Hydroxyl-functionalized phenyl silicone oils and methods for their preparation, low density foamed silicone gels and methods for their preparation, and electronic instruments

Abstract

The present application provides a hydroxyl functionalized phenyl silicone oil and a preparation method thereof, a low-density foamed silicone rubber and a preparation method thereof, and an electronic instrument. The hydroxyl functionalized phenyl silicone oil comprises -(CH2) a OH groups, the preparation method comprising: condensation reaction of an enol compound with a silazane to obtain a compound X; addition reaction of the compound X with a double-end hydrogen-containing phenyl silicone oil to obtain a compound Y; alcoholysis reaction of the compound Y with an alcohol substance to obtain the hydroxyl functionalized phenyl silicone oil. The present application also provides a low-density foamed silicone rubber, the raw material of which comprises the above hydroxyl functionalized phenyl silicone oil and is prepared by using a two-component preparation method. The present application improves the surface tension and reaction speed of the foamed silicone rubber system by using the hydroxyl functionalized phenyl silicone oil, and thus a uniform and fine low-density high-foaming ratio foam can be formed.

Description

Technical Field

[0001] This application relates to the field of polymer materials technology, and in particular to a hydroxyl-functionalized phenyl silicone oil and its preparation method, low-density foamed silicone and its preparation method, and electronic instruments. Background Technology

[0002] As new energy electric vehicles gain increasing popularity, the automotive industry needs to achieve breakthroughs in their technological research. The key to these breakthroughs lies in the charging and discharging technology and safety performance of high-energy-density lithium batteries. Safety performance, in particular, is a major obstacle to the development of electric vehicles. Lithium batteries must maintain excellent waterproof and dustproof properties during use, and their tendency to overheat and spontaneously combust is a primary concern affecting their safety. Because liquid foamed silicone materials possess excellent flame retardancy, environmental friendliness, aging resistance, and resilience, they can be used to improve the working environment of lithium batteries, providing a reliable foundation for their application in new energy vehicles.

[0003] Silicone rubber foam is a porous polymer elastomer that combines the properties of both silicone rubber and foam materials. It is widely used in defense, transportation, electronics, furniture, sealing, and electrical insulation. In addition to the excellent properties of silicone rubber, it also boasts advantages such as light weight, damping effect, and good thermal insulation. Furthermore, it possesses unique advantages over other foam materials, including high and low temperature resistance, weather resistance, and environmental friendliness. Currently, commercially available foamed silicone rubber uses α,W-dihydroxypolydimethylsiloxane, which has a low surface tension. This makes the gas produced during foaming prone to breakage, hindering the formation of a uniform, fine, low-density, high-expansion-ratio foam.

[0004] Therefore, in order to improve the performance of silicone rubber foam materials, it is necessary to improve the raw materials in silicone rubber foam materials to obtain foamed silicone materials with high foaming rate. Summary of the Invention

[0005] The purpose of this application is to provide a hydroxyl-functionalized phenyl silicone oil and its preparation method, a low-density foamed silicone and its preparation method, and an electronic instrument.

[0006] To achieve the above objectives, the technical solution of this application is as follows:

[0007] In a first aspect, this application provides a hydroxyl-functionalized phenyl silicone oil comprising -(CH2). a OH group, where a is an integer from 2 to 5.

[0008] In conjunction with the first aspect, in a preferred embodiment, the chemical structural formula of the hydroxyl-functionalized phenyl silicone oil is HO(CH2). a (CH3)2SiO[(CH3)2SiO] m[(C6H5)2SiO] n Si(CH3)2(CH2) a OH, where m≥1, n≥1, and m and n are integers.

[0009] Secondly, this application provides a method for preparing the hydroxyl-functionalized phenyl silicone oil described in the first aspect, comprising:

[0010] The enol compound was condensed with a silazane to give compound X;

[0011] Compound X was reacted with a double-ended hydrogen-containing phenyl silicone oil to obtain compound Y;

[0012] The compound Y was subjected to an alcoholysis reaction with an alcohol to obtain the hydroxyl-functionalized phenyl silicone oil.

[0013] In conjunction with the second aspect, in a preferred embodiment, the preparation method satisfies at least one of the following conditions:

[0014] A. The enol compound includes at least one of vinyl alcohol, allyl alcohol, and enbutanol;

[0015] B. The silazane comprises at least one of hexamethyldisilazane and tetramethyldivinyldisilazane;

[0016] C. The chemical structural formula of the aforementioned hydrogen-terminated phenyl silicone oil is H(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2H, where m≥1, n≥1, and m and n are positive integers;

[0017] D. The phenyl content in the double-ended hydrogen-containing phenyl silicone oil is 5wt%-30wt%;

[0018] E. The hydrogen content in the double-ended hydrogen-containing phenyl silicone oil is 0.01wt%-0.1wt%;

[0019] F. The alcohols mentioned include either methanol or ethanol;

[0020] G. The addition reaction also requires the addition of a platinum-containing catalyst, wherein the platinum content in the platinum-containing catalyst is 3000ppm-5000ppm.

[0021] Thirdly, this application also provides a low-density foamed silicone, the raw materials of which include: the hydroxyl-functionalized phenyl silicone oil described in the first aspect, modified reinforcing filler, modified flame-retardant filler, phenyl vinyl silicone oil, phenyl MQ silicone resin, phenyl hydrogen-containing silicone oil, catalyst and inhibitor.

[0022] In conjunction with the third aspect, in a preferred embodiment, the low-density foamed silicone meets at least one of the following conditions:

[0023] H. The modified reinforcing filler is a reinforcing filler modified with a phenylsilane coupling agent;

[0024] I. The modified flame-retardant filler is a flame-retardant filler modified with a phenylsilane coupling agent;

[0025] J. The chemical structural formula of the phenyl vinyl silicone oil is: (CH2=CH)(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2(CH=CH2);

[0026] K. The chemical structural formula of the phenyl hydrogen-containing silicone oil is: (CH3)3SiO[(CH3)HSiO] m [(C6H5)2SiO] n Si(CH3)3;

[0027] L. The hydrogen content in the phenyl-containing hydrogen silicone oil is 0.1wt%-1.6wt%; the phenyl content is 5wt%-30wt%.

[0028] M. The phenyl MQ silicone resin includes at least one of phenyl vinyl MQ silicone resin and phenyl methyl MQ silicone resin;

[0029] N. The ratio of M-units to Q-units in the phenyl MQ silicone resin is (0.8-1):1;

[0030] O. The catalyst includes a phenylplatinum catalyst;

[0031] P. The inhibitors include at least one of ethynylcyclohexanol and 1-(1-propynyl)cyclohexanol.

[0032] More preferably, the low-density foamed silicone also satisfies at least one of the following conditions:

[0033] Q. The phenylsilane coupling agent comprises at least one of phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, and methylphenyldimethoxysilane;

[0034] R. The reinforcing filler includes at least one of fumed silica and precipitated silica;

[0035] S. The flame-retardant filler includes at least one of aluminum hydroxide and magnesium hydroxide;

[0036] T. In the modified reinforcing filler, 25g-50g of the phenylsilane coupling agent is added to every 1000g of the reinforcing filler for the modification treatment;

[0037] U. In the modified flame retardant filler, 25g-50g of the phenylsilane coupling agent is added to every 1000g of the flame retardant filler for the modification treatment;

[0038] V. The platinum content in the phenylplatinum catalyst is 3000ppm-5000ppm.

[0039] Fourthly, this application provides a method for preparing the low-density foamed silicone described in the third aspect, comprising:

[0040] The raw materials, including the hydroxyl-functionalized phenyl silicone oil, the phenyl MQ silicone resin, the phenyl vinyl silicone oil, the modified reinforcing filler, and the modified flame retardant filler, are mixed and ground, and then the catalyst is added to obtain component A.

[0041] The raw materials comprising the hydroxyl-functionalized phenyl silicone oil, the phenyl MQ silicone resin, the phenyl vinyl silicone oil, the modified reinforcing filler, the modified flame retardant filler, the phenyl hydrogen-containing silicone oil, and the inhibitor are mixed and ground to obtain component B;

[0042] After mixing component A and component B in a certain proportion, the mixture is calendered into sheets and then heated to cure, thus obtaining the low-density foamed silicone.

[0043] In conjunction with the fourth aspect, the method for preparing the low-density foamed silicone meets at least one of the following conditions:

[0044] a. In component A, the mass ratio of the hydroxyl-functionalized phenyl silicone oil, the phenyl MQ silicone resin, the phenyl vinyl silicone oil, the modified reinforcing filler, the modified flame-retardant filler, and the catalyst is (25-40):(3-5):(10-15):(30-40):(40-55):(0.1-0.5);

[0045] b. In component B, the mass ratio of the hydroxyl-functionalized phenyl silicone oil, the phenyl MQ silicone resin, the phenyl vinyl silicone oil, the modified reinforcing filler, the modified flame-retardant filler, the phenyl hydrogen-containing silicone oil, and the inhibitor is (25-40):(3-5):(10-15):(30-40):(40-55):(10-15):(0.1-0.3);

[0046] c. The fineness of the product from the grinding process is 80-100 mesh;

[0047] d. Component A and component B are mixed in a mass ratio of 1:(0.9-1.1);

[0048] e. The temperature for heat curing is 70℃-100℃.

[0049] Fifthly, this application also provides an electronic instrument comprising the low-density foamed silicone described in the third aspect.

[0050] The beneficial effects of this application are:

[0051] In the hydroxyl-functionalized phenyl silicone oil of this application, -(CH2) is introduced. n The OH group can enhance the reactivity and reaction rate of silicone oil, while the phenyl group in phenyl silicone oil can significantly increase the surface tension of the silicone rubber system. Therefore, when this hydroxyl-functionalized phenyl silicone oil is applied to a foamed silicone system, it can form a uniform and fine foam. The preparation method of the hydroxyl-functionalized phenyl silicone oil in this application is simple, utilizing common polymeric raw materials and common chemical reaction mechanisms to prepare high-purity hydroxyl-functionalized phenyl silicone oil.

[0052] The low-density foamed silicone of this application utilizes raw materials such as hydroxyl-functionalized phenyl silicone oil, phenyl vinyl silicone oil, and phenyl hydrogen-containing silicone oil, which significantly increases the surface tension of the system, thereby retaining more gas within the system and forming a uniform, fine, low-density, high-expansion-ratio foam. Introducing phenyl groups into the system also enhances the tensile strength of the low-density foamed silicone. Furthermore, the hydroxyl-functionalized phenyl silicone oil in the raw materials contains -(CH2). n The OH groups, after functionalization, significantly increase the reaction rate, enabling the generation of a large amount of gas in a short time, thereby forming a uniform, fine, low-density, high-expansion-ratio foam. The preparation method of this low-density foamed silicone is simple, has a short production cycle, and high production efficiency, making it suitable for large-scale production.

[0053] The electronic instruments provided in this application can be widely used in fields such as national defense, transportation, electronics, furniture, sealing and electrical insulation, and especially in foamed silicone gaskets for new energy vehicle batteries. Attached Figure Description

[0054] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0055] Figure 1 A side view of the low-density foamed silicone prepared in Example 1 before it was colored;

[0056] Figure 2 Side view of the low-density foamed silicone prepared in Example 1 and Comparative Example 5 after coloring. Detailed Implementation

[0057] As used in this article:

[0058] "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such a composition, step, method, article, or apparatus. The conjunction "composed of" excludes any unnamed elements, steps, or components.

[0059] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0060] In these embodiments, unless otherwise specified, the portions and percentages are all by weight.

[0061] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (K is any number representing a multiplier). It is important to understand that, unlike the number of parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0062] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0063] To address the technical problem of using α,w-dihydroxypolydimethylsiloxane and hydrogen-containing silicone oil to produce hydrogen gas for foaming silicone, which is commonly used in the market, the low surface tension of α,w-dihydroxypolydimethylsiloxane makes it easy for the generated gas to break, hindering the formation of uniform, fine, low-density, high-expansion-ratio foams, this application first provides a hydroxyl-functionalized phenyl silicone oil containing -(CH2). a An OH group, wherein a is an integer from 2 to 5. More preferably, a = 3.

[0064] In a preferred embodiment, the chemical structural formula of the hydroxyl-functionalized phenyl silicone oil is HO(CH2). a (CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2(CH2) a OH, where m≥1, n≥1, and m and n are positive integers.

[0065] In addition, this application also provides a method for preparing the above-mentioned hydroxyl-functionalized phenyl silicone oil, including:

[0066] S1. The enol compound is condensed with silazane to obtain compound X;

[0067] S2. Compound X is reacted with dihydrogen-terminated phenyl silicone oil by addition reaction to obtain compound Y;

[0068] S3. Compound Y is subjected to an alcoholysis reaction with an alcohol to obtain hydroxyl-functionalized phenyl silicone oil.

[0069] In a preferred embodiment, the enol compound in S1 includes at least one of vinyl alcohol, allyl alcohol, and allyl butanol, more preferably allyl alcohol.

[0070] In a preferred embodiment, the silazane in S1 includes at least one of hexamethyldisilazane and tetramethyldivinyldisilazane.

[0071] Considering that silazanes containing special groups may introduce some reactive groups, such as tetramethyldisyldisilazane which contains vinyl groups, it can interfere with subsequent reactions and can also react with hydrogen-containing silicone oils. Therefore, this application prefers to use hexamethyldisilazane to react with enol compounds.

[0072] The chemical structural formula of hexamethyldisilazane is as follows:

[0073]

[0074] Therefore, when the enol compound is allyl alcohol, the condensation reaction process in S1 is as follows:

[0075] 2CH2=CHCH2OH+(CH3)3SiNHSi(CH3)3→2CH2=CHCH2OSi(CH3)3+NH3.

[0076] In the reaction process of S1, the silazane is actually first hydrolyzed, and then undergoes a deamination condensation reaction with hexamethyldisilazane to prepare compound X, which is CH2=CHCH2OSi(CH3)3. The main purpose of this reaction is to protect the hydroxyl groups in allyl alcohol with silazane.

[0077] In a preferred embodiment, the chemical structural formula of the double-ended hydrogen-containing phenyl silicone oil in S2 is H(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2H, where m≥1, n≥1, and m and n are positive integers.

[0078] Furthermore, the phenyl content in the double-ended hydrogen-containing phenyl silicone oil is 5wt%-30wt%; the hydrogen content is 0.01wt%-0.1wt%.

[0079] In a preferred embodiment, the addition reaction in S2 further requires the addition of a platinum-containing catalyst, wherein the platinum content in the platinum-containing catalyst is 3000ppm-5000ppm.

[0080] Specifically, the addition reaction in S2 proceeds as follows: H(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2H+CH2=CHCH2OSi(CH3)3→(CH3)3SiO(CH2)3(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2(CH2)3OSi(CH3)3.

[0081] The compound Y obtained by the addition reaction is a phenyl silicone oil, but its functional groups do not have special groups for reaction and foaming. Therefore, hydroxyl-functionalized phenyl silicone oil is prepared by the alcoholysis reaction in S3.

[0082] In a preferred embodiment, the alcohol in S3 includes either methanol or ethanol, more preferably methanol.

[0083] Specifically, the alcoholysis reaction in S3 is as follows: (CH3)3SiO(CH2)3(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO]n Si(CH3)2(CH2)3OSi(CH3)3+CH3OH→HO(CH2)3(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2(CH2)3OH.

[0084] This application also provides a low-density foamed silicone, the raw materials of which include the above-mentioned hydroxyl-functionalized phenyl silicone oil, modified reinforcing filler, modified flame-retardant filler, phenyl vinyl silicone oil, phenyl MQ silicone resin, phenyl hydrogen-containing silicone oil, catalyst and inhibitor.

[0085] In a preferred embodiment, the modified reinforcing filler is a reinforcing filler modified with a phenylsilane coupling agent; the modified flame-retardant filler is a flame-retardant filler modified with a phenylsilane coupling agent.

[0086] It should be noted that the modification process specifically includes: first, mixing the reinforcing filler or flame-retardant filler with water; then, spraying the phenylsilane coupling agent onto the mixed filler using a spraying device, stirring continuously during the spraying process and continuing to stir after spraying to ensure that the filler and phenylsilane coupling agent are fully and evenly mixed; then, filtering out the water with a filter screen; and finally, drying the powder in an oven to a constant weight to obtain the modified reinforcing filler or modified flame-retardant filler.

[0087] More preferably, the reinforcing filler includes at least one of fumed silica and precipitated silica, more preferably 1500 mesh fumed silica.

[0088] The flame-retardant filler includes at least one of aluminum hydroxide and magnesium hydroxide, more preferably 2000-mesh aluminum hydroxide.

[0089] The phenylsilane coupling agent includes at least one of phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, and methylphenyldimethoxysilane.

[0090] During the modification process, 20g-50g of phenylsilane coupling agent is added to every 1000g of reinforcing or flame-retardant filler. For example, 20g, 25g, 30g, 35g, 40g, 45g, 50g, or any value between 20g and 50g can be added. More preferably, 25g-35g of phenyltriethoxysilane coupling agent is added to every 1000g.

[0091] In a preferred embodiment, the chemical structural formula of the phenyl vinyl silicone oil in the raw material is: (CH2=CH2)(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO]n Si(CH3) 2( CH2=CH2).

[0092] The kinematic viscosity of phenyl vinyl silicone oil at 25°C is 5000 mPa·s-10000 mPa·s, and the phenyl content is 5 w%-30 w%.

[0093] In a preferred embodiment, the chemical structural formula of the phenyl hydrogen-containing silicone oil in the raw material is: (CH3)3SiO[(CH3)HSiO] m [(C6H5)2SiO] n Si(CH3)3.

[0094] The hydrogen content in phenyl-containing silicone oil is 0.1wt%-1.6wt%; the phenyl content is 5wt%-30wt%.

[0095] In a preferred embodiment, the phenyl MQ silicone resin includes at least one of phenyl vinyl MQ silicone resin and phenyl methyl MQ silicone resin, more preferably phenyl vinyl MQ silicone grease.

[0096] The phenyl content in the phenyl MQ silicone resin is 15wt% to 45wt%; the ratio of M-chain segments to Q-chain segments is (0.8-1):1, more preferably M:Q = 0.8:1.

[0097] In a preferred embodiment, the catalyst comprises a phenylplatinum catalyst.

[0098] More preferably, the platinum content in the phenylplatinum water is 3000ppm-5000ppm.

[0099] In a preferred embodiment, the inhibitor includes at least one of ethynylcyclohexanol and 1-(1-propynyl)cyclohexanol.

[0100] This application provides a method for preparing the above-mentioned low-density foamed silicone, including:

[0101] (1) After mixing and grinding the raw materials including the hydroxyl-functionalized phenyl silicone oil, phenyl MQ silicone resin, phenyl vinyl silicone oil, modified reinforcing filler and modified flame retardant filler, a catalyst is added to obtain component A.

[0102] (2) Mix and grind the raw materials including the hydroxyl-functionalized phenyl silicone oil, phenyl MQ silicone resin, phenyl vinyl silicone oil, modified reinforcing filler, modified flame retardant filler, phenyl hydrogen-containing silicone oil and inhibitor to obtain component B;

[0103] (3) Mix the components A and B in proportion, calender into sheets, heat and cure to obtain the low-density foamed silicone.

[0104] In a preferred embodiment, the mass ratio of hydroxyl-functionalized phenyl silicone oil, phenyl MQ silicone resin, phenyl vinyl silicone oil, modified reinforcing filler, modified flame-retardant filler, and the catalyst in component A is (25-40):(3-5):(10-15):(30-40):(40-55):(0.1-0.5), for example, it can be 25:3:10:30:40:0.1 or 28:3.5:11:32:42. :0.2, 30:4:12:35:45:0.3, 32:4.5:13:38:48:0.4, 35:5:14:40:50:0.5, 38:5:15:40:52:0.5, 40:5:15:40:55:0.5 or any value between (25-40):(3-5):(10-15):(30-40):(40-55):(0.1-0.5).

[0105] In a preferred embodiment, the mass ratio of the hydroxyl-functionalized phenyl silicone oil, phenyl MQ silicone resin, phenyl vinyl silicone oil, modified reinforcing filler, modified flame-retardant filler, phenyl hydrogen-containing silicone oil, and inhibitor in component B is (25-40):(3-5):(10-15):(30-40):(40-55):(10-15):(0.1-0.3), for example, it can be 25:3:10:30:40:10:0.1, 28:3.5:11:32:42:11: 0.2, 30:4:12:35:45:12:0.3, 32:4.5:13:38:48:13:0.4, 35:5:14:40:50:14:0.5, 38:5:15:40:52:15:0.5, 40:5:15:40:55:15:0.5 or any value between (25-40):(3-5):(10-15):(30-40):(40-55):(10-15):(0.1-0.5).

[0106] In a preferred embodiment, when preparing component A, the raw materials, including hydroxyl-functionalized phenyl silicone oil, phenyl MQ silicone resin, phenyl vinyl silicone oil, modified reinforcing filler and modified flame retardant filler, are first mixed and then stirred at a stirring speed of 800 r / min for 40 min. Then, the mixture is ground on a three-roll mill until the fineness reaches 80-100 mesh. Finally, the catalyst is added and stirred thoroughly and uniformly, and then filtered to obtain component A.

[0107] In a preferred embodiment, when preparing component B, the mixed materials are stirred at a stirring speed of 800 r / min for 60 min, then ground on a three-roll mill until the fineness reaches 80-100 mesh, and finally thoroughly stirred and filtered to obtain component B.

[0108] It should be noted that when preparing these two components, different models of vacuum mixers available on the market can be used for mixing, and all mixing must be carried out under vacuum conditions, specifically -0.1 MPa to -0.08 MPa. This is mainly to ensure that air bubbles in the raw materials are removed as much as possible during the mixing process, preventing large bubbles from forming in the subsequently prepared low-density foamed silicone, which would make it difficult to form a uniform, fine, low-density foam with a high foaming ratio.

[0109] In a preferred embodiment, component A and component B are mixed in a mass ratio of 1:(0.9-1.1), more preferably in a 1:1 ratio.

[0110] After the two components are mixed, they need to be dynamically stirred at a stirring speed of 1500-1800 r / min to achieve uniformity. Dynamic stirring is carried out using dynamic mixing equipment, which can cut large bubbles in the system into more small bubbles, thereby forming a uniform and dense foam. Then, the foam is pressed onto a calender by a pressure plate, and the thickness of the calender is controlled by the gap between the rollers.

[0111] In a preferred embodiment, the temperature for heat curing after calendering is 70℃-100℃, for example, it can be 70℃, 80℃, 90℃, 100℃ or any value between 70℃ and 100℃.

[0112] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0113] Example 1

[0114] This embodiment provides a hydroxyl-functionalized phenyl silicone oil, the preparation method of which includes the following steps:

[0115] Allyl alcohol and hexamethyldisilazane were mixed and reacted to prepare CH2=CHCH2OSi(CH3)3, which was then reacted with dihydrogen-terminated phenyl silicone oil (its chemical structural formula is: H(CH3)2SiO[(CH3)2SiO)). m [(C6H5)2SiO] n An addition reaction was carried out using a platinum catalyst with a platinum content of 3000 ppm (Si(CH3)2H) to prepare (CH3)3SiO(CH2)3(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] nSi(CH3)2(CH2)3OSi(CH3)3, and finally subjected to alcoholysis with methanol, yields hydroxyl-functionalized phenyl silicone oil with the chemical formula HO(CH2)3(CH3)2SiO[(CH3)2SiO]. m [(C6H5)2SiO] n Si(CH3)2(CH2)3OH.

[0116] This embodiment also provides a low-density foamed silicone, the raw materials of which include: hydroxyl-functionalized phenyl silicone oil, phenyl vinyl silicone oil (kinematic viscosity at 25°C is 5000 mPa·s, phenyl content is about 10 wt%), phenyl MQ silicone resin (M:Q = 0.8, phenyl content is about 20 wt%), phenyl hydrogen-containing silicone oil (hydrogen content is about 1 wt%; phenyl content is 10%), phenyltriethoxysilane-modified fumed silica, phenyltriethoxysilane-modified aluminum hydroxide, inhibitor acetylenecyclohexanol and catalyst phenylplatinum complex.

[0117] The preparation method of phenyltriethoxysilane modified fumed silica includes: mixing 1000g of 1500-mesh fumed silica with 10kg of distilled water, stirring at 500rpm for 10min, adding 30g of phenyltriethoxysilane coupling agent using a spray device, and then continuing to mix at 2000rpm for 20min. The mixed material is then filtered to remove moisture, and after filtration, it is placed in a vacuum oven and dried at 105℃ to constant weight to obtain phenyltriethoxysilane modified fumed silica.

[0118] The preparation method of phenyltriethoxysilane modified aluminum hydroxide includes: mixing 1000g of 2000-mesh aluminum hydroxide with 10kg of distilled water, stirring at 500rpm for 10min, adding 30g of phenyltriethoxysilane coupling agent using a spray device, and then continuing to mix at 2000rpm for 20min. Then, filtering the mixed material to remove moisture using a filter screen, and placing it in a vacuum oven to dry at 105℃ to constant weight to obtain phenyltriethoxysilane modified aluminum hydroxide.

[0119] Methods for preparing low-density foamed silicone include:

[0120] Step 1: Prepare component A. First, mix 30g of modified fumed silica, 25g of hydroxyl-functionalized phenyl silicone oil, 4g of phenyl MQ silicone resin, 12g of phenyl vinyl silicone oil, and 50g of modified aluminum hydroxide together. Stir at 800r / min for 40min, then grind on a three-roll mill to a fineness of 80 mesh. Finally, add 0.3g of highly active phenyl platinum complex, stir thoroughly until homogeneous, and filter to obtain component A.

[0121] Step 2: Prepare component B. First, mix 30g of modified fumed silica, 25g of hydroxyl-functionalized phenyl silicone oil, 4g of phenyl MQ silicone resin, 12g of phenyl vinyl silicone oil, 50g of modified aluminum hydroxide, 12g of phenyl hydrogen silicone oil, and 0.1g of the inhibitor acetylene cyclohexanol together. Stir at 800r / min for 60min, then grind on a three-roll mill until the fineness is 80 mesh. Finally, after thorough mixing, filter to obtain component B.

[0122] Step 3: Mixing the adhesive, mixing components A and B in a 1:1 mass ratio, stirring at 1800 r / min until homogeneous, pressing it onto a calender by air pressure, controlling the thickness by the gap between the rollers, and heating and curing at 100℃ to obtain low-density foamed silicone.

[0123] Example 2

[0124] Similar to Example 1, except that in the low-density foamed silicone preparation method, the amount of hydroxyl-functionalized phenyl silicone oil added to components A and B is changed to 40g.

[0125] Example 3

[0126] Similar to Example 1, except that in the low-density foamed silicone preparation method, the amount of phenyl hydrogen silicone oil added to component B is changed to 15g.

[0127] Example 4

[0128] Similar to Example 1, except that in the low-density foamed silicone preparation method, the hydrogen content of the phenyl hydrogen-containing silicone oil in component B is changed to 0.4 wt%.

[0129] Example 5

[0130] Similar to Example 1, except that in the preparation method of low-density foamed silica, the amount of modified fumed silica added in components A and B is changed to 40g.

[0131] Comparative Example 1

[0132] Similar to Example 1, except that in the preparation raw materials and preparation method of low-density foamed silicone, hydroxyl-functionalized phenyl silicone oil is replaced with conventional hydroxyphenyl silicone oil of the same viscosity.

[0133] Comparative Example 2

[0134] Similar to Example 1, except that: the double-ended hydrogen-containing phenyl silicone oil was replaced with double-ended hydrogen-containing silicone oil to prepare hydroxyl-functionalized silicone oil; and foamed silicone oil was prepared using hydroxyl-functionalized silicone oil.

[0135] Comparative Example 3

[0136] Similar to Example 1, except that in the preparation raw materials and preparation method of low-density foamed silicone, hydroxyl-functionalized phenyl silicone oil is replaced with conventional hydroxyl silicone oil of the same viscosity.

[0137] Comparative Example 4

[0138] Similar to Comparative Example 2, the difference is that in the raw materials and preparation method for low-density foamed silicone, phenyl vinyl silicone oil is replaced with conventional vinyl silicone oil of the same viscosity, phenyl MQ silicone resin is replaced with conventional MQ silicone resin of the same viscosity, and phenyl hydrogen-containing silicone oil is replaced with conventional hydrogen-containing silicone oil of the same viscosity and hydrogen content.

[0139] Comparative Example 5

[0140] Similar to Comparative Example 3, the difference is that in the raw materials and preparation method for low-density foamed silicone, phenyl vinyl silicone oil is replaced with conventional vinyl silicone oil of the same viscosity, phenyl MQ silicone resin is replaced with conventional MQ silicone resin of the same viscosity and the same M / Q ratio, and phenyl hydrogen-containing silicone oil is replaced with conventional hydrogen-containing silicone oil of the same viscosity and the same hydrogen content.

[0141] First, the surface tension of different types of silicone oils was tested. The test standard was in accordance with the standard in GB / T 18396-2008 "Ring Method for Determination of Surface Tension". The test results are shown in Table 1. The unit of surface tension is mN / m.

[0142] Table 1. Surface tension test results of different types of silicone oils

[0143]

[0144]

[0145] Based on the results in Table 1, it is clear that the surface tension of silicone oil is greatly increased after the addition of phenyl rigid groups.

[0146] Figure 1 A side view of the foamed silicone prepared in Example 1 before coloring is shown. Figure 2 Side photographs of the foamed silicone prepared in Example 1 and Comparative Example 5 after being colored with a black ink pen are shown. According to... Figure 2 The comparison clearly shows that the silicone system in Example 1 produces smaller and finer pores, forming a low-density, high-expansion-ratio foam with denser ink patterns. In contrast, Comparative Example 5 uses conventional silicone oil for bonding, resulting in larger pores that are difficult to form a fine, high-expansion-ratio foam, thus producing more dispersed ink patterns. This demonstrates that the foamed silicone prepared by the technical solution of this application contains a uniform, fine, low-density, high-expansion-ratio foam.

[0147] The performance of the foamed silicone prepared in Examples 1-5 and Comparative Examples 1-5 was tested, and the test results are shown in Table 2. The specific test standards are as follows:

[0148] Specific gravity after curing: according to the standard in ASTM D792-2007 Test Method for Density and Relative Density of Plastics, the unit is g / cc;

[0149] Pressure offset: The force measured at 25% offset according to ASTM D1056 standard for rubber sponge compression deformation, in psi;

[0150] Compression deformation (maximum): According to ASTM D1056 standard for compression deformation of rubber sponge, after compression of 70%, it is tested at 100℃ for 22 hours and then left to stand at room temperature for 30 minutes. The unit is %;

[0151] Tensile strength: in accordance with the standard of ASTM D412 method for tensile testing of vulcanized rubber and thermoplastic elastomers, in psi;

[0152] Elongation: in accordance with the standard in ASTM D412 Method for Tensile Testing of Vulcanized Rubber and Thermoplastic Elastomers, in percentage (%).

[0153] Flame retardancy rating: determined according to UL94 flame retardancy rating standard;

[0154] Breakdown voltage: ASTM D149-2009, unit is kV / mm;

[0155] Thermal conductivity: according to the standard in ASTM C518, the unit is W / m·K.

[0156] Table 2 Test results of different performance characteristics of Examples 1-5 and Comparative Examples 1-5

[0157]

[0158] As shown in Table 2, the foamed silicone prepared in this application has a low specific gravity and good tensile strength, indicating that the foamed silicone prepared in this application has a low density and good tensile strength by functionalizing phenyl silicone oil with hydroxyl groups.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0160] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the embodiments claimed above can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A low-density foamed silicone, characterized in that, The raw materials for the low-density foamed silicone include: hydroxyl-functionalized phenyl silicone oil, modified reinforcing filler, modified flame-retardant filler, phenyl vinyl silicone oil, phenyl MQ silicone resin, phenyl hydrogen-containing silicone oil, catalyst and inhibitor. The hydroxyl-functionalized phenyl silicone oil contains -(CH2). a OH group, where a is an integer from 2 to 5; The chemical structural formula of the hydroxyl-functionalized phenyl silicone oil is HO(CH2). a (CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2(CH2) a OH, where m≥1, n≥1, and m and n are integers; The modified reinforcing filler is a reinforcing filler modified with a phenylsilane coupling agent, and the reinforcing filler includes at least one of fumed silica and precipitated silica; the modified flame-retardant filler is a flame-retardant filler modified with a phenylsilane coupling agent, and the flame-retardant filler includes at least one of aluminum hydroxide and magnesium hydroxide; the catalyst includes a phenyl platinum catalyst, and the inhibitor includes at least one of acetylenol and 1-(1-propynyl)cyclohexanol; The raw materials of the low-density foamed silicone are composed of component A and component B. In component A, the mass ratio of the hydroxyl-functionalized phenyl silicone oil, the phenyl MQ silicone resin, the phenyl vinyl silicone oil, the modified reinforcing filler, the modified flame retardant filler, and the catalyst is (25-40):(3-5):(10-15):(30-40):(40-55):(0.1-0.5). In component B, the mass ratio of the hydroxyl-functionalized phenyl silicone oil, the phenyl MQ silicone resin, the phenyl vinyl silicone oil, the modified reinforcing filler, the modified flame retardant filler, the phenyl hydrogen-containing silicone oil, and the inhibitor is (25-40):(3-5):(10-15):(30-40):(40-55):(10-15):(0.1-0.3). The mass ratio of component A to component B is 1:(0.9-1.1).

2. The low-density foamed silicone as described in claim 1, characterized in that, The preparation method of the hydroxyl-functionalized phenyl silicone oil includes: The enol compound was condensed with a silazane to give compound X; Compound X was reacted with dihydrogen-terminated phenyl silicone oil by an addition reaction to obtain compound Y; The compound Y was subjected to an alcoholysis reaction with an alcohol to obtain the hydroxyl-functionalized phenyl silicone oil.

3. The low-density foamed silicone as described in claim 2, characterized in that, At least one of the following conditions must be met: A. The enol compound includes at least one of vinyl alcohol, allyl alcohol, and enbutanol; B. The silazane comprises at least one of hexamethyldisilazane and tetramethyldivinyldisilazane; C. The chemical structural formula of the aforementioned hydrogen-terminated phenyl silicone oil is H(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2H, where m≥1, n≥1, and m and n are positive integers; D. The phenyl content in the double-terminated hydrogen-containing phenyl silicone oil is 5wt%-30wt%; E. The hydrogen content in the double-ended hydrogen-containing phenyl silicone oil is 0.01wt%-0.1wt%; F. The alcohols mentioned include either methanol or ethanol; G. The addition reaction also requires the addition of a platinum-containing catalyst, wherein the platinum content in the platinum-containing catalyst is 3000ppm-5000ppm.

4. The low-density foamed silicone as described in claim 1, characterized in that, At least one of the following conditions must be met: J. The chemical structural formula of the phenyl vinyl silicone oil is: (CH2=CH)(CH3)2SiO[(CH3)2SiO] m [(C6H5)2SiO] n Si(CH3)2(CH=CH2); K. The chemical structural formula of the phenyl hydrogen-containing silicone oil is: (CH3)3SiO[(CH3)HSiO] m [(C6H5)2SiO] n Si(CH3)3; L. The hydrogen content in the phenyl-containing hydrogen silicone oil is 0.1wt%-1.6wt%; the phenyl content is 5wt%-30wt%; M. The phenyl MQ silicone resin includes at least one of phenyl vinyl MQ silicone resin and phenyl methyl MQ silicone resin; N. The ratio of M-units to Q-units in the phenylMQ silicone resin is (0.8-1):

1.

5. The low-density foamed silicone as described in claim 4, characterized in that, It also meets at least one of the following conditions: Q. The phenylsilane coupling agent comprises at least one of phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, and methylphenyldimethoxysilane; T. In the modified reinforcing filler, 25g-50g of the phenylsilane coupling agent is added to every 1000g of the reinforcing filler for the modification treatment; U. In the modified flame retardant filler, 25g-50g of the phenylsilane coupling agent is added to every 1000g of the flame retardant filler for the modification treatment; V. The platinum content in the phenylplatinum catalyst is 3000ppm-5000ppm.

6. A method for preparing low-density foamed silicone as described in any one of claims 1-5, characterized in that, include: The raw materials, including the hydroxyl-functionalized phenyl silicone oil, the phenyl MQ silicone resin, the phenyl vinyl silicone oil, the modified reinforcing filler, and the modified flame retardant filler, are mixed and ground, and then the catalyst is added to obtain component A. The raw materials comprising the hydroxyl-functionalized phenyl silicone oil, the phenyl MQ silicone resin, the phenyl vinyl silicone oil, the modified reinforcing filler, the modified flame retardant filler, the phenyl hydrogen-containing silicone oil, and the inhibitor are mixed and ground to obtain component B; After mixing component A and component B in a certain proportion, the mixture is calendered into sheets and then heated to cure, thus obtaining the low-density foamed silicone.

7. The preparation method according to claim 6, characterized in that, At least one of the following conditions must be met: c. The fineness of the product from the grinding process is 80-100 mesh; e. The temperature for heat curing is 70℃-100℃.

8. An electronic instrument, characterized in that, Includes the low-density foamed silicone as described in any one of claims 1-5.

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