阅读说明：本技术 有机硅树脂及其制备方法、有机硅导电胶组合物及有机硅导电胶 (Organic silicon resin and preparation method thereof, organic silicon conductive adhesive composition and organic silicon conductive adhesive ) 是由 易骆新 孙应发 陈永全 于 2021-09-13 设计创作，主要内容包括：本发明提供了一种有机硅树脂及其制备方法、有机硅导电胶组合物及有机硅导电胶。该有机硅树脂具有式I所示结构：其中,200≤n≤500。具有本申请结构式的有机硅树脂以硅烷偶联剂进行封端,一方面提高了该有机硅树脂的存储稳定性,另一方面在有机硅树脂的两端包含有碳碳双键,其可以通过自由基引发聚合反应,从而包括该有机硅树脂的有机硅导电胶可以实现在低温下的快速固化。同时,在有机硅树脂的侧链官能团的协同作用下进一步地延长了有机硅导电胶的可操作时间,降低了玻璃化转变温度,柔韧性好、韧性强且耐老化,不易开裂变硬变脆,能与铝、银或铜等材质能够很好的兼容和粘接。(The invention provides an organic silicon resin and a preparation method thereof, an organic silicon conductive adhesive composition and an organic silicon conductive adhesive. The organic silicon resin has a structure shown in a formula I:)

1. A silicone resin, wherein the silicone resin has a structure according to formula I:

wherein n is more than or equal to 200 and less than or equal to 500.

2. The silicone resin according to claim 1, wherein the content of vinyl groups in the silicone resin is 0.1 to 0.2 wt%, the molecular weight of the silicone resin is 14000 to 38000, and the viscosity of the silicone resin is 900 to 3000 mPa-s.

3. The preparation method of the organic silicon resin is characterized by comprising the following steps of:

carrying out condensation reaction on 1000 parts of silica gel and 15-45 parts of KH570 silane coupling agent in 0.1-2 parts of alkaline solution to obtain an organic silicon resin system,

wherein, the silica gel has a structure shown in formula II:

wherein n is more than or equal to 200 and less than or equal to 500.

4. The preparation method according to claim 3, wherein the silica gel has a hydroxyl group content of 0.08 to 0.20 wt%, preferably the silica gel has a molecular weight of 14000 to 38000, and preferably the silica gel has a viscosity of 700 to 2500 mPa-s.

5. The method according to claim 3, wherein the alkaline solution is selected from Al (OH)₃Any one or more of methanol solution of potassium hydride, methanol solution of sodium hydroxide and methanol solution of lithium hydroxide,preferably, the Al (OH)₃Al (OH) in the methanol solution of (3)₃The mass concentration of (B) is 0.1-5 wt%.

6. The organic silicon conductive adhesive composition is characterized by comprising the following components in parts by weight:

45-55 parts of organic silicon resin;

35-45 parts of a reactive diluent;

1-3 parts of a free radical initiator;

350-450 parts of silver powder,

wherein the silicone resin is the silicone resin described in claim 1 or 2, or the silicone resin is the silicone resin obtained by the production method described in any one of claims 3 to 5.

7. The organosilicon conductive adhesive composition according to claim 6, wherein the radical initiator is an organic peroxide, preferably the organic peroxide is selected from any one or more of tert-butyl neodecanoate peroxide, cumyl neoheptanoate peroxide and diisobutyryl peroxide.

8. The silicone conductive adhesive composition according to claim 6 or 7, wherein the reactive diluent is a substituted or unsubstituted acrylate, preferably the reactive diluent is one of isobornyl acrylate, isobornyl methacrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

9. The silicone conductive adhesive composition according to any one of claims 6 to 8, further comprising:

0-7 parts of a silane coupling agent;

0-5 parts of an adhesion promoter;

0-2 parts of 1-3 wt% polymerization inhibitor solution;

0-1 part of 1-3.5 wt% chelating agent solution;

preferably, the silane coupling agent is gamma-aminopropyltriethoxysilane and/or gamma-glycidoxypropyltrimethoxysilane,

preferably, the adhesion promoter is monofunctional acrylate or multifunctional acrylate, further preferably, the adhesion promoter is one or more of monofunctional acrylate CD9050, trifunctional acrylate CD9051, trifunctional acrylate CD9052 and trifunctional acrylate CD9053,

the polymerization inhibitor solution comprises a first solvent and a first active substance, wherein the first solvent is preferably polyethylene glycol 200 dimethacrylate, the first active substance is preferably selected from any one or more of 1, 4-naphthoquinone, hydroquinone and hydroquinone,

the chelating agent solution comprises a second solvent and a second active substance, the second solvent is a mixed solvent of water and propylene glycol, the mass ratio of the water to the propylene glycol is preferably 1-3: 7-9, and the second active substance is preferably selected from any one or more of ethylene diamine tetraacetic acid, sodium ethylene diamine tetraacetic acid, potassium ethylene diamine tetraacetic acid, oxalic acid, sodium oxalate and potassium oxalate.

10. The organosilicon conductive adhesive is prepared by mixing an organosilicon conductive adhesive composition, and is characterized in that the organosilicon conductive adhesive composition is the organosilicon conductive adhesive composition of any one of claims 6 to 9.

Technical Field

The invention relates to the technical field of organic silicon conductive adhesives, and particularly relates to an organic silicon resin and a preparation method thereof, an organic silicon conductive adhesive composition and an organic silicon conductive adhesive.

Background

With the vigorous advocation of energy conservation and environmental protection in China, the demand of photovoltaic power generation is increasing, and in the field, the tile (sheet) stacking technology is taken as a representative of advanced technology, so that the power of the component can be greatly improved, and the photovoltaic power generation device is widely concerned at present. The tiling (sheet) technology is to cut the cell sheet specially designed for grid line into small pieces with reasonable patterns, to arrange each small piece in an overlapping way, to weld the small pieces into strings by using special conductive adhesive materials, to laminate into assemblies after series-parallel typesetting.

According to the traditional single-component conductive adhesive, conductive fillers are removed, and the remaining organic phases can be divided into three types: the organic phase is added with initiator, curing agent and catalyst, which can be stored in refrigerator, applied with glue at normal temperature and cured when heated. The acrylic acid type conductive adhesive adopts free radicals to initiate polymerization of carbon-carbon double bonds, can be rapidly cured at low temperature, has high strength, but has poor conductivity and insufficient toughness, and is easy to crack after aging. The epoxy conductive adhesive adopts a cross-linking agent to react with an epoxy group, has better conductivity and bonding strength, but has high curing temperature, slow speed and poor toughness. The organic silicon type conductive adhesive adopts an organic platinum compound to catalyze the double bond addition polymerization of organic silicon resin, has excellent conductivity and flexibility, has high curing speed at high temperature, but is unstable in freezing storage, short in operable time at normal temperature and low in bonding strength.

The conductive adhesive which is required at present has longer operable time (more than or equal to 3 days) at normal temperature, can be quickly cured at low temperature (less than 30 seconds at 110 ℃), has good adhesion (the shear strength is more than 3MPa) and good toughness (the glass transition temperature is lower than minus 50 ℃), and particularly needs to improve the photoelectric conversion rate on a solar photovoltaic laminated assembly, so that higher conductive performance (less than 1.0 multiplied by 10) is also needed^-3Ω · cm). However, the single-component conductive adhesive used in the photovoltaic solar industry cannot meet the requirements of the latest process at present.

Disclosure of Invention

The invention mainly aims to provide an organic silicon resin and a preparation method thereof, an organic silicon conductive adhesive composition and an organic silicon conductive adhesive, and aims to solve the problems of short operable time, high glass transition temperature, poor flexibility and poor aging resistance of the organic silicon conductive adhesive in the prior art.

In order to achieve the above object, according to one aspect of the present invention, there is provided a silicone resin having a structure represented by formula I:

wherein n is more than or equal to 200 and less than or equal to 500.

Further, the content of vinyl in the organic silicon resin is 0.1-0.2 wt%, the molecular weight of the organic silicon resin is 14000-38000, and the viscosity of the organic silicon resin is 900-3000 mPa & s.

According to another aspect of the present invention, there is provided a method for preparing a silicone resin, comprising the following steps: carrying out condensation reaction on 1000 parts of silica gel and 15-45 parts of KH570 silane coupling agent in 0.1-2 parts of alkaline solution to obtain an organic silicon resin system, wherein the silica gel has a structure shown in a formula II:

wherein n is more than or equal to 200 and less than or equal to 500.

Further, the content of hydroxyl groups in the silica gel is 0.08 to 0.20 wt%, the molecular weight of the silica gel is preferably 14000 to 38000, and the viscosity of the silica gel is preferably 700 to 2500mPa · s.

Further, the alkaline solution is selected from Al (OH)₃Preferably Al (OH), potassium hydride, sodium hydroxide, or lithium hydroxide, preferably₃Al (OH) in the methanol solution of (3)₃The mass concentration of (B) is 0.1-5 wt%.

According to another aspect of the invention, the organic silicon conductive adhesive composition comprises, by weight, 45-55 parts of an organic silicon resin, 35-45 parts of a reactive diluent, 1-3 parts of a radical initiator, and 350-450 parts of silver powder, wherein the organic silicon resin is the organic silicon resin or the organic silicon resin obtained by the preparation method.

Further, the radical initiator is an organic peroxide, and preferably the organic peroxide is one or more selected from the group consisting of tert-butyl neodecanoate peroxide, cumyl neoheptanoate peroxide and diisobutyryl peroxide.

Further, the reactive diluent is a substituted or unsubstituted acrylate, and preferably, the reactive diluent is one of isobornyl acrylate, isobornyl methacrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

Further, the organic silicon conductive adhesive composition also comprises 0-7 parts of a silane coupling agent, 0-5 parts of an adhesion promoter, 0-2 parts of 1-3 wt% of a polymerization inhibitor solution and 0-1 part of 1-3.5 wt% of a chelating agent solution; preferably, the silane coupling agent is gamma-aminopropyltriethoxysilane and/or gamma-glycidoxypropyltrimethoxysilane, the adhesion promoter is preferably monofunctional acrylate or multifunctional acrylate, the adhesion promoter is further preferably one or more of monofunctional acrylate CD9050, trifunctional acrylate CD9051, trifunctional acrylate CD9052 and trifunctional acrylate CD9053, the polymerization inhibitor solution comprises a first solvent and a first active substance, the first solvent is preferably polyethylene glycol 200 dimethacrylate, the first active substance is preferably one or more of 1, 4-naphthoquinone, hydroquinone and hydroquinone, the chelating agent solution comprises a second solvent and a second active substance, the second solvent is a mixed solvent of water and propylene glycol, preferably the mass ratio of water to propylene glycol is 1-3: 7-9, preferably the second active is selected from any one or more of ethylenediaminetetraacetic acid, sodium ethylenediaminetetraacetate, potassium ethylenediaminetetraacetate, oxalic acid, sodium oxalate, potassium oxalate.

According to another aspect of the invention, the silicone conductive adhesive is prepared by mixing a silicone conductive adhesive composition, wherein the silicone conductive adhesive composition is the silicone conductive adhesive composition.

By applying the technical scheme of the invention, the organic silicon resin with the structural formula is terminated by the silane coupling agent, so that the storage stability of the organic silicon resin is improved on one hand, and carbon-carbon double bonds are contained at two ends of the organic silicon resin on the other hand, and the organic silicon conductive adhesive containing the organic silicon resin can be rapidly cured at low temperature by initiating polymerization reaction through free radicals. Meanwhile, the operable time of the organic silicon conductive adhesive is further prolonged under the synergistic action of the side chain functional groups of the organic silicon resin, the glass transition temperature is reduced, the flexibility is good, the toughness is strong, the aging resistance is realized, the cracking and hardening are not easy to occur, the brittleness is not easy to occur, and the organic silicon conductive adhesive can be well compatible and bonded with materials such as aluminum, silver or copper.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.

As analyzed by the background art, the organic silicon conductive adhesive in the prior art has the problems of short operable time, high glass transition temperature, poor flexibility and poor aging resistance, and in order to solve the problems, the invention provides an organic silicon resin, a preparation method thereof, an organic silicon conductive adhesive composition and an organic silicon conductive adhesive.

In one exemplary embodiment of the present application, a silicone resin is provided having a structure represented by formula I:

wherein n is more than or equal to 200 and less than or equal to 500.

The organic silicon resin with the structural formula is terminated by a silane coupling agent, so that the storage stability of the organic silicon resin is improved, and carbon-carbon double bonds are contained at two ends of the organic silicon resin and can initiate polymerization reaction through free radicals, so that the organic silicon conductive adhesive containing the organic silicon resin can be quickly cured at a low temperature. Meanwhile, the operable time of the organic silicon conductive adhesive is further prolonged under the synergistic action of the side chain functional groups of the organic silicon resin, the glass transition temperature is reduced, the flexibility is good, the toughness is strong, the aging resistance is realized, the cracking and hardening are not easy to occur, the brittleness is not easy to occur, and the organic silicon conductive adhesive can be well compatible and bonded with materials such as aluminum, silver or copper.

The vinyl content in the organic silicon resin influences the curing rate of the organic silicon conductive adhesive at low temperature, preferably 0.1-0.2 wt% of the vinyl content in the organic silicon resin, which is beneficial to realizing more rapid curing of the organic silicon conductive adhesive at low temperature, preferably 14000-38000 of the molecular weight of the organic silicon resin, and preferably 900-3000 mPa & s of the viscosity of the organic silicon resin. The mutual dispersion and fusion of the organic silicon resin and other components in the organic silicon conductive adhesive are facilitated, and the organic silicon conductive adhesive with excellent and stable performance is obtained better.

In another exemplary embodiment of the present application, there is provided a method for preparing a silicone resin, the method comprising, in parts by weight: carrying out condensation reaction on 1000 parts of silica gel and 15-45 parts of KH570 silane coupling agent in 0.1-2 parts of alkaline solution to obtain an organic silicon resin system, wherein the silica gel has a structure shown in a formula II:

wherein n is more than or equal to 200 and less than or equal to 500.

Silica gel has excellent flexibility, can be used as matrix resin of the organic silicon conductive adhesive, and the KH570 silane coupling agent is used for blocking the hydroxyl groups on the two sides of the silica gel, so that the storage stability of the organic silicon resin is improved, and carbon-carbon double bonds are introduced into the two ends of the molecules of the organic silicon resin, and the polymerization reaction can be initiated through free radicals, thereby realizing the rapid curing at low temperature. And then the organic silicon resin which has good flexibility and can realize quick curing at low temperature is obtained, and the preparation method is simple and has lower cost.

As the matrix resin of the organic silicon conductive adhesive, the hydroxyl content of the silica gel is preferably 0.08-0.20 wt%, so that the specific sufficient carbon-carbon double bonds of the organic silicon resin are ensured. The molecular weight of the silica gel is preferably 14000-38000, and the viscosity of the silica gel is preferably 700-2500 mPa & s. The KH570 silane coupling agent and the silica gel are dispersed more effectively, and the reaction efficiency is improved as much as possible.

In one embodiment of the present application, the alkaline solution is selected from Al (OH)₃The methanol solution of (4), the methanol solution of potassium hydride, the methanol solution of sodium hydroxide, and the methanol solution of lithium hydroxide, preferably Al (OH) described above₃Al (OH) in the methanol solution of (3)₃The mass concentration of (B) is 0.1-5 wt%.

The KH570 silane coupling agent reacts with silica gel to remove methanol, and the alkaline solution can promote the rapid removal of hydrogen on hydroxyl in silica gel molecule, preferably Al (OH) with the mass concentration₃The methanol solution helps to further promote the hydrogen removal reaction at the hydroxyl group, thereby improving the efficiency of the above condensation reaction.

In another exemplary embodiment of the present application, there is provided a silicone conductive paste composition, including, in parts by weight: 45-55 parts of organic silicon resin, 35-45 parts of reactive diluent, 1-3 parts of free radical initiator and 350-450 parts of silver powder, wherein the organic silicon resin is the organic silicon resin or the organic silicon resin obtained by the preparation method.

The organic silicon resin with the structural formula can be subjected to free radical initiated polymerization reaction, so that the organic silicon conductive adhesive containing the organic silicon resin can be quickly cured at low temperature. The reactive diluent can reduce the viscosity of the organic silicon resin, and can promote the free radical polymerization reaction between the double bonds in the reactive diluent and the organic silicon resin under the action of the free radical initiator. Therefore, under the synergistic action of the components, the organic silicon conductive adhesive which has the advantages of short operable time, low glass transition temperature, good flexibility, strong toughness, aging resistance, difficult cracking, hardening and embrittlement, good compatibility with materials such as aluminum, silver or copper and the like and good bonding effect is obtained.

The radical initiator is preferably an organic peroxide, and the organic peroxide is preferably one or more selected from the group consisting of tert-butyl neodecanoate peroxide, cumyl neoheptanoate peroxide and diisobutyryl peroxide. Therefore, the free radical initiator can generate free radicals more quickly, and has wide sources and lower cost.

In one embodiment of the present application, the reactive diluent is a substituted or unsubstituted acrylate, and preferably the reactive diluent is one of isobornyl acrylate, isobornyl methacrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate.

The active diluent can exert the diluting effect, simultaneously, the unsaturated double bond of the active diluent can further carry out free radical polymerization reaction with the organic silicon resin, and the functional group on the molecule of the active diluent can further improve the adhesive force of the organic silicon conductive adhesive and the metal.

The silver powder is used as the conductive filler to improve the conductivity of the organic silicon conductive adhesive, preferably, the silver powder is flaky silver powder, the average particle size of the silver powder is preferably 5.0-10.0 mu m, the tap density of the silver powder is preferably 3.0-6.0 g/mL, and the specific surface area of the silver powder is preferably 0.3-0.6 m²The weight loss on ignition of the silver powder at 540 ℃ for 1 hour is preferably less than or equal to 0.65%. Thereby being beneficial to enhancing the synergistic effect between other components in the organic silicon conductive adhesive composition and the silver powder and giving full play to the conductivity of the silver powder as much as possible, thereby improving the overall conductivity of the organic silicon conductive adhesive.

In an embodiment of the present application, the silicone conductive paste composition further includes: 0-7 parts of silane coupling agent, 0-5 parts of adhesion promoter, 0-2 parts of 1-3 wt% polymerization inhibitor solution and 0-1 part of 1-3.5 wt% chelating agent solution; preferably, the silane coupling agent is gamma-aminopropyltriethoxysilane and/or gamma-glycidoxypropyltrimethoxysilane.

The silane coupling agent is preferably added, so that the binding force of the silver powder and components such as the organic silicon resin can be increased, and the conductivity and the binding strength of the organic silicon conductive adhesive are improved.

Preferably, the adhesion promoter is monofunctional acrylate or multifunctional acrylate, and further preferably, the adhesion promoter is one or more of monofunctional acrylate CD9050, trifunctional acrylate CD9051, trifunctional acrylate CD9052 and trifunctional acrylate CD9053, so that the adhesion between the organosilicon conductive adhesive and metal is improved.

The polymerization inhibitor solution comprises a first solvent and a first active substance, the first solvent is preferably polyethylene glycol 200 dimethacrylate, the first active substance is preferably selected from any one or more of 1, 4-naphthoquinone, hydroquinone and hydroquinone, the chelating agent solution comprises a second solvent and a second active substance, the second solvent is a mixed solvent of water and propylene glycol, the mass ratio of the water to the propylene glycol is preferably 1-3: 7-9, and the second active substance is preferably selected from any one or more of ethylene diamine tetraacetic acid, sodium ethylene diamine tetraacetic acid, potassium ethylene diamine tetraacetic acid, oxalic acid, sodium oxalate and potassium oxalate. The preferable polymerization inhibitor solution and polymerization inhibitor solution are beneficial to improving the stability of the organic silicon conductive adhesive during production, freezing storage and gluing at normal temperature. Thereby further improving the comprehensive performance of the organosilicon conductive adhesive under the auxiliary action of the additive.

In another exemplary embodiment of the present application, a silicone conductive adhesive is provided, which is prepared by mixing a silicone conductive adhesive composition, wherein the silicone conductive adhesive composition is the aforementioned silicone conductive adhesive composition.

The organic silicon resin with the structural formula can be subjected to free radical initiated polymerization reaction, so that the organic silicon conductive adhesive containing the organic silicon resin can be quickly cured at low temperature. The reactive diluent can reduce the viscosity of the organic silicon resin, and can promote the free radical polymerization reaction between the double bonds in the reactive diluent and the organic silicon resin under the action of the free radical initiator. Therefore, the organosilicon conductive adhesive obtained under the synergistic effect of the components has the advantages of short operable time, low glass transition temperature, good flexibility, strong toughness, aging resistance, difficult cracking, hardening and embrittlement, and can be well compatible and bonded with materials such as aluminum, silver or copper.

In addition, the organosilicon conductive adhesive can be cured at 110-150 ℃ for 10-30 seconds, such as at 150 ℃ for 10 seconds, at 130 ℃ for 15 seconds, or at 110 ℃ for 30 seconds.

The advantageous effects of the present application will be described below with reference to specific examples and comparative examples.

Example 1

(1) Preparation of the silicone resin: 1000 g of silica gel having a viscosity of 1000 mPas, a molecular weight of 26000 and a hydroxyl group content of 0.10 wt% and a structure represented by formula II and n ═ 350, and 40 g of KH570 silane coupling agent were put into a stirred tank, and after stirring the mixture uniformly, 1 g of 5 wt% Al (OH) was added₃The methanol solution of (2) was used as a catalyst, and stirred under vacuum for about 2 hours. And (3) pumping a small amount of resin into a small beaker, adding a small amount of tert-butyl titanate catalyst, uniformly stirring by using a glass rod, if the resin in the beaker is not crosslinked and thickened, indicating that the end-capping reaction is finished, and otherwise, continuously stirring.

(2) Preparing base glue: weighing 47.00 g of the organic silicon resin prepared in the step (1), 40.00 g of hydroxypropyl methacrylate, 0.94 g of KH550 silane coupling agent, 4.72g of CD9051 adhesion promoter, 0.94 g of 3 wt% hydroquinone solution and 0.47 g of 3.5% EDTA solution at 25 ℃, sequentially adding the materials into a double-planet high-speed dispersion machine for stirring, wherein the rotating speed of a planet stirring frame is 80 revolutions per minute, the rotating speed of a high-speed dispersion machine is 500 revolutions per minute, and uniformly mixing the materials for 15 minutes.

(3) Adding conductive fillers: the conductive filler is flake silver powder with the average particle diameter of 6.04 mu m, the tap density of 4.72g/mL and the specific surface area of 0.41m²The weight loss on ignition (1 hour at 540 ℃) was 0.28%. 403.44 g of silver powder is added into the mixed base rubber, the rotating speed of a planetary stirring frame is kept unchanged at 80 r/min, the rotating speed of a high-speed disperser is increased to 1500 r/min, and the mixture is fully stirred for 2 hours.

(4) Adding an initiator: adding 2.49 g of cumyl peroxyneodecanoate as a free radical initiator into the conductive adhesive in the step (3), keeping the rotating speed unchanged, and fully stirring for 2 hours.

(5) Discharging and canning: and after stirring is finished, vacuumizing for 15 minutes to remove bubbles to obtain the organic silicon conductive adhesive, filling the organic silicon conductive adhesive into a formulated container, and sealing and storing the organic silicon conductive adhesive in a refrigerator at the temperature of-20 ℃.

Example 2

(1) Preparation of the silicone resin: 1000 g of silica gel having a viscosity of 2000 mPas, a molecular weight of 36000 and a hydroxyl group content of 0.09 wt% and a structure represented by formula II (n-485) and 36 g of KH570 silane coupling agent were added to a stirred tank, and after stirring the mixture uniformly, 1 g of 5 wt% Al (OH) was added₃The methanol solution of (2) was used as a catalyst, and stirred under vacuum for about 2 hours. And (3) pumping a small amount of resin into a small beaker, adding a small amount of tert-butyl titanate catalyst, uniformly stirring by using a glass rod, if the resin in the beaker is not crosslinked and thickened, indicating that the end-capping reaction is finished, and otherwise, continuously stirring.

(2) Preparing base glue: weighing 45.00 g of the organic silicon resin prepared in the step (1), 36.16 g of isobornyl methacrylate, 0.94 g of KH560 silane coupling agent, 3.45 g of CD9052 adhesion promoter, 0.94 g of 3 wt% p-phenylenediamine solution and 0.47 g of 3.5 wt% sodium oxalate solution at 25 ℃, sequentially adding the materials into a double-planet high-speed dispersion machine for stirring, wherein the rotating speed of a planet stirring frame is 80 revolutions per minute, the rotating speed of the high-speed dispersion machine is 500 revolutions per minute, and uniformly mixing the materials for 15 minutes.

(3) Adding conductive fillers: the conductive filler is flake silver powder with average particle diameter of 7.04 μm, tap density of 5.72g/mL, and specific surface area of 0.31m²The weight loss on ignition (1 hour at 540 ℃) was 0.38%. 410.15 g of silver powder is added into the mixed base rubber, the rotating speed of a planetary stirring frame is kept unchanged at 80 r/min, the rotating speed of a high-speed disperser is increased to 1500 r/min, and the mixture is fully stirred for 2 hours.

(4) Adding an initiator: adding 2.89 g of cumyl peroxyneoheptanoate as a free radical initiator into the conductive adhesive in the step (3), keeping the rotating speed unchanged, and fully stirring for 2 hours.

(5) Discharging and canning: and after stirring is finished, vacuumizing for 15 minutes to remove bubbles to obtain the organic silicon conductive adhesive, filling the organic silicon conductive adhesive into a formulated container, and sealing and storing the organic silicon conductive adhesive in a refrigerator at the temperature of-20 ℃.

Example 3

(1) Preparation of the silicone resin: 1000 g of silica gel having a viscosity of 1500 mPas, a molecular weight of 31000 and a hydroxyl group content of 0.095 wt%, a structure represented by formula II and n.415, and 38 g of KH570 silane coupling agent were added to a stirred tank, and after stirring the mixture uniformly, 1 g of 5 wt% Al (OH) was added₃The methanol solution of (2) was used as a catalyst, and stirred under vacuum for about 2 hours. And (3) pumping a small amount of resin into a small beaker, adding a small amount of tert-butyl titanate catalyst, uniformly stirring by using a glass rod, if the resin in the beaker is not crosslinked and thickened, indicating that the end-capping reaction is finished, and otherwise, continuously stirring.

(2) Preparing base glue: weighing 50.00 parts of the organic silicon resin prepared in the step (1), 40.16 g of hydroxyethyl methacrylate, 0.94 g of KH560 silane coupling agent, 0.45 g of CD9053 adhesion promoter, 0.94 g of 3 wt% 1, 4-naphthoquinone solution and 0.47 g of 3.5% oxalic acid solution at 25 ℃, sequentially adding the materials into a double-planet high-speed dispersion machine for stirring, wherein the rotating speed of a planet stirring frame is 80 revolutions per minute, the rotating speed of the high-speed dispersion machine is 500 revolutions per minute, and uniformly mixing the materials for 15 minutes.

(3) Adding conductive fillers: the conductive filler is flake silver powder with the average particle diameter of 8.04 mu m, the tap density of 5.22g/mL and the specific surface area of 0.29m²The weight loss on ignition (1 hour at 540 ℃) was 0.48%. 405.75 g of silver powder is added into the mixed base rubber, the rotating speed of a planetary stirring frame is kept unchanged at 80 r/min, the rotating speed of a high-speed disperser is increased to 1500 r/min, and the mixture is fully stirred for 2 hours.

(4) Adding an initiator: adding 1.89 g of radical initiator diisobutyronitrile peroxide into the mixed conductive adhesive, keeping the rotating speed unchanged, and fully stirring for 2 hours.

(5) Discharging and canning: and after stirring is finished, vacuumizing for 15 minutes to remove bubbles to obtain the organic silicon conductive adhesive, filling the organic silicon conductive adhesive into a formulated container, and sealing and storing the organic silicon conductive adhesive in a refrigerator at the temperature of-20 ℃.

Example 4

(1) Preparation of the silicone resin: 1000 g of silica gel having a viscosity of 700 mPas, a molecular weight of 15000 and a hydroxyl group content of 0.15 wt% and a structure represented by formula II (n is 200) and 44 g of KH570 silane coupling agent are added into a stirring kettle, and after uniform stirring, 1 g of 5 wt% Al (OH) is added₃The methanol solution of (2) was used as a catalyst, and stirred under vacuum for about 2 hours. And (3) pumping a small amount of resin into a small beaker, adding a small amount of tert-butyl titanate catalyst, uniformly stirring by using a glass rod, if the resin in the beaker is not crosslinked and thickened, indicating that the end-capping reaction is finished, and otherwise, continuously stirring.

(2) Preparing base glue: weighing 47.21 g of the organic silicon resin prepared in the step (1), 39.66 g of isobornyl acrylate, 0.94 g of KH560 silane coupling agent, 4.72g of CD9050 adhesion promoter, 0.94 g of 3 wt% 1, 4-naphthoquinone solution and 0.47 g of 3.5% EDTA disodium salt solution at 25 ℃, sequentially adding the materials into a double-planet high-speed dispersion machine for stirring, wherein the rotating speed of a planet stirring frame is 80 revolutions per minute, the rotating speed of the high-speed dispersion machine is 500 revolutions per minute, and uniformly mixing the materials for 15 minutes.

(3) Adding conductive fillers: the conductive filler is flake silver powder with the average particle diameter of 5.04 mu m, the tap density of 3.72g/mL and the specific surface area of 0.51m²The weight loss on ignition (1 hour at 540 ℃) was 0.18%. 404.17 g of silver powder is added into the mixed base rubber, the rotating speed of a planetary stirring frame is kept unchanged at 80 r/min, the rotating speed of a high-speed disperser is increased to 1500 r/min, and the mixture is fully stirred for 2 hours.

(4) Adding an initiator: adding 1.89 g of tert-butyl peroxyneodecanoate as a free radical initiator into the mixed conductive adhesive, keeping the rotating speed unchanged, and fully stirring for 2 hours.

(5) Discharging and canning: and after stirring is finished, vacuumizing for 15 minutes to remove bubbles to obtain the organic silicon conductive adhesive, filling the organic silicon conductive adhesive into a formulated container, and sealing and storing the organic silicon conductive adhesive in a refrigerator at the temperature of-20 ℃.

Example 5

Example 5 differs from example 1 in that,

and (2) weighing 45.00 g of the organic silicon resin prepared in the step (1) at 25 ℃, and finally obtaining the organic silicon conductive adhesive.

Example 6

Example 6 differs from example 1 in that,

and (2) weighing 55.00 g of the organic silicon resin prepared in the step (1) at the temperature of 25 ℃, and finally obtaining the organic silicon conductive adhesive.

Example 7

Example 7 differs from example 1 in that,

weighing 47.00 g of the organic silicon resin prepared in the step (1), 35.00 g of hydroxypropyl methacrylate, 0.94 g of KH550 silane coupling agent, 0.5 g of CD9051 adhesion promoter, 0.94 g of 3 wt% hydroquinone solution and 0.47 g of 3.5% EDTA solution at 25 ℃, sequentially adding the materials into a double-planet high-speed dispersion machine for stirring, wherein the rotating speed of a planet stirring frame is 80 revolutions per minute, the rotating speed of a high-speed dispersion machine is 500 revolutions per minute, and uniformly mixing the materials for 15 minutes. 350 g of silver powder is added into the mixed base adhesive, 1 g of cumyl peroxyneodecanoate as a free radical initiator is added into the conductive adhesive in the step (3), the rotating speed is kept unchanged, and the mixture is fully stirred for 2 hours. Finally obtaining the organic silicon conductive adhesive.

Comparative example 1

Comparative example 1 is different from example 1 in that,

the silicone resin in example 1 was replaced with acrylic polyurethane (sartomer product CN966H 90).

Comparative example 2

(1) The preparation of the organic silicon resin selects PV39 type vinyl organic silicon resin of new material Gnethig in Jiangxi, the viscosity is 10000 mPa.s, and the vinyl content is 5.1 wt%.

(2) Preparing base glue: under the condition of 25 ℃, 55.00 g of vinyl organic silicon resin in the step (1), 40.00 g of hydrogen-containing silicone oil (produced by soaring new material Co., Ltd. in Jiangxi, the viscosity is 1000 mPa.s, and the hydrogen content is 0.3 wt%), 0.71 g of F522 type adhesion promoter and 0.07 g of KM06 type adhesion promoter produced by soaring new material Co., Ltd. in Jiangxi, and 0.07 g of TW-2 type inhibitor produced by high polymer material Co., Ltd. in Ju, are sequentially added into a double-planet high-speed dispersion machine for stirring, the rotating speed of a planet stirring frame is 80 r/min, the rotating speed of a high-speed dispersion machine is 500 r/min, and the materials are uniformly mixed for 15 min.

(3) Adding conductive fillers: the conductive filler is flake silver powder with the average particle diameter of 5.04 mu m, the tap density of 3.72g/mL and the specific surface area of 0.51m²The weight loss on ignition (1 hour at 540 ℃) was 0.18%. 403.44 g of silver powder is added into the mixed base rubber, the rotating speed of a planetary stirring frame is kept unchanged at 80 r/min, the rotating speed of a high-speed disperser is increased to 1500 r/min, and the mixture is fully stirred for 2 hours.

(4) Adding an initiator: 0.07 g of PL-9 type platinum catalyst complex (5000ppm) produced by Jumei Polymer materials Co., Ltd, Dongguan was added to the mixed conductive adhesive, the rotation speed was kept constant, and the mixture was stirred sufficiently for 2 hours.

(5) Discharging and canning: and after stirring is finished, vacuumizing for 15 minutes to remove bubbles to obtain the organic silicon conductive adhesive, filling the organic silicon conductive adhesive into a formulated container, and sealing and storing the organic silicon conductive adhesive in a refrigerator at the temperature of-20 ℃.

The silicone resins obtained in examples 1 to 4 above were each tested for vinyl content, molecular weight, viscosity, and the test results are listed in table 1.

TABLE 1

Examples	Content of vinyl groups/%)	Molecular weight	viscosity/mPas
				Example 1	0.12％	26400	1100
Example 2	0.1％	36500	1900
				Example 3	0.11％	32000	1600
Example 4	0.18％	15500	750

The following tests were carried out on the silicone conductive pastes obtained in the above examples 1 to 7, comparative example 1 and comparative example 2:

(1) the operable time test method comprises the steps of storing the organic silicon conductive adhesive at 25 ℃, monitoring the viscosity change, and when the viscosity is increased or reduced by more than 50 percent of the original value, the elapsed time is '@ 25 ℃ operable time';

(2) the glass transition temperature was measured using a TMA thermomechanical analyzer manufactured by Hitachi corporation;

(3) the volume resistivity was measured using a model ST2258C multifunctional digital four-probe tester manufactured by suzhou crystal lattice electronics ltd;

(4) the aging condition is that the temperature is 85 ℃ and the humidity of 85 percent is aged for 1000 hours;

(5) the bonding strength is tested by a universal tensile testing machine; and the results of the above tests are shown in table 2.

TABLE 2

It can be known from the table that the organic silicon conductive adhesive prepared in the embodiment is cured by adopting the free radical polymerization reaction of the organic silicon resin, has the characteristics of long operable time, low glass transition temperature, good flexibility, aging resistance and the like, and meets the requirements of the sizing process, the adhesive property and the conductivity of the laminated tile assembly. The conductive adhesive prepared in the comparative example 1 is cured by adopting the free radical polymerization reaction of acrylic polyurethane, and although the bonding strength is high, the glass transition temperature is higher, the flexibility is poorer, and the aging resistance and the conductivity are poorer. The conductive adhesive prepared in the comparative example 2 is cured by addition polymerization of organic silicon resin, and although the glass reaction temperature is low, the flexibility is good, the conductivity is good, and the aging resistance is high, the operation time is short, and the adhesive applying process cannot be met.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects:

the organic silicon resin with the structural formula is terminated by a silane coupling agent, so that the storage stability of the organic silicon resin is improved, and carbon-carbon double bonds are contained at two ends of the organic silicon resin and can initiate polymerization reaction through free radicals, so that the organic silicon conductive adhesive containing the organic silicon resin can be quickly cured at a low temperature. Meanwhile, the operable time of the organic silicon conductive adhesive is further prolonged under the synergistic action of the side chain functional groups of the organic silicon resin, the glass transition temperature is reduced, the flexibility is good, the toughness is strong, the aging resistance is realized, the cracking and hardening are not easy to occur, the brittleness is not easy to occur, and the organic silicon conductive adhesive can be well compatible and bonded with materials such as aluminum, silver or copper.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.