Adhesive with high vertical tensile strength and preparation method thereof

Abstract

The invention provides an adhesive with high vertical tensile strength and a preparation method thereof, and the adhesive comprises 100 parts of liquid epoxy resin, 50-150 parts of solid epoxy resin, 20-30 parts of engineering plastic flexibilizer, 8-15 parts of curing agent and 0-10 parts of filler. The adhesive disclosed by the invention is high in vertical tensile strength, the vertical tensile strength is greater than 70 MPa, the adhesive has excellent bonding and curing effects, and the test strength reaches 80 MPa or above. The adhesive provided by the invention is a single-component product and does not need to be blended again during use. The adhesive disclosed by the invention is good in stability, the shelf life at room temperature is half a year, the shelf life is 1 year when the adhesive is stored in a refrigerator at 0-5 DEG C, and the adhesive can be continuously used after the shelf life is reached and the strength is tested The paste adhesive disclosed by the invention can be directly used, and is more convenient to use after being prepared into an adhesive film. The adhesive disclosed by the invention can be used for testing the bonding strength of a thermal spraying coating.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy resin adhesives, relates to a single-component adhesive, and specifically relates to an adhesive with high vertical tensile strength and a preparation method thereof. Background Art

[0002] Adhesives are used in inspections in many fields because they are easy to use, do not damage the materials being inspected, and the bonding strength can be adjusted according to the use requirements. For example, the thermal spray coating bonding strength test method specified in the MH / T 3027-3013 "Thermal Spray Coating Bond Strength Test" standard requires the use of adhesives. The adhesives recommended in its appendix are all adhesive models produced in the United States. This may be because the demand for adhesives in the thermal spray industry is relatively small, and its tensile strength requirements are increasing, requiring the vertical tensile bonding strength to reach more than 70MPa. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide an adhesive with high vertical tensile strength and a preparation method, so as to solve the technical problem that the vertical tensile strength of the adhesive in the prior art needs to be further improved.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0005] The invention discloses an adhesive with high vertical tensile strength, which is made of the following raw materials: liquid epoxy resin, solid epoxy resin, engineering plastic toughening agent, curing agent and filler.

[0006] Specifically, the invention comprises the following raw materials, in parts by weight: 100 parts of liquid epoxy resin, 50-150 parts of solid epoxy resin, 20-30 parts of engineering plastic toughening agent, 8-15 parts of curing agent and 0-10 parts of filler.

[0007] Preferably, the following raw materials are included in parts by weight: 100 parts of liquid epoxy resin, 100 parts of solid epoxy resin, 25 parts of engineering plastic toughening agent, 12 parts of curing agent, and 5 parts of filler.

[0008] The present invention also has the following technical features:

[0009] Preferably, the liquid epoxy resin is E51 epoxy resin; the solid epoxy resin is E20 epoxy resin; the engineering plastic toughening agent is polyethersulfone; the curing agent is dicyandiamide; and the filler is fumed silica.

[0010] Specifically, the vertical tensile strength of the adhesive with high vertical tensile strength is greater than 70 MPa.

[0011] Preferably, the vertical tensile strength of the adhesive with high vertical tensile strength is greater than or equal to 80 MPa.

[0012] The present invention also protects a method for preparing an adhesive with high vertical tensile strength, the method comprising the following steps:

[0013] Step 1: Mix and stir the particles of liquid epoxy resin and engineering plastic toughening agent at room temperature, heat to 120-140° C., and keep warm for 2-5 hours. Stir continuously during the heating and keeping warm process until the engineering plastic toughening agent is completely dissolved in the liquid epoxy resin to obtain a resin system.

[0014] Step 2: Add solid epoxy resin into the resin system, and stir evenly after the solid epoxy resin is melted.

[0015] Step 3: Set the heating temperature to 60-100° C., wait for the resin system to cool down naturally to 60-100° C., and continue stirring during the process.

[0016] Step 4: After the resin system is cooled to 60-100° C., a curing agent and a filler are added and stirred for 30-60 minutes to evenly mix the curing agent and the filler with the resin to obtain a preliminary adhesive.

[0017] Step 5: The preliminary adhesive is further mixed evenly by a three-roller machine to eliminate bubbles and agglomerated particles, thereby obtaining an adhesive with high vertical tensile strength.

[0018] Furthermore, the method also includes step six.

[0019] Step six, using a film making machine to make the adhesive with high vertical tensile strength into a 0.1-0.25 mm thick film, and cutting it into the required size and shape for use as needed.

[0020] Compared with the prior art, the present invention has the following technical effects:

[0021] (I) The adhesive of the present invention has high vertical tensile strength, which is greater than 70 MPa, and has excellent bonding and curing effect, with a test strength of more than 80 MPa.

[0022] (II) The adhesive of the present invention is a single-component product and does not need to be re-mixed when used.

[0023] (III) The adhesive of the present invention has good stability, with a shelf life of half a year at room temperature and a shelf life of one year in a refrigerator at 0-5°C. After the shelf life, if the strength test is qualified, it can continue to be used.

[0024] (IV) The paste adhesive of the present invention can be used directly, and is more convenient to use after being made into an adhesive film.

[0025] (V) The adhesive of the present invention can be used for thermal spray coating bonding strength testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a schematic diagram of the process for preparing the adhesive film with high vertical tensile strength.

[0027] Figure 2 It is a schematic diagram of the bonding sample of the present invention, and the bonding sample is connected to an electronic universal testing machine during testing.

[0028] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0029] It should be noted that, unless otherwise specified, all equipment and raw materials in the present invention are equipment and raw materials known in the prior art.

[0030] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0031] Example:

[0032] This embodiment provides an adhesive with high vertical tensile strength, which is made of the following raw materials, measured in parts by weight: 100 parts of liquid epoxy resin, 100 parts of solid epoxy resin, 25 parts of engineering plastic toughening agent, 12 parts of curing agent, and 5 parts of filler.

[0033] In this embodiment, the liquid epoxy resin is E51 epoxy resin; the solid epoxy resin is E20 epoxy resin; the engineering plastic toughening agent is polyethersulfone (PES) with the brand name PESU3600P produced by Solvay; the curing agent is dicyandiamide; and the filler is fumed silica.

[0034] like Figure 1 As shown, the preparation method of the adhesive with high vertical tensile strength comprises the following steps:

[0035] Step 1: In a beaker or reactor, mix and stir the particles of liquid epoxy resin and engineering plastic toughening agent at room temperature, heat to 120-140° C., and keep warm for 2-5 hours. Stir continuously at a low speed during the heating and keeping warm process until the engineering plastic toughening agent is completely dissolved in the liquid epoxy resin to obtain a resin system, which is a light yellow transparent liquid.

[0036] Step 2: Add solid epoxy resin into the resin system, and stir evenly after the solid epoxy resin is melted.

[0037] Step 3: Set the heating temperature to 60-100° C., wait for the resin system to cool down naturally to 60-100° C., and continue stirring during the process.

[0038] Step 4: After the resin system is cooled to 60-100° C., a curing agent and a filler are added and stirred at high speed for 30-60 minutes to evenly mix the curing agent and the filler with the resin to obtain a preliminary adhesive.

[0039] Step 5: The preliminary adhesive is further mixed evenly by a three-roller machine to eliminate bubbles and agglomerated particles, thereby obtaining an adhesive with high vertical tensile strength.

[0040] Step six, using a film making machine to make the adhesive with high vertical tensile strength into a 0.1-0.25 mm thick film, and cutting it into the required size and shape for use as needed.

[0041] The adhesive with high vertical tensile strength prepared in this embodiment was subjected to a vertical tensile strength test, and the test strength reached above 80 MPa.

[0042] The adhesive with high vertical tensile strength prepared in this embodiment has a shelf life of half a year at room temperature and a shelf life of one year in a refrigerator at 0-5°C. After the shelf life, it can continue to be used if the strength test is qualified, indicating that the adhesive of the present invention has good stability.

[0043] like Figure 2 As shown, the method of using the adhesive with high vertical tensile strength is:

[0044] First, adhesive film: After the surface of the bonded material is treated as required, heat it to 60-70℃ in an oven, stick the adhesive film on the treated surface, and then stick another bonded material on the other side of the adhesive film, clamp and fix it with a pressure of 0.05-0.1MPa, heat it to 185℃ in the oven and keep it warm for 2-3 hours. After cooling to room temperature with the furnace, remove the glue squeezed around the bonding surface, and it can be used for bonding strength test.

[0045] Second, paste adhesive: After the surface of the bonded material is treated as required, heat it to 60-70℃ in an oven, heat the adhesive to 60~70℃, scrape the adhesive onto the treated surface, apply a thin layer, scrape evenly, and then stick the other bonded material on the adhesive, use a clamp to clamp and fix it or use a special tooling to pressurize and fix it with a pressure of 0.05~0.1MPa, put it in a 185℃ oven for 2~3 hours, cool it to room temperature with the furnace, remove the glue squeezed around the bonding surface, and it can be used for bonding strength testing.

[0046] The adhesive with high vertical tensile strength of the present invention can be used for thermal spray coating bonding strength test, or other tests requiring high bonding strength or short-term high-strength bonding. The adhesive is a single-component epoxy resin structural adhesive, which is a paste at room temperature and can be heated to soften and then applied for bonding, or made into a film for bonding and use more conveniently. It adopts high temperature curing, and the vertical tensile strength at room temperature after complete curing is greater than 70MPa, and the test can reach 80MPa or even higher.

Claims

1. An adhesive with high vertical tensile strength, characterized in that: The invention is made of the following raw materials: liquid epoxy resin, solid epoxy resin, engineering plastic toughening agent, curing agent and filler.

2. The adhesive with high vertical tensile strength as claimed in claim 1, characterized in that: The invention is made of the following raw materials in parts by weight: 100 parts of liquid epoxy resin, 50-150 parts of solid epoxy resin, 20-30 parts of engineering plastic toughening agent, 8-15 parts of curing agent and 0-10 parts of filler.

3. The adhesive with high vertical tensile strength as claimed in claim 1, characterized in that: The invention is made of the following raw materials in parts by weight: 100 parts of liquid epoxy resin, 100 parts of solid epoxy resin, 25 parts of engineering plastic toughening agent, 12 parts of curing agent and 5 parts of filler.

4. The adhesive with high vertical tensile strength as claimed in claim 1, characterized in that: The liquid epoxy resin is E51 epoxy resin; the solid epoxy resin is E20 epoxy resin; the engineering plastic toughening agent is polyethersulfone; the curing agent is dicyandiamide; and the filler is fumed silica.

5. The adhesive with high vertical tensile strength as claimed in claim 1, characterized in that: The vertical tensile strength of the adhesive with high vertical tensile strength is greater than 70Mpa.

6. The adhesive with high vertical tensile strength as claimed in claim 5, characterized in that: The vertical tensile strength of the adhesive with high vertical tensile strength is greater than or equal to 80Mpa.

7. A method for preparing an adhesive with high vertical tensile strength as claimed in any one of claims 1 to 6, the method comprising the following steps: Step 1: Mix and stir the particles of liquid epoxy resin and engineering plastic toughening agent at room temperature, heat to 120-140° C., and keep warm for 2-5 hours, stirring continuously during the heating and keeping warm process until the engineering plastic toughening agent is completely dissolved in the liquid epoxy resin to obtain a resin system; Step 2, adding solid epoxy resin to the resin system, and stirring evenly after the solid epoxy resin is melted; Step 3, setting the heating temperature to 60-100°C, and allowing the resin system to cool naturally to 60-100°C, with continuous stirring during the process; Step 4: After the resin system is cooled to 60-100°C, a curing agent and a filler are added and stirred for 30-60 minutes to uniformly mix the curing agent and the filler with the resin to obtain a preliminary adhesive; Step 5: The preliminary adhesive is further mixed evenly by a three-roller machine to eliminate bubbles and agglomerated particles, thereby obtaining an adhesive with high vertical tensile strength.

8. The method for preparing an adhesive with high vertical tensile strength as claimed in claim 7, characterized in that: The method further comprises step six; Step six, using a film making machine to make the adhesive with high vertical tensile strength into a 0.1-0.25 mm thick film, and cutting it into the required size and shape for use as needed.

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