CN116496741A - A kind of dual curing epoxy adhesive and preparation method thereof - Google Patents

Abstract

The invention discloses a dual-curing epoxy adhesive, which relates to the field of adhesives, and comprises the following components in parts by weight: 20-56 parts of epoxy resin; 20-40 parts of epoxy acrylate oligomer; 20-30 parts of diluent; 1-3 parts of photoinitiator; 1-8 parts of thermal initiator; 1-2 parts of silane coupling agent; The preparation method of the agent comprises the following steps: (1) mixing the formula amount diluent, photoinitiator, and thermal initiator together, and heating at 60° C. in the dark to form a uniform transparent system; (2) cooling the above-mentioned uniform transparent system to 18 Below ℃, add the remaining materials in the formula, keep the temperature below 18℃ and avoid light, stir and mix evenly at low speed, degassing, and get the final product; the invention has no solvent, the raw materials used are convenient and easy to obtain, and the viscosity is low , Customers have a lot of room to adjust the formula according to actual needs, and can adjust it according to their needs. The connection process is convenient and suitable for assembly line applications.

Description

A kind of dual curing epoxy adhesive and preparation method thereof

technical field

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

Background technique

With the rapid development of the electronics industry, the application range of electronic products is becoming wider and wider, and the requirements for electronic adhesives are becoming more and more stringent. In recent years, the dual curing method combining ultraviolet light and other curing methods has attracted more and more attention, and the dual curing method of ultraviolet light and heat curing is also an important research and development direction.

At present, UV thermosetting dual curing is mostly used in paint and ink products with solvents and cationic curing epoxy systems for 3D printing. The present invention relates to a solvent-free, easy-to-obtain raw material, The low-viscosity, fast radical-curable UV thermosetting dual-cure system adhesive formulation design and corresponding preparation method.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned defects in the prior art, and provide a dual-curing epoxy adhesive and a preparation method thereof, which solve the technical problems in the prior art.

To achieve the above object, the invention provides a dual curing epoxy adhesive and a preparation method thereof, comprising the following components by weight:

In the above technical solution, the epoxy resin is bisphenol F epoxy resin.

In the above technical solution, the epoxy acrylate oligomer is one or more of Changxing Chemical 621A-80, 6202, 6210G, 6235, 6265.

In the above technical solution, the diluent is one or more of tetrahydrofuran acrylate, propylene isobornyl, hydroxyethyl methacrylate, hydroxybutyl acrylate, and morpholine acrylate.

In the above technical solution, the photoinitiator is 1-hydroxycyclohexyl phenyl ketone and/or 2,4,6 (trimethylbenzoyl) diphenylphosphine oxide.

In the above technical solution, the thermal initiator is selected from Fuji Kasei FXR1081 and/or FXR1020 low-temperature latent modified amine epoxy curing agent.

In the above technical scheme, the mercaptan is trimethylolpropane tris(3-mercaptopropionate) and/or pentaerythritol tetrakis(3-mercaptopropionate).

In the above technical solution, it is characterized in that the silane coupling agent is γ-glycidoxypropyltrimethoxysilane and/or γ-(methacryloyloxy)propyltrimethoxysilane.

In the above technical solution, the curing method of the adhesive is thermal curing or UV curing or UV curing first and then thermal curing.

The technical solution also provides the preparation method in the above-mentioned technical solution, comprising the following steps:

(1) Mix the formula diluent, photoinitiator, and thermal initiator together, and heat at 60°C in the dark to form a uniform transparent system;

(2) The temperature of the above-mentioned homogeneous transparent system is lowered to below 18°C, and the remaining materials in the formula are added, kept at a temperature below 18°C and protected from light, mixed evenly at a low speed, and defoamed to obtain the final finished adhesive.

Compared with prior art, the beneficial effect of the present invention is:

1. The adhesive prepared by the present invention can be cured by a single UV curing method, a thermal curing method, or a UV+thermosetting method. The curing speed is fast, the curing depth is deep, and the bonding strength is good.

2. The prepared adhesive can be quickly cured and positioned under UV curing conditions for 5-10 seconds, and the curing thickness can reach 15-20mm. It can be cured under heat curing conditions (110°C) for 20-40 minutes. The obtained adhesive High hardness and good strength.

3. The raw materials used in this technical solution are convenient and easy to obtain, with a wide range of choices, and there is no solvent, and the operation is simple. In addition, this technical solution has low viscosity, and the customer has a relatively large room for formula adjustment according to actual needs. You can choose to deploy according to your needs. The technical scheme has convenient connection process and is suitable for mass production and assembly line applications.

Detailed ways

Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between the various components in a certain posture , if the specific posture changes, the directional indication also changes accordingly.

In the present invention, unless otherwise specified and limited, the terms "connection" and "fixation" should be understood in a broad sense, for example, "fixation" can be a fixed connection, a detachable connection, or an integral body; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be an internal communication between two elements or an interaction relationship between two elements, unless otherwise clearly defined. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In addition, if there are descriptions involving "first", "second" and so on in the embodiments of the present invention, the descriptions of "first", "second" and so on are only for descriptive purposes, and should not be interpreted as indicating or implying Its relative importance or implicitly indicates the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the meaning of "and/or" appearing in the whole text includes three parallel schemes, taking "A and/or B" as an example, including scheme A, scheme B, or schemes that both A and B satisfy. In addition, the technical solutions of the various embodiments can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist , nor within the scope of protection required by the present invention.

Embodiment one

The present embodiment provides a dual curing epoxy adhesive, which includes the following components by weight:

The curing method of this technical solution can be thermal curing or UV curing or first UV and then thermal curing. After the UV lamp is irradiated, the double bonds in the epoxy acrylate oligomers are quickly cured, so that the viscosity of the adhesive rises rapidly to achieve preliminary bonding. The effect, and then initiate the polymerization of epoxy groups under the action of heat, so that the bonding strength is further improved, and deep curing can be achieved. Preferably, the epoxy resin is bisphenol F epoxy resin. The epoxy acrylate oligomer is one or more of Changxing Chemical 621A-80, 6202, 6210G, 6235, 6265.

Preferably, the photoinitiator is 1-hydroxycyclohexyl phenyl ketone (184) and/or 2,4,6 (trimethylbenzoyl) diphenylphosphine oxide (TOP). Among them, TOP is a light yellow powder with an effective absorption peak of 350-400nm and absorbs to about 420nm. It is a highly efficient free radical (I) type photoinitiator. Both benzoyl and phosphoryl free radicals can initiate polymerization, so the photocuring speed is fast, it also has photobleaching effect, and has low volatility, and can also be used for transparent coatings, especially suitable for products with low odor requirements. 184 is a white crystalline powder with effective absorption peaks at 246nm and 278nm. It is a highly efficient and non-yellowing free radical (I) type solid photoinitiator. There is no benzyl group in the solution, and the degree of yellowing is also very small. Both photoinitiators used in the technical solution have the characteristics of non-yellowing, so that the technical solution can be used after being exposed to sunlight for a long time after being cured.

The thermal initiator of the technical solution is selected from Fuji Kasei FXR1081 and/or FXR1020 low-temperature latent modified amine epoxy curing agent. Both FXR-1081 and FXR1020 are easy to disperse in epoxy resin, and the mixed resin has good storage stability at room temperature, and when FXR-1081 and FXR1020 are mixed, the amount of addition can be greatly reduced even if it is very small Its hardening temperature will not destroy the storage stability of the overall mixing system.

Preferably, the thiol is trimethylolpropane tris(3-mercaptopropionate) (TMPMP) and/or pentaerythritol tetrakis(3-mercaptopropionate) (PETMP). In this technical solution, mercaptan is added to increase the speed of the adhesive in thermal curing. The silane coupling agent of this technical solution is preferably γ-glycidyl ether oxypropyl trimethoxysilane (KH560) and/or γ-(methacryloxy) propyl trimethoxysilane (KH570), which can improve the Adhesive strength of technical solutions. The diluent of this technical scheme is preferably tetrahydrofuran acrylate (THFA), propylene isobornyl ester (IBOA), hydroxyethyl methacrylate (HEMA), hydroxybutyl acrylate (4HBA), acryloylmorpholine (ACMO) one or several.

The technical solution also provides its preparation method of the above-mentioned dual curing epoxy adhesive, comprising the following steps:

(1) Mix the formula diluent, photoinitiator, and thermal initiator together, and heat at 60°C in the dark to form a uniform transparent system;

(2) Cool down the above homogeneous transparent system to below 18°C, add the remaining materials in the formula, keep the temperature below 18°C, use a mixer or a three-roller to grind all the materials at a low speed and mix them evenly, and protect them from light during the stirring process measures, defoaming, to obtain the final finished adhesive.

Example 1

In this embodiment, the components of the adhesive in Example 1 are used for different combinations, and the specific weight parts of each component are shown in the table below.

Table 1 is the composition of adhesive in embodiment 1

Component name parts by weight Cycloaliphatic Epoxy Resin 621A-80 6202 6210G25 25 Bisphenol F type epoxy resin South Asia 170 40 Thinner THFA 4HBA 26 Photoinitiator 184 2 thermal initiator FXR1081 FXR1020 6 A silane coupling agent KH560 KH570 1

2. The preparation method of the adhesive is:

(1) Mix the formula diluent, photoinitiator, and thermal initiator together, and heat at 60°C in the dark to form a uniform transparent system;

(2) The temperature of the above homogeneous transparent system is lowered to below 18°C, add the remaining materials in the formula, keep low temperature (below 18°C) and disperse away from light at a low speed, stir and mix evenly (you can use a mixer to stir at a low speed, or you can use a three-roll machine to grind, and make a good light-proof measures), defoaming, to obtain a dual-curing epoxy adhesive.

3. Result test

The viscosity of the adhesive produced by the above steps is 2200CPS.

Table 2 is embodiment 1 adhesive performance test result

Shear Strength Data:

Test method: Use the same batch of PC sheets (specification 20*50mm), bond and fully cure with the rubber to be tested, make a test sample and place it at room temperature for 1 hour, measure the bonding area with a vernier caliper, and use a tensile testing machine to test Shear force, the specific experimental data are shown in Table 3:

Table 3 is embodiment 1 adhesive shear strength test result

test piece Shear strength MPa Pure UV curing 1.17 UV curing + 80 ℃ baking 60min 6.33 Pure heat curing (baking at 110°C for 20min) 4.45

Example 2

In this embodiment, the components of the adhesive in Example 1 are used for different combinations, and the specific weight parts of each component are shown in the table below.

Table 4 is the composition of adhesive in embodiment 2

Component name parts by weight Cycloaliphatic Epoxy Resin 6210G 6235 6202 twenty three Bisphenol F type epoxy resin South Asia 170 40 Thinner THFA IBOA ACMO 26 Photoinitiator TPO 1 thermal initiator FXR1081 4 A silane coupling agent KH560 KH570 1 Mercaptan TMPMP PETMP 5

2. The preparation method of the adhesive is:

(1) Mix the formula diluent, photoinitiator, and thermal initiator together, and heat at 60°C in the dark to form a uniform transparent system;

(2) The temperature of the above homogeneous transparent system is lowered to below 18°C, add the remaining materials in the formula, keep low temperature (below 18°C) and disperse away from light at a low speed, stir and mix evenly (you can use a mixer to stir at a low speed, or you can use a three-roll machine to grind, and make a good light-proof measures), defoaming, to obtain a dual-curing epoxy adhesive.

3. Result test

The viscosity of the adhesive produced by the above steps is 2400CPS.

Table 5 is embodiment 2 adhesive performance test result

Shear Strength Data:

Test method: Use the same batch of PC sheets (size 20*50mm), bond and fully cure with the glue to be tested, make test samples and place them at room temperature for 1 hour, measure the bonding area with a vernier caliper, and use a tensile testing machine to test Shear force, the specific experimental data are shown in Table 6:

Table 6 is embodiment 2 adhesive shear strength test result

test piece Shear strength MPa Pure UV curing 1.42 UV curing + 80°C baking for 60min 5.31 Pure heat curing (baking at 110°C for 20min) 3.77

Example 3

In this example, the components of the adhesive in Example 1 were used for different combinations, and the specific parts by weight of each component are shown in Table 7.

The composition of adhesive in table 7 embodiment 3

Component name parts by weight Cycloaliphatic Epoxy Resin 621A-80 6265 twenty three Bisphenol F type epoxy resin South Asia 170 40 Thinner HEMA 4HBA IBOA 29 Photoinitiator TPO 1 thermal initiator FXR1081 FXR1020 6 A silane coupling agent KH560 KH570 1

2. The preparation method of the adhesive is:

(1) Mix the formula diluent, photoinitiator, and thermal initiator together, and heat at 60°C in the dark to form a uniform transparent system;

(2) The temperature of the above homogeneous transparent system is lowered to below 18°C, add the remaining materials in the formula, keep low temperature (below 18°C) and disperse away from light at a low speed, stir and mix evenly (you can use a mixer to stir at a low speed, or you can use a three-roll machine to grind, and make a good light-proof measures), defoaming, to obtain a dual-curing epoxy adhesive.

3. Result test

The viscosity of the adhesive produced by the above steps is 1800CPS.

Table 8 is embodiment 3 adhesive shear strength test result

Shear Strength Data:

Test method: Use the same batch of PC sheets (specification 20*50mm), bond and fully cure with the rubber to be tested, make a test sample and place it at room temperature for 1 hour, measure the bonding area with a vernier caliper, and use a tensile testing machine to test Shear force, the specific experimental data are shown in Table 3:

Table 8 is embodiment 3 adhesive shear strength test result

test piece Shear strength MPa Pure UV curing 1.66 UV curing + 80 ℃ baking 60min 5.63 Pure heat curing (baking at 110°C for 20min) 5.12

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. The dual-curing epoxy adhesive is characterized by comprising the following components in parts by weight:

2. the dual cure epoxy adhesive of claim 1 wherein the epoxy resin is bisphenol F type epoxy resin.

3. The dual cure epoxy adhesive of claim 1, wherein the epoxy acrylate oligomer is one or more of the long-standing chemical 621A-80, 6202, 6210g,6235, 6265.

4. The dual-curing epoxy adhesive according to claim 1, wherein the diluent is one or more of tetrahydrofuranyl acrylate, isobornyl acrylate, hydroxyethyl methacrylate, hydroxybutyl acrylate and morpholine acrylate.

5. A dual cure epoxy adhesive according to claim 1, wherein the photoinitiator is 1-hydroxycyclohexyl phenyl ketone and/or 2,4,6 (trimethylbenzoyl) diphenyl phosphine oxide.

6. The dual cure epoxy adhesive process of claim 1 wherein the thermal initiator is selected from the group consisting of low temperature latent modified amine epoxy curatives rich in FXR1081 and/or FXR 1020.

7. A dual cure epoxy adhesive according to claim 1, wherein the thiol is trimethylolpropane tris (3-mercaptopropionate) and/or pentaerythritol tetrakis (3-mercaptopropionate).

8. The dual cure epoxy adhesive of claim 1, wherein the silane coupling agent is gamma-glycidoxypropyl trimethoxysilane and/or gamma- (methacryloyloxy) propyl trimethoxysilane.

9. The dual cure epoxy adhesive of claim 1 wherein the adhesive cures by thermal curing or UV-before-thermal curing.

10. The method for preparing the dual-curing epoxy adhesive according to any one of claims 1 to 9, comprising the following steps:

(1) Mixing the formula amount of diluent, photoinitiator and thermal initiator together, and heating at 60 ℃ in a dark place to form a uniform transparent system;

(2) And cooling the uniform transparent system to below 18 ℃, adding the rest materials in the formula, keeping the temperature below 18 ℃ and keeping out of light, stirring and mixing uniformly at a low speed, and defoaming to obtain the final finished adhesive.