Anti-falling heat-conducting gel, preparation method thereof and electronic instrument
阅读说明：本技术 一种抗跌落导热凝胶及其制备方法、电子仪器 (Anti-falling heat-conducting gel, preparation method thereof and electronic instrument ) 是由 戴如勇 林学好 陆兰硕 陈维斌 潘泰康 李永波 王世金 陈婉 于 2021-10-08 设计创作，主要内容包括：本申请提供一种抗跌落导热凝胶及其制备方法、电子仪器。该抗跌落导热凝胶包括：单封端乙烯基硅油80份～95份；MQ硅树脂5份～10份；含氢硅油2份～3份；导热填料880份～900份；有机硅锚固剂5份～10份；催化剂0.3份～0.6份；抑制剂0.1份～0.2份。将上述原料除催化剂外进行第一混合,得到混合基料；再加入催化剂进行第二混合,经过反应后,即得抗跌落导热凝胶。该导热凝胶的导热性能优异,且粘附性好,抗跌落性能优越,在一些易碰撞、跌落的电子仪器上使用时,导热凝胶会牢固的粘附在仪器上,不发生滑移现象,极大提高了电子仪器的安全可靠性。(The application provides an anti-drop heat-conducting gel, a preparation method thereof and an electronic instrument. The anti-drop thermally conductive gel comprises: 80-95 parts of single-end-capped vinyl silicone oil; 5-10 parts of MQ silicon resin; 2-3 parts of hydrogen-containing silicone oil; 880-900 parts of heat-conducting filler; 5-10 parts of organic silicon anchoring agent; 0.3 to 0.6 portion of catalyst; 0.1 to 0.2 portion of inhibitor. Carrying out first mixing on the raw materials except for the catalyst to obtain a mixed base material; and adding a catalyst for second mixing, and reacting to obtain the anti-falling heat-conducting gel. The heat-conducting gel has excellent heat-conducting property, good adhesion and excellent anti-falling property, and when the heat-conducting gel is used on some electronic instruments which are easy to collide and fall, the heat-conducting gel can be firmly adhered to the instruments, the slippage phenomenon is avoided, and the safety and reliability of the electronic instruments are greatly improved.)
1. An anti-drop heat-conducting gel is characterized by comprising the following components in parts by weight:
80-95 parts of single-end-capped vinyl silicone oil;
5-10 parts of MQ silicon resin;
2-3 parts of hydrogen-containing silicone oil;
880-900 parts of heat-conducting filler;
5-10 parts of organic silicon anchoring agent;
0.3 to 0.6 portion of catalyst;
0.1 to 0.2 portion of inhibitor.
2. The drop-resistant, thermally conductive gel of claim 1, wherein the MQ silicone resin has a M: the molar ratio of Q is (1.5-2.5): 1.
3. the drop-resistant thermally conductive gel of claim 1, wherein the single-blocked vinyl silicone oil is polydimethylsiloxane having only one vinyl group at one end of the molecular chain;
the kinematic viscosity of the single-end capping vinyl silicone oil at 25 ℃ is 500mPa & s-1000 mPa & s.
4. The drop-resistant thermally conductive gel of claim 1, wherein the hydrogen content of the hydrogen-containing silicone oil is 0.1 wt% to 0.75 wt%;
the hydrogen-containing silicone oil comprises at least one of side chain hydrogen-containing silicone oil and terminal hydrogen-containing silicone oil.
5. The drop-resistant thermally conductive gel of claim 1, wherein the thermally conductive filler comprises at least one of spherical aluminum oxide, aluminum hydroxide, aluminum nitride, zinc oxide, boron nitride, magnesium oxide;
the kinematic viscosity of the organic silicon anchoring agent at 25 ℃ is 50-100 mPa & s;
the catalyst is a platinum catalyst, and the concentration of the platinum catalyst is 3000 ppm-5000 ppm.
6. The drop-resistant thermally conductive gel of any one of claims 1-5, wherein the inhibitor comprises at least one of ethynl cyclohexanol, 1- (1-propynyl) cyclohexanol.
7. A preparation method of the anti-drop heat-conducting gel as claimed in any one of claims 1 to 6, which is characterized by comprising the following steps:
firstly mixing raw materials including single-end-capped vinyl silicone oil, MQ silicone resin, hydrogen-containing silicone oil, heat-conducting filler, organic silicon anchoring agent and inhibitor to obtain a mixed base material;
and adding a catalyst into the mixed base material for second mixing, and reacting to obtain the anti-falling heat-conducting gel.
8. The method for preparing a drop-resistant thermally conductive gel according to claim 7, wherein the molar ratio of the M unit capping agent to the Q unit silicate in the preparation of the MQ silicone resin is (1.5-2.5): 1;
the M unit blocking agent comprises at least one of hexamethyldisiloxane, tetramethyldivinyldisiloxane and tetramethyldihydro-disiloxane;
the Q-unit silicate comprises at least one of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate.
9. The preparation method of the anti-drop heat-conducting gel according to any one of claims 7 to 8, wherein the first mixing and the second mixing are stirred under a vacuum condition, wherein the vacuum condition is-0.1 MPa to-0.08 MPa;
the stirring time of the first mixing is 28 min-32 min, and the stirring time of the second mixing is 18 min-22 min.
10. An electronic instrument comprising the anti-drop thermal conductive gel according to any one of claims 1 to 6.
Technical Field
The invention relates to the technical field of heat-conducting gel, in particular to anti-falling heat-conducting gel, a preparation method thereof and an electronic instrument.
Background
With the rapid development of electronic information technology, the assembly of related electronic components in electronic instruments is miniaturized and densified, but the strength of the electronic components is weak and weak along with the temperature change, and heat conduction and packaging protection are required, so that heat conduction materials with low elastic modulus and ultralow stress are required to relax and protect sensitive electronic components from mechanical stress caused by thermal cycling and stress caused by external force. In the heat conduction material, the heat conduction silicone grease has no crosslinking reaction, so that oil and powder are easily separated, and silicone oil is separated out and becomes dry and ineffective after being used for a long time; the heat-conducting silica gel sheet has a certain thickness, and the processing technology of the heat-conducting silica gel sheet is cut in a regular shape, so that an irregular heat-conducting interface is difficult to fill; the heat-conducting gel has excellent heat-conducting property, can be well filled by technologies such as smearing, dispensing and the like aiming at a heat-conducting interface with extremely small interface thickness or irregular interface thickness, and has good stability. Therefore, more and more electronic products are beginning to use thermally conductive gel materials. However, in some electronic instruments, such as mobile phones and drones, the heat conducting gel often slips due to collision and falling of the equipment, so that the heat is difficult to be effectively conducted, and the instrument fails.
Based on this, in order to solve the problem that the heat-conducting gel slides and fails due to collision and falling of electronic equipment, it is urgently needed to develop a heat-conducting gel with good adhesion and falling resistance.
Disclosure of Invention
The invention aims to provide a heat-conducting gel with excellent anti-falling performance, a preparation method thereof and an electronic instrument.
In order to achieve the above purpose, the specific technical scheme of the application is as follows:
an anti-drop heat-conducting gel comprises the following components in parts by weight:
80-95 parts of single-end-capped vinyl silicone oil;
5-10 parts of MQ silicon resin;
2-3 parts of hydrogen-containing silicone oil;
880-900 parts of heat-conducting filler;
5-10 parts of organic silicon anchoring agent;
0.3 to 0.6 portion of catalyst;
0.1 to 0.2 portion of inhibitor.
Preferably, in the MQ silicone resin, M: the molar ratio of Q is (1.5-2.5): 1.
preferably, the single-end-capped vinyl silicone oil is polydimethylsiloxane with only one vinyl at one end of a molecular chain;
the kinematic viscosity of the single-end capping vinyl silicone oil at 25 ℃ is 500mPa & s-1000 mPa & s.
Preferably, the hydrogen content of the hydrogen-containing silicone oil is 0.1 wt% to 0.75 wt%;
the hydrogen-containing silicone oil comprises at least one of side chain hydrogen-containing silicone oil and terminal hydrogen-containing silicone oil.
Preferably, the heat conducting filler comprises at least one of spherical aluminum oxide, aluminum hydroxide, aluminum nitride, zinc oxide, boron nitride and magnesium oxide;
the kinematic viscosity of the organic silicon anchoring agent at 25 ℃ is 50-100 mPa & s;
the catalyst is a platinum catalyst, and the concentration of the platinum catalyst is 3000 ppm-5000 ppm.
Preferably, the inhibitor is at least one of ethynl cyclohexanol and 1- (1-propynyl) cyclohexanol.
The application also provides a preparation method of the anti-falling heat-conducting gel, which comprises the following steps:
firstly mixing raw materials including single-end-capped vinyl silicone oil, MQ silicone resin, hydrogen-containing silicone oil, heat-conducting filler, organic silicon anchoring agent and inhibitor to obtain a mixed base material;
and adding a catalyst into the mixed base material for second mixing, and reacting to obtain the anti-falling heat-conducting gel.
Preferably, in the process of preparing the MQ silicon resin, the molar ratio of the M unit end capping agent to the Q unit silicate is (1.5-2.5): 1;
the M unit blocking agent comprises at least one of hexamethyldisiloxane, tetramethyldivinyldisiloxane and tetramethyldihydro-disiloxane;
the Q-unit silicate comprises at least one of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate.
Preferably, the first mixing and the second mixing need to be stirred under a vacuum condition, wherein the vacuum condition is-0.1 MPa to-0.08 MPa;
the stirring time of the first mixing is 28 min-32 min, and the stirring time of the second mixing is 18 min-22 min.
The application also provides an electronic instrument, which comprises the anti-falling heat-conducting gel.
The invention has the beneficial effects that:
the anti-drop heat-conducting gel provided by the application uses single-end vinyl silicone oil to replace common vinyl silicone oil, so that the cross-linking density of the heat-conducting gel is lower; the organic silicon anchoring agent is used for replacing a common silane coupling agent, so that the adhesion of the heat-conducting gel is improved; and MQ silicon resin is also added, and the adhesiveness of the heat-conducting gel is further improved by utilizing the good compatibility of organic groups in the MQ silicon resin and the vinyl silicone oil. The heat-conducting gel anti-falling device has the advantages that the heat-conducting gel anti-falling performance prepared finally is superior through the synergistic interaction of the single-ended vinyl silicone oil, the MQ silicone resin and the organic silicon anchoring agent, when the heat-conducting gel anti-falling device is used on some electronic instruments which are easy to collide and fall, the heat-conducting gel anti-falling performance is excellent, the heat-conducting gel is firmly adhered to the instruments, the sliding phenomenon does not occur, and the heat-conducting performance is excellent.
The application also provides a preparation method of the anti-falling heat-conducting gel, the production process is simple and easy to implement, and compared with the double-component heat-conducting gel, the single-component heat-conducting gel greatly shortens the production period and has high production efficiency.
The application also provides an electronic instrument, and the anti-falling heat conduction gel prepared by the application can be applied to the electronic instrument to play roles in heat conduction, packaging, protection and the like. Even if the electronic instrument is collided, dropped, etc., the heat conducting gel will not slip, so as to protect the electronic instrument effectively.
Drawings
To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed for the embodiments and the comparative examples 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 test picture of samples before and after a drop in example 1;
FIG. 2 is a test picture of a sample before and after dropping in example 2;
FIG. 3 is a test picture of a sample before and after dropping in example 3;
FIG. 4 is a test picture of samples before and after falling in example 4;
FIG. 5 is a test picture of samples before and after falling in example 5;
FIG. 6 is a test picture of samples before and after falling in example 6;
FIG. 7 is a test picture of the sample before and after falling of comparative example 1;
FIG. 8 is a test picture of a sample before and after dropping of comparative example 2;
fig. 9 is a test picture of the sample before and after falling of comparative example 3.
Detailed Description
The terms as used herein:
"prepared from … …" is synonymous with "comprising". 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 … …" 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 … …" appears in a clause of the subject matter of the claims rather than 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 the range "1 ~ 5" is disclosed, the ranges described should be construed to include the ranges "1 ~ 4", "1 ~ 3", "1 ~ 2 and 4 ~ 5", "1 ~ 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 any 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).
The application provides an anti-falling heat conduction gel, by weight, includes:
80-95 parts of single-end-capped vinyl silicone oil (specifically, any value between 80 parts, 82 parts, 84 parts, 86 parts, 87 parts, 89 parts, 91 parts, 93 parts, 95 parts or 85-95 parts);
5-10 parts of MQ silicon resin (specifically, any value between 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts or 5-10 parts);
880 to 900 parts of a thermally conductive filler (specifically, 880 parts, 881 parts, 883 parts, 885 parts, 887 parts, 889 parts, 891 parts, 893 parts, 895 parts, 897 parts, 897.5 parts, 898 parts, 899 parts, 900 parts or any value between 880 and 900 parts);
2 to 3 parts of hydrogen-containing silicone oil (specifically, 2 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, 3 parts or any value between 2 parts and 3 parts);
5-10 parts of organosilicon anchoring agent (specifically, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts or any value between 5-10 parts);
0.3 to 0.6 portion of catalyst (specifically, 0.3 portion, 0.35 portion, 0.4 portion, 0.45 portion, 0.5 portion, 0.55 portion, 0.6 portion or any value between 0.3 and 0.6 portion);
0.1 to 0.2 portion of inhibitor (specifically, any value between 0.1, 0.12, 0.14, 0.16, 0.18, 0.2 or 0.1 to 0.2 portion can be used).
Preferably, in the MQ silicone resin, M: the molar ratio of Q is (1.5-2.5): 1 (specifically, 1.5: 1, 1.6: 1, 1.7: 1, 1.8: 1, 1.9: 1, 2.0: 1, 2.1: 1, 2.2: 1, 2.3: 1, 2.4: 1, 2.5: 1 or (any value between 1.5 and 2.5)) 1.
In this regard, MQ silicone refers to M units (R) containing monofunctional siloxane units3SiO1/2) And Q units (SiO) containing tetrafunctional siloxane units4/2) The organosilicon compound is subjected to cohydrolysis-polycondensation reaction to generate the silicone grease with a three-dimensional spherical structure. Generally, the MQ silicon resin is a compact spheroid with a double-layer structure, wherein a sphere core is cage-shaped SiO with Si-O chain connection, higher density and polymerization degree of 15-502The spherical shell is R with lower density3SiO1/2And (3) a layer. The performance of MQ silicone resin mainly depends on the synthesis process conditions and the type and the number of organic groups in the molecule, namely the number ratio of M chain links to Q chain links; and due to the difference of the organic group R on the spherical shell, the MQ silicone resin also has various different types, such as methyl MQ silicone resin, methyl hydrogen-containing MQ silicone resin, methyl phenyl MQ silicone resin, vinyl MQ silicone resin, phenyl MQ silicone resin, fluorine-containing MQ silicone resin, and the like. To ensure that the MQ silicone resin does not participate as much as possible in the addition reaction of the thermally conductive gel crosslinking process, the methyl MQ silicone resin is generally selected for addition.
In some embodiments of the present application, the MQ silicone resin has M: the molar ratio of Q is (1.5-2.5): 1, with M commonly sold on the market: the Q molar ratio is 4: compared with the MQ silicone resin of 5, the MQ silicone resin has obviously more M chain links than Q chain links, so that the compatibility with other components in the heat-conducting gel can be further increased, and the adhesiveness of the heat-conducting gel is greatly improved. Meanwhile, since M: the proportion of Q is large, so that the network crosslinking degree of the MQ silicon resin structure is low, and the influence on the hardness of the heat-conducting gel is lower after the heat-conducting gel is added.
In some embodiments herein, the mono-blocked vinyl silicone oil used herein is a polydimethylsiloxane having only one vinyl group at one end of the molecular chain, and has a specific molecular formula of Si (CH3)3O [ (CH3)2SiO ] n (CH3)2Si-CH ═ CH 2. Wherein n in the molecular structural formula is a positive integer which makes the kinematic viscosity of the single-end capping vinyl silicone oil at 25 ℃ be 500 mPas-1000 mPas (specifically 500 mPas, 600 mPas, 700 mPas, 800 mPas, 900 mPas, 1000 mPas or any value between 500 mPas-1000 mPas).
Specifically, the low-viscosity single-end-capped vinyl silicone oil is used, and compared with double-end-capped vinyl silicone oil, side-chain vinyl silicone oil and end-side vinyl silicone oil, the cross-linking density of the base silicone oil is reduced after addition reaction is carried out on the base silicone oil, and micro-cross-linked heat-conducting gel is formed, so that the hardness of the heat-conducting gel is greatly reduced, and the heat-conducting gel is ensured not to generate large stress on an electronic instrument when used.
In some embodiments of the present application, the hydrogen content of the hydrogen-containing silicone oil is 0.1 wt% to 0.75 wt% (specifically, any value between 0.1 wt%, 0.18 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.75 wt%, or 0.1 wt% to 0.75 wt%).
Specifically, the hydrogen-containing silicone oil of the present application includes at least one of a side chain hydrogen-containing silicone oil and a terminal hydrogen-containing silicone oil. When the terminal side hydrogen-containing silicone oil is subjected to addition reaction with the vinyl silicone oil, the crosslinking density is easily increased, and the hardness of the heat-conducting gel is improved. Therefore, in order to further reduce the degree of crosslinking of the thermally conductive gel, side chain hydrogen-containing silicone oil and terminal hydrogen-containing silicone oil are preferable in the present application.
Further, in a preferred embodiment of the present application, the hydrogen-containing silicone oil is selected from side chain hydrogen-containing silicone oils having a hydrogen content of 0.18 wt%.
In some embodiments of the present application, the thermally conductive filler comprises at least one of spherical alumina, aluminum hydroxide, aluminum nitride, zinc oxide, boron nitride, magnesium oxide.
Specifically, the spherical alumina composition of different particle diameters is selected for use in this application, utilizes the filler cooperation of variation in size to use, can reduce the porosity of heat conduction filler in the base member, forms compact heap structure, has improved the heat conductivility of heat conduction gel greatly.
Further, in a preferred embodiment of the present application, the thermally conductive filler is selected from spherical alumina of 1 μm, 5 μm and 40 μm, respectively, and the mass ratio between the respective particle diameters is 1: 1.5: 2.5.
in some embodiments of the present application, silicone anchors are added to the thermally conductive gel of the present application to further improve the adhesion of the thermally conductive gel. The molecular structure of the organosilicon anchoring agent is as follows:
wherein n and m are positive integers which make the kinematic viscosity of the silicone anchoring agent at 25 ℃ to be 50 to 100 mPas (specifically, 50 mPas, 60 mPas, 70 mPas, 80 mPas, 90 mPas, 100 mPas or any value between 50 mPas and 100 mPas).
It should be noted that the adhesion referred to in this application refers to the adhesion that occurs when the residual force field on the surface of the object attracts the particles of the solid or liquid in close contact with the object. The phenomenon of adhesion, which is essentially the same as adsorption, is a result of surface forces acting between two substances. And bonding refers to a method of firmly joining together the same or different materials by the adhesive force generated on the solid surface. Adhesion is not the same as adhesion, and generally a rubber substrate with a high hardness adheres better, while a softer rubber substrate adheres better.
In some embodiments of the present application, the catalyst is a platinum catalyst at a concentration of 3000ppm to 5000ppm (specifically, 3000ppm, 3500ppm, 4000ppm, 4500ppm, 5000ppm or any value between 3000ppm and 5000 ppm).
The platinum catalyst is also called a Karster catalyst, a platinum curing agent, platinum water and the like, is a light yellow liquid, and can rapidly catalyze the addition crosslinking reaction of the vinyl-containing siloxane and the hydrogen-containing siloxane. The platinum catalyst used in the application is platinum water produced by Dongguan Shang Sanqi synthetic materials Co., Ltd, and the specific chemical name is a diethylene tetramethyl disiloxane platinum complex with the molecular formula of C8H18OPtSi 2.
In some embodiments herein, the inhibitor is at least one of ethynl cyclohexanol, 1- (1-propynyl) cyclohexanol.
The application provides an anti-drop heat-conducting gel which adjusts M in MQ silicon resin: the molar ratio of Q ensures that the network crosslinking degree in the MQ silicon resin is lower, the influence on the hardness of the heat-conducting gel is reduced, and the adhesiveness of the heat-conducting gel is improved; the single-end vinyl silicone oil is used for replacing common vinyl silicone oil, so that the crosslinking density of the heat-conducting gel is lower; and the organic silicon anchoring agent is used for replacing a common silane coupling agent, so that the adhesion of the heat-conducting gel is further enhanced. The heat-conducting gel prepared finally has excellent anti-falling performance through the synergistic interaction of the single-ended vinyl silicone oil, the MQ silicone resin with high M/Q molar ratio and the organic silicon anchoring agent.
The application also provides a preparation method of the anti-drop heat-conducting gel, which comprises the following steps:
firstly mixing raw materials including single-end-capped vinyl silicone oil, MQ silicone resin, hydrogen-containing silicone oil, heat-conducting filler, organic silicon anchoring agent and inhibitor to obtain a mixed base material; and then, adding a catalyst into the mixed base material for second mixing, and reacting to obtain the anti-falling heat-conducting gel.
In some embodiments of the present application, the first mixing and the second mixing are performed under vacuum conditions, wherein the vacuum conditions are-0.1 MPa to-0.08 MPa; the stirring time of the first mixing is 28 min-32 min, and the stirring time of the second mixing is 18 min-22 min. Specifically, the stirring time of the first mixing is 30min, and the stirring time of the second mixing is 20 min.
Specifically, a vacuum planetary mixer can be used as production equipment to prepare the heat-conducting gel. During the first mixing, the rotating speed of the vacuum planetary stirrer can be set to be 10rpm, and the stirring time is set to be 30 min; while the second mixing is being performed, the rotation speed may be continuously maintained at 10rpm, but the stirring time may be set to 20 min.
The MQ silicone resin used in the application can be directly purchased as a finished product sold in the market, and can also be prepared to produce the MQ silicone resin. In some embodiments herein, the molar ratio of the M unit capping agent to the Q unit silicate in the preparation of the MQ silicone resin is (1.5-2.5): 1.
specifically, the M unit blocking agent includes at least one of hexamethyldisiloxane, tetramethyldivinyldisiloxane, and tetramethyldihydro-disiloxane. Further, hexamethyldisiloxane is selected as the M unit blocking agent in the present application.
Specifically, the silicate of Q unit comprises at least one of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate. Further, the application selects tetraethoxysilane as the silicate of the Q unit.
The preparation process of the MQ silicon resin comprises the following steps:
(1) stirring raw materials comprising 120-210 parts by weight of hexamethyldisiloxane, 180-220 parts by weight of deionized water and 40-60 parts by weight of absolute ethyl alcohol for 50-70 min under the conditions that the pH is 1.5-2.5 and the temperature is 70-90 ℃ to obtain a first solution;
(2) adding 100-110 parts by weight of ethyl orthosilicate into the first solution, and continuously stirring for 4-6 hours at the temperature of 70-90 ℃ to obtain a second solution;
(3) cooling the second solution to room temperature, adding 180-250 parts by weight of 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 0.01-0.03 weight part of tetramethylammonium hydroxide, and heating to 100-110 ℃ for polymerization reaction for 2.5-3.5 h to obtain the colorless and transparent MQ silicon resin.
In the preparation process, when the molar mass ratio of hexamethyldisiloxane to tetraethoxysilane is (1.5-2.5): 1, M: MQ silicone resin with the molar ratio of Q being (1.5-2.5): 1. In the step (1), stirring for 60min under the conditions that the PH is 2 and the temperature is 80 ℃ to carry out pre-reaction to obtain a first solution; in the step (2), stirring for 5 hours at the temperature of 80 ℃ to obtain a second solution; the polymerization time in step (4) may be 3 hours.
The application also provides an electronic instrument, which comprises the anti-falling heat-conducting gel. The heat-conducting gel prepared by the application inherits the advantages of good affinity, weather resistance, high and low temperature resistance, good insulativity and the like of a silica gel material, has strong plasticity, can meet the filling of an uneven interface, and can be widely applied to the fields of LED chips, communication equipment, mobile phone CPUs (central processing units), memory modules, IGBTs (insulated gate bipolar transistors) and other power modules and power semiconductors in a smearing mode, a dispensing mode and the like. Because the heat conduction gel anti-falling performance of this application is superior, when using on mobile device such as some unmanned aerial vehicle, unmanned car, cell-phone, greatly improved electronic product's reliability.
Embodiments of the present invention will be described in detail below with reference to specific examples, but those skilled in the art will appreciate 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 not indicated by the manufacturer, and are all conventional products available commercially.
Example 1
The embodiment provides a fall-resistant heat-conducting gel, specifically includes:
first, preparation of M: MQ silicone resin with a Q molar ratio of 2:1, comprising:
(1) stirring 162.38g of hexamethyldisiloxane, 200g of deionized water and 50g of absolute ethyl alcohol for 60min at the pH of 2 and the temperature of 80 ℃ to obtain a first solution;
(2) adding 104.164g of tetraethoxysilane into the first solution, and continuously stirring for 5 hours at the temperature of 80 ℃ to obtain a second solution;
(3) cooling the second solution to room temperature, adding 200g of simethicone (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, and heating to 100 for polymerization reaction for 3 hours to obtain M: MQ silicone resin with a Q molar ratio of 2: 1.
Then, preparing a drop-resistant thermally conductive gel comprising:
87g of a mono-blocked vinyl silicone oil having a kinematic viscosity of 500 mPas, 8g of M: MQ silicon resin with the Q molar ratio of 2:1, 2g of side chain hydrogen-containing silicone oil with the hydrogen content of 0.18 wt%, 179.5g of 1 mu m spherical alumina, 269.25g of 5 mu m spherical alumina, 448.75g of 40 mu m spherical alumina, 5g of organosilicon anchoring agent with the kinematic viscosity of 50mPa & s and 0.1g of ethynl cyclohexanol are added into a vacuum planetary stirrer and stirred for 30min at the rotating speed of-0.08 MPa and 10rpm to obtain a mixed base stock;
and then, adding 0.3g of 3000ppm platinum catalyst into the mixed base material, stirring for 20min at the rotating speed of 10rpm under-0.08 MPa, and carrying out full reaction to obtain the anti-falling 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
The same as example 1, except that M: the Q molar ratio is 1.5: 1 MQ silicone resin in which the addition amount of hexamethyldisiloxane became 108.25 g;
in preparing the drop-resistant thermally conductive gel, 8g of M: the Q molar ratio is 1.5: 1 MQ silicone resin.
Example 4
The same as in example 1, except that the amount of the side chain hydrogen-containing silicone oil added was changed to 3 g.
Example 5
The same as example 1, except that the amount of addition of the one-terminal vinyl silicone oil was changed to 82g, while the amount of addition of the 1 μm spherical alumina was changed to 180.5g, the amount of addition of the 1 μm spherical alumina was changed to 270.75g, and the amount of addition of the 1 μm spherical alumina was changed to 451.25 g.
Example 6
The same as in example 1, except that the amount of addition of the one-terminal vinyl silicone oil was changed to 82g, and the amount of addition of the silicone anchoring agent was changed to 10 g.
Comparative example 1
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 2
The same as example 1, except that M: the Q molar ratio is 2:1 MQ silicone, replaced with a conventional M: q is 4: 5 MQ silicone resin.
Comparative example 3
The same as example 1, except that the silicone anchoring agent was replaced with a silane coupling agent of γ -aminopropyltriethoxysilane.
The heat-conducting silica gels provided in examples 1 to 6 and comparative examples 1 to 3 were tested for various properties: testing the thermal conductivity of the thermally conductive gel according to the standard in ASTM D5470-2017; testing the thermal resistance of the thermally conductive gel according to the standard in ASTM D5470-2017; testing the dispensing rate according to the extrusion quality of 90psi, 1mm glue nozzle and 1 min; the specific gravity after curing was measured according to the standard in ASTM D792-2007 test methods for Density and relative Density of plastics. The drop test was tested according to GB-T-2423.8-1995 drop test method. Finally, the results of the various performance tests are shown in table 1.
With regard to drop testing, it is primarily intended to simulate the free fall to which a product may be subjected during use, investigating the ability of the product to resist accidental impacts. The drop height is usually based on the product weight and the probability of a possible drop, and the drop surface should be a smooth, hard, rigid surface made of concrete or steel. Therefore, the experiment condition of the application is that 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 the experiment of falling on the rigid surface of the concrete. The drop height of the test is 1.5 m, the drop times of the test sample are 10 times, and the drop direction is vertical. The product of the same embodiment uses 6 samples to carry out tests before falling and after falling, if the 6 samples are still in the center of the glass after 10 times of falling tests, and the position does not deviate, namely, the result of the falling test is judged to be: no drop occurs; if any sample in the 6 samples has a certain deviation after the drop test is finished, the drop test result is judged to be: and (6) falling. The results of the specific drop test can be seen in the figure.
In fig. 1, a is a picture of 6 samples before the thermal conductive gel prepared in example 1 is dropped, and b is a picture of the 6 samples after 10 drop tests. By comparing the graphs a and b in fig. 1, it can be seen that the thermal conductive gel in the glass sheet still firmly adheres to the glass sheet without slipping after the 6 samples are subjected to the drop test.
Fig. 2, a, b, is a picture of 6 samples before the thermally conductive gel prepared in example 2 is dropped, and b is a picture of 6 samples after 10 drop tests. Also, no slippage occurred after these samples had fallen.
Fig. 3, a, b, and c are pictures of 6 samples before dropping the thermal conductive gel prepared in example 3, and 10 dropping tests of the 6 samples. Also, no slippage occurred after these samples had fallen.
Fig. 4, a, b, and c are pictures of 6 samples before dropping the thermal conductive gel prepared in example 4, and 10 dropping tests of the 6 samples. Also, no slippage occurred after these samples had fallen.
Fig. 5, a, b, and c are pictures of 6 samples before dropping the thermal conductive gel prepared in example 5, and 10 dropping tests of the 6 samples. Also, no slippage occurred after these samples had fallen.
Fig. 6 a is a picture of 6 samples before dropping the thermal conductive gel prepared in example 6, and b is a picture of 10 dropping tests performed on the 6 samples. Also, no slippage occurred after these samples had fallen.
Fig. 7 shows a picture of 6 samples before dropping the thermally conductive gel prepared in comparative example 1, and b picture of 10 dropping tests of the 6 samples. By comparing the graphs a and b of fig. 7, it can be seen that the thermal conductive gel of 2 samples of the 6 test samples completely separated from the glass plate, and that the significant slip phenomenon occurred in 1 sample.
Fig. 8 shows a picture of 6 samples before dropping the thermally conductive gel prepared in comparative example 2, and b picture of 10 dropping tests of the 6 samples. Comparing the a diagram and the b diagram of fig. 8, it can be found that the heat conductive gel of 2 samples of the 6 test samples completely separated from the glass plate, and the weak slip phenomenon occurred in the other 2 samples.
Fig. 9, a, b, is a picture of 6 samples before the thermally conductive gel prepared in comparative example 3 is dropped, and b is a picture of 6 samples after 10 drop tests. By comparing the graphs a and b of fig. 9, it can be seen that in 6 test samples, 4 samples of the thermal conductive gel completely separated from the glass plate, and 2 samples of the thermal conductive gel had a significant slip phenomenon.
TABLE 1 data of various properties of the thermally conductive gels of examples 1-6 and comparative examples 1-3
Through the test results and the drop test results of the embodiments 1 to 6 and the comparative examples 1 to 3, it can be obviously found that the anti-drop performance of the heat-conducting gel prepared by the technical scheme of the application is greatly improved on the basis of not influencing the heat-conducting performance, and particularly, through the drop test picture results of the comparative examples 1 to 3, the synergistic interaction of the single-ended vinyl silicone oil, the MQ silicone resin with high M/Q molar ratio and the organic silicon anchoring agent is shown, so that the prepared heat-conducting gel has good adhesiveness and excellent anti-drop performance, and even if the gel falls for many times, the slip phenomenon cannot occur.
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.
Furthermore, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, 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.