Radiation curing electronic adhesive

Abstract

The invention provides a radiation curing electronic adhesive. The radiation curing electronic adhesive is prepared from the following raw materials in parts by weight: 60-80 parts of resin, 5-30 parts of filler, 1-10 parts of chain extender, 0.1-2 parts of stabilizer and 4-12 parts of initiator, the preparation process of the adhesive comprises the following steps: 1, uniformly mixing synthetic resin, a chain extender and a stabilizer at 75-85 DEG C, then heating to 115-125 DEG C, and stirring until the components are fully mixed to obtain a banburying material; 2, adding a filler and an initiator into the internal mixing material, regulating the temperature to 20-100 DEG C, keeping the constant temperature, and stirring and mixing for 20-50 minutes to obtain an adhesive layer mixed material; by adopting the filler, the filler is piled more tightly, interface phonon scattering and interface thermal resistance are reduced, a heat conduction channel is more easily formed, the maximum piling degree is formed, the number of heat conduction chains is increased, the concentration of the heat conduction chains is increased, and therefore the heat conductivity of the adhesive is improved; a plurality of effective heat conduction channels are formed, and the heat conduction coefficient is improved.

Description

Technical Field

[0001] The invention belongs to the field of adhesives, in particular to a radiation-cured electronic adhesive. Background Art

[0002] Electronic grade adhesives are specially used for bonding, sealing, potting, coating, structural bonding, co-coating and SMT patching of electronic and electrical components, and have a wide range of applications. General electronic grade adhesives should also have excellent bonding and waterproof properties, and also require less toxic volatile substances, and corrosion resistance, oxidation resistance, high temperature resistance and other characteristics. According to demand, they can also be divided into insulating adhesives and conductive adhesives.

[0003] Traditional adhesives are cured by baking after coating, which not only wastes energy, but also releases a series of solvents, which may lead to fire accidents. At the same time, the curing process of baking is costly and occupies a large area, which does not meet the requirements of energy conservation, emission reduction and environmental friendliness. EB (electron beam) curing technology has its unique advantages in equipment, process technology and actual effect, which can meet people's comprehensive requirements for high efficiency, energy saving, environmental protection and economy in the product production process. EB (electron beam) curing technology has the unique advantages of solvent-free processing (no environmental pollution), energy saving (about 1 / 5-1 / 10 of the energy consumption of thermal curing technology), fast curing speed (0.1-10 seconds) (high production efficiency), no heat (film does not shrink and distort, and can process heat-sensitive materials), compact design (occupies 90% less space than traditional thermal curing), and wide practicality (can be used for decoration, printing, laminates, silicone release coatings and solvent-free adhesives). Therefore, the EB (electron beam) curing technology is summarized as having "5E" characteristics internationally, namely, low energy consumption; Ecological balance; Economic efficiency; Excellent performance; Easy operation. However, the curing adhesives currently in widespread use still cannot meet the requirements of low temperature and quick drying.

[0004] In summary, the present invention provides a radiation-curable electronic adhesive to solve the above problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a radiation-curable electronic adhesive to solve the problem that the curing adhesive in the prior art still cannot meet the requirements of low temperature and quick drying.

[0006] A radiation-curable electronic adhesive comprises the following raw materials by weight:

[0007] 60-80 parts of resin, 5-30 parts of filler, 1-10 parts of chain extender, 0.1-2 parts of stabilizer and 4-12 parts of initiator;

[0008] The preparation process of the adhesive includes:

[0009] Step 1: Mix the synthetic resin, chain extender and stabilizer at 75-85°C, then heat to 115-125°C, and stir until fully mixed to obtain a mixed material;

[0010] Step 2: Add filler and initiator to the mixed material, adjust the temperature to 20-100°C, maintain constant temperature, and stir and mix for 20-50 minutes to obtain a rubber layer mixture;

[0011] Step 3: coating the adhesive layer mixture to obtain an adhesive layer, and irradiating it with an electron beam to obtain an adhesive.

[0012] Further, the resin includes one or a combination of silicone resin, acrylic resin, polyester resin and polyether resin; oxygen-modified silicone resin or acrylic-modified silicone resin;

[0013] The active terminal groups of the acrylic resin, polyester resin and polyether resin are unsaturated vinyl groups, unsaturated allyl groups or epoxy groups.

[0014] Furthermore, the filler is mica and graphene, wherein the mass ratio of the particle size distribution of 12-14 μm, 6-7 μm, and 1.5-1.7 μm is 4-8:1-5:1.

[0015] Further, the chain extender includes a hydrophilic chain extender and a small molecule chain extender;

[0016] Wherein, the hydrophilic chain extender includes at least one of ethylene glycol, 1,4-butanediol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, 1,6-hexanediol, trimethylolpropane, neopentyl glycol, butyl propyl glycol, diethyl pentanediol, 1,4-dihydroxymethyl cyclohexane and cyclohexanediol;

[0017] The small molecule chain extender includes at least one of a small molecule diol, a small molecule triol, a small molecule diamine, and a diol containing a hydrophilic group.

[0018] Furthermore, the initiator is one or more of a peroxide initiator and an azo initiator.

[0019] Furthermore, the stabilizer is one or a combination of hydroquinone, p-methoxyphenol, p-benzoquinone, 2,6-di-tert-butyltoluene, phenothiazine, and anthraquinone.

[0020] Furthermore, in the step 1, the first stirring and mixing time is 30 to 60 minutes, the stirring rate is 1000 to 1200 r / min, and the second stirring and mixing time is 30 to 40 minutes.

[0021] Furthermore, in step three, the voltage is 300 kV and the irradiation intensity is 5 to 9 Mrads.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention has the advantages of high bonding strength, low volatility, high strength, no glue oil, good insulation performance and good sealing performance, and has good storage stability. It can be stored at 2-8°C for more than 6 months without adding silane coupling agent, and will not cause abnormal operation of electrical appliances.

[0024] 2. The present invention adopts fillers to make the fillers stacked more densely, reduce interface phonon scattering and interface thermal resistance, and more easily form a heat conduction path to form a maximum stacking degree, which is beneficial to increase the number of heat conduction chains and improve the concentration of heat conduction chains, thereby improving the thermal conductivity of the adhesive. Mica and graphene are used as fillers to form multiple effective heat conduction channels and improve the thermal conductivity coefficient. The fillers are mixed into the resin, which can effectively improve the heat resistance of the adhesive and make the thermal conductivity of the adhesive play a better role.

[0025] 3. The present invention uses subsequent electron beam radiation curing to break the polymer chains in the rubber to form free radicals, which need to be recombined in the system, and the chain structure is transformed into a three-dimensional network molecular structure to form a cross-linking cure, thereby improving the stability of the adhesive and further increasing the bonding strength of the adhesive, thereby ensuring that the adhesive has good bonding strength in high or low temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart for preparing the adhesive of the present invention. DETAILED DESCRIPTION

[0027] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0028] like Figure 1 As shown, the present invention provides a radiation-curable electronic adhesive, comprising the following raw materials by weight:

[0029] 60-80 parts of resin, 5-30 parts of filler, 1-10 parts of chain extender, 0.1-2 parts of stabilizer and 4-12 parts of initiator;

[0030] The preparation process of the adhesive includes:

[0031] Step 1: Mix the synthetic resin, chain extender and stabilizer at 75-85°C, then heat to 115-125°C, and stir until fully mixed to obtain a mixed material;

[0032] Step 2: Add filler and initiator to the mixed material, adjust the temperature to 20-100°C, maintain constant temperature, and stir and mix for 20-50 minutes to obtain a rubber layer mixture;

[0033] Step 3: coating the adhesive layer mixture to obtain an adhesive layer, and irradiating it with an electron beam to obtain an adhesive.

[0034] As an embodiment of the present invention, the resin includes one or a combination of silicone resin, acrylic resin, polyester resin and polyether resin; oxygen-modified silicone resin or acrylic-modified silicone resin;

[0035] The active terminal groups of acrylic resins, polyester resins and polyether resins are unsaturated vinyl groups, unsaturated allyl groups or epoxy groups.

[0036] As an embodiment of the present invention, the filler is mica and graphene, wherein the mass ratio of the particle size distribution of 12-14 μm, 6-7 μm, and 1.5-1.7 μm is 4-8:1-5:1.

[0037] As an embodiment of the present invention, the chain extender includes a hydrophilic chain extender and a small molecule chain extender;

[0038] The hydrophilic chain extender includes at least one of ethylene glycol, 1,4-butanediol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, 1,6-hexanediol, trimethylolpropane, neopentyl glycol, butyl propyl glycol, diethyl pentanediol, 1,4-dihydroxymethyl cyclohexane and cyclohexanediol;

[0039] The small molecule chain extender includes at least one of a small molecule diol, a small molecule triol, a small molecule diamine, and a diol containing a hydrophilic group.

[0040] As an embodiment of the present invention, the initiator is one or more of a peroxide initiator and an azo initiator.

[0041] As an embodiment of the present invention, the stabilizer is one or a combination of hydroquinone, p-methoxyphenol, p-benzoquinone, 2,6-di-tert-butyltoluene, phenothiazine, and anthraquinone.

[0042] As an embodiment of the present invention, in step 1, the first stirring and mixing time is 30 to 60 minutes, the stirring rate is 1000 to 1200 r / min, and the second stirring and mixing time is 30 to 40 minutes.

[0043] As an implementation mode of the present invention, in step three, the voltage is 300 kV and the irradiation intensity is 5-9 Mrads.

[0044] The invention has the advantages of high bonding strength, low volatility, high strength, no glue oil, good insulation performance and good sealing performance, and has good storage stability. It can be stored at 2-8°C for more than 6 months without adding silane coupling agent, and will not cause abnormal operation of electrical appliances. By using fillers, the fillers are stacked more closely, reducing interface phonon scattering and interface thermal resistance, and it is easier to form a heat conduction path and form a maximum stacking degree, which is beneficial to increase the number of heat conduction chains and improve the concentration of heat conduction chains, thereby improving the thermal conductivity of the adhesive. Mica and graphene are used as fillers to form multiple An effective heat conduction channel is created to improve the thermal conductivity coefficient, and the filler is mixed into the resin, which can effectively improve the heat resistance of the adhesive and make the thermal conductivity of the adhesive play a better role. Through the subsequent electron beam radiation curing, the polymer chains in the rubber are broken to form free radicals, which need to be recombined in the system, and the chain structure is transformed into a three-dimensional network molecular structure to form a cross-linking cure, thereby improving the stability of the adhesive and further increasing the bonding strength of the adhesive, thereby ensuring that the adhesive has good bonding strength in high or low temperature environments.

[0045] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A radiation-curable electronic adhesive, characterized in that: Including the following raw materials by weight: 60-80 parts of resin, 5-30 parts of filler, 1-10 parts of chain extender, 0.1-2 parts of stabilizer and 4-12 parts of initiator; The preparation process of the adhesive includes: Step 1: Mix the synthetic resin, chain extender and stabilizer at 75-85°C, then heat to 115-125°C, and stir until fully mixed to obtain a mixed material; Step 2: Add filler and initiator to the mixed material, adjust the temperature to 20-100°C, maintain constant temperature, and stir and mix for 20-50 minutes to obtain a rubber layer mixture; Step 3: coating the adhesive layer mixture to obtain an adhesive layer, and irradiating it with an electron beam to obtain an adhesive.

2. The radiation-curable electronic adhesive according to claim 1, characterized in that: The resin includes one or a combination of silicone resin, acrylic resin, polyester resin and polyether resin; oxygen-modified silicone resin or acrylic-modified silicone resin; The active terminal groups of the acrylic resin, polyester resin and polyether resin are unsaturated vinyl groups, unsaturated allyl groups or epoxy groups.

3. The radiation-curable electronic adhesive according to claim 1, wherein: The fillers are mica and graphene, wherein the mass ratio of the particle size distribution of 12-14 μm, 6-7 μm, and 1.5-1.7 μm is 4-8:1-5:

1.

4. The radiation-curable electronic adhesive according to claim 1, wherein: The chain extender includes a hydrophilic chain extender and a small molecule chain extender; Wherein, the hydrophilic chain extender includes at least one of ethylene glycol, 1,4-butanediol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, 1,6-hexanediol, trimethylolpropane, neopentyl glycol, butyl propyl glycol, diethyl pentanediol, 1,4-dihydroxymethyl cyclohexane and cyclohexanediol; The small molecule chain extender includes at least one of a small molecule diol, a small molecule triol, a small molecule diamine, and a diol containing a hydrophilic group.

5. The radiation-curable electronic adhesive according to claim 1, wherein: The initiator is one or more of a peroxide initiator and an azo initiator.

6. The radiation-curable electronic adhesive according to claim 1, wherein: The stabilizer is one or a combination of hydroquinone, p-methoxyphenol, p-benzoquinone, 2,6-di-tert-butyltoluene, phenothiazine and anthraquinone.

7. The radiation-curable electronic adhesive according to claim 1, wherein: In the step 1, the first stirring and mixing time is 30 to 60 minutes, the stirring rate is 1000 to 1200 r / min, and the second stirring and mixing time is 30 to 40 minutes.

8. The radiation-curable electronic adhesive according to claim 1, wherein: In the step 3, the voltage is 300 kV and the irradiation intensity is 5-9 Mrads.

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