An aluminum substrate that can be photocured and shaped after bending.

Abstract

The invention discloses an aluminum substrate which can realize photocuring and shaping after bending. The aluminum substrate comprises an aluminum plate, a heat-conducting photocuring shaping adhesive and a copper foil. The heat-conducting photocuring shaping adhesive consists of a modified epoxy acrylate prepolymer, a modified chloroprene rubber, pentaerythritol triacrylate, an epoxy curing agent, a composite modified heat-conducting filler, a photoinitiator, a defoamer, a leveling agent, an antioxidant, a cross-linking agent, a viscosity regulator, a catalyst, a chain extender and a flame retardant. The aluminum substrate can be bent arbitrarily before photocuring and shaping, and can meet the diversified shapes and all-round lighting requirements of LED lamps. After bending, the aluminum substrate can be irradiated with UV ultraviolet light to realize photocuring and shaping, and unnecessary deformation will not occur, so that the processing, production and use of the special aluminum substrate are convenient.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum-based circuit boards, and more specifically to an aluminum substrate that can be photocured and shaped after being bent. Background Art

[0002] In a high-temperature working environment, LEDs will have problems such as color deviation, reduced brightness, shortened service life, and even immediate failure. To avoid the above problems, the circuit board carrying the LED is required to be able to promptly and fully conduct the heat generated by the LED when it is working. At present, aluminum substrates (also known as aluminum-based copper-clad circuit boards) are widely used to carry LEDs to meet the requirements for substrate thermal conductivity. However, the existing aluminum substrates only have certain heat dissipation performance, cannot be bent, are not flexible, and are easy to break. At the same time, it is also difficult to solve the problems of LED lighting in all directions, various shapes, and technical applications to improve processing efficiency.

[0003] In order to improve this problem, the applicant has developed an aluminum substrate material that can be bent arbitrarily and a method for making the same. The patent application number is CN201610175572.2. The aluminum substrate material includes an aluminum plate, a heat-conducting adhesive and a copper foil. The copper foil is bonded to the aluminum plate through the heat-conducting adhesive. The structural design is ingenious and reasonable. The aluminum substrate and the copper foil are innovatively combined through the heat-conducting adhesive. The aluminum substrate has good flexibility and is not easy to break. It can be bent arbitrarily, which can meet the diversified shapes of LED lamps and the needs of all-round lighting. Moreover, the heat generated by the LED lamp can be quickly transferred to the aluminum substrate through the heat-conducting adhesive, and quickly dissipated by the aluminum substrate, thereby achieving the purpose of rapid heat dissipation and good heat dissipation effect. However, the aluminum substrate still has the following shortcomings: the aluminum substrate is flexible. Although it can be bent arbitrarily, it cannot be guaranteed that it will not deform after bending. For example, after being bent into a preset shape, it may collide or cause unnecessary deformation in other subsequent processing operations. Therefore, based on actual use needs, it is necessary to develop an aluminum substrate that can be permanently shaped after bending. Summary of the invention

[0004] The object of the present invention is to overcome the above-mentioned defects in the prior art and provide an aluminum substrate that can be photocured and shaped after being bent.

[0005] To achieve the above object, the present invention provides an aluminum substrate that can be photocured after bending, comprising an aluminum plate and a copper foil, wherein the aluminum plate is bonded to the copper foil via a thermally conductive photocurable adhesive coated on the surface of the aluminum plate, wherein the thermally conductive photocurable adhesive is composed of the following raw materials in percentage by mass:

[0006]

[0007] The composite modified thermal conductive filler comprises aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano aluminum oxide, and the mass ratio of the aluminum nitride modified by pre-sealed alkoxy ester siloxane to the modified nano aluminum oxide is 1:(2-4).

[0008] Preferably, the method for preparing the thermal light-curing setting adhesive comprises the following steps:

[0009] According to the preset mass percentage, the modified epoxy acrylate prepolymer, modified chloroprene rubber, pentaerythritol triacrylate, defoamer, leveling agent, antioxidant, crosslinking agent, viscosity regulator, catalyst, chain extender and flame retardant are respectively added to the reaction kettle, the agitator is turned on, and the mixture is stirred for 0.5 to 2 hours at a temperature of 25 to 40°C. The composite modified thermal conductive filler is added and stirred for 0.5 to 1 hour. The epoxy curing agent is added and stirred for 0.5 to 1 hour. The photoinitiator is added, and the mixture is vacuumed to -0.1 MPa and stirred at the pressure for 1 to 2 hours. The mixture is then vacuum defoamed and discharged to obtain a thermal conductive light-curing setting glue.

[0010] Preferably, the method for preparing the modified epoxy acrylate prepolymer comprises the following steps:

[0011] Under the condition of nitrogen, the epoxy glycerol ester is heated to 65-70°C, and then the fluorinated acrylate is added dropwise, and then the temperature is raised to 100-120°C, cooled to room temperature and discharged to obtain the epoxy acrylate prepolymer;

[0012] The epoxy acrylate prepolymer and the silica sol are mixed and stirred, and after being stirred evenly, 3-phenyl-2-acrylic acid is added to carry out an esterification reaction to obtain a modified epoxy acrylate prepolymer;

[0013] The molar ratio of the carboxyl group of 3-phenyl-2-acrylic acid to the epoxy group in the epoxy acrylate prepolymer is 0.2:1.

[0014] Preferably, the preparation of the composite modified thermally conductive filler comprises the following steps:

[0015] Add ethanol to the reaction kettle, use acetic acid to adjust Ph to 4-6.5, then add coupling agent, aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, start stirring, control the speed to 60-90r / min, take out after stirring for 10-15min, rinse with ethanol and dry, and vacuum dry at 80-120°C for 20-40min to obtain a composite modified thermal conductive filler;

[0016] Wherein, the coupling agent is propyltrimethoxysilane or phenylsiloxane.

[0017] Preferably, the preparation method of the pre-blocked alkoxy ester siloxane-modified aluminum nitride comprises the following steps:

[0018] Add hydroxy silicone oil, vinyl trimethoxysilane and dimethylamine into a reaction kettle, turn on the stirrer, stir for 30 to 60 minutes, then heat to 80 to 120° C., and perform alkoxylation capping reaction for 2 to 4 hours under nitrogen protection to obtain alkoxy-capped polydimethylsiloxane;

[0019] Adding alkoxy-terminated polydimethylsiloxane into anhydrous toluene to dissolve it, thereby obtaining an alkoxy-terminated polydimethylsiloxane toluene solution;

[0020] Methylamine was added to the toluene solution of alkoxy-terminated polydimethylsiloxane, and after dissolving, it was dripped into the flask through a constant pressure dropping funnel, heated to 70-90°C for reaction for 2-5h, and then placed in a rotary evaporator, and evaporated for 1.5-3h at a pressure of -0.1MPa and a temperature of 55-70°C to obtain a blocked alkoxy ester siloxane;

[0021] Adding blocked alkoxy ester siloxane to the ethanol solution at a molar ratio of 1:3 to obtain a blocked alkoxy ester siloxane ethanol solution;

[0022] Aluminum nitride is dispersed in ethanol, and subjected to a hydrolysis reaction with a silane coupling agent for 4 to 5 hours to obtain a hydrophobically modified aluminum nitride solution, and then purified and dried to obtain hydrophobic aluminum nitride; wherein the silane coupling agent is γ-aminopropyltriethoxysilane or glycidoxytrimethoxysilane;

[0023] According to the mass ratio (200-300):1, the hydrophobic aluminum nitride and the blocked alkoxy ester siloxane ethanol solution are added to a stirring device, stirred for 1-2 hours at a temperature of 100-110°C and a rotation speed of 800-1000r / min, then taken out and placed in a 60-90°C oven for drying for 2-3 hours to obtain pre-blocked alkoxy ester siloxane-modified aluminum nitride.

[0024] Preferably, the preparation method of the modified nano-alumina comprises the following steps:

[0025] The nano-alumina is dispersed in ethanol, and a maleic anhydride grafting compatibilizer is added, followed by purification and drying to obtain modified nano-alumina.

[0026] Preferably, the modified chloroprene rubber is a modified chloroprene rubber in which hydroxyethyl cellulose is grafted into molecular groups and has hydrophilic and lipophilic properties.

[0027] Preferably, the epoxy curing agent is at least one of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and bismaleimide.

[0028] Preferably, the photoinitiator is at least one of 1-hydroxy-cyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide and benzophenone.

[0029] Preferably, the defoamer is a siloxane-modified defoamer;

[0030] Preferably, the leveling agent is a silicone leveling agent or an acrylic leveling agent.

[0031] Preferably, the antioxidant is at least one of a hindered amine antioxidant, a hindered phenol antioxidant, and a thioester.

[0032] Preferably, the crosslinking agent is tripropylene glycol diacrylate or 1,6-hexanediol diacrylate.

[0033] Preferably, the adhesion regulator is ethylene glycol diglycidyl ether or neopentyl glycol diglycidyl ether.

[0034] Preferably, the catalyst is at least one of bismuth laurate, dibutyltin dilaurate, and zinc neodecanoate.

[0035] Preferably, the chain extender is at least one of 1,3-butanediol, ethylenediamine and triethanolamine.

[0036] Preferably, the flame retardant is at least one of diethyl ethyl phosphate, isopropylated triphenyl phosphate and triphenyl phosphate.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The aluminum substrate of the present invention is composed of an aluminum plate, a thermal conductive light-curing setting glue and a copper foil. The copper foil is bonded to the aluminum plate by the thermal conductive light-curing setting glue coated on the surface thereof. It can be bent arbitrarily before light-curing and setting, which can meet the diversified shapes and all-round lighting needs of LED lamps. After bending, it can be irradiated with UV ultraviolet light to achieve light-curing and setting, and unnecessary deformation will not occur, which is convenient for the processing, production and use of the special aluminum substrate.

[0039] 2. The thermally conductive light-curing setting adhesive of the present invention is a secondary curing thermally conductive adhesive, which can be semi-cured under preset temperature curing conditions, and can have strong adhesion with aluminum plates and copper foils, avoiding the problem of reduced adhesion between the aluminum plates and copper foils due to too low epoxy content. Afterwards, it can be cured by ultraviolet rays at room temperature to form a fully cured thermally conductive layer with very high hardness, avoiding unnecessary deformation of the aluminum substrate.

[0040] 3. The epoxy curing agent of the present invention can carry out a heat-curing cross-linking reaction on the modified epoxy acrylate prepolymer, the modified chloroprene rubber and the pentaerythritol triacrylate, and then under the irradiation of UV ultraviolet light, the modified epoxy acrylate prepolymer and the pentaerythritol triacrylate are initiated by the photoinitiator to carry out free radical polymerization to complete the photocuring cross-linking reaction.

[0041] 4. The present invention mixes epoxy acrylate prepolymer and silica sol, stirs them, and adds 3-phenyl-2-acrylic acid to carry out esterification reaction to obtain modified epoxy acrylate prepolymer. Silica sol can make the modified epoxy acrylate prepolymer have good water resistance, mechanical properties, weather resistance, and aging resistance, and can improve the thermal conductivity of the modified epoxy acrylate prepolymer. The modified epoxy acrylate prepolymer has the characteristics of good photosensitivity and high bonding strength. In addition, 3-phenyl-2-acrylic acid can realize cinnamic acid modification of epoxy acrylate prepolymer, and the molar ratio of carboxyl group in 3-phenyl-2-acrylic acid to epoxy group in epoxy acrylate prepolymer is controlled at 0.2:1, so that the epoxy group in the heat-conductive light-curing setting glue can have a strong bonding force with the aluminum plate and copper foil.

[0042] 5. The modified epoxy acrylate prepolymer and pentaerythritol triacrylate of the present invention can be wrapped around the outside of the composite modified thermal conductive filler to buffer the external force, thereby enhancing the strength and toughness of the thermal conductive light-curing setting adhesive.

[0043] 6. The composite modified thermal conductive filler of the present invention comprises aluminum nitride and modified nano-alumina modified by pre-sealed alkoxy ester siloxane, and the aluminum nitride and modified nano-alumina modified by pre-sealed alkoxy ester siloxane are both subjected to hydrophobic treatment, so that the compatibility of the composite modified thermal conductive filler with the thermal conductive light-curing setting glue can be improved. The aluminum nitride and modified nano-alumina modified by pre-sealed alkoxy ester siloxane have good dispersibility in the thermal conductive light-curing setting glue, which can avoid the separation and sedimentation of the filler in the colloid, and it can form a three-dimensional network thermal conductive path in the system, which can improve the thermal conductive effect, and can achieve high thermal conductivity by filling a thermal conductive filler with less mass. In addition, the aluminum nitride and modified nano-alumina modified by pre-sealed alkoxy ester siloxane have good properties such as good temperature resistance and low thermal expansion coefficient.

[0044] 7. The modified chloroprene rubber of the present invention can improve the flexibility, crack resistance and tensile strength of the thermal conductive light-curing setting adhesive. After being grafted with hydroxyethyl cellulose, the hydrophilicity and lipophilicity of the chloroprene rubber can be improved, thereby improving the hydrophilicity and bonding strength of the thermal conductive light-curing setting adhesive.

[0045] 8. The viscosity modifier of the present invention can undergo a cross-linking reaction with the curing agent, resulting in a more uniform and dense cross-linked network structure.

[0046] 9. The present invention uses a chain extender to significantly improve the peel strength of the thermal light-curing setting adhesive.

[0047] 10. The present invention uses antioxidants and flame retardants, and has better antioxidant and flame retardant properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 It is a schematic diagram of the structure of an aluminum substrate that can be photocured and shaped after bending, provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] Please refer to Figure 1 An embodiment of the present invention provides an aluminum substrate that can be photocured after bending, including an aluminum plate 1, a thermally conductive photocurable adhesive 2 and a copper foil 3. The aluminum plate 1 is bonded to the copper foil 3 through the thermally conductive photocurable adhesive 2 coated on the surface of the aluminum plate 1.

[0052] In specific implementation, the aluminum plate 1 can be preferably an O-state aluminum plate, which has better flexibility. The copper foil 3 can be preferably a rolled copper foil, which has better conductivity and high ductility, and further improves the overall flexibility, good flexibility and long service life in meeting the purpose of conductivity.

[0053] The preparation method of the aluminum substrate is as follows:

[0054] (1) Prepare aluminum plate and copper foil;

[0055] (2) preparing a thermally conductive light-curing setting adhesive;

[0056] (3) evenly coating a thermally conductive light-curing adhesive on one surface of the aluminum plate to form a thermally conductive adhesive layer, and then baking the thermally conductive adhesive layer at a temperature of 60 to 110° C.;

[0057] (4) The copper foil is laminated and pressed onto the thermal conductive adhesive layer by a laminating machine, and then baked at a temperature of 80 to 120° C. to obtain an aluminum substrate.

[0058] The use of aluminum substrate is as follows:

[0059] After the aluminum substrate is bent arbitrarily, it is irradiated with a UV lamp (wavelength 300-400nm) for 5-30s to initiate the curing of the thermal light-curing setting adhesive, thereby completing the setting of the aluminum substrate.

[0060] The preparation example of the thermal light curing setting glue is as follows:

[0061] Example 1

[0062] The thermal conductive light-curing setting glue can be composed of the following raw materials in percentage by mass: 20% of modified epoxy acrylate prepolymer; 10% of modified chloroprene rubber; 14% of pentaerythritol triacrylate; 25% of epoxy curing agent; 10% of composite modified thermal conductive filler; 4% of photoinitiator; 1% of defoaming agent; 1% of leveling agent; 4% of antioxidant; 3% of cross-linking agent; 3% of viscosity regulator; 2% of catalyst; 1% of chain extender; and 2% of flame retardant.

[0063] The preparation method of the thermal light-curing setting glue comprises the following steps:

[0064] According to the preset mass percentage, modified epoxy acrylate prepolymer, modified chloroprene rubber, pentaerythritol triacrylate, defoamer, leveling agent, antioxidant, crosslinker, viscosity regulator, catalyst, chain extender and flame retardant are respectively added to the reactor, the agitator is turned on, and the mixture is stirred for 1 hour at 30°C. The composite modified thermal conductive filler is added and stirred for 0.5 hour. The epoxy curing agent is added and stirred for 0.5 hour. The photoinitiator is added and the mixture is vacuumed to -0.1 MPa. The mixture is stirred at the pressure for 1 hour. The thermal conductive light-curing setting glue is obtained by vacuum defoaming and discharging.

[0065] The preparation method of the modified epoxy acrylate prepolymer comprises the following steps:

[0066] Under the condition of nitrogen, the epoxy glycerol ester is heated to 65°C, and then the fluorinated acrylate is added dropwise, and then the temperature is raised to 100°C, cooled to room temperature and discharged to obtain epoxy acrylate prepolymer;

[0067] The epoxy acrylate prepolymer and the silica sol are mixed and stirred, and after being stirred evenly, 3-phenyl-2-acrylic acid is added to carry out an esterification reaction to obtain a modified epoxy acrylate prepolymer;

[0068] The molar ratio of the carboxyl group of 3-phenyl-2-acrylic acid to the epoxy group in the epoxy acrylate prepolymer is 0.2:1.

[0069] The composite modified thermal conductive filler includes aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, and the mass ratio of the aluminum nitride modified by pre-sealed alkoxy ester siloxane to the modified nano-alumina is 1:2;

[0070] The preparation of the composite modified thermal conductive filler comprises the following steps:

[0071] Add ethanol to the reaction kettle, use acetic acid to adjust Ph to 5, then add coupling agent, aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, start stirring, control the speed to 60r / min, take out after stirring for 10 minutes, rinse with ethanol and dry, and vacuum dry at 80°C for 20 minutes to obtain a composite modified thermal conductive filler;

[0072] Wherein, the coupling agent is propyltrimethoxysilane or phenylsiloxane.

[0073] The method for preparing pre-blocked alkoxy ester siloxane-modified aluminum nitride comprises the following steps:

[0074] Add hydroxy silicone oil, vinyl trimethoxysilane and dimethylamine into the reaction kettle, turn on the stirrer, stir for 30 minutes, then heat to 80°C, and carry out alkoxylation capping reaction for 2 hours under nitrogen protection to obtain alkoxy-capped polydimethylsiloxane;

[0075] Adding alkoxy-terminated polydimethylsiloxane into anhydrous toluene to dissolve it, thereby obtaining an alkoxy-terminated polydimethylsiloxane toluene solution;

[0076] Methylamine was added to the toluene solution of alkoxy-terminated polydimethylsiloxane, and after dissolving, it was dripped into the flask through a constant pressure dropping funnel, heated to 70°C for reaction for 2 hours, and then placed in a rotary evaporator, evaporated for 1.5 hours at a pressure of -0.1 MPa and a temperature of 55°C to obtain a blocked alkoxy ester siloxane;

[0077] Adding blocked alkoxy ester siloxane to the ethanol solution at a molar ratio of 1:3 to obtain a blocked alkoxy ester siloxane ethanol solution;

[0078] Aluminum nitride is dispersed in ethanol, and subjected to a hydrolysis reaction with a silane coupling agent for 4 hours to obtain a hydrophobic aluminum nitride solution, which is then purified and dried to obtain hydrophobic aluminum nitride; wherein the silane coupling agent is γ-aminopropyltriethoxysilane or glycidoxytrimethoxysilane;

[0079] Hydrophobic aluminum nitride and blocked alkoxy ester siloxane ethanol solution were added to a stirring device at a mass ratio of 200:1, stirred for 1 hour at a temperature of 100°C and a rotation speed of 800 r / min, then taken out and placed in a 60°C oven for drying for 3 hours to obtain pre-blocked alkoxy ester siloxane-modified aluminum nitride.

[0080] The preparation method of modified nano-alumina comprises the following steps:

[0081] The nano-alumina is dispersed in ethanol, and a maleic anhydride grafting compatibilizer is added, followed by purification and drying to obtain modified nano-alumina.

[0082] In this embodiment, the epoxy curing agent is methyl hexahydrophthalic anhydride. The photoinitiator is 1-hydroxy-cyclohexyl phenone. The defoamer is a siloxane-modified defoamer. The leveling agent is an organic silicone leveling agent. The antioxidant is a hindered phenol antioxidant. The crosslinking agent is tripropylene glycol dipropylene glycol. The adhesive regulator is ethylene glycol diglycidyl ether. The catalyst is bismuth neodecanoate; the chain extender is 1,3-butanediol. The flame retardant is diethyl ethyl phosphate.

[0083] Example 2

[0084] The thermal conductive light-curing setting glue can be composed of the following raw materials in percentage by mass: 30% of modified epoxy acrylate prepolymer; 10% of modified chloroprene rubber; 10% of pentaerythritol triacrylate; 29% of epoxy curing agent; 10% of composite modified thermal conductive filler; 5% of photoinitiator; 1% of defoaming agent; 0.5% of leveling agent; 1% of antioxidant; 1% of cross-linking agent; 1% of viscosity regulator; 0.5% of catalyst; 0.5% of chain extender; and 0.5% of flame retardant.

[0085] The preparation method of the thermal light-curing setting glue comprises the following steps:

[0086] According to the preset mass percentage, modified epoxy acrylate prepolymer, modified chloroprene rubber, pentaerythritol triacrylate, defoamer, leveling agent, antioxidant, crosslinker, viscosity regulator, catalyst, chain extender and flame retardant are respectively added to the reaction kettle, the agitator is turned on, and the mixture is stirred for 1 hour at a temperature of 30°C. The composite modified thermal conductive filler is added and stirred for 0.5 hour. The epoxy curing agent is added and stirred for 0.6 hour. The photoinitiator is added, and the mixture is vacuumed to -0.1MPa and stirred at the pressure for 1.5 hours. The mixture is then defoamed and discharged by vacuum to obtain the thermal conductive light-curing setting glue.

[0087] The preparation method of the modified epoxy acrylate prepolymer comprises the following steps:

[0088] Under the condition of nitrogen, the epoxy glycerol ester is heated to 65°C, and then the fluorinated acrylate is added dropwise, and then the temperature is raised to 110°C, cooled to room temperature and discharged to obtain the epoxy acrylate prepolymer;

[0089] The epoxy acrylate prepolymer and the silica sol are mixed and stirred, and after being stirred evenly, 3-phenyl-2-acrylic acid is added to carry out an esterification reaction to obtain a modified epoxy acrylate prepolymer;

[0090] The molar ratio of the carboxyl group of 3-phenyl-2-acrylic acid to the epoxy group in the epoxy acrylate prepolymer is 0.2:1.

[0091] The composite modified thermal conductive filler includes aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, and the mass ratio of the aluminum nitride modified by pre-sealed alkoxy ester siloxane to the modified nano-alumina is 1:3;

[0092] The preparation of the composite modified thermal conductive filler comprises the following steps:

[0093] Add ethanol to the reaction kettle, use acetic acid to adjust Ph to 5, then add coupling agent, aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, start stirring, control the speed to 70r / min, take out after stirring for 10 minutes, rinse with ethanol and dry, and vacuum dry at 100°C for 30 minutes to obtain a composite modified thermal conductive filler;

[0094] Wherein, the coupling agent is propyltrimethoxysilane or phenylsiloxane.

[0095] The method for preparing pre-blocked alkoxy ester siloxane-modified aluminum nitride comprises the following steps:

[0096] Add hydroxy silicone oil, vinyl trimethoxysilane and dimethylamine into the reaction kettle, turn on the stirrer, stir for 40 minutes, then heat to 100°C, and carry out alkoxylation capping reaction for 3 hours under nitrogen protection to obtain alkoxy-capped polydimethylsiloxane;

[0097] Adding alkoxy-terminated polydimethylsiloxane into anhydrous toluene to dissolve it, thereby obtaining an alkoxy-terminated polydimethylsiloxane toluene solution;

[0098] Methylamine was added to the toluene solution of alkoxy-terminated polydimethylsiloxane, and after dissolving, it was dripped into the flask through a constant pressure dropping funnel, heated to 80°C for reaction for 3 hours, and then placed in a rotary evaporator, evaporated for 2 hours at a pressure of -0.1 MPa and a temperature of 60°C to obtain a blocked alkoxy ester siloxane;

[0099] Adding blocked alkoxy ester siloxane to the ethanol solution at a molar ratio of 1:3 to obtain a blocked alkoxy ester siloxane ethanol solution;

[0100] Aluminum nitride is dispersed in ethanol, and subjected to a hydrolysis reaction with a silane coupling agent for 4.5 hours to obtain a hydrophobic aluminum nitride solution, which is then purified and dried to obtain hydrophobic aluminum nitride; wherein the silane coupling agent is γ-aminopropyltriethoxysilane or glycidoxytrimethoxysilane;

[0101] At a mass ratio of 250:1, hydrophobic aluminum nitride and blocked alkoxy ester siloxane ethanol solution were added to a stirring device, stirred for 1.5 hours at a temperature of 110°C and a rotation speed of 900 r / min, then taken out and placed in a 70°C oven for drying for 2.5 hours to obtain pre-blocked alkoxy ester siloxane-modified aluminum nitride.

[0102] The preparation method of modified nano-alumina comprises the following steps:

[0103] The nano-alumina is dispersed in ethanol, and a maleic anhydride grafting compatibilizer is added, followed by purification and drying to obtain modified nano-alumina.

[0104] In this embodiment, the epoxy curing agent is methyltetrahydrophthalic anhydride. The photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide. The defoamer is a siloxane-modified defoamer. The leveling agent is an acrylate leveling agent. The antioxidant is a hindered amine antioxidant. The crosslinking agent is 1,6-hexanediol diacrylate. The adhesive regulator is neopentyl glycol diglycidyl ether. The catalyst is bismuth laurate. The chain extender is ethylenediamine; and the flame retardant is isopropylated triphenyl phosphate.

[0105] Example 3

[0106] The thermal conductive light-curing setting glue can be composed of the following raw materials in percentage by mass: 25% of modified epoxy acrylate prepolymer; 15% of modified chloroprene rubber; 10% of pentaerythritol triacrylate; 25% of epoxy curing agent; 12% of composite modified thermal conductive filler; 4% of photoinitiator; 2% of defoaming agent; 1% of leveling agent; 1% of antioxidant; 1% of cross-linking agent; 2% of viscosity regulator; 1% of catalyst; 0.5% of chain extender; and 0.5% of flame retardant.

[0107] The preparation method of the thermal light-curing setting glue comprises the following steps:

[0108] According to the preset mass percentage, modified epoxy acrylate prepolymer, modified chloroprene rubber, pentaerythritol triacrylate, defoamer, leveling agent, antioxidant, crosslinker, viscosity regulator, catalyst, chain extender and flame retardant are respectively added to the reactor, the agitator is turned on, and the mixture is stirred for 1.5 hours at 40°C. The composite modified thermal conductive filler is added and stirred for 0.5 hours. The epoxy curing agent is added and stirred for 1 hour. The photoinitiator is added, and the mixture is vacuumed to -0.1MPa and stirred at the pressure for 2 hours. The mixture is then defoamed and discharged by vacuum to obtain a thermally conductive light-curing setting glue.

[0109] The preparation method of the modified epoxy acrylate prepolymer comprises the following steps:

[0110] Under the condition of nitrogen, the epoxy glycerol ester is heated to 70°C, and then the fluorinated acrylate is added dropwise, and then the temperature is raised to 120°C, cooled to room temperature and discharged to obtain the epoxy acrylate prepolymer;

[0111] The epoxy acrylate prepolymer and the silica sol are mixed and stirred, and after being stirred evenly, 3-phenyl-2-acrylic acid is added to carry out an esterification reaction to obtain a modified epoxy acrylate prepolymer;

[0112] The molar ratio of the carboxyl group of 3-phenyl-2-acrylic acid to the epoxy group in the epoxy acrylate prepolymer is 0.2:1.

[0113] The composite modified thermal conductive filler includes aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, and the mass ratio of the aluminum nitride modified by pre-sealed alkoxy ester siloxane to the modified nano-alumina is 1:4;

[0114] The preparation of the composite modified thermal conductive filler comprises the following steps:

[0115] Add ethanol to the reaction kettle, use acetic acid to adjust Ph to 6.5, then add coupling agent, aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, start stirring, control the speed to 90r / min, take out after stirring for 10 minutes, rinse with ethanol and dry, and vacuum dry at 120°C for 40 minutes to obtain a composite modified thermal conductive filler;

[0116] Wherein, the coupling agent is propyltrimethoxysilane or phenylsiloxane.

[0117] The method for preparing pre-blocked alkoxy ester siloxane-modified aluminum nitride comprises the following steps:

[0118] Add hydroxy silicone oil, vinyl trimethoxysilane and dimethylamine into the reaction kettle, turn on the stirrer, stir for 60 minutes, then heat to 120°C, and carry out alkoxylation capping reaction for 4 hours under nitrogen protection to obtain alkoxy-capped polydimethylsiloxane;

[0119] Adding alkoxy-terminated polydimethylsiloxane into anhydrous toluene to dissolve it, thereby obtaining an alkoxy-terminated polydimethylsiloxane toluene solution;

[0120] Methylamine was added to the toluene solution of alkoxy-terminated polydimethylsiloxane, and after dissolving, it was dripped into the flask through a constant pressure dropping funnel, heated to 90°C for reaction for 5 hours, and then placed in a rotary evaporator, evaporated for 3 hours at a pressure of -0.1MPa and a temperature of 70°C to obtain a blocked alkoxy ester siloxane;

[0121] Adding blocked alkoxy ester siloxane to the ethanol solution at a molar ratio of 1:3 to obtain a blocked alkoxy ester siloxane ethanol solution;

[0122] Aluminum nitride is dispersed in ethanol, and subjected to a hydrolysis reaction with a silane coupling agent for 5 hours to obtain a hydrophobically modified aluminum nitride solution, and then purified and dried to obtain hydrophobic aluminum nitride; wherein the silane coupling agent is γ-aminopropyltriethoxysilane or glycidoxytrimethoxysilane;

[0123] Hydrophobic aluminum nitride and blocked alkoxy ester siloxane ethanol solution were added to a stirring device at a mass ratio of 300:1, stirred for 2 hours at a temperature of 110°C and a rotation speed of 1000 r / min, then taken out and placed in a 90°C oven for drying for 3 hours to obtain pre-blocked alkoxy ester siloxane-modified aluminum nitride.

[0124] The preparation method of modified nano-alumina comprises the following steps:

[0125] The nano-alumina is dispersed in ethanol, and a maleic anhydride grafting compatibilizer is added, followed by purification and drying to obtain modified nano-alumina.

[0126] In this embodiment, the epoxy curing agent is bismaleimide. The photoinitiator is benzophenone. The defoamer is a siloxane-modified defoamer. The leveling agent is an organosilicon leveling agent. The antioxidant is a thioester. The crosslinking agent is 1,6-hexanediol diacrylate. The adhesive regulator is neopentyl glycol diglycidyl ether. The catalyst is dibutyltin dilaurate. The chain extender is triethanolamine. The flame retardant is triphenyl phosphate.

[0127] Example 4

[0128] The thermal conductive light-curing setting glue can be composed of the following raw materials in percentage by mass: 20% of modified epoxy acrylate prepolymer; 10% of modified chloroprene rubber; 10% of pentaerythritol triacrylate; 30% of epoxy curing agent; 20% of composite modified thermal conductive filler; 4% of photoinitiator; 1% of defoaming agent; 0.5% of leveling agent; 1% of antioxidant; 1% of cross-linking agent; 1% of viscosity regulator; 0.5% of catalyst; 0.5% of chain extender; and 0.5% of flame retardant.

[0129] The preparation method of the thermal light-curing setting glue comprises the following steps:

[0130] According to the preset mass percentage, modified epoxy acrylate prepolymer, modified chloroprene rubber, pentaerythritol triacrylate, defoamer, leveling agent, antioxidant, crosslinker, viscosity regulator, catalyst, chain extender and flame retardant are respectively added to the reaction kettle, the agitator is turned on, and the mixture is stirred for 1 hour at 40°C. The composite modified thermal conductive filler is added and stirred for 1 hour. The epoxy curing agent is added and stirred for 1 hour. The photoinitiator is added and the mixture is vacuumed to -0.1MPa and stirred at the pressure for 1 hour. The mixture is then defoamed and discharged by vacuum to obtain a thermal conductive light-curing setting glue.

[0131] The preparation method of the modified epoxy acrylate prepolymer comprises the following steps:

[0132] Under the condition of nitrogen, the epoxy glycerol ester is heated to 70°C, and then the fluorinated acrylate is added dropwise, and then the temperature is raised to 120°C, cooled to room temperature and discharged to obtain the epoxy acrylate prepolymer;

[0133] The epoxy acrylate prepolymer and the silica sol are mixed and stirred, and after being stirred evenly, 3-phenyl-2-acrylic acid is added to carry out an esterification reaction to obtain a modified epoxy acrylate prepolymer;

[0134] The molar ratio of the carboxyl group of 3-phenyl-2-acrylic acid to the epoxy group in the epoxy acrylate prepolymer is 0.2:1.

[0135] The composite modified thermal conductive filler includes aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, and the mass ratio of the aluminum nitride modified by pre-sealed alkoxy ester siloxane to the modified nano-alumina is 1:3;

[0136] The preparation of the composite modified thermal conductive filler comprises the following steps:

[0137] Add ethanol to the reaction kettle, use acetic acid to adjust Ph to 6.5, then add coupling agent, aluminum nitride modified by pre-sealed alkoxy ester siloxane and modified nano-alumina, start stirring, control the speed to 90r / min, take out after stirring for 10 minutes, rinse with ethanol and dry, and vacuum dry at 100°C for 20 minutes to obtain a composite modified thermal conductive filler;

[0138] Wherein, the coupling agent is propyltrimethoxysilane or phenylsiloxane.

[0139] The method for preparing pre-blocked alkoxy ester siloxane-modified aluminum nitride comprises the following steps:

[0140] Add hydroxy silicone oil, vinyl trimethoxysilane and dimethylamine into the reaction kettle, turn on the stirrer, stir for 30 minutes, then heat to 120°C, and carry out alkoxylation capping reaction for 2 hours under nitrogen protection to obtain alkoxy-capped polydimethylsiloxane;

[0141] Adding alkoxy-terminated polydimethylsiloxane into anhydrous toluene to dissolve it, thereby obtaining an alkoxy-terminated polydimethylsiloxane toluene solution;

[0142] Methylamine was added to the toluene solution of alkoxy-terminated polydimethylsiloxane, and after dissolving, it was dripped into the flask through a constant pressure dropping funnel, heated to 90°C for reaction for 2h, and then placed in a rotary evaporator, evaporated for 2h at a pressure of -0.1MPa and a temperature of 70°C to obtain a blocked alkoxy ester siloxane;

[0143] Adding blocked alkoxy ester siloxane to the ethanol solution at a molar ratio of 1:3 to obtain a blocked alkoxy ester siloxane ethanol solution;

[0144] Aluminum nitride is dispersed in ethanol, and subjected to a hydrolysis reaction with a silane coupling agent for 4 hours to obtain a hydrophobic aluminum nitride solution, which is then purified and dried to obtain hydrophobic aluminum nitride; wherein the silane coupling agent is γ-aminopropyltriethoxysilane or glycidoxytrimethoxysilane;

[0145] Hydrophobic aluminum nitride and blocked alkoxy ester siloxane ethanol solution were added to a stirring device at a mass ratio of 200:1, stirred for 1 hour at a temperature of 110°C and a rotation speed of 1000 r / min, then taken out and placed in a 60°C oven for drying for 2 hours to obtain pre-blocked alkoxy ester siloxane-modified aluminum nitride.

[0146] The preparation method of modified nano-alumina comprises the following steps:

[0147] The nano-alumina is dispersed in ethanol, and a maleic anhydride grafting compatibilizer is added, followed by purification and drying to obtain modified nano-alumina.

[0148] In this embodiment, the epoxy curing agent is methyl hexahydrophthalic anhydride. The photoinitiator is benzophenone. The defoamer is a siloxane-modified defoamer. The leveling agent is an acrylate leveling agent. The antioxidant is thioester. The crosslinking agent is tripropylene glycol dipropylene glycol. The adhesive regulator is ethylene glycol diglycidyl ether. The catalyst is zinc neodecanoate. The chain extender is triethanolamine. The flame retardant is diethyl ethyl phosphate.

[0149] The thermal light-curing adhesives of Examples 1 to 4 and the aluminum substrate with the thermal light-curing adhesive were subjected to relevant performance tests. The test table is as follows:

[0150]

[0151] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An aluminum substrate that can be photocured after bending, comprising an aluminum plate and a copper foil, characterized in that: The aluminum plate is bonded to the copper foil via a heat-conducting light-curing adhesive coated on its surface. The heat-conducting light-curing adhesive is composed of the following raw materials in percentage by mass: The composite modified thermal conductive filler comprises aluminum nitride modified with pre-sealed alkoxy ester siloxane and modified nano-alumina, wherein the mass ratio of the aluminum nitride modified with pre-sealed alkoxy ester siloxane to the modified nano-alumina is 1:(2-4); The preparation method of the thermal conductive light curing setting glue comprises the following steps: According to the preset mass percentage, the modified epoxy acrylate prepolymer, modified chloroprene rubber, pentaerythritol triacrylate, defoamer, leveling agent, antioxidant, crosslinking agent, viscosity modifier, catalyst, chain extender, and flame retardant are respectively added to the reaction kettle, the stirrer is turned on, and the mixture is stirred at a temperature of 25 to 40° C. for 0.5 to 2 hours, the composite modified thermal conductive filler is added, and the mixture is stirred for 0.5 to 1 hour, the epoxy curing agent is added, and the mixture is stirred for 0.5 to 1 hour, the photoinitiator is added, the mixture is vacuumed to -0.1 MPa, and the pressure is maintained and stirred for 1 to 2 hours, and then the mixture is vacuum defoamed and discharged to obtain the thermal conductive light-curing setting adhesive; The preparation method of the modified epoxy acrylate prepolymer comprises the following steps: Under nitrogen flow, the epoxy glycerol ester is heated to 65-70°C, and then the fluorinated acrylate is added dropwise, and then the temperature is raised to 100-120°C, cooled to room temperature, and discharged to obtain an epoxy acrylate prepolymer; The epoxy acrylate prepolymer and the silica sol are mixed and stirred, and after stirring evenly, 3-phenyl-2-acrylic acid is added to carry out an esterification reaction to obtain a modified epoxy acrylate prepolymer; The molar ratio of the carboxyl group of 3-phenyl-2-propenoic acid to the epoxy group in the epoxy acrylate prepolymer is 0.2:1; The preparation of the composite modified thermally conductive filler comprises the following steps: Add ethanol to the reaction kettle, use acetic acid to adjust the pH to 4-6.5, then add a coupling agent, pre-blocked alkoxy ester siloxane-modified aluminum nitride and modified nano-alumina, start stirring, control the speed to 60-90 r / min, stir for 10-15 minutes, take out, rinse with ethanol, dry, and vacuum dry at 80-120° C. for 20-40 minutes to obtain a composite modified thermal conductive filler; Wherein, the coupling agent is propyltrimethoxysilane or phenylsiloxane; The preparation method of the pre-blocked alkoxy ester siloxane-modified aluminum nitride comprises the following steps: Add hydroxy silicone oil, vinyltrimethoxysilane and dimethylamine to the reaction kettle, start the stirrer, stir for 30 to 60 minutes, then heat to 80 to 120° C., and carry out alkoxylation capping reaction under nitrogen protection for 2 to 4 hours to obtain alkoxy-terminated polydimethylsiloxane; adding alkoxy-terminated polydimethylsiloxane into anhydrous toluene to dissolve it, thereby obtaining an alkoxy-terminated polydimethylsiloxane toluene solution; Methylamine was added to the toluene solution of alkoxy-terminated polydimethylsiloxane, and after dissolving, it was added dropwise to the flask through a constant pressure dropping funnel, and the temperature was raised to 70-90°C for reaction for 2-5 hours. Then, the solution was placed in a rotary evaporator and evaporated at a pressure of -0.1 MPa and a temperature of 55-70°C for 1.5-3 hours to obtain blocked alkoxy ester siloxane; Adding blocked alkoxy ester siloxane to the ethanol solution at a molar ratio of 1:3 to obtain a blocked alkoxy ester siloxane ethanol solution; Aluminum nitride is dispersed in ethanol and subjected to a hydrolysis reaction with a silane coupling agent for 4 to 5 hours to obtain a hydrophobically modified aluminum nitride solution, which is then purified and dried to obtain hydrophobic aluminum nitride; wherein the silane coupling agent is γ-aminopropyltriethoxysilane or glycidoxytrimethoxysilane; The hydrophobic aluminum nitride and the blocked alkoxy ester siloxane ethanol solution were added to a stirring device in a mass ratio of (200-300):1, stirred at a temperature of 100-110°C and a rotation speed of 800-1000 r / min for 1-2 hours, then taken out and placed in a 60-90°C oven for drying for 2-3 hours to obtain pre-blocked alkoxy ester siloxane-modified aluminum nitride.

2. The aluminum substrate capable of being photocured and shaped after being bent according to claim 1, characterized in that: The preparation method of the modified nano-alumina comprises the following steps: The nano-alumina is dispersed in ethanol, and a maleic anhydride grafting compatibilizer is added, followed by purification and drying to obtain modified nano-alumina.

3. The aluminum substrate capable of being photocured and shaped after being bent according to claim 1, characterized in that: The epoxy curing agent is at least one of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and bismaleimide; The photoinitiator is at least one of 1-hydroxy-cyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and benzophenone.

4. The aluminum substrate capable of being photocured and shaped after being bent according to claim 1, wherein: The modified chloroprene rubber is a modified chloroprene rubber in which hydroxyethyl cellulose is grafted into molecular groups and has hydrophilic and lipophilic properties.

5. The aluminum substrate capable of being photocured and shaped after being bent according to claim 1, characterized in that: The defoaming agent is a silicone modified defoaming agent; The leveling agent is an organic silicon leveling agent or an acrylic leveling agent; The antioxidant is at least one of a hindered amine antioxidant, a hindered phenol antioxidant, and a thioester; The cross-linking agent is tripropylene glycol diacrylate or 1,6-hexanediol diacrylate; The viscosity modifier is ethylene glycol diglycidyl ether or neopentyl glycol diglycidyl ether.

6. The aluminum substrate capable of being photocured and shaped after being bent according to claim 1, characterized in that: The catalyst is at least one of bismuth laurate, dibutyltin dilaurate, and zinc neodecanoate; The chain extender is at least one of 1,3-butanediol, ethylenediamine, and triethanolamine; The flame retardant is at least one of diethyl ethyl phosphate, isopropylated triphenyl phosphate, and triphenyl phosphate.

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