Electronic packaging adhesive and preparation method thereof

Abstract

The present application relates to the field of packaging adhesives, and in particular to an electronic packaging adhesive and a preparation method thereof. The electronic packaging adhesive, in parts by mass, comprises the following raw materials: 60-90 parts of a complex polyol, 20-40 parts of an isocyanate, 10-20 parts of a modified resin, 5-8 parts of a plasticizer, 1-2 parts of a chain extender, 0.3-1.2 parts of a catalyst, 1-3 parts of an antioxidant, 2-4 parts of a leveling agent, and 0.5-1.2 parts of a defoaming agent. The polyurethane electronic packaging adhesive prepared in the present application can maintain excellent mechanical properties while maintaining good waterproof and moisture resistance, high temperature stability, aging and corrosion resistance, and other properties, thereby meeting the diverse performance requirements of existing electronic components for polyurethane packaging adhesives, and has a very excellent market application prospect.

Description

Technical Field

[0001] The present application relates to the field of packaging adhesives, and in particular to an electronic packaging adhesive and a preparation method thereof. Background Art

[0002] Electronic packaging adhesive is a material specially designed to protect electronic components from environmental factors. It is mainly used in the packaging process of chips, circuit boards and other sensitive components in electronic devices to enhance the reliability and durability of electronic products, especially in integrated circuits (ICs), microprocessors and other sensitive electronic devices.

[0003] Traditional electronic packaging adhesives are mainly composed of polymer matrices such as epoxy resins, silicone resins, and polyurethanes, which usually have good high-temperature stability, sealing, mechanical properties, and stress relief. In particular, polyurethane packaging adhesives have been increasingly used in recent years due to their excellent flexibility, adhesion, and diverse curing methods. However, at the same time, as electronic devices develop towards miniaturization and high performance, traditional electronic packaging materials have gradually revealed some shortcomings, which are reflected in polyurethane packaging adhesives, mainly in moisture sensitivity, insufficient waterproofness, lack of sufficient mechanical properties, and poor aging and corrosion resistance. These problems limit the further application of polyurethane electronic packaging adhesives.

[0004] Therefore, in order to solve the above problems, the present application provides a polyurethane electronic packaging adhesive and a preparation method thereof. The polyurethane electronic packaging adhesive prepared in the present application can maintain excellent mechanical properties while maintaining good waterproof and moisture resistance, high temperature stability, aging and corrosion resistance and other properties, thereby meeting the diverse performance requirements of existing electronic components for polyurethane packaging adhesives and having very excellent market application prospects. Summary of the invention

[0005] In order to solve the above problems, the first aspect of the present application provides an electronic packaging adhesive, the raw materials of which are, by mass: 60~90 parts of complex polyol, 20~40 parts of isocyanate, 10~20 parts of modified resin, 5~8 parts of plasticizer, 1~2 parts of chain extender, 0.3~1.2 parts of catalyst, 1~3 parts of antioxidant, 2~4 parts of leveling agent, and 0.5~1.2 parts of defoaming agent.

[0006] As a preferred solution, the mass ratio of the complex polyol, isocyanate and modified resin is (70-80): (25-35): (15-20).

[0007] As a preferred solution, the mass ratio of the complex polyol, isocyanate and modified resin is (72-76): (26-30): (16-18).

[0008] As a preferred solution, the isocyanate is diphenylmethane diisocyanate.

[0009] As a preferred solution, the complex polyol is a combination of polyether polyol, polyester polyol and modified polyester polyol.

[0010] As a preferred solution, the mass ratio of the polyether polyol, polyester polyol and modified polyester polyol is (3-4): (2-2.5): (1-1.5).

[0011] As a preferred solution, the mass ratio of the polyether polyol, polyester polyol and modified polyester polyol is (3.5-3.8):(2.2-2.4):(1.1-1.3).

[0012] As a preferred solution, the polyether polyol is a copolyether glycol of propylene oxide and ethylene oxide.

[0013] As a preferred solution, the number average molecular weight of the polyether polyol is 2000~2500Da.

[0014] As a preferred solution, the polyester polyol is poly(1,4-butylene adipate).

[0015] As a preferred solution, the number average molecular weight of the polyester polyol is 1000-2000 Da.

[0016] As a preferred scheme, the preparation method of the modified polyester polyol comprises the following steps: S1: neopentyl glycol, terminal hydroxyl polysulfide, organic acid and catalyst are mixed and added to a reaction container, stirred and mixed at 400-500 rpm for 30-40 minutes, and then heated to 140-150°C to remove water until the water content of the mixture is ≤0.5wt%; S2: after the water removal is completed, the reaction container is treated with nitrogen, and then sealed and evacuated to vacuum, and the temperature is increased to 190-220°C for insulation reaction for 10-14 hours, until the hydroxyl value of the reaction product is in the range of 70-80 mgKOH / g, and then the pressure is reduced to normal pressure, and naturally cooled to room temperature, and the product is taken out.

[0017] As a preferred solution, the organic acid is a combination of adipic acid and terephthalic acid; the mass ratio of adipic acid to terephthalic acid is (4-5): (0.8-1.4).

[0018] As a preferred solution, the catalyst is tetraisopropyl titanate or titanium isopropoxide titanate.

[0019] As a preferred solution, the mass ratio of the neopentyl glycol, the terminal hydroxyl polysulfide, the organic acid and the catalyst is (10-12): (8-10): (26-32): (3.5-4).

[0020] As a preferred solution, the viscosity of the hydroxy-terminated polysulfide is 1000-2000 mPa·s at 25°C.

[0021] As a preferred solution, the number average molecular weight of the hydroxy-terminated polysulfide is 1500-2500 Da.

[0022] In the present application, by adding the above-mentioned compounded polyether polyol, polyester polyol and modified polyester polyol, the mechanical properties, waterproofness, high temperature resistance and aging corrosion resistance of the polyurethane electronic packaging adhesive can be greatly improved. The combination of the terminal hydroxyl polythioether polyester polyol and the polyether and polyester polyol added in the present application can firstly introduce more active groups and reaction sites in the process of forming the polyurethane system of the encapsulant, thereby greatly increasing the speed of building the molecular chain network inside the system, and can increase the density of the network inside the system by the mutual entanglement of long and short chains, thereby effectively enhancing the connection effect of the sealant itself when external forces act, and greatly improving its upper limit of bearing capacity; in addition, the polythioether in the added modified polyester has a stronger intermolecular effect with the polyester polyol and polyether polyol molecules, while enhancing the cohesive force, greatly reducing the contact probability of water molecules and active free groups inside the system, thereby limiting their free efficiency inside the system, and can greatly increase the penetration resistance of water molecules and active molecules under long-term use and high temperature and high humidity active environment, thereby greatly delaying the moisture permeation and aging corrosion of the encapsulant, enhancing the internal space steric hindrance, reducing the probability of negative reactions, and thus obtaining excellent performance.

[0023] As a preferred scheme, the preparation method of the modified resin comprises the following steps: S1: adding hydroxyethyl methacrylate, n-octyl acrylate, isobornyl acrylate and benzophenone into a reaction container, irradiating with a wavelength of 300-450nm under nitrogen for reaction for 2-2.5h, and washing the product with ethanol for 2-3 times after the reaction is completed to obtain a prepolymer; S2: mixing the prepolymer with acrylamide, oxalic acid and hydroxymethyl bisphenol F diglycidyl ether uniformly, adding them into an acetone solvent and stirring to mix uniformly, then adding benzoyl peroxide in sequence, heating to 110-120°C, sealing the reaction kettle, and stirring for 6-8h under nitrogen protection; S3: after the reaction of S2 is completed, filtering to obtain a preproduct, adding the preproduct into deionized water, then adding glutaric anhydride and titanate coupling agent, maintaining the temperature at 65-70°C for reaction for 2-2.5h, filtering the product after completion, washing with ethanol for 2-3 times, and vacuum drying at 70-80°C to obtain the product.

[0024] As a preferred solution, the mass ratio of hydroxyethyl methacrylate, n-octyl acrylate and isobornyl acrylate is (8-12):(3-5):(1-2).

[0025] As a preferred solution, the mass ratio of the prepolymer, acrylamide, oxalic acid and hydroxymethyl bisphenol F diglycidyl ether is (8-10): (35-40): (3-5): (4-6).

[0026] As a preferred solution, the mass ratio of the pre-product, glutaric anhydride and titanate coupling agent is (20-30): (5-7): (0.2-0.3).

[0027] As a preferred solution, the titanate coupling agent is triisopropoxy titanate acetate.

[0028] The modified resin added in the present application can effectively improve the mechanical properties, waterproofness and aging corrosion resistance of polyurethane electronic packaging glue. The addition of modified resin can rely on its good number of active groups to play a better cross-linking role with the polyurethane in the system, thereby assisting the construction of a dense network system inside the system, and it can also play a good connecting role in the sealant. The long molecular chain carried by the modified resin can greatly enhance the connection between the raw materials inside the sealant, while playing a good molecular guidance and barrier role, which can not only reduce the free efficiency of active molecules, but also greatly increase the penetration path length and resistance of water molecules in the system, thereby obtaining excellent barrier effects under high temperature and high humidity environments, and in actual use, it can also prevent the penetration and corrosive reaction of corrosive substances with water molecules as carriers.

[0029] As a preferred solution, the plasticizer is at least one of dioctyl phthalate, didecyl phthalate, triethyl citrate, dioctyl adipate, tri(2-chloroethyl) phosphate, epoxy soybean oil, and epoxy fatty acid methyl ester.

[0030] As a preferred solution, the plasticizer is a combination of dioctyl adipate and epoxidized soybean oil.

[0031] As a preferred solution, the mass ratio of dioctyl adipate to epoxidized soybean oil is (3-4): (1-1.5).

[0032] As a preferred solution, the chain extender is at least one of 1,6-hexanediol, neopentyl glycol, diethylenetriamine, diaminodicyclohexylmethane, and dimercaptoethanol.

[0033] As a preferred solution, the chain extender is a combination of 1,6-hexanediol and diethylenetriamine.

[0034] As a preferred solution, the mass ratio of 1,6-hexanediol to diethylenetriamine is (2-2.5): (1-1.2).

[0035] As a preferred solution, the catalyst is at least one of dibutyltin dilaurate, triethylamine, N,N-dimethylcyclohexylamine, triethylenediamine, stannous octoate, and dimethylcyclohexylmethylamine.

[0036] As a preferred solution, the catalyst is dibutyltin dilaurate.

[0037] As a preferred solution, the antioxidant is at least one of 2,6-di-tert-butyl-4-methylphenol, tert-butylhydroxyanisole, tris(2,4-di-tert-butylphenyl)phosphite, triphenyl phosphite, dilaurylthiodipropionate, and distearylthiodipropionate.

[0038] As a preferred solution, the antioxidant is a combination of 2,6-di-tert-butyl-4-methylphenol and triphenyl phosphite.

[0039] As a preferred solution, the mass ratio of 2,6-di-tert-butyl-4-methylphenol to triphenyl phosphite is (3-4):(0.4-0.8).

[0040] As a preferred solution, the leveling agent is polydimethylsiloxane or modified polysiloxane.

[0041] As a preferred solution, the leveling agent is any one of BYK-307, BYK-333, BYK-341, BYK-348, DC-62, and DC-65.

[0042] As a preferred solution, the leveling agent is BYK-341.

[0043] As a preferred solution, the defoaming agent is at least one of silicone defoaming agents.

[0044] The second aspect of the present application provides a method for preparing the above-mentioned electronic packaging glue, which specifically includes the following steps: S1: Mix the complex polyol, plasticizer, chain extender, antioxidant, leveling agent and defoamer, and stir at 500-800rpm for 20-30min to obtain a premix; S2: Slowly add the catalyst to the premix, and stir at 200-300rpm for 5-10min; S3: Under stirring at 200-300rpm, slowly add the isocyanate to the premix, control the temperature to 60-75°C, stir for 10-15min, then heat to 90-110°C, and keep warm for reaction for 2-3h. After the reaction is completed, take out the product, vacuum degas for 0.5-1h, and transfer it to a storage container for drying under inert gas protection.

[0045] The beneficial effects of this application are:

[0046] 1. The electronic packaging adhesive provided in the present application can maintain excellent mechanical properties while maintaining good waterproof and moisture resistance, high temperature stability, aging and corrosion resistance and other properties, thereby meeting the diverse performance requirements of existing electronic components for polyurethane packaging adhesives and having very excellent market application prospects.

[0047] 2. The electronic packaging glue provided in the present application, the added combination of terminal hydroxyl polysulfide polyester polyol and polyether, polyester polyol can firstly introduce more active groups and reaction sites in the process of forming the polyurethane system of the packaging glue, thereby greatly increasing the speed of building the molecular chain network inside the system, and can increase the density of the network inside the system through the mutual entanglement of long and short chains, thereby effectively enhancing the connection effect of the sealant itself when external force acts, greatly improving its upper limit of bearing capacity, and obtaining excellent mechanical properties.

[0048] 3. An electronic packaging glue provided in the present application has a stronger separation effect between the polysulfide added to the modified polyester and the polyester polyol and polyether polyol molecules, which enhances the cohesive force while greatly reducing the contact probability of water molecules and active free groups inside the system, thereby limiting their free efficiency inside the system. It can greatly increase the penetration resistance of water molecules and active molecules under long-term use and high temperature and high humidity active environment, thereby greatly delaying the moisture permeability and aging corrosion of the packaging glue, enhancing the internal space steric hindrance, reducing the probability of negative reactions, and thus obtaining excellent performance.

[0049] 4. The electronic packaging glue provided in the present application, the added modified resin can effectively improve the mechanical properties, waterproofness and aging corrosion resistance of the polyurethane electronic packaging glue. The addition of the modified resin can rely on its good number of active groups to play a better cross-linking role with the polyurethane in the system, thereby assisting the construction of a dense network system inside the system, and it can also play a good connecting role in the sealant. The long molecular chain carried by the modified resin can greatly enhance the connection between the raw materials inside the sealant, while playing a good molecular guidance and barrier role, which can not only reduce the free efficiency of active molecules, but also greatly increase the penetration path length and resistance of water molecules in the system, thereby obtaining excellent barrier effects under high temperature and high humidity environments, and in actual use, it can also prevent the penetration and corrosive reactions of corrosive substances with water molecules as carriers. DETAILED DESCRIPTION

[0050] The following will further explain and demonstrate the technical solutions in the above invention content of this application in the form of specific implementation schemes. The following embodiments are only practical examples used to illustrate and explain the contents of the technical solutions in the specification, and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the invention content of this application should be included in the scope to be protected by this application.

[0051] In the following examples, unless otherwise specified, the raw materials are all commercially available products, or can be prepared by methods well known to those skilled in the art.

[0052] Example 1

[0053] Example 1 The first aspect provides an electronic packaging adhesive, the raw materials of which are, by mass, 74.5 parts of complex polyol, 26.2 parts of isocyanate, 17.6 parts of modified resin, 7.5 parts of plasticizer, 1.6 parts of chain extender, 0.9 parts of catalyst, 2.6 parts of antioxidant, 3.8 parts of leveling agent, and 1.1 parts of defoaming agent.

[0054] The composite polyol is a composition of polyether polyol, polyester polyol and modified polyester polyol, and the mass ratio of the three is 3.6:2.3:1.2.

[0055] The isocyanate is diphenylmethane diisocyanate.

[0056] The polyether polyol is a copolyether glycol of propylene oxide and ethylene oxide, has a number average molecular weight of 2000 Da, and is purchased from BASF under the model Pluracol® P2000.

[0057] The polyester polyol is poly(1,4-butylene adipate) with a number average molecular weight of 1900 Da, and is purchased from BASF under the model number of Plastomers® 1900.

[0058] The preparation method of modified polyester polyol comprises the following steps, calculated by mass: S1: 11.6 parts of neopentyl glycol, 9.4 parts of terminal hydroxyl polysulfide, 28.8 parts of organic acid and 3.8 parts of catalyst are mixed and added to a reaction container, stirred and mixed at 450rpm for 40min, and then heated to 140°C to remove water until the water content of the mixture is ≤0.5wt%; S2: after the removal of water, the reaction container is treated with nitrogen, and then sealed and evacuated to vacuum, and the temperature is raised to 220°C for insulation reaction for 12h, until the hydroxyl value of the reaction product is 72.4mgKOH / g, and then the pressure is reduced to normal pressure, naturally cooled to room temperature, and the product is taken out.

[0059] The organic acid is a composition of adipic acid and terephthalic acid; the mass ratio of adipic acid to terephthalic acid is 4.2:1.2; and the catalyst is tetraisopropyl titanate.

[0060] The viscosity of the hydroxy-terminated polysulfide is 1900 mPa·s at 25° C., and the number average molecular weight is 2200 Da. It is purchased from Lubrizol Corporation and is a product of model Estane TR-2200.

[0061] The preparation method of the modified resin comprises the following steps, calculated by mass: S1: adding 10.8 parts of hydroxyethyl methacrylate, 4.2 parts of n-octyl acrylate, 1.5 parts of isobornyl acrylate and 0.6 parts of benzophenone into a reaction container, irradiating with nitrogen at a wavelength of 400 nm for 2.2 hours, and after the reaction is completed, washing the product with ethanol for 3 times to obtain a prepolymer; S2: mixing 9.5 parts of the prepolymer with 36.5 parts of acrylamide, 3.8 parts of oxalic acid and 4.5 parts of hydroxymethyl bisphenol F diglycidyl ether Add evenly into 360 parts of acetone solvent and stir to mix evenly, then add 0.4 parts of benzoyl peroxide in turn, heat to 115°C, seal the reactor, and react for 8 hours under nitrogen protection; S3: After the reaction of S2 is completed, filter to obtain the pre-product, add 24.5 parts of the pre-product to 200 parts of deionized water, then add 5.5 parts of glutaric anhydride and 0.28 parts of titanate coupling agent, maintain the temperature at 65°C for 2.2 hours, filter the product after completion, wash with ethanol for 3 times, and dry in a vacuum oven at 75°C to obtain the product.

[0062] The titanate coupling agent is triisopropoxy titanate acetate.

[0063] The plasticizer is a combination of dioctyl adipate and epoxidized soybean oil, with a mass ratio of 3.2:1.4. The epoxidized soybean oil was purchased from the MY epoxidized soybean oil product sold by Shandong Mingyue Chemical Co., Ltd.

[0064] The chain extender is a composition of 1,6-hexanediol and diethylenetriamine, and the mass ratio of the two is 2.2:1.2.

[0065] The catalyst is dibutyltin dilaurate; the antioxidant is a combination of 2,6-di-tert-butyl-4-methylphenol and triphenyl phosphite, and the mass ratio of the two is 3.8:0.6.

[0066] The leveling agent is BYK-341; the defoaming agent is BYK-066N.

[0067] The second aspect of the present embodiment provides a method for preparing the above-mentioned electronic packaging glue, which specifically includes the following steps: S1: Mix the complex polyol, plasticizer, chain extender, antioxidant, leveling agent and defoamer, and stir at 600rpm for 25min to obtain a premix; S2: Slowly add the catalyst to the premix, and stir at 250rpm for 8min; S3: Under stirring at 200rpm, slowly add the isocyanate to the premix, control the temperature to 70°C, stir for 15min, then heat to 105°C, and keep warm for reaction for 3h. After the reaction is completed, take out the product, vacuum degas for 1h and transfer it to a storage container for drying under inert gas protection.

[0068] Example 2

[0069] Example 2 The first aspect provides an electronic packaging adhesive, the raw materials of which are, by mass, 79.6 parts of complex polyol, 32.2 parts of isocyanate, 15.5 parts of modified resin, 7.6 parts of plasticizer, 1.8 parts of chain extender, 1.1 parts of catalyst, 2.4 parts of antioxidant, 2.9 parts of leveling agent, and 0.9 parts of defoaming agent.

[0070] The composite polyol is a composition of polyether polyol, polyester polyol and modified polyester polyol, and the mass ratio of the three is 3.2:2.5:1.5.

[0071] The isocyanate is diphenylmethane diisocyanate.

[0072] The polyether polyol is a copolyether glycol of propylene oxide and ethylene oxide, has a number average molecular weight of 2000 Da, and is purchased from BASF under the model Pluracol® P2000.

[0073] The polyester polyol is poly(1,4-butylene adipate) with a number average molecular weight of 1900 Da, and is purchased from BASF under the model number of Plastomers® 1900.

[0074] The preparation method of modified polyester polyol comprises the following steps, calculated by mass: S1: 11.6 parts of neopentyl glycol, 9.4 parts of terminal hydroxyl polysulfide, 28.8 parts of organic acid and 3.8 parts of catalyst are mixed and added to a reaction container, stirred and mixed at 450rpm for 40min, and then heated to 140°C to remove water until the water content of the mixture is ≤0.5wt%; S2: after the removal of water, the reaction container is treated with nitrogen, and then sealed and evacuated to vacuum, and the temperature is raised to 220°C for insulation reaction for 12h, until the hydroxyl value of the reaction product is 72.4mgKOH / g, and then the pressure is reduced to normal pressure, naturally cooled to room temperature, and the product is taken out.

[0075] The organic acid is a composition of adipic acid and terephthalic acid; the mass ratio of adipic acid to terephthalic acid is 4.2:1.2; and the catalyst is tetraisopropyl titanate.

[0076] The viscosity of the hydroxy-terminated polysulfide is 1900 mPa·s at 25° C., and the number average molecular weight is 2200 Da. It is purchased from Lubrizol Corporation and is a product of model Estane TR-2200.

[0077] The preparation method of the modified resin comprises the following steps, calculated by mass: S1: adding 10.8 parts of hydroxyethyl methacrylate, 4.2 parts of n-octyl acrylate, 1.5 parts of isobornyl acrylate and 0.6 parts of benzophenone into a reaction container, irradiating with nitrogen at a wavelength of 400 nm for 2.2 hours, and after the reaction is completed, washing the product with ethanol for 3 times to obtain a prepolymer; S2: mixing 9.5 parts of the prepolymer with 36.5 parts of acrylamide, 3.8 parts of oxalic acid and 4.5 parts of hydroxymethyl bisphenol F diglycidyl ether Add evenly into 360 parts of acetone solvent and stir to mix evenly, then add 0.4 parts of benzoyl peroxide in turn, heat to 115°C, seal the reactor, and react for 8 hours under nitrogen protection; S3: After the reaction of S2 is completed, filter to obtain the pre-product, add 24.5 parts of the pre-product to 200 parts of deionized water, then add 5.5 parts of glutaric anhydride and 0.28 parts of titanate coupling agent, maintain the temperature at 65°C for 2.2 hours, filter the product after completion, wash with ethanol for 3 times, and dry in a vacuum oven at 75°C to obtain the product.

[0078] The titanate coupling agent is triisopropoxy titanate acetate.

[0079] The plasticizer is a combination of dioctyl adipate and epoxidized soybean oil, with a mass ratio of 3.2:1.4. The epoxidized soybean oil was purchased from the MY epoxidized soybean oil product sold by Shandong Mingyue Chemical Co., Ltd.

[0080] The chain extender is a composition of 1,6-hexanediol and diethylenetriamine, and the mass ratio of the two is 2.2:1.2.

[0081] The catalyst is dibutyltin dilaurate; the antioxidant is a combination of 2,6-di-tert-butyl-4-methylphenol and triphenyl phosphite, and the mass ratio of the two is 3.8:0.6.

[0082] The leveling agent is BYK-341; the defoaming agent is BYK-066N.

[0083] The second aspect of the present embodiment provides a method for preparing the above-mentioned electronic packaging glue, which specifically includes the following steps: S1: Mix the complex polyol, plasticizer, chain extender, antioxidant, leveling agent and defoamer, and stir at 600rpm for 25min to obtain a premix; S2: Slowly add the catalyst to the premix, and stir at 250rpm for 10min; S3: Under stirring at 200rpm, slowly add the isocyanate to the premix, control the temperature to 70°C, stir for 15min, then heat to 105°C, and keep warm for reaction for 3h. After the reaction is completed, take out the product, vacuum degas for 1h and transfer it to a storage container for drying and protection by inert gas.

[0084] Example 3

[0085] Example 3 The first aspect provides an electronic packaging glue, the raw materials of which are, by mass, 70 parts of complex polyol, 25 parts of isocyanate, 15 parts of modified resin, 5 parts of plasticizer, 1 part of chain extender, 0.3 parts of catalyst, 1 part of antioxidant, 2 parts of leveling agent, and 0.5 parts of defoaming agent.

[0086] The composite polyol is a composition of polyether polyol, polyester polyol and modified polyester polyol, and the mass ratio of the three is 3:2:1.

[0087] The isocyanate is diphenylmethane diisocyanate.

[0088] The polyether polyol is a copolyether glycol of propylene oxide and ethylene oxide, has a number average molecular weight of 2000 Da, and is purchased from BASF under the model Pluracol® P2000.

[0089] The polyester polyol is poly(1,4-butylene adipate) with a number average molecular weight of 1900 Da, and is purchased from BASF under the model number of Plastomers® 1900.

[0090] The preparation method of modified polyester polyol comprises the following steps, calculated by mass: S1: 10 parts of neopentyl glycol, 8 parts of terminal hydroxyl polysulfide, 26 parts of organic acid and 3.5 parts of catalyst are mixed and added to a reaction container, stirred and mixed at 450rpm for 40min, and then heated to 145°C to remove water until the water content of the mixture is ≤0.5wt%; S2: after the removal of water, the reaction container is treated with nitrogen, and then sealed and evacuated to vacuum, and the temperature is raised to 220°C for insulation reaction for 12h, until the hydroxyl value of the reaction product is 72.2mgKOH / g, and then the pressure is reduced to normal pressure, naturally cooled to room temperature, and the product is taken out.

[0091] The organic acid is a composition of adipic acid and terephthalic acid; the mass ratio of the adipic acid to the terephthalic acid is 4:0.8; and the catalyst is tetraisopropyl titanate.

[0092] The viscosity of the hydroxy-terminated polysulfide is 1900 mPa·s at 25° C., and the number average molecular weight is 2200 Da. It is purchased from Lubrizol Corporation and is a product of model Estane TR-2200.

[0093] The preparation method of the modified resin comprises the following steps, calculated by mass: S1: adding 8 parts of hydroxyethyl methacrylate, 3 parts of n-octyl acrylate, 1 part of isobornyl acrylate and 0.6 parts of benzophenone into a reaction container, irradiating with a wavelength of 350nm under nitrogen for reaction for 2 hours, and washing the product with ethanol for 2 times after the reaction is completed to obtain a prepolymer; S2: mixing 8 parts of the prepolymer with 35 parts of acrylamide, 3 parts of oxalic acid and 4 parts of hydroxymethyl bisphenol F diglycidyl ether uniformly, adding them into 360 parts of acetone solvent, stirring and mixing uniformly, then adding 0.4 parts of benzoyl peroxide in turn, heating to 110°C and sealing the reaction kettle, and stirring and reacting for 6 hours under nitrogen protection; S3: after the reaction of S2 is completed, filtering to obtain a preproduct, adding 20 parts of the preproduct into 200 parts of deionized water, then adding 5 parts of glutaric anhydride and 0.2 parts of titanate coupling agent, maintaining the temperature at 65°C for reaction for 2 hours, filtering the product after completion, washing with ethanol for 2 times, and vacuum drying at 70°C to obtain the product.

[0094] The titanate coupling agent is triisopropoxy titanate acetate.

[0095] The plasticizer is a composition of dioctyl adipate and epoxidized soybean oil, and the mass ratio of the two is 3: 1. The epoxidized soybean oil was purchased from the MY epoxidized soybean oil product sold by Shandong Mingyue Chemical Co., Ltd.

[0096] The chain extender is a composition of 1,6-hexanediol and diethylenetriamine, and the mass ratio of the two is 2:1.

[0097] The catalyst is dibutyltin dilaurate; the antioxidant is a combination of 2,6-di-tert-butyl-4-methylphenol and triphenyl phosphite, and the mass ratio of the two is 3:0.4.

[0098] The leveling agent is BYK-341; the defoaming agent is BYK-066N.

[0099] The second aspect of the present embodiment provides a method for preparing the above-mentioned electronic packaging glue, which specifically includes the following steps: S1: Mix the complex polyol, plasticizer, chain extender, antioxidant, leveling agent and defoamer, and stir at 500rpm for 20min to obtain a premix; S2: Slowly add the catalyst to the premix, and stir at 200rpm for 5min; S3: Under stirring at 200rpm, slowly add the isocyanate to the premix, control the temperature to 60°C, stir for 10min, then heat to 90°C, and keep warm for reaction for 2h. After the reaction is completed, take out the product, vacuum degas for 0.5h and transfer it to a storage container for drying and protection by inert gas.

[0100] Example 4

[0101] Example 4 The first aspect provides an electronic packaging glue, the raw materials of which are, by mass, 80 parts of complex polyol, 35 parts of isocyanate, 20 parts of modified resin, 8 parts of plasticizer, 2 parts of chain extender, 1.2 parts of catalyst, 3 parts of antioxidant, 4 parts of leveling agent, and 1.2 parts of defoaming agent.

[0102] The composite polyol is a composition of polyether polyol, polyester polyol and modified polyester polyol, and the mass ratio of the three is 4:2.5:1.5.

[0103] The isocyanate is diphenylmethane diisocyanate.

[0104] The polyether polyol is a copolyether glycol of propylene oxide and ethylene oxide, has a number average molecular weight of 2000 Da, and is purchased from BASF under the model Pluracol® P2000.

[0105] The polyester polyol is poly(1,4-butylene adipate) with a number average molecular weight of 1900 Da, and is purchased from BASF under the model number of Plastomers® 1900.

[0106] The preparation method of modified polyester polyol comprises the following steps, calculated by mass: S1: 12 parts of neopentyl glycol, 10 parts of terminal hydroxyl polysulfide, 32 parts of organic acid and 4 parts of catalyst are mixed and added to a reaction container, stirred and mixed at 500 rpm for 40 minutes, and then heated to 150°C to remove water until the water content of the mixture is ≤0.5wt%; S2: after the removal of water, the reaction container is treated with nitrogen, and then sealed and evacuated to vacuum, and the temperature is raised to 220°C for insulation reaction for 14 hours, until the hydroxyl value of the reaction product is 72.3 mgKOH / g, and then the pressure is reduced to normal pressure, naturally cooled to room temperature, and the product is taken out.

[0107] The organic acid is a composition of adipic acid and terephthalic acid; the mass ratio of the adipic acid to the terephthalic acid is 5:1.4; and the catalyst is tetraisopropyl titanate.

[0108] The viscosity of the hydroxy-terminated polysulfide is 1900 mPa·s at 25° C., and the number average molecular weight is 2200 Da. It is purchased from Lubrizol Corporation and is a product of model Estane TR-2200.

[0109] The preparation method of the modified resin comprises the following steps, calculated by mass: S1: adding 12 parts of hydroxyethyl methacrylate, 5 parts of n-octyl acrylate, 2 parts of isobornyl acrylate and 0.6 parts of benzophenone into a reaction container, irradiating with nitrogen at a wavelength of 450nm for 2.5h, and after the reaction is completed, washing the product with ethanol for 3 times to obtain a prepolymer; S2: mixing 10 parts of the prepolymer with 40 parts of acrylamide, 5 parts of oxalic acid and 6 parts of hydroxymethyl bisphenol F diglycidyl ether and adding Add to 360 parts of acetone solvent and stir to mix evenly, then add 0.4 parts of benzoyl peroxide in turn, heat to 120°C, seal the reactor, and react for 8 hours under nitrogen protection; S3: After the reaction of S2 is completed, filter to obtain the pre-product, add 30 parts of the pre-product to 200 parts of deionized water, then add 7 parts of glutaric anhydride and 0.3 parts of titanate coupling agent, maintain the temperature at 70°C for 2.5 hours, filter the product after completion, wash with ethanol for 3 times, and dry in a vacuum oven at 80°C to obtain the product.

[0110] The titanate coupling agent is triisopropoxy titanate acetate.

[0111] The plasticizer is a combination of dioctyl adipate and epoxidized soybean oil, with a mass ratio of 4:1.5. The epoxidized soybean oil was purchased from the MY epoxidized soybean oil product sold by Shandong Mingyue Chemical Co., Ltd.

[0112] The chain extender is a composition of 1,6-hexanediol and diethylenetriamine, and the mass ratio of the two is 2.5:1.2.

[0113] The catalyst is dibutyltin dilaurate; the antioxidant is a combination of 2,6-di-tert-butyl-4-methylphenol and triphenyl phosphite, and the mass ratio of the two is 4:0.8.

[0114] The leveling agent is BYK-341; the defoaming agent is BYK-066N.

[0115] The second aspect of the present embodiment provides a method for preparing the above-mentioned electronic packaging glue, which specifically includes the following steps: S1: Mix the complex polyol, plasticizer, chain extender, antioxidant, leveling agent and defoamer, and stir at 800rpm for 30min to obtain a premix; S2: Slowly add the catalyst to the premix, and stir at 300rpm for 10min; S3: Under stirring at 300rpm, slowly add the isocyanate to the premix, control the temperature to 75°C, stir for 15min, then heat to 110°C, and keep warm for reaction for 3h. After the reaction is completed, take out the product, vacuum degas for 1h and transfer it to a storage container for drying under inert gas protection.

[0116] Comparative Example 1

[0117] The specific implementation method of this comparative example is basically the same as that of Example 1, except that: the raw materials of the electronic packaging adhesive, in parts by mass, are: 85.5 parts of complex polyol, 31.4 parts of isocyanate, 5.5 parts of modified resin, 7.5 parts of plasticizer, 1.6 parts of chain extender, 0.9 parts of catalyst, 2.6 parts of antioxidant, 3.8 parts of leveling agent, and 1.1 parts of defoaming agent.

[0118] Comparative Example 2

[0119] The specific implementation method of this comparative example is basically the same as that of Example 1, except that: the raw materials of the electronic packaging adhesive, in parts by mass, are: 70.5 parts of complex polyol, 22.4 parts of isocyanate, 28.8 parts of modified resin, 7.5 parts of plasticizer, 1.6 parts of chain extender, 0.8 parts of catalyst, 2.6 parts of antioxidant, 3.8 parts of leveling agent, and 1.1 parts of defoaming agent.

[0120] Comparative Example 3

[0121] The specific implementation of this comparative example is basically the same as that of Example 1, except that the composite polyol is a composition of polyether polyol, polyester polyol and modified polyester polyol, and the mass ratio of the three is 6:1.5:0.4.

[0122] Comparative Example 4

[0123] The specific implementation of this comparative example is basically the same as that of Example 1, except that the composite polyol is a composition of polyether polyol, polyester polyol and modified polyester polyol, and the mass ratio of the three is 2:3:2.5.

[0124] Comparative Example 5

[0125] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified polyester polyol comprises the following steps, calculated by mass: S1: 18.8 parts of neopentyl glycol, 4.2 parts of terminal hydroxyl polysulfide, 39.5 parts of organic acid and 5.5 parts of catalyst are mixed and added to a reaction container, stirred and mixed at 450rpm for 40min, and then heated to 140°C to remove water until the water content of the mixture is ≤0.5wt%; S2: after the water removal is completed, the reaction container is treated with nitrogen, and then sealed and evacuated to vacuum, and the temperature is raised to 220°C for insulation reaction for 12h, until the hydroxyl value of the reaction product is 89.5mgKOH / g, then reduced to normal pressure, naturally cooled to room temperature, and the product is taken out.

[0126] Comparative Example 6

[0127] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified polyester polyol comprises the following steps, calculated by mass: S1: 7.8 parts of neopentyl glycol, 16.5 parts of terminal hydroxyl polysulfide, 20.4 parts of organic acid and 2.6 parts of catalyst are mixed and added to a reaction container, stirred and mixed at 450rpm for 40min, and then heated to 140°C to remove water until the water content of the mixture is ≤0.5wt%; S2: after the water removal is completed, the reaction container is treated with nitrogen, and then sealed and evacuated to vacuum, and the temperature is raised to 220°C for insulation reaction for 12h, until the hydroxyl value of the reaction product is 72.4mgKOH / g, the pressure is reduced to normal pressure, and naturally cooled to room temperature, and the product is taken out.

[0128] Comparative Example 7

[0129] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified resin comprises the following steps, calculated by mass: S1: 18.5 parts of hydroxyethyl methacrylate, 1.5 parts of n-octyl acrylate, 0.2 parts of isobornyl acrylate and 0.4 parts of benzophenone are added to a reaction container and irradiated with nitrogen at a wavelength of 400 nm for 2.4 hours. After the reaction is completed, the product is washed with ethanol for 3 times to obtain a prepolymer; S2: 9.5 parts of the prepolymer are mixed with 36.5 parts of acrylamide, 3.8 parts of oxalic acid and 4.5 1. 2 parts of hydroxymethyl bisphenol F diglycidyl ether are mixed evenly and added to 360 parts of acetone solvent, and stirred to mix evenly. Then, 0.4 parts of benzoyl peroxide are added in sequence, the temperature is raised to 115°C, the reactor is sealed, and the reaction is stirred for 8 hours under nitrogen protection; S3: After the reaction of S2 is completed, the pre-product is filtered to obtain the pre-product, 24.5 parts of the pre-product are added to 200 parts of deionized water, and then 5.5 parts of glutaric anhydride and 0.28 parts of titanate coupling agent are added, and the temperature is maintained at 65°C for 2.2 hours. After completion, the product is filtered, washed with ethanol for 3 times, and dried under vacuum at 75°C to obtain the product.

[0130] Comparative Example 8

[0131] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified resin comprises the following steps, calculated by mass: S1: 10.8 parts of hydroxyethyl methacrylate, 4.2 parts of n-octyl acrylate, 1.5 parts of isobornyl acrylate and 0.6 parts of benzophenone are added into a reaction vessel and irradiated with nitrogen at a wavelength of 400 nm for 2.2 hours. After the reaction is completed, the product is washed with ethanol for 3 times to obtain a prepolymer; S2: 15.5 parts of the prepolymer are mixed with 22.5 parts of acrylamide, 1.5 parts of oxalic acid and 1. 5 parts of hydroxymethyl bisphenol F diglycidyl ether are mixed evenly and added to 360 parts of acetone solvent, and stirred to mix evenly. Then, 0.4 parts of benzoyl peroxide are added in sequence, the temperature is raised to 115°C, the reactor is sealed, and the reaction is stirred for 8 hours under nitrogen protection; S3: After the reaction of S2 is completed, the pre-product is filtered to obtain a product, 24.5 parts of the pre-product are added to 200 parts of deionized water, and then 3 parts of glutaric anhydride and 0.12 parts of titanate coupling agent are added, and the temperature is maintained at 65°C for 2.2 hours. After completion, the product is filtered, washed with ethanol for 3 times, and vacuum dried at 75°C to obtain the product.

[0132] Performance Evaluation

[0133] Mechanical properties: The elongation at break of the polyurethane encapsulant prepared in the examples and comparative examples was tested using a universal testing machine at 25° C. and 50% relative humidity. The test values ​​were averaged over 10 tests and recorded in Table 1.

[0134] Adhesion: With reference to standard GB / T 2791-1995, the polyurethane encapsulating adhesives of the embodiments and comparative examples were subjected to T-peel strength adhesion test, and the initial adhesion and final adhesion were measured. The test values ​​were averaged from 10 tests and recorded in Table 1.

[0135] Waterproof and moisture permeability: The moisture permeability of the polyurethane encapsulant prepared in the embodiment and the comparative example was tested with reference to GB / T 1037-2021, and the test value was the average value of 10 tests and recorded in Table 1.

[0136] Corrosion resistance: After curing the polyurethane encapsulation adhesives prepared in the embodiments and comparative examples, samples of 2 cm×2 cm×0.2 cm were prepared for salt spray resistance test. The test environment temperature was 35±2°C, the humidity was 98±2%, the test solution was 5wt% NaCl solution, and the test time was 200 h. After the test, the cured hot melt adhesive was observed for corrosion, shedding, cracking and blistering. If so, it was recorded as unqualified, otherwise it was qualified. 50 samples were tested in each group, and the qualified rate was recorded in Table 1.

[0137] Table 1 Performance test results

[0138]

[0139] It can be seen from the examples and comparative examples of the present application and the data results in Table 1 that examples 1-4 of the present application have obvious advantages over comparative examples 1-8 in terms of mechanical properties, waterproof properties, bonding properties and aging resistance. This is mainly due to the combined effect of the modified polyols, modified resins, and other matching schemes specified in the present application. Comparative examples 1-8 did not adopt the technical scheme specified in the present application, resulting in obvious disadvantages in the above-mentioned performance tests, which further proves the necessity of the technical scheme specified in the present application for the technical effect of the present application and solving technical problems.

Claims

1. An electronic packaging adhesive, characterized in that: In parts by mass, the raw materials are: 60-90 parts of complex polyol, 20-40 parts of isocyanate, 10-20 parts of modified resin, 5-8 parts of plasticizer, 1-2 parts of chain extender, 0.3-1.2 parts of catalyst, 1-3 parts of antioxidant, 2-4 parts of leveling agent, and 0.5-1.2 parts of defoamer; The composite polyol is a composition of polyether polyol, polyester polyol and modified polyester polyol; the mass ratio of the polyether polyol, polyester polyol and modified polyester polyol is (3-4): (2-2.5): (1-1.5); The number average molecular weight of the polyether polyol is 2000-2500Da; The number average molecular weight of the polyester polyol is 1000-2000Da; Preparation method of modified polyester polyol The following steps are involved: S1: neopentyl glycol, terminal hydroxyl polysulfide, organic acid and catalyst are mixed and added to a reaction container, stirred and mixed at 400-500 rpm for 30-40 min, and then heated to 140-150°C to remove water until the water content of the mixture is ≤0.5wt%; S2: After the water removal is completed, the reaction container is treated with nitrogen, and then sealed and evacuated to vacuum, and the temperature is raised to 190-220°C for insulation reaction for 10-14h, until the hydroxyl value of the reaction product is within the range of 70-80 mgKOH / g, and then reduced to normal pressure, naturally cooled to room temperature, and the product is taken out; The organic acid is a combination of adipic acid and terephthalic acid; the mass ratio of adipic acid to terephthalic acid is (4-5): (0.8-1.4); The mass ratio of the neopentyl glycol, the hydroxyl-terminated polysulfide, the organic acid and the catalyst is (10-12): (8-10): (26-32): (3.5-4); The plasticizer is at least one of dioctyl phthalate, didecyl phthalate, triethyl citrate, dioctyl adipate, tri(2-chloroethyl) phosphate, epoxy soybean oil, and epoxy fatty acid methyl ester; The catalyst is at least one of dibutyltin dilaurate, triethylamine, N,N-dimethylcyclohexylamine, triethylenediamine, stannous octoate, and dimethylcyclohexylmethylamine; The chain extender is at least one of 1,6-hexanediol, neopentyl glycol, diethylenetriamine, diaminodicyclohexylmethane, and dimercaptoethanol; The antioxidant is at least one of 2,6-di-tert-butyl-4-methylphenol, tert-butyl hydroxyanisole, tris(2,4-di-tert-butylphenyl)phosphite, triphenyl phosphite, dilaurylthiodipropionate, and distearylthiodipropionate; The preparation method of the modified resin comprises the following steps: S1: adding hydroxyethyl methacrylate, n-octyl acrylate, isobornyl acrylate and benzophenone into a reaction container, irradiating with a wavelength of 300-450nm under nitrogen for 2-2.5h, and washing the product with ethanol for 2-3 times after the reaction is completed to obtain a prepolymer; S2: mixing the prepolymer with acrylamide, oxalic acid and hydroxymethyl bisphenol F diglycidyl ether uniformly, adding them into an acetone solvent and stirring to mix uniformly, then adding benzoyl peroxide in sequence, heating to 110-120°C, sealing the reaction kettle, and stirring for 6-8h under nitrogen protection; S3: after the reaction of S2 is completed, filtering to obtain a preproduct, adding the preproduct into deionized water, then adding glutaric anhydride and titanate coupling agent, maintaining the temperature at 65-70°C for reaction for 2-2.5h, filtering the product after completion, washing with ethanol for 2-3 times, and vacuum drying at 70-80°C to obtain the product; The mass ratio of hydroxyethyl methacrylate, n-octyl acrylate and isobornyl acrylate is (8-12): (3-5): (1-2); The mass ratio of the prepolymer, acrylamide, oxalic acid and hydroxymethyl bisphenol F diglycidyl ether is (8-10): (35-40): (3-5): (4-6).

2. The electronic packaging adhesive according to claim 1, characterized in that: The mass ratio of the complex polyol, isocyanate and modified resin is (70-80): (25-35): (15-20).

3. The electronic packaging adhesive according to claim 2, characterized in that: The polyether polyol is a copolyether diol of propylene oxide and ethylene oxide; and the isocyanate is diphenylmethane diisocyanate.

4. The electronic packaging adhesive according to claim 3, characterized in that: The polyester polyol is poly(1,4-butylene adipate).

5. The electronic packaging adhesive according to claim 4, characterized in that: The viscosity of the terminal hydroxyl polysulfide is 1000-2000 mPa·s at 25° C.; the number average molecular weight of the terminal hydroxyl polysulfide is 1500-2500 Da.

6. The electronic packaging adhesive according to claim 5, characterized in that: The leveling agent is polydimethylsiloxane or modified polysiloxane.

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