CN115536849A

CN115536849A - Titanium hybrid MQ silicon resin, anti-sagging heat conduction gel, preparation method of anti-sagging heat conduction gel and electronic instrument

Info

Publication number: CN115536849A
Application number: CN202211247227.7A
Authority: CN
Inventors: 戴如勇; 陆兰硕; 林学好
Original assignee: Meixin New Materials Co ltd
Current assignee: Meixin New Materials Co ltd
Priority date: 2022-10-12
Filing date: 2022-10-12
Publication date: 2022-12-30
Anticipated expiration: 2042-10-12
Also published as: CN115536849B

Abstract

The application provides titanium hybridized MQ silicon resin, an anti-sagging heat conduction gel, a preparation method thereof and an electronic instrument, and relates toThe technical field of heat-conducting gel. The chemical composition of the titanium hybrid MQ silicon resin comprises M chain links (R) ₃ SiO _1/2 ) Q chain element (SiO) _4/2 ) And titanium-containing T chain units (TiO) _4/2 ) Wherein M: q: the molar ratio of T is (4.5-7.5): 1:2. the application also provides an anti-sagging heat-conducting gel, and the raw materials of the gel comprise the titanium hybridized MQ silicon resin and the modified heat-conducting filler treated by the titanate coupling agent. The preparation method of the anti-sagging heat-conducting gel comprises the following steps: mixing the above materials. The heat-conducting gel prepared by the method has good anti-sagging performance and adhesiveness and excellent heat-conducting performance through the synergistic interaction among the raw material components, and does not sag after being impacted at high and low temperatures.

Description

Titanium hybridized MQ silicon resin, anti-sagging heat conduction gel, preparation method of anti-sagging heat conduction gel and electronic instrument

Technical Field

The application relates to the technical field of heat conduction gel, in particular to titanium hybrid MQ silicon resin, an anti-sagging heat conduction gel, a preparation method of the anti-sagging heat conduction gel and an electronic instrument.

Background

With the rapid development of science and technology, people have higher and higher demands and requirements on portable electronic products. In order to achieve portability of electronic products, related electronic components in the products are gradually becoming integrated, miniaturized and densified, but in highly integrated electronic instruments, the amount of heat generated per unit volume is increasing. Therefore, it is necessary to conduct and dissipate the heat in time to avoid damage to the equipment caused by thermal cycling. In the electronic instruments, some high thermal conductive materials have been hot spots for technical research.

Among the heat conduction materials, materials such as heat conduction silicone grease and heat conduction silicone sheets fail due to long-term use or are only suitable for regular heat conduction interfaces and are difficult to fill irregular interfaces, so that the heat conduction gel is not suitable for different complex scenes, has excellent performance, can be used for heat conduction interfaces with extremely small interface thickness or irregular interface thickness through technologies such as smearing and dispensing, and becomes a common heat conduction material in more and more electronic instruments. However, some electronic devices are used in harsh environments and at extreme temperatures, and the heat conducting gel may have a vertical flow phenomenon, which makes it difficult to effectively conduct heat. Based on this, it is necessary to develop a thermally conductive gel that has good adhesion, resists sagging, and is resistant to high and low temperatures.

Disclosure of Invention

The application aims to provide titanium hybrid MQ silicon resin, anti-sagging heat conduction gel, a preparation method of the anti-sagging heat conduction gel and an electronic instrument. By selecting the titanium hybrid MQ silicon resin as the raw material of the anti-sagging heat-conducting gel, the prepared heat-conducting gel is ensured to have excellent anti-sagging performance, and the heat-conducting performance is excellent after high-low temperature impact tests.

In order to achieve the above purpose, the technical scheme of the application is as follows:

a titanium hybridized MQ silicon resin comprises a chemical composition of an M chain link, a Q chain link and a titanium-containing T chain link, wherein the unit chain links are represented as follows:

[R ₃ SiO _1/2 ] _x [SiO _4/2 ] _y [TiO _4/2 ] _z ；

wherein R comprises at least one of C1-C10 linear or branched alkyl, phenyl and vinyl; x: y: z = (4.5 to 7.5): 1:2.

preferably, the source of the M mer comprises at least one of hexamethyldisiloxane, tetramethyldivinyldisiloxane, tetramethyldihydro-disiloxane;

the source of the Q chain link comprises at least one of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate;

the source of the titanium-containing T chain segments comprises at least one of tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, n-butyl titanate, and tetraisobutyl titanate.

The application also provides an anti-sagging heat-conducting gel, and the raw materials of the gel comprise the titanium hybrid MQ silicon resin and the modified heat-conducting filler treated by the titanate coupling agent.

Preferably, the modified thermally conductive filler satisfies at least one of the following conditions a to c:

a. the titanate coupling agent comprises at least one of tetrabutyl titanate, triisostearoyl isopropyl titanate, isopropyl tri-titanate and diisostearoyl ethyl phthalate;

b. the heat-conducting filler comprises at least one of spherical aluminum oxide, zinc oxide, magnesium oxide, aluminum hydroxide, aluminum nitride, boron nitride and silicon carbide;

c. and 20-50 g of titanate coupling agent is added into every 1000g of the heat-conducting filler.

Preferably, the feedstock comprises: 80-95 parts of single-end-capped vinyl silicone oil, 850-950 parts of modified heat-conducting filler, 5-10 parts of titanium hybrid MQ silicone resin, 5-10 parts of rosin modified silane coupling agent, 2-3 parts of hydrogen-containing silicone oil, 0.3-0.6 part of catalyst and 0.1-0.2 part of inhibitor.

Further, the anti-sagging heat-conducting gel satisfies at least one of the following conditions d-h:

d. the kinematic viscosity of the single-end-capped vinyl silicone oil at 25 ℃ is 500-1000 mPa & s;

e. the rosin modified silane coupling agent comprises rosin modified aminopropyl triethoxysilane;

f. the hydrogen content of the hydrogen-containing silicone oil is 0.1wt% -0.75 wt%;

g. the catalyst comprises platinum water, and the platinum content in the catalyst is 3000 ppm-5000 ppm;

h. the inhibitor comprises at least one of ethynl cyclohexanol and 1- (1-propynyl) cyclohexanol.

The application also provides a preparation method of the anti-vertical flow heat conduction gel, which comprises the following steps: mixing raw materials including the titanium hybrid MQ silicon resin and the modified heat-conducting filler to obtain the anti-sagging heat-conducting gel.

Preferably, when the raw materials of the anti-sagging heat-conducting gel further comprise single-end-capped vinyl silicone oil, rosin modified silane coupling agent, hydrogen-containing silicone oil, inhibitor and catalyst, the preparation method comprises the following steps:

carrying out first mixing on raw materials including the titanium hybridized MQ silicon resin, the modified heat-conducting filler, the single-end-capped vinyl silicone oil, the rosin modified silane coupling agent, the hydrogen-containing silicone oil and the inhibitor to obtain a mixture;

and secondly, mixing the mixture with the catalyst to obtain the heat-conducting gel.

Preferably, the first mixing and the second mixing are independently performed under vacuum conditions ranging from-0.1 MPa to-0.08 MPa;

the first mixing time is 25min to 35min, and the second mixing time is 15min to 25min.

The application also provides an electronic instrument comprising the anti-sagging heat-conducting gel.

The beneficial effect of this application:

the titanium-containing T chain link is introduced into the titanium-hybridized MQ silicon resin, so that the temperature resistance of the silicon resin is greatly improved, the silicon resin can still maintain the self performance in extreme high-low temperature environments, and when the titanium-hybridized MQ silicon resin is applied to organic silicon materials such as silicone gel or silicone rubber, the titanium-hybridized MQ silicon resin still can have an excellent tackifying effect, and meanwhile, the temperature resistance of the organic silicon materials is also improved.

According to the anti-sagging heat-conducting gel, the titanium hybrid MQ silicon resin and the modified heat-conducting filler treated by the titanate coupling agent are used as raw materials, so that the weather resistance of the heat-conducting gel is greatly improved, the heat-conducting gel has excellent high and low temperature resistance, the modified heat-conducting filler can be combined with silicone oil in the heat-conducting gel more firmly, the phenomenon that the powder oil is separated from the heat-conducting gel after long-time work is avoided, and the anti-sagging performance of the heat-conducting gel is improved.

Furthermore, the single-end-capped vinyl silicone oil is used in the anti-sagging heat-conducting gel, the crosslinking density of the heat-conducting gel can be reduced, the rosin modified silane coupling agent is used for replacing a common silane coupling agent, the adhesion of the heat-conducting gel is improved, the high and low temperature resistance of the titanium hybrid MQ silicon resin is further improved by utilizing the excellent weather resistance and high and low temperature resistance of the titanium hybrid MQ silicon resin, the heat-conducting filler is treated by utilizing the titanate coupling agent, the silicone oil and the heat-conducting powder are firmly combined, the finally prepared heat-conducting gel is excellent in anti-sagging performance through the synergistic effect of the single-end-capped vinyl silicone oil, the titanium hybrid MQ silicon resin, the modified heat-conducting filler and the rosin modified silane coupling agent, and can be firmly adhered to an instrument even if used in an extreme high and low temperature environment, the sagging phenomenon does not occur, and the heat-conducting performance is excellent.

The preparation method of the anti-vertical flow heat conduction gel is simple in process, short in production period and high in production efficiency, and can be used for large-scale production and preparation.

The application provides an among the electronic instrument through using the anti-sagging heat conduction gel of this application, can play the effect of encapsulation, heat conduction, protection, and in extreme high low temperature environment, the adhesion of heat conduction gel still keeps better, and the heat conductivility is excellent, provides stable guarantee for electronic instrument's normal work.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the embodiments will be briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope of the present invention.

FIG. 1 is a graph showing the test results of the sample of example 1 before and after 1000H high and low temperature thermal shock;

FIG. 2 is a graph showing the test pictures of the sample of example 2 before and after 1000H high and low temperature cold and heat shock;

FIG. 3 is a graph showing the test results of example 3 before and after 1000H high and low temperature cold and heat shock;

FIG. 4 is a graph showing the test results of example 4 before and after 1000H high and low temperature thermal shock;

FIG. 5 is a graph showing the test results of example 5 before and after 1000H high and low temperature thermal shock;

FIG. 6 is a graph showing the test results of example 6 before and after 1000H high and low temperature thermal shock;

FIG. 7 is a sample test picture of comparative example 1 before and after 1000H high and low temperature thermal shock;

FIG. 8 is a graph showing the test results of comparative example 2 before and after 1000H high and low temperature thermal shock;

FIG. 9 is a graph showing the test results of comparative example 3 before and after 1000H high and low temperature thermal shock;

FIG. 10 is a graph showing the test pictures of the sample of comparative example 4 before and after 1000H high and low temperature thermal shock.

Detailed Description

The terms as used herein:

"consisting of 8230%" \8230, preparation "and" comprising "are synonymous. The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of 823070, 8230composition" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of 8230' \8230"; composition "appears in a clause of the subject matter of the claims and not immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the recited range should be interpreted to include ranges of "1 to 4," "1 to 3," "1 to 2 and 4 to 5," "1 to 3 and 5," and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In these examples, the parts and percentages are by mass unless otherwise indicated.

"part by mass" means a basic unit of measure indicating a mass ratio of a plurality of components, and 1 part may represent an arbitrary unit mass, for example, 1g or 2.689 g. If we say that the part by mass of the component A is a part by mass and the part by mass of the component B is B part by mass, the ratio of the part by mass of the component A to the part by mass of the component B is a: b. alternatively, the mass of the A component is aK and the mass of the B component is bK (K is an arbitrary number, and represents a multiple factor). It is unmistakable that, unlike the parts by mass, the sum of the parts by mass of all the components is not limited to 100 parts.

"and/or" is used to indicate that one or both of the illustrated conditions may occur, e.g., a and/or B includes (a and B) and (a or B).

In a first aspect, the present application provides a titanium hybrid MQ silicone resin having a chemical composition comprising M-mer, Q-mer, and titanium-containing T-mer, the unit mer of which is represented by: [ R ] ₃ SiO _1/2 ] _x [SiO _4/2 ] _y [TiO _4/2 ] _z ；

Wherein R comprises at least one of C1-C10 linear or branched alkyl, phenyl and vinyl; x: y: z = (4.5 to 7.5): 1:2, for example, may be 4.5:1: 2. 5.0:1: 2. 5.5:1: 2. 6.0:1: 2. 6.5:1: 2. 7.0:1: 2. 7.5:1:2 or (4.5-7.5): 1: any value between 2.

It should be noted that MQ silicone resins are also classified into different types due to the difference of organic groups R, and when all R are methyl, they are called methyl MQ silicone resins; when the part R is H, the methyl hydrogen-containing MQ silicon resin is called; and methyl phenyl MQ silicon resin, vinyl MQ silicon resin, phenyl MQ silicon resin, fluorine-containing MQ silicon resin and the like. The performance and the application range of the MQ silicon resin mainly depend on the synthesis process condition and the type and the number of organic groups in molecules, namely the number ratio of M chain links to Q chain links; the M chain link containing the organic group R is mainly used for increasing the compatibility with other components and playing a role in tackifying, and the Q chain link is mainly used for improving the strength of the composite material and playing a role in reinforcing. In addition to the M chain link and the Q chain link, the titanium-containing T chain link is added into the MQ silicon resin to form the titanium hybrid MQ silicon resin, and structural units of Si-O-Si, si-O-Ti and Ti-O-Ti exist in the silicon resin, so that the silicon resin has the characteristics of common MQ silicon resin, has excellent weather resistance and high and low temperature resistance, and can still maintain excellent bonding performance under extreme high and low temperature environments.

The general MQ silicon resin is mainly prepared by carrying out cohydrolysis polycondensation reaction on compounds containing M chain links and Q chain links, and the titanium hybrid MQ silicon resin in the application contains M chain links (R) in addition ₃ SiO _1/2 ) And Q chain link (SiO) _4/2 ) Contains tetrafunctional titanoxane units (TiO) in addition to the organosilicon compound of (a) _4/2 ) The compounds of (2) also participate in the cohydrolytic polycondensation reaction.

In some alternative embodiments, the source of M mer comprises at least one of hexamethyldisiloxane, tetramethyldivinyldisiloxane, tetramethyldihydrodisiloxane.

In some alternative embodiments, the source of Q mer comprises at least one of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, butyl orthosilicate.

In some alternative embodiments, the source of titanium-containing T-mer comprises at least one of tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, n-butyl titanate, tetraisobutyl titanate.

In some alternative embodiments, a method of preparing a titanium hybrid MQ silicone resin, comprises:

(1) Uniformly stirring raw materials including hexamethyldisiloxane, deionized water and ethanol under the conditions that the pH value is 1.5-2.5 and the temperature is 70-90 ℃ to obtain a first solution;

(2) Adding tetraethoxysilane and tetrabutyl titanate into the first solution, and continuously mixing and stirring at the temperature of 70-90 ℃ to obtain a second solution;

(3) Cooling the second solution to room temperature, adding dimethyl silicone oil, extracting, standing, layering, and discharging an acid water layer to obtain a hydrolysate;

(4) And (3) washing the obtained hydrolysate to be neutral, adding tetramethylammonium hydroxide, heating to 100-110 ℃, and carrying out polymerization reaction to obtain the titanium hybrid MQ silicon resin.

In a second aspect, the present application also provides an anti-sagging thermal conductive gel, the raw materials of which include the titanium hybrid MQ silicone resin described above and a modified thermal conductive filler treated with a titanate coupling agent.

It should be noted that, the specific treatment process of the modified heat conductive filler is not specifically limited, and may be: mixing the heat-conducting filler with water, spraying the titanate coupling agent into the heat-conducting filler by using a spraying device, continuously stirring in the spraying process, continuously stirring after the spraying is finished, filtering out moisture by using a filter screen after the heat-conducting filler and the titanate coupling agent are fully and uniformly mixed, and drying the powder in an oven to constant weight.

In some alternative embodiments, the titanate coupling agent comprises at least one of tetrabutyl titanate, isopropyl triisostearate, isopropyl tri-titanate, ethyl diisostearoylphthalate. More preferably, the titanate coupling agent is isopropyl triisostearate.

In some alternative embodiments, the thermally conductive filler includes at least one of spherical alumina, zinc oxide, magnesium oxide, aluminum hydroxide, aluminum nitride, boron nitride, and silicon carbide.

It can be understood that because the hole is more between the granule of heat conduction filler and the granule, these holes can influence thermal transmission efficiency, consequently for the heat conductivility that improves heat conduction gel, reduce the porosity between the filler, the heat conduction filler that has selected different particle size for use has been used in the cooperation to this application for form compact pile structure between the heat conduction filler.

In some alternative embodiments, 20g to 50g of the titanate coupling agent is added to 1000g of the thermally conductive filler for modification, for example, 20g, 25g, 30g, 35g, 40g, 45g, 50g, or any value between 20g and 50g may be added. More preferably, 25g to 35g of the titanate coupling agent is added per 1000 g.

In some alternative embodiments, the anti-sagging heat-conducting gel comprises the following raw material components in parts by weight: 80 to 95 parts of mono-blocked vinyl silicone oil, for example, 80 parts, 82 parts, 84 parts, 86 parts, 88 parts, 90 parts, 92 parts, 94 parts, 95 parts or any value between 80 parts and 95 parts;

850 to 950 parts of the modified heat-conducting filler, for example, 850 to 860 parts, 870 parts, 880 parts, 890 parts, 900 parts, 910 parts, 920 parts, 930 parts, 940 parts, 950 parts or any value between 850 and 950 parts;

the titanium hybrid MQ silicon resin is 5 to 10 parts, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts or any value between 5 parts and 10 parts;

the rosin-modified silane coupling agent is 5 to 10 parts, and may be, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, or any value between 5 and 10 parts;

2 to 3 parts of hydrogen-containing silicone oil, for example, 2 parts, 2.3 parts, 2.5 parts, 2.8 parts, 3 parts or any value between 2 and 3 parts;

0.3 to 0.6 part of catalyst, which may be, for example, 0.3 part, 0.35 part, 0.4 part, 0.45 part, 0.5 part, or any value between 0.3 and 0.6 part;

the inhibitor is 0.1 to 0.2 parts, and may be, for example, 0.1 part, 0.13 part, 0.15 part, 0.18 part, 0.2 part, or any value between 0.1 and 0.2 parts.

In some alternative embodiments, the rosin-modified silane coupling agent comprises a rosin-modified aminopropyltriethoxysilane having the molecular structure:

as can be understood, the rosin modified silane coupling agent is added into the heat-conducting gel, and the advantage that the groups on the surface of the rosin modified silane coupling agent are easy to react with the groups of the bonding base material and form chemical bond connection is utilized to improve the adhesive force of the heat-conducting gel.

In some alternative embodiments, the mono-blocked vinyl silicone oil has a kinematic viscosity at 25 ℃ of 500 to 1000 mPas, for example 500, 600, 700, 800, 900, 1000 or any value between 500 and 1000 mPas.

Compared with double-end-capping vinyl silicone oil, side-chain vinyl silicone oil and end-side vinyl silicone oil, the single-end-capping vinyl silicone oil has lower crosslinking density after addition reaction, and can reduce the hardness of the heat-conducting gel, thereby reducing the stress of the heat-conducting gel on an electronic instrument during use.

In some alternative embodiments, the hydrogen content of the hydrogen-containing silicone oil is 0.1wt% to 0.75wt%, and may be, for example, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.75wt%, or any value between 0.1wt% and 0.75 wt%. More preferably, the hydrogen-containing silicone oil has a hydrogen content of 0.18wt%.

The hydrogen-containing silicone oil of the present application includes at least one of a side chain hydrogen-containing silicone oil and a terminal side hydrogen-containing silicone oil. It is obvious that the hydrogen-containing silicone oil on the end side has hydrogen bonds at both the end-capping position and the side chain position, and therefore, when the addition reaction proceeds, the crosslinking density of the heat conductive gel is likely to increase, and the hardness is likely to increase. Therefore, in the present application, it is preferable to use a side chain hydrogen-containing silicone oil and a single terminal hydrogen-containing silicone oil.

In some alternative embodiments, the catalyst comprises platinum-gold water, and the platinum content in the catalyst is from 3000ppm to 5000ppm, and may be, for example, 3000ppm, 4000ppm, 5000ppm, or any value between 3000ppm and 5000 ppm. The catalyst can be also called platinum catalyst and Kaersit catalyst, is a light yellow liquid, and can rapidly catalyze the addition crosslinking reaction between vinyl-containing siloxane and hydrogen-containing siloxane.

In some alternative embodiments, the inhibitor comprises at least one of ethynl cyclohexanol, 1- (1-propynyl) cyclohexanol.

In a third aspect, the present application further provides a preparation method of the anti-sagging heat-conducting gel, including: mixing raw materials including the modified heat-conducting filler and the titanium hybrid MQ silicon resin to obtain the heat-conducting gel.

Further, when the raw materials of the anti-sagging heat-conducting gel further comprise single-end-capped vinyl silicone oil, rosin modified silane coupling agent, hydrogen-containing silicone oil, inhibitor and catalyst, the preparation method comprises the following steps:

(1) Carrying out first mixing on raw materials including the titanium hybrid MQ silicon resin, the modified heat-conducting filler, the single-end-capped vinyl silicone oil, the rosin modified silane coupling agent, the hydrogen-containing silicone oil and the inhibitor to obtain a mixture;

(2) And secondly, mixing the mixture with the catalyst to obtain the heat-conducting gel.

It should be noted that, when preparing the heat conductive gel, different types of vacuum mixers available in the market can be used for stirring. Wherein, the first mixing and the second mixing are carried out under the vacuum condition which is-0.1 MPa to-0.08 MPa. The main purpose is to ensure that bubbles in the raw materials are removed as much as possible during the mixing process of the raw materials, and prevent the final performance of the heat-conducting gel from being affected by the bubbles in the gel when the heat-conducting gel is used subsequently.

In some alternative embodiments, the time required for the first mixing is 25min to 35min, for example 25min, 28min, 30min, 32min, 35min or any value between 25min and 35 min; the time required for the second mixing is 15 to 25min, and may be, for example, 15min, 18min, 20min, 22min, 25min or any value between 15 and 25min.

Embodiments of the present invention will be described in detail below with reference to specific examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are conventional products which are not indicated by manufacturers and are commercially available.

Example 1

This example provides a titanium hybrid MQ silicone resin, the unit chain links of which are shown below:

[R ₃ SiO _1/2 ] _x [SiO _4/2 ] _y [TiO _4/2 ] _z ；

wherein R is-CH ₃ ；x：y：z＝6：1：2。

The M: q: the molar ratio of T is 6:1:2, the preparation method of the titanium hybrid MQ silicon resin comprises the following steps:

(1) Stirring 162.38g of hexamethyldisiloxane, 200g of deionized water and 50g of absolute ethyl alcohol for 60min under the conditions that the pH is 2 and the temperature is 80 ℃ to obtain a first solution;

(2) Adding 34.721g of ethyl orthosilicate and 69.442g of tetrabutyl titanate into the first solution, and continuously stirring for 5 hours at 80 ℃ to obtain a second solution;

(3) Cooling the second solution to room temperature, adding 200g of dimethyl silicone oil (the viscosity is 50mPa & s), extracting, standing, layering, and discharging an acid water layer to obtain a hydrolysate;

(4) And (3) washing the obtained hydrolysate to be neutral, adding 0.02g of tetramethylammonium hydroxide, heating to 100 ℃, and carrying out polymerization reaction for 3 hours to obtain M: q: the T molar ratio is 6:1:2, a titanium hybrid MQ silicone resin.

The present embodiments also provide an anti-sagging heat-conducting gel, comprising: 87g of singly-terminated vinyl silicone oil, 897.5g of modified heat-conducting filler, 5g of rosin-modified silane coupling agent, 8g of M: q: the molar ratio of T is 6:1:2 of titanium hybridized MQ silicon resin, 2g of side chain hydrogen-containing silicone oil, 0.1g of ethynl cyclohexanol and 0.3g of platinum water.

The preparation method of the modified heat-conducting filler comprises the following steps: 200g of 1-micron spherical alumina, 300g of 5-micron spherical alumina and 500g of 20-micron spherical alumina are mixed with 10kg of distilled water, the mixture is stirred for 10min at the rotating speed of 500rpm, 30g of titanate coupling agent is added by a spraying device, then the mixture is continuously mixed for 20min at the rotating speed of 2000rpm, the mixed material is filtered by a filter screen, the filtered material is placed in a vacuum oven, and the dried material is dried to constant weight at 105 ℃ to obtain the modified heat-conducting filler.

The preparation method of the anti-sagging heat-conducting gel comprises the following steps:

(1) 87g of a mono-blocked vinyl silicone oil having a kinematic viscosity of 500 mPas, 8g of M: q: the T molar ratio is 6:1:2, 2g of titanium hybrid MQ silicon resin, 2g of side chain hydrogen-containing silicone oil with the hydrogen content of 0.18wt%, 897.5g of modified heat-conducting filler, 5g of rosin modified silane coupling agent and 0.1g of ethynl cyclohexanol, adding into a vacuum planetary stirrer, and stirring at the rotating speed of-0.08 MPa and 10rpm for 30min to obtain a mixture;

(2) And adding 0.3g of 5000ppm platinum water into the mixture, stirring for 20min at the rotating speed of-0.08 MPa and 10rpm, and carrying out full reaction to obtain the heat-conducting gel.

Example 2

The same as in example 1 except that the kinematic viscosity of the mono-blocked vinyl silicone oil became 1000 mPas.

Example 3

Same as example 1, except that M: q: the molar ratio of T is 4:1:2, wherein the addition amount of hexamethyldisiloxane became 108.25g.

Example 4

The same as in example 1, except that the amount of the side chain hydrogen-containing silicone oil added was changed to 3g.

Example 5

The same as example 1, except that the amount of the one-terminal vinyl silicone oil added was changed to 82g, and the amount of the modified heat conductive filler added was changed to 902.5g.

Example 6

The same as in example 1, except that the amount of the mono-blocked vinyl silicone oil added was changed to 82g, and the amount of the rosin-modified silane coupling agent added was changed to 10g.

Comparative example 1

The same as in example 1, except that the rosin-modified silane coupling agent was replaced with a silane coupling agent of γ -aminopropyltriethoxysilane.

Comparative example 2

The same as example 1, except that the titanium hybrid MQ silicone resin was replaced with a conventional M: q molar ratio is 4:5 MQ silicone resin.

Comparative example 3

The same as in example 1, except that the single-ended vinyl silicone oil having a kinematic viscosity of 500 mPas was replaced with the double-ended vinyl silicone oil having a kinematic viscosity of 500 mPas.

Comparative example 4

The same as example 1, except that the modified thermally conductive filler was obtained by treating the thermally conductive filler with a titanate coupling agent instead of the conventional silane coupling agent γ - (2, 3-glycidoxy) propyltrimethoxysilane.

And (3) carrying out performance detection on the prepared heat-conducting gel, wherein the specific detection standard is as follows:

coefficient of thermal conductivity: according to the standard in ASTM D5470-2017, the unit is W/m.k;

thermal resistance: according to the standard in ASTM D5470-2017, the unit is in2/W at DEG C;

dispensing rate: the mass extruded at 1min was measured in g according to 90psi,1mm rubber nozzle;

specific gravity after curing: in g/cc according to ASTM D792-2007 Standard for testing Density and relative Density of plastics;

vertical flow test: the high and low temperature cold and heat shocks were simultaneously increased according to ASTM D2202-2000 (2006) sealant slump test method. Wherein, the high-low temperature cold and hot impact conditions are as follows: the cured heat-conducting gel is tested for 1000H at the circulating temperature of-40-150 ℃, and the time of each high-temperature and low-temperature circulation is 10min. The vertical flow test is mainly used for simulating the product to sag due to the gravity possibly suffered by the product during the use under different high and low temperature environments, and the anti-gravity capability of the product under the impact of high and low temperature is investigated. Generally, because the adhesive product is cured and sags, the resistance to gravity at normal temperature is tested, but the heat-conducting gel is always in a gel state, so that the phenomenon of sagging caused by gravity can occur during the use of the adhesive product. The vertical flow test of the thermally conductive gel requires the addition of high and low temperature cold and thermal shock conditions as a reference standard.

According to the vertical flow test condition, the heat conducting gel with the diameter of 10-20 mm and the height of 2mm is clamped between two pieces of glass to perform a high-low temperature cold and heat shock test. The product of the same example uses 6 or 7 samples for the test before and after the vertical flow, if all samples are still in the center of the glass after the high and low temperature cold and hot shock test and the position is not shifted, the test result is determined as follows: no vertical flow exists; if any sample in the samples generates certain deviation after the high and low temperature impact test is finished, judging that the test result is as follows: and (4) vertical flow. The results of the specific vertical flow test can be seen in the figure.

FIG. 1 is a picture of the thermally conductive gel prepared in example 1 before and after high and low temperature thermal shock. Wherein, the upper row in fig. 1 is samples before high and low temperature thermal shock, and the lower row is samples after high and low temperature thermal shock (the vertical arrangement sequence of the samples before and after high and low temperature thermal shock in fig. 2-10 is the same as that in fig. 1). Fig. 2,3, 4, 5 and 6 are pictures of the thermally conductive gel prepared in examples 2-6 before and after high and low temperature thermal shock. According to the sample conditions of fig. 1-6, it is obvious that the thermally conductive gel samples prepared by the present application have no phenomenon of vertical flow even after high and low temperature cold and hot shock.

Fig. 7, 8, 9 and 10 correspond to the images of the thermally conductive gels prepared in comparative examples 1 to 4 before and after high and low temperature thermal shock, respectively. According to fig. 7-10, it is evident that all samples in fig. 7 slip downward from their original positions after being subjected to high and low temperature thermal shock, which indicates that the samples have poor adhesion and generate vertical flow after being subjected to high and low temperature thermal shock; the samples in FIG. 8 have obvious vertical flow after high and low temperature cold and heat shock, and some samples have poor adhesion and directly fall off from the glass plate; although some of the samples in fig. 9 and 10 have good state after high and low temperature thermal shock, the positions of the individual samples are shifted to some extent, which indicates that the samples prepared by the formulation still have a vertical flow phenomenon after high and low temperature thermal shock.

The results of examining the different properties of examples 1 to 6 and comparative examples 1 to 4 are shown in Table 1.

TABLE 1

As can be seen from Table 1, the heat-conducting gel prepared by the method is excellent in heat-conducting property and good in anti-vertical flow property. Further, the heat-conducting gel prepared by the method has good adhesion and excellent anti-sagging performance through the synergistic interaction of the single-ended vinyl silicone oil, the titanium hybridized MQ silicone resin, the modified heat-conducting filler and the rosin modified silane coupling agent, and does not sag even after 1000 hours of high-low temperature cold and hot impact.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Moreover, those of skill in the art will appreciate that while some embodiments herein include some features included in other embodiments, not others, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Claims

1. A titanium-hybrid MQ silicone resin, wherein the chemical composition of the titanium-hybrid MQ silicone resin comprises M-mer, Q-mer, and titanium-containing T-mer, the unit mer of which is represented as:

[R ₃ SiO _1/2 ] _x [SiO _4/2 ] _y [TiO _4/2 ] _z ；

2. the titanium hybrid MQ silicone resin of claim 1, wherein the source of M mer comprises at least one of hexamethyldisiloxane, tetramethyldivinyldisiloxane, tetramethyldihydrodisiloxane;

3. An anti-sagging thermal conductive gel, characterized in that the raw materials of the anti-sagging thermal conductive gel comprise the titanium hybrid MQ silicone resin of claim 1 or 2 and a modified thermal conductive filler treated with a titanate coupling agent.

4. An anti-sagging heat transfer gel as recited in claim 3, wherein at least one of the following conditions a-c is satisfied:

a. the titanate coupling agent comprises at least one of tetrabutyl titanate, triisostearoyl isopropyl titanate, isopropyl trititanate and diisostearoyl ethyl phthalate;

c. and 20g to 50g of the titanate coupling agent is added into every 1000g of the heat-conducting filler.

5. The anti-sag, thermally conductive gel according to claim 3, wherein the materials for the anti-sag, thermally conductive gel comprise: 80-95 parts of single-end-capped vinyl silicone oil, 850-950 parts of modified heat-conducting filler, 5-10 parts of titanium hybrid MQ silicone resin, 5-10 parts of rosin modified silane coupling agent, 2-3 parts of hydrogen-containing silicone oil, 0.3-0.6 part of catalyst and 0.1-0.2 part of inhibitor.

6. The anti-sagging heat transfer gel of claim 5, wherein at least one of the following conditions d-h is satisfied:

d. the kinematic viscosity of the single-end-capped vinyl silicone oil at 25 ℃ is 500-1000 mPa s;

7. A method for preparing the anti-sagging heat-conducting gel of any one of claims 3 to 6, comprising: mixing raw materials including the titanium hybrid MQ silicon resin and the modified heat-conducting filler to obtain the anti-sagging heat-conducting gel.

8. The method of claim 7, wherein when the raw materials of the anti-sagging heat-conductive gel further include a mono-blocked vinyl silicone oil, a rosin-modified silane coupling agent, a hydrogen-containing silicone oil, an inhibitor, and a catalyst, the method comprises:

and carrying out second mixing on the mixture and the catalyst to obtain the heat-conducting gel.

9. The method of claim 8, wherein the first mixing and the second mixing are each independently performed under vacuum conditions ranging from-0.1 MPa to-0.08 MPa;

10. An electronic device comprising the anti-sagging thermal gel of any one of claims 3 to 6.