CN118834604A - High-temperature-resistant photo-curing transfer adhesive and preparation method thereof - Google Patents

Abstract

The invention provides a high-temperature-resistant photo-curing transfer printing adhesive and a preparation method thereof, and relates to the technical field of transfer printing adhesive preparation. The transfer printing adhesive comprises 75-80 parts of acrylate monomer, 20-25 parts of epoxy resin, 1-3 parts of photoinitiator, 5-8 parts of microcapsule for encapsulating epoxy resin and amine curing agent, 1-2 parts of thermal initiator, 1-2 parts of high-temperature curing monomer and 1-3 parts of auxiliary agent. The high-temperature-resistant photo-curing transfer adhesive prepared by the formula and the preparation method provided by the invention has higher thermal stability and durability exposed to a high-temperature environment.

Description

A kind of high temperature resistant light curing transfer adhesive and preparation method thereof

Technical Field

The invention provides a high temperature resistant light curing transfer adhesive and a preparation method thereof, and relates to the technical field of transfer adhesive preparation.

Background Art

Photocurable transfer adhesive is a type of adhesive that cures rapidly under ultraviolet (UV) or visible light irradiation through the action of photoinitiators. Compared with traditional heat-curing and chemical-curing adhesives, photocurable transfer adhesives have the advantages of fast curing speed, simple operation, and environmental friendliness. Therefore, photocurable transfer adhesives are widely used in electronic component packaging, microelectronic device manufacturing, printed circuit board (PCB) assembly and other fields. The curing mechanism of photocurable transfer adhesive mainly relies on the photoinitiator to produce active seeds (such as free radicals or cations) under light. These active seeds initiate monomers or oligomers to undergo polymerization reactions to form a polymer network structure, thereby achieving the curing of the adhesive. According to the type of photoinitiator, the curing mechanism of photocurable transfer adhesive can be divided into two categories: free radical polymerization and cationic polymerization. Photocurable transfer adhesives are usually composed of the following parts: Photoinitiator: responsible for producing active seeds under light, and is a key component of the photocuring process. Commonly used photoinitiators include acetophenones, benzophenones and ketone compounds. Monomers and oligomers: provide reactive groups to form a polymer network structure after curing. Common monomers include acrylates, epoxy resins, and urethanes. Additives: including leveling agents, defoamers, plasticizers, etc., to improve the processing and performance of light-curing transfer adhesives. Light-curing transfer adhesives are widely used in electronic packaging, printed circuit board manufacturing, fiber optic connector manufacturing, and microelectronic device assembly. For example, in PCB manufacturing, light-curing transfer adhesives are used for bonding and protection of components; in fiber optic connector manufacturing, light-curing transfer adhesives are used for fixing and sealing optical fibers.

2. Although photocurable transfer adhesive has many advantages, it still faces some difficulties in high temperature resistance. Photocurable transfer adhesive usually performs well at room temperature or low temperature, but in high temperature environment, due to the intensified thermal motion of the polymer chain, it is easy to cause thermal decomposition or performance degradation of the adhesive. For example, in the field of electronic packaging, the working environment temperature may exceed 150°C, which puts higher requirements on the thermal stability of photocurable transfer adhesive. In high temperature environment, the mismatch of thermal expansion coefficient between photocurable transfer adhesive and substrate can easily lead to interfacial stress concentration, thereby causing bonding failure. For example, in the high temperature welding process of printed circuit boards, the mismatch of thermal expansion coefficient may cause cracking or peeling of the adhesive layer, affecting the reliability of the circuit board. Long-term exposure to high temperature environment may cause thermal aging of photocurable transfer adhesive, such as yellowing, embrittlement, etc. This not only affects the mechanical properties of the adhesive, but may also cause its electrical properties to deteriorate, thereby affecting the stability and life of electronic devices.

In order to improve the high temperature resistance of photocurable transfer adhesives, researchers have proposed a variety of solutions, mainly including the development of high temperature stable photoinitiators, the screening of high performance heat resistant monomers and oligomers, and the introduction of nanocomposites. However, high temperature stable photoinitiators may not be as good as traditional photoinitiators in terms of photoinitiation efficiency and curing speed. Therefore, it is necessary to weigh the high temperature stability and curing performance of photoinitiators in practical applications. In addition, high temperature stable photoinitiators may show poor compatibility in certain monomer and oligomer systems, affecting the overall performance of the adhesive. Monomers and oligomers with high glass transition temperature and high thermal decomposition temperature usually have high viscosity and low fluidity, which increases the processing difficulty of photocurable transfer adhesives. For example, monomers and oligomers containing aromatic ring structures are prone to bubbles and unevenness during mixing and coating, affecting the quality of the cured adhesive layer. In addition, the high cost of these monomers and oligomers limits their application in large-scale production. The uniformity of the dispersion of nanofillers in photocurable transfer adhesives is a key factor affecting their performance. Nanofillers are prone to agglomeration in the matrix, resulting in uneven dispersion of the fillers, which in turn affects the mechanical properties and thermal stability of the adhesive. In order to improve the dispersibility of nanofillers, it is usually necessary to modify their surface or adopt special dispersion technology, but this increases the preparation cost and process complexity. The interfacial bonding strength between the nanofillers and the photocuring transfer adhesive matrix is an important factor affecting the performance of the composite material. Insufficient interfacial bonding strength can cause the composite material to be prone to interfacial peeling in a high temperature environment, affecting the high temperature resistance of the adhesive. In order to improve the interfacial bonding strength, the nanofillers need to be chemically modified to increase their compatibility with the matrix, but this also increases the difficulty and cost of material preparation.

Summary of the invention

In order to solve the above problems, the present invention provides a high temperature resistant light curing transfer adhesive and a preparation method thereof, and the specific scheme is as follows:

A high temperature resistant light curing transfer adhesive comprises the following components:

Acrylate monomer, epoxy resin, photoinitiator, microcapsule encapsulating epoxy resin and amine curing agent, thermal initiator, high temperature curing monomer, additives.

Preferably, the components include, by mass, 75-80 parts of acrylate monomer, 20-25 parts of epoxy resin, 1-3 parts of photoinitiator, 5-8 parts of microcapsules encapsulating epoxy resin and amine curing agent, 1-2 parts of thermal initiator, 1-2 parts of high temperature curing monomer, and 1-3 parts of auxiliary agent.

Preferably, the photoinitiator is benzophenone (BP) or 1-hydroxycyclohexyl phenyl ketone (HCPK).

Preferably, the acrylate monomer includes one or more of dipropylene glycol diacrylate, trimethylolpropane triacrylate (TMPTA), and triethylene glycol diacrylate (TTEGDA).

Preferably, the epoxy resin includes one or more of bisphenol A epoxy resin (DGEBA), epoxy acrylate resin (EAA), and bisphenol F epoxy resin (DGEBF).

Preferably, the thermal initiator includes one or more of benzoyl peroxide (BPO), dicumyl peroxide (DCP), and methyl ethyl ketone peroxide (MEKP).

Preferably, the high temperature curing monomer includes one or more of bisphenol A acrylate, aromatic polyimide monomer (PMDA), and polyphenylene sulfide monomer (PPS).

Preferably, the auxiliary agent includes one or more of a leveling agent, a defoaming agent, a plasticizer, and a thermal stability enhancer.

Preferably, the leveling agent includes one or more of silicon dioxide nanoparticles, silicone oil (PDMS), and fluorinated silicone (FSi).

Preferably, the defoaming agent includes one or more of silicone defoaming agent (AFS), polyether modified silicone (PMS), and polyacrylate (PPA).

Preferably, the plasticizer includes one or more of dibutyl phthalate (DBP), triethyl citrate (TEC), and dibutyl dioctanoate (DIDA).

Preferably, the thermal stability enhancer includes one or more of nano-alumina (Al ₂ O ₃ ), nano-titanium dioxide (TiO ₂ ), and nano-zinc oxide (ZnO).

Preferably, the preparation method of the microcapsules encapsulating epoxy resin and amine curing agent comprises: in a stirrer, dissolving gelatin in deionized water at a specific temperature to obtain a gelatin solution; mixing the epoxy resin and the amine curing agent and adding them to the gelatin solution, maintaining high-speed stirring to form an oil-in-water emulsion; adding the gum arabic solution under continuous stirring to form stable microcapsules; adjusting the pH, continuing stirring, so that the gelatin and the gum arabic form a copolymer wall; cooling to obtain microcapsules containing the epoxy resin and the amine curing agent, filtering out the solid and drying.

Preferably, the epoxy resin includes one or more of bisphenol A epoxy resin (DGEBA), epoxy acrylate resin (EAA), and bisphenol F epoxy resin (DGEBF).

Preferably, the amine curing agent includes one or more of polyethylene polyamine (PEPA), triethylenetetramine (TETA), and isophorone diamine (IPDA).

Preferably, the content of the gelatin solution is 5-10wt%, the temperature of the deionized water is 40-50°C, and the stirring speed is 300-500rpm; the epoxy resin and the amine curing agent are mixed in a mass ratio of 1:1, added to the gelatin solution at 20-30vol% of the total volume fraction of the system, and the high-speed stirring speed is 1000-1500rpm; the mass ratio of gelatin to gum arabic is 1:1, the concentration of the gum arabic solution is 20-30wt%, and the stirring speed is 500-800rpm. m; the pH is adjusted to 4.0-4.2 using 0.1-0.2M acetic acid solution or 0.1M hydrochloric acid solution; the cooling is to slowly cool the emulsion to room temperature with a stirring speed of 300-500rpm and a cooling time of 1-1.5h; during the cooling process, glutaraldehyde is added with a concentration of 0.5-1wt%, and stirring is continued for 30-40min after the addition is completed; after filtering, the solid is washed with deionized water and dried in a vacuum drying oven at a temperature of 50-60°C for 8-12h.

The present invention also provides a method for preparing the above-mentioned high temperature resistant light-curing transfer adhesive, comprising:

Mix the acrylate monomer and epoxy resin according to the formula; add the photoinitiator and stir evenly; add the auxiliary agent and continue to stir evenly; add the microcapsules encapsulating the epoxy resin and the amine curing agent, stir at a low speed until they are evenly dispersed; add the thermal initiator and the high-temperature curing monomer, keep stirring at a low speed until they are evenly mixed, and obtain the high-temperature resistant photocuring transfer adhesive.

The beneficial effects of the present invention are as follows:

The high temperature resistant photocurable transfer adhesive obtained by the formula and preparation method provided by the present invention has high thermal stability and durability when exposed to high temperature environment.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified.

Preparation Example 1: Preparation of microcapsules encapsulating epoxy resin and amine curing agent:

In a blender, gelatin is dissolved in deionized water at a specific temperature to obtain a gelatin solution; epoxy resin and amine curing agent are mixed and added to the gelatin solution, and high-speed stirring is maintained to form an oil-in-water emulsion; under continuous stirring, a gum arabic solution is added to form stable microcapsules; the pH is adjusted and stirring is continued to form a copolymer wall of gelatin and gum arabic; microcapsules containing epoxy resin and amine curing agent are obtained by cooling, and the solid is filtered and dried.

The epoxy resin includes bisphenol A epoxy resin (DGEBA).

The amine curing agent includes polyethylene polyamine (PEPA).

The content of the gelatin solution is 5wt%, the temperature of deionized water is 40°C, and the stirring speed is 300rpm; the epoxy resin and the amine curing agent are mixed in a mass ratio of 1:1, added to the gelatin solution at 20vol% of the total volume fraction of the system, and the high-speed stirring speed is 1000rpm; the mass ratio of gelatin to gum arabic is 1:1, the concentration of the gum arabic solution is 20wt%, and the stirring speed is 500rpm; the pH is adjusted by using a 0.1M acetic acid solution to adjust the pH to 4.0; the cooling is to slowly cool the emulsion to room temperature, the stirring speed is 300rpm, and the cooling time is 1h; during the cooling process, glutaraldehyde is added at a concentration of 0.5wt%, and stirring is continued for 30min after the addition is completed; the solid is washed with deionized water after filtration, and dried in a vacuum drying oven at a temperature of 50°C for 12h.

Preparation Example 2: Preparation of microcapsules encapsulating epoxy resin and amine curing agent:

In a blender, gelatin is dissolved in deionized water at a specific temperature to obtain a gelatin solution; epoxy resin and amine curing agent are mixed and added to the gelatin solution, and high-speed stirring is maintained to form an oil-in-water emulsion; under continuous stirring, a gum arabic solution is added to form stable microcapsules; the pH is adjusted and stirring is continued to form a copolymer wall of gelatin and gum arabic; microcapsules containing epoxy resin and amine curing agent are obtained by cooling, and the solid is filtered and dried.

The epoxy resin includes epoxy acrylate resin (EAA).

The amine curing agent includes triethylenetetramine (TETA).

The content of the gelatin solution is 10wt%, the temperature of deionized water is 50°C, and the stirring speed is 500rpm; the epoxy resin and the amine curing agent are mixed in a mass ratio of 1:1, and are added to the gelatin solution at 30vol% of the total volume fraction of the system, and the high-speed stirring speed is 1500rpm; the mass ratio of gelatin to gum arabic is 1:1, the concentration of the gum arabic solution is 30wt%, and the stirring speed is 800rpm; the pH is adjusted by using a 0.2M acetic acid solution to adjust the pH to 4.2; the cooling is to slowly cool the emulsion to room temperature, with a stirring speed of 500rpm and a cooling time of 1.5h; during the cooling process, glutaraldehyde is added at a concentration of 1wt%, and stirring is continued for 40min after the addition is completed; the solid is washed with deionized water after filtration, and dried in a vacuum drying oven at a temperature of 60°C for 8h.

Preparation Example 3: Preparation of microcapsules encapsulating epoxy resin and amine curing agent:

In a blender, gelatin is dissolved in deionized water at a specific temperature to obtain a gelatin solution; epoxy resin and amine curing agent are mixed and added to the gelatin solution, and high-speed stirring is maintained to form an oil-in-water emulsion; under continuous stirring, a gum arabic solution is added to form stable microcapsules; the pH is adjusted and stirring is continued to form a copolymer wall of gelatin and gum arabic; microcapsules containing epoxy resin and amine curing agent are obtained by cooling, and the solid is filtered and dried.

The epoxy resin includes bisphenol F epoxy resin (DGEBF).

The amine curing agent includes isophoronediamine (IPDA).

The content of the gelatin solution is 8wt%, the temperature of deionized water is 45°C, and the stirring speed is 400rpm; the epoxy resin and the amine curing agent are mixed in a mass ratio of 1:1, and are added to the gelatin solution at 25vol% of the total volume fraction of the system, and the high-speed stirring speed is 1000rpm; the mass ratio of gelatin to gum arabic is 1:1, the concentration of the gum arabic solution is 25wt%, and the stirring speed is 700rpm; the pH is adjusted by using a 0.1M hydrochloric acid solution to adjust the pH to 4.0; the cooling is to slowly cool the emulsion to room temperature, the stirring speed is 400rpm, and the cooling time is 1h; during the cooling process, glutaraldehyde is added at a concentration of 0.8wt%, and stirring is continued for 35min after the addition is completed; the solid is washed with deionized water after filtration, and dried in a vacuum drying oven at a temperature of 55°C for 10h.

Example 1 Preparation of high temperature resistant light curing transfer adhesive:

formula:

75 parts of acrylate monomer, 25 parts of epoxy resin, 3 parts of photoinitiator, 8 parts of microcapsules encapsulating epoxy resin and amine curing agent (Preparation Example 1), 2 parts of thermal initiator, 2 parts of high temperature curing monomer, and 3 parts of auxiliary agent.

The photoinitiator is benzophenone (BP).

The acrylate monomer includes dipropylene glycol diacrylate.

The epoxy resin includes bisphenol A epoxy resin (DGEBA).

The thermal initiator includes benzoyl peroxide (BPO).

The high temperature curing monomer includes bisphenol A acrylate.

The auxiliary agents include leveling agents, defoaming agents, plasticizers, and thermal stability enhancers.

The leveling agent includes silicon dioxide nanoparticles.

The defoaming agent includes a silicone defoaming agent (AFS).

The plasticizer includes dibutyl phthalate (DBP).

The thermal stability enhancer includes nano-alumina (Al ₂ O ₃ ).

Preparation process:

Mix the acrylate monomer and epoxy resin according to the formula; add the photoinitiator and stir evenly; add the auxiliary agent and continue to stir evenly; add the microcapsules encapsulating the epoxy resin and the amine curing agent, stir at a low speed until they are evenly dispersed; add the thermal initiator and the high-temperature curing monomer, keep stirring at a low speed until they are evenly mixed, and obtain the high-temperature resistant photocuring transfer adhesive.

Example 2 Preparation of high temperature resistant light curing transfer adhesive:

formula:

75 parts of acrylate monomer, 25 parts of epoxy resin, 3 parts of photoinitiator, 8 parts of microcapsules encapsulating epoxy resin and amine curing agent (Preparation Example 1), 2 parts of thermal initiator, 2 parts of high temperature curing monomer, and 3 parts of auxiliary agent.

The photoinitiator is 1-hydroxycyclohexyl phenyl ketone (HCPK).

The acrylate monomer includes trimethylolpropane triacrylate (TMPTA).

The epoxy resin includes epoxy acrylate resin (EAA).

The thermal initiator includes dicumyl peroxide (DCP).

The high temperature curing monomer includes aromatic polyimide monomer (PMDA).

The auxiliary agents include leveling agents, defoaming agents, plasticizers, and thermal stability enhancers.

The leveling agent includes silicone oil (PDMS).

The defoaming agent includes polyether-modified silicone (PMS).

The plasticizer includes triethyl citrate (TEC).

The thermal stability enhancer includes nano titanium dioxide (TiO ₂ ).

Preparation process:

Mix the acrylate monomer and epoxy resin according to the formula; add the photoinitiator and stir evenly; add the auxiliary agent and continue to stir evenly; add the microcapsules encapsulating the epoxy resin and the amine curing agent, stir at a low speed until they are evenly dispersed; add the thermal initiator and the high-temperature curing monomer, keep stirring at a low speed until they are evenly mixed, and obtain the high-temperature resistant photocuring transfer adhesive.

Example 3 Preparation of high temperature resistant light curing transfer adhesive:

formula:

75 parts of acrylate monomer, 25 parts of epoxy resin, 3 parts of photoinitiator, 8 parts of microcapsules encapsulating epoxy resin and amine curing agent (Preparation Example 1), 2 parts of thermal initiator, 2 parts of high temperature curing monomer, and 3 parts of auxiliary agent.

The photoinitiator is benzophenone (BP).

The acrylate monomer includes triethylene glycol diacrylate (TTEGDA).

The epoxy resin includes bisphenol F epoxy resin (DGEBF).

The thermal initiator includes methyl ethyl ketone peroxide (MEKP).

The high temperature curing monomer includes polyphenylene sulfide monomer (PPS).

The auxiliary agents include leveling agents, defoaming agents, plasticizers, and thermal stability enhancers.

The leveling agent includes fluorinated silicone (FSi).

The defoaming agent includes polyacrylate (PPA).

The plasticizer includes dibutyl dioctanoate (DIDA).

The thermal stability enhancer includes nano zinc oxide (ZnO).

Preparation process:

Mix the acrylate monomer and epoxy resin according to the formula; add the photoinitiator and stir evenly; add the auxiliary agent and continue to stir evenly; add the microcapsules encapsulating the epoxy resin and the amine curing agent, stir at a low speed until they are evenly dispersed; add the thermal initiator and the high-temperature curing monomer, keep stirring at a low speed until they are evenly mixed, and obtain the high-temperature resistant photocuring transfer adhesive.

Example 4 Preparation of high temperature resistant light curing transfer adhesive:

formula:

75 parts of acrylate monomer, 25 parts of epoxy resin, 3 parts of photoinitiator, 8 parts of microcapsules encapsulating epoxy resin and amine curing agent (Preparation Example 2), 2 parts of thermal initiator, 2 parts of high temperature curing monomer, and 3 parts of auxiliary agent.

The photoinitiator is benzophenone (BP).

The acrylate monomer includes triethylene glycol diacrylate (TTEGDA).

The epoxy resin includes bisphenol F epoxy resin (DGEBF).

The thermal initiator includes methyl ethyl ketone peroxide (MEKP).

The high temperature curing monomer includes polyphenylene sulfide monomer (PPS).

The auxiliary agents include leveling agents, defoaming agents, plasticizers, and thermal stability enhancers.

The leveling agent includes fluorinated silicone (FSi).

The defoaming agent includes polyacrylate (PPA).

The plasticizer includes dibutyl dioctanoate (DIDA).

The thermal stability enhancer includes nano zinc oxide (ZnO).

Preparation process:

Mix the acrylate monomer and epoxy resin according to the formula; add the photoinitiator and stir evenly; add the auxiliary agent and continue to stir evenly; add the microcapsules encapsulating the epoxy resin and the amine curing agent, stir at a low speed until they are evenly dispersed; add the thermal initiator and the high-temperature curing monomer, keep stirring at a low speed until they are evenly mixed, and obtain the high-temperature resistant photocuring transfer adhesive.

Example 5 Preparation of high temperature resistant light curing transfer adhesive:

formula:

75 parts of acrylate monomer, 25 parts of epoxy resin, 3 parts of photoinitiator, 8 parts of microcapsules encapsulating epoxy resin and amine curing agent (Preparation Example 3), 2 parts of thermal initiator, 2 parts of high temperature curing monomer, and 3 parts of auxiliary agent.

The photoinitiator is benzophenone (BP).

The acrylate monomer includes triethylene glycol diacrylate (TTEGDA).

The epoxy resin includes bisphenol F epoxy resin (DGEBF).

The thermal initiator includes methyl ethyl ketone peroxide (MEKP).

The high temperature curing monomer includes polyphenylene sulfide monomer (PPS).

The auxiliary agents include leveling agents, defoaming agents, plasticizers, and thermal stability enhancers.

The leveling agent includes fluorinated silicone (FSi).

The defoaming agent includes polyacrylate (PPA).

The plasticizer includes dibutyl dioctanoate (DIDA).

The thermal stability enhancer includes nano zinc oxide (ZnO).

Preparation process:

Mix the acrylate monomer and epoxy resin according to the formula; add the photoinitiator and stir evenly; add the auxiliary agent and continue to stir evenly; add the microcapsules encapsulating the epoxy resin and the amine curing agent, stir at a low speed until they are evenly dispersed; add the thermal initiator and the high-temperature curing monomer, keep stirring at a low speed until they are evenly mixed, and obtain the high-temperature resistant photocuring transfer adhesive.

Example 6 Preparation of high temperature resistant light curing transfer adhesive:

formula:

80 parts of acrylate monomer, 20 parts of epoxy resin, 1 part of photoinitiator, 5 parts of microcapsules encapsulating epoxy resin and amine curing agent, 1 part of thermal initiator, 1 part of high-temperature curing monomer, and 1 part of auxiliary agent.

The photoinitiator is benzophenone (BP).

The acrylate monomer includes triethylene glycol diacrylate (TTEGDA).

The epoxy resin includes bisphenol F epoxy resin (DGEBF).

The thermal initiator includes methyl ethyl ketone peroxide (MEKP).

The high temperature curing monomer includes polyphenylene sulfide monomer (PPS).

The auxiliary agents include leveling agents, defoaming agents, plasticizers, and thermal stability enhancers.

The leveling agent includes fluorinated silicone (FSi).

The defoaming agent includes polyacrylate (PPA).

The plasticizer includes dibutyl dioctanoate (DIDA).

The thermal stability enhancer includes nano zinc oxide (ZnO).

Preparation process:

Mix the acrylate monomer and epoxy resin according to the formula; add the photoinitiator and stir evenly; add the auxiliary agent and continue to stir evenly; add the microcapsules encapsulating the epoxy resin and the amine curing agent, stir at a low speed until they are evenly dispersed; add the thermal initiator and the high-temperature curing monomer, keep stirring at a low speed until they are evenly mixed, and obtain the high-temperature resistant photocuring transfer adhesive.

Example 7 Preparation of high temperature resistant light curing transfer adhesive:

formula:

80 parts of acrylate monomer, 25 parts of epoxy resin, 3 parts of photoinitiator, 8 parts of microcapsules encapsulating epoxy resin and amine curing agent, 2 parts of thermal initiator, 2 parts of high temperature curing monomer, and 3 parts of auxiliary agent.

The photoinitiator is benzophenone (BP).

The acrylate monomer includes triethylene glycol diacrylate (TTEGDA).

The epoxy resin includes bisphenol F epoxy resin (DGEBF).

The thermal initiator includes methyl ethyl ketone peroxide (MEKP).

The high temperature curing monomer includes polyphenylene sulfide monomer (PPS).

The auxiliary agents include leveling agents, defoaming agents, plasticizers, and thermal stability enhancers.

The leveling agent includes fluorinated silicone (FSi).

The defoaming agent includes polyacrylate (PPA).

The plasticizer includes dibutyl dioctanoate (DIDA).

The thermal stability enhancer includes nano zinc oxide (ZnO).

Preparation process:

Mix the acrylate monomer and epoxy resin according to the formula; add the photoinitiator and stir evenly; add the auxiliary agent and continue to stir evenly; add the microcapsules encapsulating the epoxy resin and the amine curing agent, stir at a low speed until they are evenly dispersed; add the thermal initiator and the high-temperature curing monomer, keep stirring at a low speed until they are evenly mixed, and obtain the high-temperature resistant photocuring transfer adhesive.

The difference between Comparative Example 1 and Example 3 is that no microcapsules encapsulating epoxy resin and amine curing agent are added.

The difference between Comparative Example 2 and Example 3 is that no high temperature curing elevator and thermal initiator are added.

Comparative Example 3: Commercially available light-curing transfer adhesive: LOCTITE ECCOBOND LUXA4035T, manufactured by Henkel.

Comparative Example 4: Commercially available light-curing adhesive: Permabond UV639, manufactured by Permabond.

Comparative Example 5: 6.8 wt % of microcapsules encapsulating epoxy resin and amine curing agent (Preparation Example 1) were added to the photocurable transfer adhesive described in Comparative Example 3 and mixed evenly.

Performance testing:

Sample preparation: Degas the above transfer adhesive sample under vacuum conditions to remove bubbles during the mixing process. Evenly apply the light-curing transfer adhesive on the surface of the substrate (glass). Pre-cure under an ultraviolet light source (such as a UV lamp with a wavelength of 365nm) for 10 minutes. Secondary curing: Place the pre-cured sample in a heat curing oven for secondary heating and curing. The curing temperature is 100°C and the time is 1 hour (Comparative Example 2 does not perform secondary curing). Obtain the test sample

1. Thermogravimetric analysis (TGA)

Test standard: ASTM E1131

Operation steps: Sample preparation: Take 0.5-5 mg transfer gel sample. Instrument settings: Set the temperature range of the TGA instrument from room temperature to 800°C, with a heating rate of 10°C/min. Test process: Place the sample in a platinum crucible and perform thermogravimetric analysis in a nitrogen environment, recording the curve of the sample mass changing with temperature. Data analysis: Determine the initial decomposition temperature (T_onset) and maximum decomposition temperature (T_max) of the sample.

Evaluation criteria: Initial decomposition temperature (T_onset): >250℃

Maximum decomposition temperature (T_max): >350℃

Thermal weight loss rate: <5% below 200℃

2. Differential Scanning Calorimetry (DSC)

Test standard: ASTM D3418

Operation steps: Prepare the sample: Take 5-10 mg of transfer gel sample.

Instrument settings: Set the temperature range of the DSC instrument from room temperature to 300°C, with a heating rate of 10°C/min. Test process: Place the sample in an aluminum crucible, perform DSC testing in a nitrogen environment, and record the curve of the heat flow of the sample changing with temperature. Data analysis: Determine the glass transition temperature (Tg) of the sample.

Evaluation criteria: Glass transition temperature (Tg): >120℃

3. Tensile test

Test standard: ASTM D638

Operation steps: Prepare the sample: Prepare a standard dumbbell-shaped specimen according to the above steps, with a thickness of 1mm. Instrument settings: Use an electronic universal testing machine and set the tensile rate to 5mm/min. Test process: Clamp the sample on the testing machine, apply tensile force until the sample breaks, and record the tensile strength and elongation at break.

4. Shear test

Test standard: ASTM D1002

Operation steps: Prepare the sample: Prepare a single lap shear specimen according to the above steps, with an overlap area of 12.5mm x 25mm. Instrument settings: Use an electronic universal testing machine and set the tensile rate to 1.3mm/min. Test process: Clamp the sample on the testing machine, apply shear force until the sample fails, and record the shear strength.

5. Durability test

Test standard: ASTM D3045

Operation steps: Sample preparation: Prepare the specimens for tensile and shear tests according to the same specifications. Aging treatment: Place the specimens in a high temperature environment of 150°C for 1000 hours. Mechanical property test: After aging treatment, repeat the tensile and shear tests and record the changes in mechanical properties before and after aging. The test results are shown in Tables 1 and 2.

Table 1 Thermal stability test results

Table 2 High temperature environment durability test results

From the above results, it can be seen that the formula and preparation method provided by the present invention, the thermal initiator and high-temperature curing monomer therein contribute significantly to the thermal stability of the material. Similarly, the microcapsules encapsulating epoxy resin and amine curing agent also contribute to the thermal stability to a certain extent. In addition, when the thermal initiator, high-temperature curing monomer and microcapsules encapsulating epoxy resin and amine curing agent are present in the formula at the same time, the two work synergistically to greatly improve the thermal stability.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

The present invention and its implementation methods are described above, and such description is not restrictive, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design methods and embodiments similar to the technical solution without creativity, which should all fall within the protection scope of the present invention.

Claims (10)

1. A high temperature resistant photo-curing transfer adhesive is characterized in that: the composition comprises the following components:

Acrylate monomer, epoxy resin, photoinitiator, microcapsule for encapsulating epoxy resin and amine curing agent, thermal initiator, high-temperature curing monomer and auxiliary agent.

2. The high temperature resistant photo-curable transfer paste according to claim 1, wherein: the components comprise the following components in parts by weight: 75-80 parts of acrylate monomer, 20-25 parts of epoxy resin, 1-3 parts of photoinitiator, 5-8 parts of microcapsule encapsulating epoxy resin and amine curing agent, 1-2 parts of thermal initiator, 1-2 parts of high-temperature curing monomer and 1-3 parts of auxiliary agent.

3. The high temperature resistant photo-curable transfer paste according to claim 1, wherein: the photoinitiator is diphenyl ketone (BP) or 1-hydroxycyclohexyl phenyl ketone (HCPK).

4. The high temperature resistant photo-curable transfer paste according to claim 1, wherein: the acrylic ester monomer comprises one or more than two of dipropylene glycol diacrylate, trimethylolpropane triacrylate (TMPTA) and triethylene glycol diacrylate (TTEGDA); the epoxy resin comprises one or more of bisphenol A epoxy resin (DGEBA), epoxy acrylate resin (EAA) and bisphenol F epoxy resin (DGEBF).

5. The high temperature resistant photo-curable transfer paste according to claim 1, wherein: the thermal initiator comprises one or more of Benzoyl Peroxide (BPO), dicumyl peroxide (DCP) and Methyl Ethyl Ketone Peroxide (MEKP); the high-temperature curing monomer comprises one or more of bisphenol A acrylic ester, aromatic Polyimide Monomer (PMDA) and polyphenylene sulfide monomer (PPS).

6. The high temperature resistant photo-curable transfer paste according to claim 1, wherein: the auxiliary agent comprises one or more than two of a leveling agent, a defoaming agent, a plasticizer and a thermal stability enhancer; the leveling agent comprises one or more than two of silicon dioxide nano particles, silicone oil (PDMS) and Fluorinated Silicone (FSi); the defoamer comprises one or more than two of silicone defoamer (AFS), polyether Modified Silicone (PMS) and polyacrylate (PPA); the plasticizer comprises one or more of dibutyl phthalate (DBP), triethyl citrate (TEC) and dibutyl dioctanoate (DIDA); the thermal stability enhancer comprises one or more of nano aluminum oxide (Al ₂O₃), nano titanium dioxide (TiO ₂) and nano zinc oxide (ZnO).

7. The high temperature resistant photo-curable transfer paste according to claim 1, wherein: the preparation method of the microcapsule for encapsulating the epoxy resin and the amine curing agent comprises the following steps: dissolving gelatin in deionized water at a specific temperature in a stirrer to obtain gelatin solution; mixing epoxy resin and amine curing agent, adding into gelatin solution, and stirring at high speed to form water-in-oil emulsion; adding acacia gum solution under continuous stirring to form stable microcapsule; regulating pH, and continuing stirring to form copolymer wall by gelatin and acacia; cooling to obtain microcapsule containing epoxy resin and amine curing agent, filtering to obtain solid and drying.

8. The high temperature resistant photo-curable transfer adhesive according to claim 7, wherein: in the preparation method of the microcapsule for encapsulating the epoxy resin and the amine curing agent, the epoxy resin comprises one or more than two of bisphenol A epoxy resin (DGEBA), epoxy acrylate resin (EAA) and bisphenol F epoxy resin (DGEBF); the amine curing agent comprises one or more than two of polyethylene polyamine (PEPA), triethylene tetramine (TETA) and isophorone diamine (IPDA).

9. The high temperature resistant photo-curable transfer adhesive according to claim 7, wherein: in the preparation method of the microcapsule for encapsulating the epoxy resin and the amine curing agent, the content of the gelatin solution is 5-10wt%, the temperature of deionized water is 40-50 ℃, and the stirring speed is 300-500rpm; the epoxy resin and the amine curing agent are mixed according to the mass ratio of 1:1, and added into the gelatin solution in a proportion of 20-30vol% of the total volume fraction of the system, and the high-speed stirring speed is 1000-1500rpm; the mass ratio of gelatin to acacia is 1:1, the concentration of acacia solution is 20-30wt% and the stirring speed is 500-800rpm; the pH is regulated to 4.0-4.2 by using 0.1-0.2M acetic acid solution or 0.1M hydrochloric acid solution; the emulsion is slowly cooled to room temperature, the stirring speed is 300-500rpm, and the cooling time is 1-1.5h; during the cooling process, glutaraldehyde is added with the concentration of 0.5-1wt%, and stirring is continued for 30-40min after the addition is finished; and (3) washing the solid by deionized water after filtering, and drying in a vacuum drying oven at 50-60 ℃ for 8-12h.

10. A method for preparing the high temperature resistant photo-curing transfer adhesive as claimed in any one of claims 1 to 9, which is characterized in that: comprising the following steps: mixing acrylate monomer and epoxy resin according to a formula; adding a photoinitiator and uniformly stirring; adding an auxiliary agent, and continuously and uniformly stirring; adding microcapsules encapsulating epoxy resin and amine curing agent, and stirring at a low speed until the microcapsules are uniformly dispersed; and adding a thermal initiator and a high-temperature curing monomer, and stirring at a low speed until the mixture is uniformly mixed to obtain the high-temperature-resistant photo-curing transfer printing adhesive.