One-component epoxy structural adhesive for nickel metal bonding and preparation method thereof

Abstract

The present invention relates to the technical field of epoxy structural adhesives, and in particular to a single-component epoxy structural adhesive and a preparation method for nickel metal bonding. The present application discloses a single-component epoxy structural adhesive for nickel metal bonding, including bisphenol A type epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, hydroxy acrylic resin, stress release agent, diluent, dicyandiamide, organic urea, fumed silica, coupling agent, wetting agent, defoamer, colorant, by fusing bisphenol A type epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, hydroxy acrylic resin at 180-190 ° C, and then adding other remaining additives to obtain epoxy structural adhesive. The epoxy structural adhesive prepared by the present application has high shear strength, strong anti-drop ability, and the adhesive force is not significantly reduced under high temperature and high humidity, and can be applied on the surface of nickel-based metal materials.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy structural adhesives, and in particular to a single-component epoxy structural adhesive for nickel metal bonding and a preparation method thereof. Background Art

[0002] Epoxy structural adhesive is a solvent-free, liquid epoxy resin adhesive that cures at room temperature or with heat. After curing, the adhesive layer is medium to hard, making it resistant to extreme shock and vibration. The adhesive layer exhibits excellent mechanical properties, electrical insulation, and the ability to withstand temperature fluctuations and flexural tearing stresses. Epoxy structural adhesive is non-corrosive and exhibits excellent adhesion to metals, ceramics, vulcanized rubber, fiberglass, and carbon fiber products, as well as heat and oil resistance.

[0003] Nickel is an inert material, making it difficult to form chemical bonds. Its surface is also relatively smooth, making it difficult to achieve effective physical bonding. Furthermore, the surface of nickel reacts with moisture, which penetrates the adhesive's inner layers over time, causing the adhesive's strength to gradually decrease. Therefore, nickel-based materials are considered difficult to bond. Currently available epoxy structural adhesives exhibit weak bonding strength to nickel, with shear strengths of only around 15 PMa, poor drop resistance, and significant bond degradation in high temperatures and humidity.

[0004] Therefore, it is necessary to propose a single-component epoxy structural adhesive that can be used for nickel metal bonding and has high shear strength, strong drop resistance, and little decrease in adhesion under high temperature and high humidity, as well as a preparation method. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies in the prior art, the present invention aims to provide a one-component epoxy structural adhesive for nickel metal bonding and a preparation method thereof.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A one-component epoxy structural adhesive for nickel metal bonding comprises the following raw materials in parts by weight:

[0008]

[0009] Preferably, the stress release agent is an organosilicon dendrimer. For example, the weight of the organosilicon dendrimer can be 5 parts, 6 parts, 7 parts or 8 parts, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0010] Preferably, the diluent is o-phenyl glycidyl ether. For example, the weight of o-phenyl glycidyl ether can be 6 parts, 7 parts, 8 parts, 9 parts or 10.05 parts, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0011] Preferably, the coupling agent is γ-glycidyloxypropyltrimethoxysilane. For example, the weight of γ-glycidyloxypropyltrimethoxysilane can be 1 part, 2 parts, or 3 parts, but is not limited to the values ​​listed. Other values ​​not listed within the numerical range are also applicable.

[0012] Preferably, the wetting agent is BYK-333. For example, the weight percentage of BYK-333 can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, or 0.5 part, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0013] Preferably, the defoaming agent is BYK-054. For example, the weight of BYK-054 can be 0.1 part, 0.2 part, 0.3 part, 0.4 part or 0.5 part, but is not limited to the values ​​listed above. Other values ​​not listed within the numerical range are also applicable.

[0014] Preferably, the colorant is carbon black. For example, the weight of carbon black can be 0.1 part, 0.2 part, 0.3 part, 0.4 part or 0.5 part, but is not limited to the values ​​listed above. Other values ​​not listed within the numerical range are also applicable.

[0015] Preferably, the weight average molecular weight of the bisphenol A epoxy resin is 340-390. For example, the weight average molecular weight of the bisphenol A epoxy resin is within the range of 340-350, 350-360, 360-370, 370-380, or 380-390, but is not limited to the listed values. Other values ​​within the numerical range not listed are also applicable.

[0016] Preferably, the viscosity of the phenolic modified epoxy resin is 6000-7100 cps. For example, the viscosity of the bisphenol-formaldehyde modified epoxy resin is 6000 cps, 6300 cps, 6600 cps, 7000 cps, or 7100 cps, but the viscosity is not limited to the listed values. Other values ​​within the numerical range not listed are also applicable.

[0017] In this application, bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin play the role of bonding and heat-resistant molding; the stress release agent silicone dendrimer is an elastic particle that increases the toughness and elasticity of the system, provides a buffering effect during impact or falling, and releases stress in time to prevent cracking. The epoxy diluent o-phenyl glycidyl ether reduces the viscosity of the system, improves the fluidity of the adhesive, and facilitates the dispensing process; dicyandiamide is a curing agent component that reacts with the resin components in the system to harden and form. Organic urea is a curing accelerator component that reduces the chemical reaction temperature and increases the chemical reaction rate. Fumed silica is a thixotropic agent that controls the fluidity of the adhesive and the dispensing thickness. The silane coupling agent KH560 improves the compatibility between the resin and the particles and improves the adhesive's adhesion to the interface. The wetting agent BYK-333 improves the fluidity of the adhesive and its wetting ability to the interface, allowing the adhesive to better contact with the interface, thereby improving the adhesion to the interface. Defoamer BYK-054 is used to eliminate bubbles in the adhesive after mixing to prevent voids from forming after curing, which could affect performance. Colorant carbon black provides color and gloss.

[0018] In the present application, bisphenol A epoxy resin itself has good mechanical properties, strong adhesion to metal, and certain adhesion to metal nickel; phenolic epoxy resin has excellent heat resistance, and is added to the system to improve the overall heat resistance, ensuring that the mechanical properties are not significantly weakened under high temperature conditions; glycidyl ester epoxy resin is a multifunctional epoxy resin, which increases the cross-linking density after curing, increases the body strength, and has excellent adhesion, heat resistance, and weather resistance, which can effectively improve shear strength, temperature resistance, and moisture resistance; dicyclopentadiene epoxy resin has excellent heat resistance, low moisture absorption, low elasticity and high adhesion, which significantly improves the high temperature and moisture resistance of the adhesive, increases adhesion and improves shear strength; hydroxyl acrylic resin has excellent bonding properties to metal substrates, significantly improves adhesion to nickel substrates, and improves shear strength; curing agent dicyandiamide cured epoxy resin has good bonding properties and high Tg, and also improves shear strength and temperature resistance.

[0019] The method for preparing the above-mentioned one-component epoxy structural adhesive for nickel metal bonding comprises the following steps:

[0020] At 180-190°C, bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin are stirred and dispersed according to weight percentage for 3-4 hours to obtain a transparent uniform liquid;

[0021] After the homogeneous liquid is cooled to room temperature, it is transferred to a stirring kettle, and dicyandiamide and organic urea are added according to the weight percentage composition. Stir and disperse at 0-10°C for 1-2 hours at a stirring speed of 1000-1500 r / min;

[0022] Reduce the stirring speed to 200-500 r / min, add the remaining other additives according to the weight percentage composition, and after the addition is completed, adjust the stirring speed to 1500-2000 r / min, stir and disperse for 1-2 hours to obtain a one-component epoxy structural adhesive.

[0023] The beneficial effects of the present invention are:

[0024] In this application, by fusing bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin at 180-190°C and then adding other remaining additives, the epoxy structural adhesive obtained has high shear strength and strong drop resistance, and the adhesion strength does not decrease significantly under high temperature and high humidity, and can be used on the surface of nickel-based metal materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings and examples.

[0026] Figure 1 This is a diagram showing the weight ratio of the raw materials used in Examples 1-5 and Comparative Examples 1-6 of the epoxy structural adhesive of the present application;

[0027] Figure 2 This is a summary of the performance results of the epoxy structural adhesives prepared in Examples 1-5 and Comparative Examples 1-6 of the present application. DETAILED DESCRIPTION

[0028] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the embodiments. The contents mentioned in the embodiments are not intended to limit the present invention.

[0029] As used herein, "and / or" includes the term of any and all combinations of one or more of the associated listed items. The terms used herein are only used to describe specific embodiments and are not intended to limit the invention. As used herein, the singular forms "a", "an", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It is further understood that "including", when used in this specification, specifies the stated features, integers, steps, operations, elements and / or components, but does not preclude the existence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0030] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It is further understood that terms, such as those defined in commonly used dictionaries, are interpreted in accordance with their meanings in the context of the relevant art and are not idealized or overly formalized unless expressly defined herein.

[0031] The exemplary inventions described herein may suitably lack any one or more element limitations not specifically disclosed herein. Therefore, terms such as "comprises," "includes," "contains," and the like should be understood broadly and non-restrictively. In addition, the terminology used herein is used as a description, not a limitation, and it is unintentional to use these terminology expressions that do not include any equivalent characteristics, but only describe a portion of their characteristics, but various modifications are possible within the scope of the invention according to the rights. Therefore, although the present invention has been specifically disclosed through preferred embodiments and optional features, the modifications disclosed herein to embody the changes of the invention may be recorded by those skilled in the art, and such modifications and changes will be considered to be within the scope of the invention.

[0032] The raw materials or reagents used in the embodiments of the present invention and the comparative examples are all purchased from market mainstream manufacturers, and those who do not specify the manufacturer or those who do not specify the concentration are all raw materials or reagents of the analytical grade that can be conventionally obtained, as long as the desired effect can be played, there are no particular restrictions. The instruments and equipment such as the stirring device used in the present embodiment are all purchased from market main manufacturers, as long as the desired effect can be played, there are no particular restrictions. In the present embodiment, if specific technology or conditions are not specified, the technology or conditions described according to the document in this area or according to the product specification are carried out.

[0033] For example, the weight average molecular weight of bisphenol A epoxy resin is 340-390, and the bisphenol A epoxy resin is purchased from Guangzhou Hanyuan Trading Co., Ltd. NY128.

[0034] The viscosity of the phenolic modified epoxy resin is 6000-7100 cps (25° C.), and the phenolic modified epoxy resin is purchased from CVC Thermoset Specialties Company, USA as EPALLOY8240.

[0035] The viscosity of the glycidyl ester epoxy resin is 1600-2000 cps (25° C.), and the glycidyl ester epoxy resin is purchased from Dow Chemical TDE-85 in the United States.

[0036] The viscosity of dicyclopentadiene epoxy resin is 300-450 cps (150°C), low viscosity at high temperature, and was purchased from Hunan Jiashengde Technology Co., Ltd. DPNE1501.

[0037] The weight average molecular weight of the hydroxy acrylic resin is 20,000, and the hydroxy acrylic resin is purchased from Guangzhou Changhao Trading Co., Ltd. SGR016A.

[0038] The organosilicon dendrimer is a micron elastic material purchased from Shanghai Xibo Chemical Co., Ltd. Alternatively, the organosilicon dendrimer can be prepared according to the preparation method of CN201210398306.8 or other existing technologies.

[0039] The fumed silica was oleophilic and low oil absorption type, purchased from Degussa R220.

[0040] Dicyandiamide, white powder, model: Huntsman Chemical OMICURE-DDA-5, used as a latent curing agent, cures at high temperature and has good low temperature stability.

[0041] Organic urea, white powder, model: Aziken Chemical Co., Ltd., DYHARD UR300, acts as a curing accelerator to accelerate the reaction rate and reduce the reaction temperature.

[0042] Example 1

[0043] A one-component epoxy structural adhesive for nickel metal bonding, comprising Figure 1 The weight parts of the raw materials.

[0044] The preparation method of the above-mentioned epoxy structural adhesive comprises the following steps:

[0045] At 180°C, bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin were stirred and dispersed according to weight percentage for 3 hours to obtain a transparent uniform liquid;

[0046] After the homogeneous liquid is cooled to room temperature, it is transferred to a stirring kettle, and dicyandiamide and organic urea are added according to the weight percentage composition. Condensation water (below 0°C) is turned on, and the stirring speed of the stirrer is adjusted to 1000r / min, and the stirring is dispersed for 1h;

[0047] Keep the condensed water circulating, reduce the stirring speed to 200 r / min, add the remaining other additives according to the weight percentage composition, adjust the stirring speed to 1500 r / min after the addition is completed, stir and disperse for 1 hour to obtain a one-component epoxy structural adhesive.

[0048] Example 2

[0049] A one-component epoxy structural adhesive for nickel metal bonding, comprising Figure 1 The weight parts of the raw materials.

[0050] The preparation method of the above-mentioned epoxy structural adhesive comprises the following steps:

[0051] At 190°C, bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin were stirred and dispersed according to weight percentage for 4 hours to obtain a transparent uniform liquid;

[0052] After the homogeneous liquid is cooled to room temperature, it is transferred to a stirring kettle, and dicyandiamide and organic urea are added according to the weight percentage composition. Condensation water (below 10°C) is turned on, and the stirring speed of the stirrer is adjusted to 1500r / min, and the stirring is dispersed for 2h;

[0053] Keep the condensed water circulating, reduce the stirring speed to 500 r / min, add the remaining other additives according to the weight percentage composition, adjust the stirring speed to 2000 r / min after the addition is completed, stir and disperse for 2 hours to obtain a one-component epoxy structural adhesive.

[0054] Example 3

[0055] A one-component epoxy structural adhesive for nickel metal bonding, comprising Figure 1 The weight parts of the raw materials.

[0056] The preparation method of the above-mentioned epoxy structural adhesive comprises the following steps:

[0057] At 185°C, bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin were stirred and dispersed according to weight percentage for 3.5 hours to obtain a transparent uniform liquid;

[0058] After the homogeneous liquid was cooled to room temperature, it was transferred to a stirring kettle, and dicyandiamide and organic urea were added according to the weight percentage composition. Condensation water was turned on (below 5°C), and the stirring speed of the stirrer was turned on to 1300r / min, and the stirring was dispersed for 1.5h;

[0059] Keep the condensed water circulating, reduce the stirring speed to 400 r / min, add the remaining other additives according to the weight percentage composition, adjust the stirring speed to 1800 r / min after the addition is completed, stir and disperse for 1.5 hours to obtain a one-component epoxy structural adhesive.

[0060] Example 4

[0061] A one-component epoxy structural adhesive for nickel metal bonding, comprising Figure 1 The weight parts of the raw materials.

[0062] The preparation method of the above-mentioned epoxy structural adhesive comprises the following steps:

[0063] At 180°C, bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin were stirred and dispersed according to weight percentage for 4 hours to obtain a transparent uniform liquid;

[0064] After the homogeneous liquid is cooled to room temperature, it is transferred to a stirring kettle, and dicyandiamide and organic urea are added according to the weight percentage composition. Condensation water (below 0°C) is turned on, and the stirring speed of the stirrer is adjusted to 1500r / min, and the stirring is dispersed for 1h;

[0065] Keep the condensed water circulating, reduce the stirring speed to 500 r / min, add the remaining other additives according to the weight percentage composition, adjust the stirring speed to 1500 r / min after the addition is completed, stir and disperse for 2 hours to obtain a one-component epoxy structural adhesive.

[0066] Example 5

[0067] A one-component epoxy structural adhesive for nickel metal bonding, comprising Figure 1 The weight parts of the raw materials.

[0068] The preparation method of the above-mentioned epoxy structural adhesive comprises the following steps:

[0069] At 190°C, bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin were stirred and dispersed according to weight percentage for 3 hours to obtain a transparent uniform liquid;

[0070] After the homogeneous liquid is cooled to room temperature, it is transferred to a stirring kettle, and dicyandiamide and organic urea are added according to the weight percentage composition. Condensation water (below 10°C) is turned on, and the stirring speed of the stirrer is adjusted to 1000r / min, and the stirring is dispersed for 2h;

[0071] Keep the condensed water circulating, reduce the stirring speed to 200 r / min, add the remaining other additives according to the weight percentage composition, adjust the stirring speed to 2000 r / min after the addition is completed, stir and disperse for 1 hour to obtain a one-component epoxy structural adhesive.

[0072] Comparative Example 1

[0073] An epoxy structural adhesive, comprising Figure 1 The corresponding parts by weight of raw materials used;

[0074] The preparation method of the above epoxy structural adhesive is consistent with that of Example 1.

[0075] Comparative Example 2

[0076] An epoxy structural adhesive, comprising Figure 1 The corresponding parts by weight of raw materials used;

[0077] The preparation method of the above epoxy structural adhesive is consistent with that of Example 1.

[0078] Comparative Example 3

[0079] An epoxy structural adhesive, comprising Figure 1 The corresponding parts by weight of raw materials used;

[0080] The preparation method of the above epoxy structural adhesive is consistent with that of Example 1.

[0081] Comparative Example 4

[0082] An epoxy structural adhesive, comprising Figure 1 The corresponding parts by weight of raw materials used;

[0083] The preparation method of the above epoxy structural adhesive is consistent with that of Example 1.

[0084] Comparative Example 5

[0085] An epoxy structural adhesive, comprising Figure 1 The corresponding parts by weight of raw materials used;

[0086] The preparation method of the above epoxy structural adhesive is consistent with that of Example 1.

[0087] Comparative Example 6

[0088] An epoxy structural adhesive, comprising Figure 1 The corresponding parts by weight of raw materials used;

[0089] The preparation method of the above epoxy structural adhesive is consistent with that of Example 1.

[0090] The performance tests of Examples 1-5 and Comparative Examples 1-6 were carried out, and the results were as follows: Figure 2 As shown in the figure, the specific shear strength test method and process are as follows: the shear strength test is performed by fixed overlap method, the glue overlap surface is nickel sheet-nickel sheet, the overlap area is 25mm*5mm, and the overlap thickness is 0.2mm. After the glue is fully cured, the shear strength is tested using a tensile test machine. The drop resistance test method and process are as follows: after the glue is bonded to the electronic components, it is dropped from a height of 1.8m onto a marble slab and dropped 40 times from different angles. The glue overlap surface does not crack. The adhesion reduction test method and process under high temperature and high humidity conditions is as follows: the shear test material that has been overlapped and cured at room temperature is exposed to high temperature and high humidity conditions (temperature 85°C, humidity 85%) for 48 hours, and then the shear strength is immediately tested using a tensile test machine. The attenuation is then converted compared to the attenuation under room temperature conditions. The epoxy structural adhesive prepared above is cured by heat curing. The curing temperature and time are 120°C*1 hour.

[0091] from Figure 1 as well as Figure 2 It can be seen that the epoxy structural adhesive prepared in Examples 1 to 5 has high shear strength (30-35 MPa), strong drop resistance (>40), and no obvious decrease in adhesion strength (17-23%) under high temperature and high humidity. It can be used on the surface of nickel-based metal materials for a long time under high temperature and high humidity conditions.

[0092] In Comparative Example 1, the high-temperature attenuation degree is significantly higher, indicating that the novolac epoxy resin has better heat resistance than the common bisphenol A epoxy resin and can reduce the high-temperature attenuation degree.

[0093] In comparative example 2, the shear strength is significantly reduced and the high-temperature attenuation degree is significantly increased, indicating that glycidyl ester resin has better mechanical and thermal properties than ordinary bisphenol A epoxy resin, and can increase the body strength, bonding strength and heat resistance.

[0094] In Comparative Example 3, the shear strength is significantly reduced and the high-temperature attenuation degree is significantly increased, indicating that dicyclopentadiene epoxy resin has better heat resistance than ordinary bisphenol A epoxy resin and can reduce the high-temperature attenuation degree.

[0095] In comparative example 4, the shear strength is significantly reduced, and the number of drop resistances is significantly reduced, indicating that the hydroxy acrylic resin can increase the toughness and bonding strength of the system, and improve the shear strength and drop resistance.

[0096] In comparative example 5, the degree of high-temperature attenuation is significantly increased, and the number of anti-drop times is significantly reduced, indicating that the silicone resin-like polymer can increase the stress release ability of the system and significantly increase the number of anti-drop times.

[0097] In Comparative Example 6, the shear strength is significantly reduced and the high-temperature attenuation degree is significantly increased, indicating that the small-molecule epoxy diluent can increase the bonding strength of the system and reduce the viscosity of the system.

[0098] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the scope of protection of the present invention.

Claims

1. A one-component epoxy structural adhesive for nickel metal bonding, characterized in that: It is composed of the following raw materials in parts by weight: The stress release agent is an organosilicon dendrimer; The diluent is o-phenyl glycidyl ether; The viscosity of phenolic modified epoxy resin is 6000-7100cps; The viscosity of glycidyl ester epoxy resin is 1600-2000cps; The viscosity of dicyclopentadiene epoxy resin is 300-450cps; The weight average molecular weight of the hydroxy acrylic resin is 20,000; The weight average molecular weight of bisphenol A epoxy resin is 340-390.

2. The one-component epoxy structural adhesive for nickel metal bonding according to claim 1, characterized in that: The coupling agent is γ-glycidyloxypropyltrimethoxysilane.

3. The one-component epoxy structural adhesive for nickel metal bonding according to claim 1, characterized in that: The wetting agent is BYK-333.

4. The one-component epoxy structural adhesive for nickel metal bonding according to claim 1, characterized in that: The defoamer is BYK-054.

5. The one-component epoxy structural adhesive for nickel metal bonding according to claim 1, characterized in that: The colorant is carbon black.

6. A method for preparing a one-component epoxy structural adhesive for nickel metal bonding according to any one of claims 1 to 5, characterized in that: The following steps are involved: At 180-190°C, according to the weight percentage composition, bisphenol A epoxy resin, phenolic modified epoxy resin, glycidyl ester epoxy resin, dicyclopentadiene epoxy resin, and hydroxy acrylic resin are stirred and dispersed for 3-4 hours to obtain a transparent uniform liquid; After the homogeneous liquid is cooled to room temperature, it is transferred to a stirring kettle, and dicyandiamide and organic urea are added according to the weight percentage composition, and stirred and dispersed at 0-10°C for 1-2h at a stirring speed of 1000-1500r / min; Reduce the stirring speed to 200-500 r / min, add the remaining other additives according to the weight percentage composition, and after the addition is completed, adjust the stirring speed to 1500-2000 r / min, stir and disperse for 1-2 hours to obtain a single-component epoxy structural adhesive.

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