CN105255416A - Room-temperature curing epoxy adhesive and preparation method thereof - Google Patents

Abstract

The invention provides a room temperature curing epoxy adhesive and a preparation method thereof, belonging to the technical field of adhesives. The method solves the problems that the existing epoxy adhesives have poor mechanical properties and cannot be quickly cured at room temperature. The adhesive includes 100 parts of epoxy resin, 15-20 parts of aromatic amine curing agent, 2-10 parts of ionic liquid, 10-20 parts of diluent, 10-15 parts of plasticizer, 5-10 parts of fiber reinforced material, filling 5-8 parts of the agent, the structural formula of the ionic liquid is shown in formula (I). The invention also provides a preparation method of a room temperature curing epoxy adhesive, which is simple and easy to implement, and the prepared adhesive can be cured at room temperature and has excellent mechanical properties.

Description

A kind of room temperature curing epoxy adhesive and preparation method thereof

technical field

The invention belongs to the technical field of adhesives, and in particular relates to a room temperature curing epoxy adhesive and a preparation method thereof.

Background technique

Epoxy adhesive is a liquid or solid adhesive composed of epoxy resin, curing agent, accelerator, modifier, etc. Since epoxy resin contains a variety of polar groups and highly active epoxy groups, it has strong adhesion to various polar materials such as metal, glass, cement, wood, and plastics. It has been widely used in industry and life because of its excellent comprehensive performance. In the application field of epoxy adhesives, room temperature curing adhesives have become the first choice in the industrial field because of their low process cost, easy operation and comprehensive performance. However, there are few heat-resistant groups in the macromolecules of the epoxy cured product in the room temperature system, and the room temperature curing temperature is low, and the crosslinking density of the cured product is small. Therefore, it is difficult for the room temperature cured epoxy system to meet the service requirements under high temperature conditions. Develop epoxy adhesives that can be cured at room temperature and used at high temperatures to meet the application needs of high-performance epoxy resins in aviation, aerospace, electronics and other industries.

At present, the application defects of room temperature curing epoxy adhesives in my country are mainly manifested in: few varieties, poor tensile strength, peel strength, and shear strength under high temperature conditions, and fast curing at room temperature are very rare and small in number. There are only dozens of room temperature curing adhesives available in the domestic market. Poor performance, only J-135, J-153 and other grades of epoxy adhesives have room temperature shear strength up to 30MPa, and the heat resistance temperature of most epoxy adhesives is only around 60°C-90°C. In recent years, some progress has been made in the research of room temperature curing and high temperature epoxy resin, but there is still no breakthrough.

Contents of the invention

The object of the present invention is to provide a room temperature curing epoxy adhesive and a preparation method thereof in order to solve the problem that the existing epoxy adhesive has poor mechanical properties and cannot be rapidly cured at room temperature.

The present invention firstly provides a room temperature curing epoxy adhesive, which comprises:

The structural formula of described ionic liquid is shown in formula (I):

In formula (I), R is BF ₄ , PF ₆ , AlCl ₄ , ZnCl ₃ or FeCl ₄ .

Preferably, the type of the epoxy resin is E-44, F-44, F-51, E-51 or TDE-85.

Preferably, the aromatic amine curing agent is selected from one or both of m-xylylenediamine, m-phenylenediamine or diaminodiphenylmethane.

Preferably, the diluent is allyl glycidyl ether, phenyl glycidyl ether or 2-ethyl-hexyl glycidyl ether.

Preferably, the plasticizer is dioctyl phthalate (DOP), polypropylene glycol diglycidyl ether or polythiol.

Preferably, the fiber reinforced material is boron fiber or glass fiber.

Preferably, the filler is selected from one or two of calcium silicate, magnesium oxide, carbon black, aluminum hydroxide or calcium carbonate.

The present invention also provides a preparation method of room temperature curing epoxy adhesive, comprising:

Mix epoxy resin with aromatic amine epoxy curing agent, stir evenly, then add ionic liquid, diluent, plasticizer, fiber reinforcement and filler, stir evenly, remove air bubbles, and obtain room temperature curing epoxy adhesive .

Beneficial effects of the present invention

The present invention firstly provides a room temperature curing epoxy adhesive, the adhesive includes an ionic liquid, the ionic liquid is a class of functionalized ionic liquid with magnetic properties, it is composed of organic cations and inorganic or organic anions, Salts that are in a liquid state at or near room temperature are widely used in the fields of electrochemistry, separation, and catalysis because of their advantages such as wide liquid range, low vapor pressure, strong solubility, and high electrochemical stability. The adhesive invented is to mix ionic liquids with different anionic structures and aromatic amine curing agents according to different mass ratios to make a series of compound curing agents at room temperature to cure epoxy resin. Tensile strength, shear, peel strength and heat resistance of the adhesive.

The invention also provides a preparation method of a room temperature curing epoxy adhesive, which is simple and easy to implement, and the prepared adhesive can be cured at room temperature and has excellent mechanical properties.

detailed description

The present invention firstly provides a room temperature curing epoxy adhesive, which comprises: 100 parts of epoxy resin, 15 to 20 parts of aromatic amine curing agent, 2 to 10 parts of ionic liquid, and 10 to 20 parts of diluent in parts by weight. 10-15 parts of plasticizer, 5-10 parts of fiber reinforcement, 5-8 parts of filler; preferably: 100 parts of epoxy resin, 15-20 parts of aromatic amine curing agent, 2-8 parts of ionic liquid , 10-15 parts of diluent, 10-15 parts of plasticizer, 5-8 parts of fiber reinforced material, 6-7 parts of filler;

The structural formula of described ionic liquid is shown in formula (I):

In formula (I), R is BF ₄ , PF ₆ , AlCl ₄ , ZnCl ₃ or FeCl ₄ .

According to the present invention, 1-hexyl-3-methylimidazolium tetrafluoroborate ([C ₆ mim]BF ₄ ), 1-hexyl-3-methylimidazolium hexafluorophosphate ([C ₆ mim]PF ₆ ), 1-hexyl-3-methylimidazolium trichloride zinc salt ([C ₆ mim]ZnCl ₃ ), 1-hexyl-3-methylimidazole tetrachloride aluminum salt ([C ₆ mim]AlCl ₄ ), 1-hexyl-3-methylimidazolium tetrachloride ferric salt ([C ₆ mim]FeCl ₄ ) is used as an ionic liquid, and the molecular structure of the ionic liquid contains a tertiary amine and a quaternary ammonium salt structure, which can initiate epoxy resin The characteristic group in the structure, the epoxy group, is ring-opening and curing and can catalyze the epoxy group. When the ionic liquid is combined with the aromatic amine curing agent to cure the epoxy resin, it can show a good synergistic effect, which can effectively overcome the aromatic amine curing. The traditional curing process of the agent requires high temperature curing before it can be used at high temperature, so that it can be cured quickly at room temperature, and the cured product can show excellent mechanical tensile strength, shear strength, peel strength and thermal properties.

According to the present invention, the type of the epoxy resin is preferably E-44, F-44, F-51, E-51 or TDE-85; the aromatic amine curing agent is preferably selected from m-xylylenediamine , one or both of m-phenylenediamine or diaminodiphenylmethane; the diluent is preferably allyl glycidyl ether, phenyl glycidyl ether or 2-ethyl-hexyl glycidyl ether; The plasticizer is preferably dioctyl phthalate, polypropylene glycol diglycidyl ether or polythiol. The fiber reinforcement material is preferably boron fiber or glass fiber; the filler is preferably selected from one or two of calcium silicate, magnesium oxide, carbon black, aluminum hydroxide or calcium carbonate.

The present invention also provides a preparation method of room temperature curing epoxy adhesive, comprising:

Mix epoxy resin with aromatic amine epoxy curing agent, stir evenly, then add ionic liquid, diluent, plasticizer, fiber reinforcement and filler, stir evenly, remove air bubbles, and obtain room temperature curing epoxy adhesive .

The above-mentioned adhesive was cast on a mold, placed at room temperature at 30-40°C to cure for 5 minutes, and its mechanical and thermal properties were tested.

The present invention will be described in further detail below in conjunction with specific examples, and the raw materials involved in the examples are all commercially available.

Example 1

Mix 100 parts of epoxy resin E-44 and 20 parts of m-phenylenediamine, stir well, then add 5 parts of 1-hexyl-3-methylimidazolium tetrafluoroborate, 10 parts of allyl glycidyl ether, 15 parts A mixture of dioctyl phthalate, 5 parts of boron fiber, 5 parts of calcium silicate, carbon black, and aluminum hydroxide (the mass ratio of calcium silicate, carbon black, and aluminum hydroxide is 3:1:2), Remove the air bubbles to prepare the adhesive, cast the adhesive on the mold for reinforcement, and place it at 30-40°C for 5 minutes to cure. The specific mechanical properties are shown in Table 1.

Example 2

Mix 100 parts of epoxy resin F-44 and 20 parts of m-xylylenediamine, stir well, then add 2 parts of 1-hexyl-3-methylimidazolium hexafluorophosphate, 12 parts of 2-ethyl-hexyl glycidol Ether, 15 parts of polypropylene glycol diglycidyl ether, 8 parts of boron fiber, 8 parts of magnesium oxide, remove air bubbles to prepare adhesive, cast the adhesive on the mold for reinforcement, and place it at 30-40°C for 5 minutes to cure . The specific mechanical properties are shown in Table 1.

Example 3

Mix 100 parts of epoxy resin F-51 and 20 parts of a mixture of m-phenylenediamine and diaminodiphenylmethane (the mass ratio of m-phenylenediamine and diaminodiphenylmethane is 3:2), stir evenly, and then Add 8 parts of 1-hexyl-3-methylimidazole zinc trichloride, 12 parts of phenyl glycidyl ether, 10 parts of polypropylene glycol diglycidyl ether and polythiol (wherein polypropylene glycol diglycidyl ether and polythiol The mass ratio of calcium carbonate and aluminum hydroxide is 2:1), 5 parts of glass fiber, 6 parts of a mixture of calcium carbonate and aluminum hydroxide (the mass ratio of calcium carbonate and aluminum hydroxide is 2:3), and the air bubbles are removed to prepare the adhesive. The adhesive is cast on the mold for reinforcement, and placed at 30-40°C for 5 minutes to cure. The specific mechanical properties are shown in Table 1.

Example 4

Mix 100 parts of epoxy resin E-51 and 20 parts of m-xylylenediamine, stir well, then add 5 parts of 1-hexyl-3-methylimidazolium tetrachloride aluminum salt, 15 parts of allyl glycidyl ether and A mixture of phenyl glycidyl ether (the mass ratio of allyl glycidyl ether and phenyl glycidyl ether is 1:2), 15 parts of polypropylene glycol diglycidyl ether, 10 parts of glass fiber, 7 parts of calcium carbonate, carbon black and aluminum hydroxide mixture (mass ratio of calcium carbonate, carbon black, and aluminum hydroxide is 3:1:1), remove air bubbles, and prepare adhesive, cast the adhesive on the mold for reinforcement, and place it at 30- Curing at 40°C for 5 minutes. The specific mechanical properties are shown in Table 1.

Example 5

Mix 100 parts of epoxy resin TDE-85 and 20 parts of diaminodiphenylmethane, stir evenly, then add 10 parts of 1-hexyl-3-methylimidazole tetraferric chloride, 10 parts of phenyl glycidyl ether, 15 parts of polypropylene glycol diglycidyl ether, 5 parts of glass fiber and 8 parts of aluminum hydroxide, remove air bubbles to prepare an adhesive, cast the adhesive on a mold for reinforcement, and place it at 30-40°C for 5 minutes to cure. The specific mechanical properties are shown in Table 1.

Comparative example 1

Mix 100 parts of epoxy resin E-44 and 20 parts of m-phenylenediamine, stir well, then add 10 parts of allyl glycidyl ether and 2-ethyl-hexyl glycidyl ether (wherein allyl glycidyl ether and The mass ratio of 2-ethyl-hexyl glycidyl ether is 1:1), 10 parts of polypropylene glycol diglycidyl ether and polythiol, wherein the mass ratio of polypropylene glycol diglycidyl ether and polythiol is 1:2), 5 parts of boron fiber, 5 parts of calcium carbonate and aluminum hydroxide (wherein the mass ratio of calcium carbonate and aluminum hydroxide is 3:1), remove air bubbles, and make an adhesive, cast the adhesive on a mold for reinforcement, and place it at 120- Curing at 150°C for 6h. The specific mechanical properties are shown in Table 1.

Table 1

Experimental parameters Comparative example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strength (MPa) 40 73 65 48 20 87 Elongation at break (%) 3 6 5 3 2 12 Shear strength (MPa) 19 18 20 twenty one 20 25 Peel strength (MPa) 31 32 33 32 30 36 Thermal degradation temperature (℃) 336 337 314 310 323 310

The descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. A room temperature curing epoxy adhesive, characterized in that, in parts by weight, comprising: The structural formula of described ionic liquid is shown in formula (I): In formula (I), R is BF ₄ , PF ₆ , AlCl ₄ , ZnCl ₃ or FeCl ₄ . 2. a kind of room temperature curing epoxy adhesive according to claim 1, is characterized in that, the model of described epoxy resin is E-44, F-44, F-51, E-51 or TDE- 85. 3. A room temperature curing epoxy adhesive according to claim 1, wherein the aromatic amine curing agent is selected from m-xylylenediamine, m-phenylenediamine or diaminodiphenylmethane one or both of them. 4. a kind of room temperature curing epoxy adhesive according to claim 1, is characterized in that, described diluent is allyl glycidyl ether, phenyl glycidyl ether or 2-ethyl-hexyl glycidol ether. 5. A room temperature curing epoxy adhesive according to claim 1, wherein the plasticizer is dioctyl phthalate, polypropylene glycol diglycidyl ether or polythiol. 6 . A room temperature curing epoxy adhesive according to claim 1 , wherein the fiber reinforcement is boron fiber or glass fiber. 7. A room temperature curing epoxy adhesive according to claim 1, wherein the filler is selected from one of calcium silicate, magnesium oxide, carbon black, aluminum hydroxide or calcium carbonate or two. 8. The preparation method of a kind of room temperature curing epoxy adhesive described in any one of claims 1-7, is characterized in that, comprises: Mix epoxy resin with aromatic amine epoxy curing agent, stir evenly, then add ionic liquid, diluent, plasticizer, fiber reinforcement and filler, stir evenly, remove air bubbles, and obtain room temperature curing epoxy adhesive .