acrylate, ethyl acrylate and methoxyethyl acrylate in a mass ratio of 2-3:10-11:3-4:1-2.

4. The high performance acrylic pressure sensitive adhesive according to claim 1, characterized in that: The functional monomer is at least one of acrylic acid, N-methoxyacrylamide, β-carboxyethyl acrylate, and hydroxyethyl acrylate.

5. The high performance acrylic pressure sensitive adhesive according to claim 1, characterized in that: The epoxy equivalent of the epoxy resin is 450-500 g / eq.

6. The high performance acrylic pressure sensitive adhesive according to claim 1, characterized in that: The initiator is at least one of metal persulfate, benzoyl peroxide and azobisisovaleronitrile.

7. The high performance acrylic pressure sensitive adhesive according to claim 1, characterized in that: The solvent is at least one of ethyl acetate, xylene, toluene and butanone.

8. The high performance acrylic pressure sensitive adhesive according to claim 1, characterized in that: Also included are 8-12 parts of fluorine-containing acrylate monomers.

9. The high performance acrylic pressure sensitive adhesive according to claim 8, characterized in that: The fluorine-containing acrylate monomer is at least one of trifluoroethyl acrylate, perfluorooctylethyl methacrylate, perfluoroalkylpropyl methacrylate, and perfluorooctylethyl acrylate.

10. The method for preparing a high-performance acrylic pressure-sensitive adhesive according to any one of claims 1 to 9, characterized in that: The steps include: (1) dissolving an initiator in a portion of a solvent and stirring uniformly to obtain an initiating solution; (2) Add acrylate monomer, functional monomer, epoxy resin and remaining solvent into the reactor, raise the reaction temperature to 75-85° C., add half of the total amount of the initiator solution dropwise therein, and then keep the temperature for 0.5-1 h; (3) adding half of the remaining initiating solution to the system of step (2) and keeping warm for 0.5-1h; (4) Then, the remaining initiating solution is added to the reaction system of step (3), and the temperature is kept for 2-3 hours. After the adhesive solution is cooled to room temperature, the high-performance acrylic pressure-sensitive adhesive is obtained.

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