CN104031603B - A kind of high thermal conductivity borapolysiloxane potting glue and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of encapsulation materials, and discloses a high thermal conductivity borapolysiloxane potting glue and a preparation method thereof. The potting glue is composed of the following components in parts by mass: 100 parts of vinyl methyl polysiloxane, 20-100 parts of vinyl methyl nano-MQ silicone resin, 5-50 parts of vinyl polyborosilicate alkane or vinyl borosiloxane, 0.05 to 0.2 parts of ethynyl cyclohexanol, 0.005 to 0.05 parts of noble metal organic compound catalyst, 0.5 to 5 parts of vinyl epoxy compound, 1 to 10 parts of borazine, 10 to 0 Parts of methyl hydrogen silicone oil and 50-120 parts of boron nitride ceramics. The high thermal conductivity boropolysiloxane potting adhesive prepared by the invention has high thermal conductivity, good sealing performance, strong adhesion, good elasticity, waterproof, moisture-proof, insulation, shock absorption, excellent high-temperature aging resistance, and can be used in high-power electronic information It has broad application prospects in the packaging of components, semiconductor communication lighting and other components.

Description

A kind of high thermal conductivity borapolysiloxane potting glue and preparation method thereof

technical field

The invention belongs to the field of packaging materials, and in particular relates to a high thermal conductivity bora polysiloxane potting glue and a preparation method thereof.

Background technique

Thermally conductive potting adhesives are widely used in electronic information, LED lighting, aviation, aerospace, national defense and other fields that require heat dissipation and heat transfer. With the rapid development of integration, miniaturization and high power of electronic equipment and semiconductor materials, higher requirements are put forward for packaging materials. In addition to providing protection against moisture, insulation, corrosion and high temperature resistance, packaging materials must It has excellent thermal conductivity, low thermal expansion coefficient and low dielectric constant and dielectric loss. A large number of experiments have proved that the possibility of device failure increases by 2 to 3 times for every 18°C increase in temperature. During the working life of electronic and semiconductor components, under the thermal cycle, the thermal expansion will cause deformation of the components and packaging materials. If there is a large difference in thermal expansion coefficient between the two, severe cracking or separation will occur. Therefore, packaging materials are required to have The thermal expansion coefficient is close to that of the silicon chip material to obtain better thermal matching. The dielectric properties of packaging materials are an important factor affecting the operation speed of integrated circuits. If the dielectric constant is too high, the signal transmission delay of the integrated circuit will increase, and the high dielectric loss will cause serious distortion of the signal during transmission. In addition, in order to improve the sealing performance between materials, the heat-conducting material needs to have good elasticity and shock-absorbing properties.

Due to the characteristics of polymer materials such as low density, excellent electrical insulation properties, excellent dielectric properties, and easy processing, in recent years, the application proportion of polymer materials in the field of packaging has increased, and gradually replaced the traditional Inorganic rigid ceramic packaging materials. Thermally conductive polysiloxane silicone rubber is not only highly compatible with silicon chip materials, but also has a close thermal expansion coefficient, low dielectric constant and dielectric loss, and has good moisture resistance, insulation, shock absorption, heat conduction, high and low temperature resistance, weather resistance and Good chemical stability plays an irreplaceable role in the fields of electronics and semiconductor components, but the thermal conductivity of traditional thermally conductive silicone rubber packaging materials is only 1-2W/(m K), which is far from meeting the needs of modern large-scale integration. High thermal conductivity requirements for circuits and high-power semiconductor components.

Chinese patent (application number 201210174410.9) discloses a silicone resin composition containing alkoxy-containing borosiloxane resin and heat-conducting and heat-resistant ceramic filler boron nitride and a thermally conductive sheet. The curing molding is based on silicone resin and alkoxy the condensation reaction. The condensation curing process is often accompanied by the release of small molecular compounds such as water, methanol, and ethanol, which are prone to bubbles and pores, often failing to meet high-standard packaging performance requirements, and seriously affecting the adhesive sealing and high-temperature aging resistance of the composition.

Contents of the invention

In order to overcome the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a high thermal conductivity borapolysiloxane potting compound.

Another object of the present invention is to provide a method for preparing the above-mentioned high thermal conductivity borapolysiloxane potting compound.

The object of the present invention is achieved through the following technical solutions:

A high thermal conductivity borapolysiloxane potting compound consists of the following components in parts by mass:

Among them, the sum of the mass of borazine and methyl hydrogen silicone oil is not less than 6 parts.

The vinyl methyl polysiloxane is terminal vinyl polydimethylsiloxane, side vinyl polydimethylsiloxane and polydimethylsiloxane containing both terminal vinyl and side vinyl One or more of them; the viscosity of the vinylmethylpolysiloxane is 1000-80000mPa·s, preferably 3000-50000mPa·s.

The structural formula of the vinyl-terminated polydimethylsiloxane is (CH ₂ ═CH)(CH ₃ ) ₂ Si[OSi(CH ₃ ) ₂ ] _n OSi(CH ₃ ) ₂ (CH=CH ₂ );( In the formula n≥2, n is an integer).

The structural formula of the pendant vinyl polydimethylsiloxane is (CH ₃ ) ₃ Si[OSi(CH ₃ ) ₂ ] _m [OSi(CH=CH ₂ )(CH ₃ )] _n OSi(CH ₃ ) ₃ ; (where m≥2, n≥2 and m, n are integers).

The structural formula of the polydimethylsiloxane containing both terminal vinyl groups and side vinyl groups is (CH ₂ ═CH)(CH ₃ ) ₂ Si[OSi(CH ₃ ) ₂ ] _m [OSi(CH═CH ₂ )(CH ₃ )] _n OSi(CH ₃ ) _3-p (CH ₂ =CH) _p (p=0,1) (where m≥2, n≥2 and m, n are integers).

The vinyl methyl nano-MQ silicone resin (Guangzhou Delta Silicone Technology Development Co., Ltd.) is a nano-organosilicon resin material formed by hydrolysis and condensation of M-group silicone monomers and Q-group silicone monomers. ; The molar ratio of the M-group organosilicon monomer to the Q-group organosilicon monomer is 0.6-1.5:1.

The M group organosilicon monomer is a monofunctional organosiloxane chain link R ₃ SiO _1/2 , the R is composed of methyl and vinyl, and the vinyl content is vinylmethyl nanometer MQ silicone resin 1.0-4.0wt% of the total mass.

The Q-group organosilicon monomer is a tetrafunctional organosiloxane chain link SiO ₂ .

The nanometer-sized MQ silicone resin is a double-layer structure compact spherical body, in which the core is Si-O chain connection, high density, cage-like SiO ₂ with a polymerization degree of 15-50, and the spherical shell is R ₃ SiO ₁ with a low density _/2 layers, the molar mass is generally 1000-8000g/mol; nano-MQ silicone resin can be dissolved and dispersed in the form of molecular level in liquid polysiloxane.

The vinyl polyborosiloxane is vinyl polyborosiloxane 1, vinyl polyborosiloxane 2 or vinyl polyborosiloxane 3;

The structural formula of the vinyl polyborosiloxane 1 is [OB(R)OSi(CH ₃ )(CH=CH ₂ )] _m , R=Ph; where m=2-100 and m is an integer;

The structural formula of the vinyl polyborosiloxane 2 is:

(CH ₂ =CH)(CH ₃ ) ₂ Si[OB(R ₁ )OSi(CH ₃ ) ₂ ] _m OSi(CH ₃ ) ₂ (CH=CH ₂ ); R ₁ =OCH ₃ , In the formula, m=2～100 and m is an integer;

The structural formula of the vinyl polyborosiloxane 3 is:

(CH ₂ =CH)(CH ₃ ) ₂ Si[OB(R ₁ )OSi(CH ₃ ) ₂ ] _m [OB(R ₁ )OSi(Ph)(R ₂ )] _n [OSi(CH ₃ ) ₂ ] _p [OSiPhR ₂ ] _q OSi(CH ₃ ) ₂ (CH=CH ₂ );

R ₁ =OCH ₃ , R ₂ =OCH ₃ , m, n, p, q are integers from 1 to 100;

The vinyl borosiloxane is RB[OSi(CH ₃ )(CH=CH ₂ )] ₂ , R=Ph.

The noble metal organic compound catalyst is more than one of platinum complexes, rhodium complexes or palladium complexes; the platinum complexes are tetrakis(triphenylphosphine)platinum Pt(PPh ₃ ) _4. Cis-bis(triphenylphosphine)platinum dichloride (PPh ₃ ) ₂ PtCl ₂ or 1,3-divinyl-1,1,3,3 tetramethyldisiloxane platinum complex; rhodium The complex of three (triphenylphosphine) carbonyl rhodium hydride (I) RhH (CO) (PPh ₃ ) ₃ ; the complex of palladium is four (triphenylphosphine) palladium Pd (PPh ₃ ) ₄ .

The vinyl epoxy compound is allyl glycidyl ether, 4-vinyl epoxycyclohexane, diglycidyl tetrahydrophthalate, epoxy acrylate or glycidyl methacrylate.

The content of hydrogen in the active silicon-hydrogen bond (Si-H) in the methyl hydrogen-containing silicone oil is 0.36-1.0% of the total mass of the methyl hydrogen-containing silicone oil; the viscosity of the methyl hydrogen-containing silicone oil is 50-1000mPa ·s.

The boron nitride ceramic is more than one of powdery boron nitride or fibrous boron nitride, the average particle size of powder boron nitride particles is 50 μm to 1 μm, and the average diameter of fibrous boron nitride is 20 to 200 μm .

The preparation method of the high thermal conductivity bora polysiloxane potting glue comprises the following steps: at room temperature, vinyl methyl polysiloxane, vinyl methyl nano MQ silicone resin, vinyl polyborosilicate alkane (or vinyl boroxane), ethynyl cyclohexanol, noble metal organic compound catalyst, vinyl epoxy compound, borazine, methyl hydrogen silicone oil and boron nitride ceramics, and then mix them at 50-70 Pre-cure at 100-150°C for 1-2 hours, and then cure at 100-150°C for 1-4 hours to obtain a borapolysiloxane potting compound with high thermal conductivity and high temperature resistance.

The noble metal catalyst forms a complex with the inhibitor ethynyl cyclohexanol at room temperature, the π electrons in the ethynyl cyclohexanol pair with the empty orbitals in the noble metal, and the catalytic activity of the metal is inhibited. With the prolongation of time and the increase of temperature, the catalytic activity of the metal is gradually released, the catalytic reaction proceeds, and the reaction is accelerated at high temperature.

The boron (B) atom in borazine contains empty orbitals, and the adjacent nitrogen (N) atoms contain lone pairs of electrons, which form pairings with each other. It is confirmed by single crystal X-ray diffraction analysis that there is a conjugated π bond in the borazine molecule, and its structure is similar to that of benzene. The physical properties of borazine are close to those of benzene, a colorless volatile liquid. But due to the different electronegativity of boron and nitrogen, the electron cloud density on the nitrogen atom is larger, and the electron cloud density on the boron atom is smaller, so the nitrogen atom still keeps its part of the alkalinity, while the boron atom keeps its part acidic. Therefore, borazine molecules contain active B-H bonds, and B-H in borazine is prone to addition or polymerization reactions at a certain temperature.

The invention uses addition-type vinyl methylpolysiloxane as the base glue, micron-sized high-thermal-conduction and high-temperature-resistant boron nitride ceramics as the heat-conducting filler, and molecular-level dispersed nano-sized vinyl methyl MQ silicone resin as the active heat-conducting filler. , with borosiloxane or polyborosiloxane as the bridging molecule, molecular-level borazine or methyl hydrogen-containing silicone oil as the crosslinking agent, under the action of a noble metal organic compound catalyst, vinyl methyl polysilicon The vinyl group in oxane and vinylmethyl MQ silicone resin and the B-H bond in borazine and the Si-H bond in methyl hydrogen-containing silicone oil are formed through borohydrogen addition and hydrosilylation polymerization reactions respectively. Silicone rubber ceramic composite material, a large number of boron atoms enter the polysiloxane main chain or side chain to form borapolysiloxane rubber, which has certain hardness and elasticity.

Addition-type liquid silicone rubber (vinyl methyl polysiloxane) does not have any solvent itself, and it is very easy to drive out the air in the pores of the contact interface. When cross-linking and curing to form rubber, no small molecules are released, the shrinkage rate is small, and the process adaptability is good. , high production efficiency, can withstand the alternating environment between high and low temperature, small internal stress, high temperature resistance.

Vinyl epoxy compound enters the siloxane main chain through metal-catalyzed addition, and the epoxy group in it maintains a high binding force to the metal, and the adhesive force is significantly improved, from the 1.5MPa adhesive strength of ordinary silica gel to Above 2.7MPa.

The thermal conductivity of boron nitride ceramic powder is as high as 55W/(m·K), and the thermal conductivity of fibrous boron nitride is higher (about 300W/(m·K)), and has a lower thermal expansion coefficient and resistivity And good chemical stability, so boron nitride can not only effectively improve the thermal conductivity of the polymer matrix, but also maintain the electrical insulation of the material. It is the first choice for the preparation of filled high thermal conductivity and insulating composite materials. The thermal conductivity of the usual silicone rubber main material is only 0.20W/(m·K). After adding micron-sized thermally conductive ceramic fillers according to the traditional method, due to the large thermal resistance between the main material and the micron-sized thermally conductive filler, the heat conduction is greatly affected. However, the thermal conductivity of the composite material at this time is only 1-2W/(m·K). The nano-scale vinylmethyl nano-MQ silicone resin with high thermal conductivity can be uniformly dispersed at the molecular level in the liquid matrix resin, effectively improving the thermal conduction path. At the same time, borazine is the precursor of boron nitride ceramics. Borazine can wet and modify the surface of boron nitride ceramic powder or fiber, which greatly improves the dispersion of boron nitride in liquid matrix resin. Borosilicate The presence of oxane or polyborosiloxane further bridges the thermally conductive boron nitride ceramic filler with the polysiloxane matrix resin, greatly reducing the thermal resistance between the liquid matrix resin and the thermally conductive ceramic filler, forming a good The heat conduction network path, the borapolysiloxane ceramic composite material formed has a very high thermal conductivity, reaching more than 9.0W/(m·K).

Compared with the prior art, the present invention has the following advantages and beneficial effects:

(1) The potting glue prepared by the present invention does not use any solvent, and the base glue (vinyl methyl polysiloxane) is easy to drive out the air in the pores of the contact interface, the shrinkage rate is small, the process adaptability is good, and the adhesion is strong. Strong, good sealing, little volume change;

(2) High thermal conductivity, good elasticity, waterproof, moisture-proof, insulation, shock absorption;

(3) Excellent high temperature aging resistance, can withstand high temperature of 300 ℃ for a long time.

Detailed ways

The present invention will be further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

Example 1: Raw material preparation

(1) Preparation of vinyl borosiloxane: add 61g of phenylboronic acid and 130g of vinyl dimethylethoxysilane in a 500ml three-necked flask equipped with a thermometer, condenser, mechanical stirrer and heating device, and stir at room temperature Make it dissolve slowly, then add 0.2 g of trifluoromethanesulfonic acid, heat to 60°C and keep for 1 hour, continue heating to 80°C, and reflux for 5 hours. Then remove the by-product ethanol by proper vacuum distillation, cool, neutralize the mixture with 2g of calcium carbonate and keep stirring at room temperature for 1 hour, filter, and obtain 140g of filtrate, which is a liquid vinyl containing phenyl group on the boron atom. Borosiloxane monomer BS1 (ie vinyl borosiloxane).

(2) Preparation of vinyl polyborosiloxane:

A. Add 61g of phenylboronic acid and 66g of methylvinyldimethoxysilane into a 250ml three-necked flask equipped with a thermometer, condenser, mechanical stirrer and heating device, stir at room temperature to dissolve slowly, and then add 0.2g of Trifluoromethanesulfonic acid, heated to 60°C and maintained for 1 hour, continued to heat to 80°C, and refluxed for 3 hours. Then through appropriate vacuum distillation and gradually increase the temperature to remove the by-product methanol, cool, neutralize the mixture with 2g of calcium carbonate and keep stirring at room temperature for 1 hour, filter, and obtain 92g of filtrate, which is a liquid containing phenyl on the boron atom Vinyl polyborosiloxane PBS2 (ie vinyl polyborosiloxane 1).

B. Add 46.5g tetramethyldivinyldisiloxane (also known as vinyl double head), 54g water and 0.2g Trifluoromethanesulfonic acid. With stirring at room temperature, a mixture of 120g dimethyldimethoxysilane and 104g trimethyl borate was added dropwise into a three-necked flask, then heated to 60°C, refluxed for 1 hour, and then gradually heated to below 85°C, while The by-product methanol is distilled off. Cool to room temperature, neutralize the mixture with 2g of calcium carbonate and keep stirring at room temperature for 1 hour, filter, and dilute the obtained filtrate with toluene, then add KOH0. In the flask, heat to 115°C for distillation, remove water, and cool to room temperature. The mixture was placed in an aluminum pan and heated at 120° C. for 1 hour in an air-circulating oven, then cooled to room temperature to obtain viscous liquid vinyl polyborosiloxane PBS3 (namely, vinyl polyborosiloxane 2 ).

C. Add 93g tetramethyldivinyldisiloxane, 108g water and 0.4g trifluoromethanesulfonic acid in a 1000ml three-necked flask equipped with a thermometer, condenser, mechanical stirrer and heating device. Under stirring at room temperature, a mixture of 198g phenyltrimethoxysilane, 120g dimethyldimethoxysilane and 104g trimethyl borate was added dropwise in a three-necked flask, then the temperature was raised to 60°C, and the reaction was refluxed for 1 hour, and then Gradually raise the temperature to below 85°C while distilling out the by-product methanol. Cool to room temperature, neutralize the mixture with 4g of calcium carbonate and keep stirring at room temperature for 2 hours, filter, and dilute the obtained filtrate with toluene, then add KOH0. In the flask, heat to 115°C for distillation, remove water, and cool to room temperature. The mixture was placed in an aluminum pan, heated at 150°C for 1 hour in an air-circulating oven, and cooled to room temperature to obtain a highly viscous liquid vinyl polyborosiloxane (containing phenyl and formaldehyde on the silicon atom). base) PBS4 (ie vinyl polyborosiloxane 3).

(3) Drying treatment of boron nitride powder: place the filler boron nitride of heat-conducting and high-temperature-resistant ceramic powder with different particle sizes in a vacuum drying oven, vacuumize, and raise the temperature to 150°C to maintain a vacuum degree (-101.3 KPa) for 3 hours, then cooled and taken out, placed in a dry box for subsequent use.

(4) Preparation of epoxy acrylate: Add 250g of E-44 epoxy resin in a 500mL round bottom flask equipped with reflux condensation, stirring and constant temperature devices, add 70g of acrylic acid, 0.01g of hydroquinone and 1g of Triphenylphosphine, heated up to 105°C for reflux reaction, reacted for 4 hours and then cooled to obtain epoxy acrylate EA1.

Preparation of High Thermal Conductivity Boropolysiloxane Potting Compound

Example 2:

At room temperature, 100g of vinyl-terminated methyl silicone oil (also known as vinyl-terminated polydimethylsiloxane, viscosity 3000mPa·s), 100g of vinylmethyl nano-MQ silicone resin (vinyl content 2.4wt%, M/Q =0.75), 5g vinyl borosiloxane BS1, 0.05g ethynyl cyclohexanol, 0.034g tetrakis (triphenylphosphine) platinum Pt (PPh ₃ ) ₄ (the content of platinum is 15wt%) (the consumption of platinum is 0.15*0.034=0.0051), 0.5g allyl glycidyl ether, 10g borazine and 120g dried boron nitride powder (average particle size 10μm) are mixed evenly, and then made according to the corresponding test method The corresponding modules were placed in an environment of 50°C for 2 hours, then heated to 100°C for 4 hours, and after cooling, the Shore hardness and thermal conductivity of the composite material (ie high thermal conductivity boropolysiloxane potting compound) were respectively measured And high temperature aging resistance and bonding strength. The test results are shown in Table 1.

Shore hardness test: directly test the hardness of silicone rubber with LX-A Shore rubber hardness tester.

Thermal conductivity: Directly test with DRL-III thermal conductivity tester.

High-temperature aging resistance test: Coat the liquid silicone rubber composite material on a clean metal aluminum plate and a ceramic substrate, cure according to the specified curing temperature and curing program, weigh and observe the appearance of the composite material, and then place it in a 300°C environment Carry out hot air aging test for 500 hours, observe the appearance changes of the silicone rubber composite material (including color, cracking, foaming and peeling of the bonding surface), weigh after cooling, and calculate the mass loss of the silicone rubber composite material.

(Shear) Adhesive Strength Test: According to GB/T13936-1992, the shear adhesive strength between the metal aluminum sheet and the potting glue is measured.

Example 3:

At room temperature, 100g of vinyl-terminated methyl silicone oil (vinyl-terminated polydimethylsiloxane, viscosity 50000mPa·s), 20g of vinylmethyl nano-MQ silicone resin (vinyl content 4.0wt%, M/Q=1.5 ), 50g vinyl polyborosiloxane PBS2, 0.2g ethynyl cyclohexanol, 0.2g bis(triphenylphosphine)platinum dichloride (PPh ₃ ) ₂ PtCl ₂ (the content of platinum is 24.2wt%)( The amount of platinum is 0.242*0.2=0.0484), 5g4-vinyl epoxycyclohexane, 6g borazine and 100g dry treated boron nitride powder (average particle size 10μm) mixed evenly, according to the corresponding The test method is to make corresponding modules, first place it in an environment of 60°C for 2 hours, then raise the temperature to 120°C, keep it warm for 3 hours, and measure the properties of composite materials (that is, high thermal conductivity boropolysiloxane potting glue) respectively after cooling. Shore hardness, thermal conductivity and high temperature aging resistance and bonding strength. The experimental test results are shown in Table 1.

Example 4:

At room temperature, 50g of terminal vinyl methyl silicone oil (terminal vinyl polydimethylsiloxane, viscosity 5000mPa s), 50g of side chain vinyl methyl silicone oil (side vinyl polydimethylsiloxane, viscosity 80000mPa s), 100g vinylmethyl nano MQ silicone resin (vinyl content 1.0wt%, M/Q=0.6), 10g vinyl polyborosiloxane PBS3, 0.1g ethynyl cyclohexanol, 0.4g tri( Triphenylphosphine) rhodium carbonyl hydride (I) RhH (CO) (PPh ₃ ) ₃ (the content of rhodium is 11.2wt%) (the consumption of rhodium is 0.4*0.112=0.0448), 2g tetrahydrophthalic acid dishrink Glyceride, 1g borazine, 10g methylhydrogen silicone oil (active hydrogen content 0.75wt%, viscosity 200mPa·s) and 40g dry-treated boron nitride powder (average particle size 50μm), 10g nitriding After the boron powder (average particle size 1μm) is mixed evenly, make corresponding modules according to the corresponding test method, first place it in the environment of 70 ℃ for 1 hour, then heat it up to 150 ℃ for 1 hour, and measure the compound after cooling. The Shore hardness, thermal conductivity, high temperature aging resistance and bonding strength of the material (ie high thermal conductivity bora polysiloxane potting compound). The experimental test results are shown in Table 1.

Example 5:

At room temperature, 100g of vinyl-terminated methyl silicone oil (vinyl-terminated polydimethylsiloxane, viscosity 1000mPa·s), 100g of vinyl-methyl nano-MQ silicone resin (vinyl content 2.4wt%, M/Q=0.75 ), 50g vinyl polyborosiloxane PBS4, 0.2g ethynyl cyclohexanol, 0.09g tetrakis(triphenylphosphine)palladium Bd(PPh ₃ ) ₄ (the content of palladium is 9.2wt%), 3g epoxy acrylic acid Ester EA1, 5g borazine, 10g methyl hydrogen-containing silicone oil (active hydrogen content 0.36wt%, viscosity 1000mPa·s) and 100g dry treated boron nitride powder (average particle size 10μm), 20g nitriding After the boron powder fibers (average diameter 200μm) are mixed evenly, they are made into corresponding modules according to the corresponding test methods. They are first placed in an environment of 70°C for 1 hour, and then heated to 130°C for 2 hours. The Shore hardness, thermal conductivity, high temperature aging resistance and bonding strength of the material (ie high thermal conductivity bora polysiloxane potting compound). The experimental test results are shown in Table 1.

Example 6:

At room temperature, 100g vinyl methyl silicone oil (polydimethylsiloxane containing both terminal vinyl groups and side vinyl groups, viscosity 10000mPa·s), 50g vinyl methyl nano MQ silicone resin (vinyl content 2.4wt%) , M/Q=0.75), 5g vinyl borosiloxane BS1, 45g vinyl polyborosiloxane PBS3, 0.2g ethynyl cyclohexanol, 0.3g tris(triphenylphosphine) rhodium carbonyl hydride (I) RhH(CO)(PPh ₃ ) ₃ (the content of rhodium is 11.2wt%), 0.3g 1,3-divinyl-1,1,3,3 tetramethyldisiloxane platinum complex (the content of platinum 0.2wt%), 2g glycidyl methacrylate, 5g borazine, 4g methyl hydrogen silicone oil (active hydrogen content 1.0wt%, viscosity 50mPa·s) and 100g dried boron nitride powder body (average particle size 10μm), 10g boron nitride powder (average particle size 50μm), and 10g boron nitride powder fiber (average diameter 20μm) are mixed evenly, and corresponding modules are made respectively according to the corresponding test methods. In the environment of 60 ℃ for 2 hours, then heated up to 140 ℃ for 1.5 hours, after cooling, the Shore hardness, thermal conductivity and high temperature aging resistance of the composite material (that is, high thermal conductivity bora polysiloxane potting glue) were respectively measured properties and bond strength. The experimental test results are shown in Table 1.

Example 7:

At room temperature, 20g terminal vinyl polydimethylsiloxane (viscosity 1000mPa s), 80g side vinyl polydimethylsiloxane (viscosity 80000mPa s), 80g vinyl methyl nano MQ silicone resin (ethylene Base content 1.0wt%, M/Q=0.6), 10g vinyl polyborosiloxane PBS2, 10g vinyl polyborosiloxane PBS4, 0.08g ethynyl cyclohexanol, 0.04g tetrakis (triphenylphosphine) Platinum Pt(PPh ₃ ) ₄ (15 wt% platinum content), 0.04g tetrakis(triphenylphosphine)palladium (9.2 wt% palladium content), 1g allyl glycidyl ether, 1g 4-vinyl epoxy Cyclohexane, 1g borazine, 7g methyl hydrogen silicone oil (active hydrogen 1.0wt%, viscosity 50mPa·s) and dried boron nitride powder (average particle size 10μm) 50g, boron nitride fiber (average diameter 100μm) 10g after mixing evenly, make corresponding modules according to the corresponding test method, first place it in the environment of 70 ℃ for 2 hours, then raise the temperature to 130 ℃ and keep it for 2 hours, after cooling, measure the composite materials respectively ( That is, the Shore hardness, thermal conductivity, high temperature aging resistance and bonding strength of high thermal conductivity borapolysiloxane potting compound. The experimental test results are shown in Table 1.

Example 8:

At room temperature, mix 80g terminal vinyl polydimethylsiloxane (viscosity 5000mPa·s), 20g side vinyl polydimethylsiloxane (viscosity 80000mPa·s), 100g vinylmethyl nano MQ silicone resin (ethylene Base content 2.4wt%, M/Q=0.75), 15g vinyl polyborosiloxane PBS2, 15g vinyl polyborosiloxane PBS3, 0.1g ethynyl cyclohexanol, 0.2g tris(triphenylphosphine) Rhodium carbonyl hydride (I) RhH (CO) (PPh ₃ ) ₃ (the content of rhodium is 11.2wt%), 0.1g two (triphenylphosphine) platinum dichloride (PPh ₃ ) ₂ PtCl ₂ (the content of platinum is 24.2wt%), 1g diglycidyl tetrahydrophthalate, 4g epoxy acrylate EA1, 3g borazine, 7g methyl hydrogen silicone oil (active hydrogen 0.75wt%, viscosity 200mPa·s) and 90g After the dried boron nitride powder (average particle size 10μm) and 10g boron nitride fiber (average diameter 100μm) are mixed evenly, corresponding modules are made according to the corresponding test methods, and they are first placed in an environment of 70°C for heat preservation. After 2 hours, the temperature was raised to 110°C and held for 3 hours. After cooling, the Shore hardness, thermal conductivity, high temperature aging resistance and bonding strength of the composite material (ie high thermal conductivity borapolysiloxane potting glue) were measured respectively. The experimental test results are shown in Table 1.

Table 1: Performance test results of potting compound

It can be seen from the table that the bora polysiloxane potting glue prepared by the present invention solidifies under the action of heat and catalyst to form a silicone rubber heat-conducting composite material with certain hardness and elasticity (Shore hardness is between 63～78A), not only sticky Strong relay (above 2.7MPa), with moisture-proof, shock-absorbing effect, also has a high thermal conductivity (up to 9.0W/(m K) above), and the composite material has no effect in the environment of high temperature 300 ℃ for 500 hours Shedding, foaming, cracking and discoloration, small internal stress, very little mass loss, only less than 2.2% mass loss after 500 hours, and excellent high temperature aging resistance.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (9)

1. a high heat conduction boron heteropolysiloxane joint sealant, is characterized in that: be made up of following component according to the mass fraction:

Wherein, the quality summation of borazine and Methyl Hydrogen Polysiloxane Fluid is no less than 6 parts; The consumption of precious metal organic compound catalyst comes in bullion content in organic compound catalyst; Described vinyl methyl polysiloxane is end-vinyl polydimethylsiloxane, side vinyldimethicone and simultaneously containing more than one in the polydimethylsiloxane of end-vinyl and side vinyl;

Described vinyl polyborosiloxane is vinyl polyborosiloxane 1, vinyl polyborosiloxane 2 or vinyl polyborosiloxane 3;

Described vinyl polyborosiloxane 1 is containing, for example lower structure:

[OB (R) OSi (CH ₃) (CH=CH ₂)] _m, wherein R=Ph, m=2 ~ 100 and m is integer;

The structural formula of described vinyl polyborosiloxane 2 is:

(CH ₂=CH) (CH ₃) ₂si [OB (R ₁) OSi (CH ₃) ₂] _moSi (CH ₃) ₂(CH=CH ₂); Wherein R ₁=OCH ₃or m=2 ~ 100 in formula and m is integer;

The structural formula of described vinyl polyborosiloxane 3 is:

(CH ₂=CH) (CH ₃) ₂si [OB (R ₁) OSi (CH ₃) ₂] _m[OB (R ₁) OSi (Ph) (R ₂)] _n[OSi (CH ₃) ₂] _p[OSi (Ph) (R ₂)] _qoSi (CH ₃) ₂(CH=CH ₂); Wherein, R ₁=OCH ₃or r ₂=OCH ₃, or in formula, m, n, p, q are the integer of 1 ~ 100;

Described vinyl Borosiloxane is RB [OSi (CH ₃) ₂(CH=CH ₂)] ₂, R=Ph.

2. high heat conduction boron heteropolysiloxane joint sealant according to claim 1, is characterized in that:

The structural formula of described end-vinyl polydimethylsiloxane is:

(CH ₂=CH) (CH ₃) ₂si [OSi (CH ₃) ₂] _noSi (CH ₃) ₂(CH=CH ₂); N>=2 in formula and n is integer;

The structural formula of described side vinyldimethicone is:

(CH ₃) ₃si [OSi (CH ₃) ₂] _m[OSi (CH=CH ₂) (CH ₃)] _noSi (CH ₃) ₃; M>=2 in formula, n>=2 and m, n are integer;

The described structural formula simultaneously containing the polydimethylsiloxane of end-vinyl and side vinyl is:

(CH ₂=CH) (CH ₃) ₂si [OSi (CH ₃) ₂] _m[OSi (CH=CH ₂) (CH ₃)] _noSi (CH ₃) _3-p(CH=CH ₂) _p; M>=2 in formula, n>=2 and m, n are integer; P=0 or 1;

The viscosity of described vinyl methyl polysiloxane is 1000 ~ 80000mPas.

3. high heat conduction boron heteropolysiloxane joint sealant according to claim 1, is characterized in that: described vinyl methyl nano MQ silicon resin forms nano-organosilicon resin material by M group organosilane monomer and Q group organosilane monomer by hydrolytic condensation; The mol ratio of described M group organosilane monomer and Q group organosilane monomer is 0.6 ~ 1.5:1.

4. high heat conduction boron heteropolysiloxane joint sealant according to claim 3, is characterized in that: described M group organosilane monomer contains simple function group organo-siloxane chain link R ₃siO _1/2, described R is made up of methyl and vinyl, and described contents of ethylene is 1.0 ~ 4.0% of vinyl methyl nano MQ silicon resin total mass;

Described Q group organosilane monomer contains four-functional group organo-siloxane chain link SiO ₂.

5. high heat conduction boron heteropolysiloxane joint sealant according to claim 1, is characterized in that: described precious metal organic compound catalyst is more than one in the complex compound of the complex compound of platinum, the complex compound of rhodium or palladium;

The complex compound of platinum is four (triphenylphosphine) platinum, suitable two (triphenylphosphine) platinum dichloride, 1,3-divinyl-1,1,3,3 tetramethyl disiloxane platinum complex; The complex compound of rhodium is three (triphenylphosphine) carbonyl hydrogenation Rh (I); The complex compound of palladium is tetrakis triphenylphosphine palladium.

6. high heat conduction boron heteropolysiloxane joint sealant according to claim 1, is characterized in that: described vinyloxirane is glycidyl allyl ether, 4 vinyl epoxy cyclohexane, tetrahydrophthalic acid 2-glycidyl ester or glycidyl methacrylate.

7. high heat conduction boron heteropolysiloxane joint sealant according to claim 1, it is characterized in that: in described Methyl Hydrogen Polysiloxane Fluid, the content of activated silica hydrogen bond hydrogen is 0.36 ~ 1.0% of Methyl Hydrogen Polysiloxane Fluid total mass, the viscosity of described Methyl Hydrogen Polysiloxane Fluid is 50 ~ 1000mPas.

8. high heat conduction boron heteropolysiloxane joint sealant according to claim 1, is characterized in that: described boron nitride ceramics is more than one in powdery boron nitride or fibrous boron nitride; Described powdery boron nitride particle median size is 50 μm ~ 1 μm, and fibrous boron nitride mean diameter is 20 ~ 200 μm.

9. the preparation method of high heat conduction boron heteropolysiloxane joint sealant according to any one of claim 1 ~ 8, it is characterized in that: comprise the following steps: at room temperature, by vinyl methyl polysiloxane, vinyl methyl nano MQ silicon resin, vinyl polyborosiloxane or vinyl Borosiloxane, ethynylcyclohexanol, precious metal organic compound catalyst, vinyloxirane is or/and epoxy acrylate, borazine, Methyl Hydrogen Polysiloxane Fluid and boron nitride ceramics mixing, then Procuring 1 ~ 2 hour at 50 ~ 70 DEG C, solidify 1 ~ 4 hour at 100 ~ 150 DEG C of temperature again, obtain high heat conduction boron heteropolysiloxane joint sealant.