High purity branched silicone oil, its preparation method and application

Abstract

The present application relates to the technical field of silicone oil preparation, and particularly relates to high-purity branched silicone oil, a preparation method and application thereof. The method comprises three steps of hydrolysis and condensation, secondary hydrolysis and deep condensation, which are respectively used for removing residual active groups such as Si-alkyloxy and Si-OH in raw materials. By introducing a deep condensation sealing agent and a catalyst, intermolecular and intramolecular condensation crosslinking reactions are effectively inhibited, and the purity and stability of the branched silicone oil are significantly improved. The obtained product has controllable viscosity, small change during thermal storage, no odor and no turbidity, and is suitable for the fields of personal care, lubrication and electronic materials with high performance requirements. The method is simple in process and suitable for industrial popularization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicone oil preparation, and particularly relates to high-purity branched silicone oil and a preparation method and application thereof. BACKGROUND

[0002] Branched silicone oil is a kind of liquid polyorganosiloxane containing branched polyorganosiloxane chains, which introduces three or four functional linkages as branching points in the linear silicone oil molecular chain. Due to the branched structure of the molecule, the entanglement between the molecular chains is larger than that of linear silicone oil, which has a shear thinning effect, is beneficial to dispersion and flow. Due to the introduction of branched chains, while maintaining the multiple excellent properties of silicone oil, it also has more excellent low temperature resistance (its freezing point can be as low as -90 DEG C), and is widely used in personal care, textile, low temperature lubrication, LED silicone rubber and other application fields.

[0003] The conventional branched silicone oil preparation methods are: (1) alkylchlorosilane co-hydrolysis method. For example, MDT branched silicone oil is prepared by mixed hydrolysis of trimethylchlorosilane, dimethyldichlorosilane and methyltrichlorosilane, and different viscosity MDT silicone oils are prepared by further ring-opening equilibrium reaction of MDT silicone oil with cyclosiloxane. (2) Alkylalkoxysilane co-hydrolysis method. For example, branched silicone oil is prepared by co-hydrolysis of methyltrimethoxysilane and dimethyldimethoxysilane in the presence of a capping agent such as hexamethyldisiloxane. (3) 1,1,1,3,5,7,7,7-octamethyl-3,5-dihydroxy-tetrasiloxane (MHTS) and cyclosiloxane are subjected to equilibrium reaction to prepare branched silicone oil. However, the above methods generally have the defect of incomplete hydrolysis reaction, especially due to the steric hindrance effect, the siloxane bond of the branched structure cannot be fully formed, finally a large amount of active functional groups such as Si-OH or Si-alkoxy are remained in the product. Such active functional groups are prone to further hydrolysis or condensation reaction during storage and use of the silicone oil, causing problems such as viscosity increase, appearance turbidity, odor generation and unstable product quality, which seriously limits the application range of branched silicone oil products.

[0004] Chinese invention patent (publication number: CN100396715C) drops phenylsilane and capping agent into water and catalyst, hydrolysis is completed, and then the oil layer is washed with alkali and washed with water until neutral. Chinese invention patent (publication number: CN102329427B) drops methyl chlorosilane mixture into a mixture of methanol and water for hydrolysis, then preferentially removes the generated hydrochloric acid, and then repeatedly adds urea to promote acid-water separation, then neutralizes with sodium carbonate and filters, and finally performs secondary equilibrium telomerization under the action of tetramethylammonium hydroxide to obtain MDT silicone oil. Chinese invention patent (CN103435806B) drops phenyltriethoxysilane into a mixture containing capping agent and acidic catalyst and water, washes with water until neutral after dropping, and then dries and removes low pressure to obtain branched phenyl silicone oil. The existing technology is to prepare branched silicone oil with T structure by hydrolysis method or hydrolysis and then equilibrium method. However, in the hydrolysis process, due to the existence of steric hindrance, etc., it is extremely easy to hydrolyze incompletely, thereby causing the existence of Si-OH or Si-alkoxy active groups. This will cause deep hydrolysis and crosslinking of the product during use or storage, resulting in quality problems such as viscosity increase, molecular weight distribution broadening, appearance hazy and turbid, and odor. During storage and use, it brings quality risks such as formula stability decline, performance decline, temperature resistance decline, and easy yellowing, which undoubtedly brings many inconveniences to use.

[0005] In view of the risk problem of residual Si-OH or Si-alkoxy active groups, Chinese invention patent (publication number: CN108892775B) prepares a mixture of D / T type cyclic branched siloxane. The mixture is prepared by equilibrium catalytic reaction of trialkoxysilane and cyclosiloxane such as D5 in the presence of acidic catalyst macromolecular ion exchange resin, then water and ring D5 are added to initiate hydrolysis and condensation, and finally the acid is neutralized and removed, and the alcohol, water and other low boiling substances are distilled. The Si-OH and Si-alkoxy content prepared by this method is 2-10% mol. However, this method focuses on introducing ring structure into the structure, and still reacts by one-step hydrolysis and condensation. Although it can reduce Si-OH and Si-alkoxy groups to some extent, it still cannot fundamentally solve the problem of residual active groups caused by insufficient hydrolysis. Huang Wenrun proposed in "MT type siloxane oligomer and polysiloxane containing MT structure" that in view of the problem of residual Si-OH and Si-alkoxy active groups, after hydrolysis is completed, the oil layer is subjected to secondary reaction with concentrated sulfuric acid, which can effectively reduce Si-OH and Si-alkoxy groups. However, the condensation degree of this method is limited, and this method is only effective for Si-OH groups exposed on the outside of the molecular structure, but almost useless for Si-OH groups wrapped inside the molecule. In addition, concentrated sulfuric acid has a dehydrating and drying effect, which makes Si-alkoxy lack a hydrolysis environment and cannot be removed, so this method still cannot completely solve the problem of residual Si-OH and Si-alkoxy active groups.

[0006] In summary, the prior art has different degrees of Si-OH and Si-alkoxy active group residual problems, resulting in low product purity, quality decline, and limited application. SUMMARY

[0007] In view of the problems of Si-OH and Si-alkoxy active group residues in the prior art of branched silicone oil, the purpose of the present application is to provide a preparation method of high-purity branched silicone oil. The method completely eliminates the residual problems of Si-OH and Si-alkoxy active functional groups caused by insufficient hydrolysis during the production of branched silicone oil by innovatively introducing a secondary hydrolysis process combined with a deep condensation reaction, thereby obtaining high-purity, high-stability branched silicone oil products. The implementation of this technical solution will effectively improve the product quality of branched silicone oil, solve the problems of viscosity change, appearance turbidity, and performance decay during storage and use, and greatly improve the application potential of branched silicone oil in the fields of fine chemicals, high-end lubricants, personal care products, and electronic packaging materials.

[0008] In order to achieve the above-mentioned purposes, the present application adopts the following technical solutions:

[0009] A preparation method of high-purity branched silicone oil, comprising the following steps:

[0010] Step one, hydrolysis and condensation reaction:

[0011] The end cap agent M, branched chain T, and linear chain D are sequentially added to the reactor and mixed uniformly, diluted with solvent, then hydrolysis and condensation catalyst and water are added for the first hydrolysis and condensation reaction, the acid water layer is removed, and the branched silicone oil primary polymer S1 is obtained;

[0012] Step two, secondary hydrolysis reaction:

[0013] The branched silicone oil primary polymer S1 obtained in step one is diluted with solvent again, then hydrolysis and condensation catalyst and water are added for secondary hydrolysis reaction, the acid water layer is removed, a neutralizing agent is added for neutralization, the solvent is removed and dried, and the neutral and dry branched silicone oil primary polymer S2 is obtained;

[0014] Step three, deep condensation reaction:

[0015] The branched silicone oil primary polymer S2 obtained in step two is added to the deep condensation end cap agent M', and a deep condensation catalyst is added for deep condensation reaction;

[0016] The end cap agent M is a silane compound represented by the general formula R1R2R3-Si-R4,

[0017] The branched chain T is a silane compound represented by the general formula R5Si(R6)3,

[0018] The linear chain D is a cyclotrisiloxane or a difunctional silane compound represented by the general formula (R7)2Si(R8)2,

[0019] The deep condensation end-capping agent M' is a silazane compound represented by the general formula (R1R2R3)2Si-NH, wherein R1, R2, R3, R5, R7 are C1-C 10 alkyl groups, R4, R8 are C1-C 10 alkyl groups or hydrolysable active groups; R6 is a hydrolysable active group.

[0020] The reaction principle of the present application is as follows:

[0021] Hydrolytic condensation reaction:

[0022] R1R2R3-Si-R4 + R5Si(R6)3 + (R7)2Si(R8)2

[0023] → (R1R2R3SiO 1 / 2 ) a (R5SiO 3 / 2 ) b1 ((R7)2SiO 2 / 2 ) c1 (R5Si-(OH) x1 (R6) x2 ) d1 ((R7)2SiO(OH) y1 (R8) y2 ) e1

[0024] Secondary hydrolysis reaction:

[0025] (R1R2R3SiO 1 / 2 ) a (R5SiO 3 / 2 ) b1 ((R7)2SiO 2 / 2 ) c1 (R5Si-(OH) x1 (R6) x2 ) d1 ((R7)2SiO(OH) y1 (R8) y2 ) e1

[0026] → (R1R2R3SiO 1 / 2 ) a (R5SiO 3 / 2 ) b2 ((R7)2SiO 2 / 2 ) c2 (R5Si-(OH) x )d2 (R7)2SiO(OH) y ) e2

[0027] Deep condensation reaction:

[0028] (R1R2R3SiO 1 / 2 ) a (R5SiO 3 / 2 ) b2 (R7)2SiO 2 / 2 ) c2 (R5Si-(OH) x ) d2 (R7)2SiO(OH) y ) e2

[0029] (R1R2R3SiO 1 / 2 ) a (R5SiO 3 / 2 ) b (R7)2SiO 2 / 2 ) c

[0030] wherein a = 1-100, b = 1-2000, c = 1-5000, branched silicone oil molecular weight is 1-100000, viscosity is 1-10000 mPa.s.

[0031] As a preference, R1, R2, R3 are the same or different, one or more of methyl, vinyl, ethyl, propyl and phenyl; R4 is one or more of methyl, vinyl, ethyl, propyl and phenyl, or, one of trimethylsiloxy, vinyldimethylsiloxy, phenyldimethylsiloxy, ethyldimethylsiloxy, chlorine, bromine, iodine, methoxy, ethoxy, propoxy and butoxy.

[0032] As a preference, R5 is one of methyl, vinyl, ethyl, propyl and phenyl; R6 is one of trimethylsiloxy, vinyldimethylsiloxy, phenyldimethylsiloxy, ethyldimethylsiloxy, chlorine, bromine, iodine, methoxy, ethoxy, propoxy and butoxy;

[0033] As a preference, R7 is one or more of methyl, vinyl, ethyl, propyl and phenyl; R8 is one or more of methyl, vinyl, ethyl, propyl and phenyl or, one of trimethylsiloxy, vinyldimethylsiloxy, phenyldimethylsiloxy, ethyldimethylsiloxy, chlorine, bromine, iodine, methoxy, ethoxy, propoxy and butoxy.

[0034] As preferred, the end-capping agent M is one or more of hexamethyldisiloxane, 1,3- divinyl disiloxane, 1,3-diphenyl disiloxane, 1,3-diethyl disiloxane, trimethylchlorosilane, vinyl dimethylchlorosilane, phenyl dimethylchlorosilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylpropoxysilane, vinyl dimethylmethoxysilane, vinyl diethoxysilane, phenyl dimethylmethoxysilane, phenyl dimethylethoxysilane, ethyl dimethylmethoxysilane, and triethylmethoxysilane.

[0035] As preferred, the branched chain segment T is one or more of methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrichlorosilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane.

[0036] As preferred, the linear chain segment D is one or more of dimethylcyclosiloxane, diethylcyclosiloxane, methyl ethyl cyclosiloxane, methyl phenyl cyclosiloxane, methyl vinyl cyclosiloxane, dimethyl dichlorosilane, dimethyl dimethoxysilane, dimethyl diethoxysilane, methyl vinyl dichlorosilane, methyl vinyl dimethoxysilane, methyl vinyl diethoxysilane, methyl phenyl dichlorosilane, methyl phenyl dimethoxysilane, methyl phenyl diethoxysilane, diphenyl dichlorosilane, diphenyl dimethoxysilane, diphenyl diethoxysilane.

[0037] As preferred, the deeply condensed end-capping agent M' is one or more of hexamethyldisilazane, 1,3-divinyl disilazane, 1,3-diphenyl disilazane, 1,3-diethyl disilazane.

[0038] As preferred, the hydrolysis condensation catalyst is one or more of sulfuric acid, hydrochloric acid, sulfonic acid, phosphoric acid, cation exchange resin in combination.

[0039] The solvent is to facilitate the hydrolysis condensation reaction can be fully carried out, on the one hand to improve the water and hydrolysis group contact opportunities, on the other hand to play a dilution effect to reduce the steric hindrance of the group. As preferred, the solvent is specifically one or more of methanol, ethanol, isopropanol, butanol, benzene, toluene, xylene, dodecyl, hexadecyl, petroleum ether.

[0040] The neutralizing agent is a basic compound used to neutralize the acidic catalyst present in the reaction system until neutral, as preferred, the neutralizing agent is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide. The addition form can be alkaline powder or alkaline aqueous solution.

[0041] The deep condensation catalyst is a metal catalyst, an amine catalyst, a metal-free catalyst, or a bio-based catalyst. The metal catalyst is an organotin catalyst, a zinc catalyst, a bismuth catalyst, or the like; the amine catalyst is a primary amine or a secondary amine; the metal-free catalyst is a guanidine or a phosphazene base catalyst; and the bio-based catalyst is a lipase catalyst. As a preferred option, the deep condensation catalyst is a metal catalyst, an amine catalyst, a metal-free catalyst, or a bio-based catalyst.

[0042] As a further preferred option, the end-capping agent M is one or more of hexamethyldisiloxane, 1,3-divinyl disiloxane, 1,3-diphenyl disiloxane, trimethylchlorosilane, vinyl dimethylchlorosilane, trimethylmethoxysilane, vinyl diethoxysilane, and phenyl dimethylmethoxysilane.

[0043] As a further preferred option, the branched chain segment T is one or more of methyltrichlorosilane, methyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane.

[0044] As a further preferred option, the linear chain segment D is one or more of dimethylcyclosiloxane, methylvinylcyclosiloxane, methylphenylcyclosiloxane, dimethyldimethoxysilane, dimethyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, methylvinyl dimethoxysilane, and methylvinyl diethoxysilane.

[0045] As a further preferred option, the hydrolysis condensation catalyst is one or more of sulfuric acid, hydrochloric acid, and a sulfonic acid.

[0046] As a further preferred option, the solvent is specifically one or more of ethanol, isopropyl alcohol, benzene, and toluene.

[0047] As a further preferred option, the neutralizing agent is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate.

[0048] As a further preferred option, the deep condensation catalyst is dibutyltin dilaurate, stannous octoate, triethylenediamine, triethylamine, or hexamethylenetetramine.

[0049] As a preferred option, the solvent is added in an amount of 1%-50% of the total amount of the reaction system; as a further preferred option, the solvent is added in an amount of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% of the total amount of the reaction system.

[0050] As a further preferred option, the hydrolysis condensation catalyst is added in an amount of 0.1-20% of the total amount of the reaction system; as a further preferred option, the hydrolysis condensation catalyst is added in an amount of 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10%, 15%, or 20% of the total amount of the reaction system.

[0051] and / or, the neutralizing agent is added in an amount of 0.1% to 20% of the total amount of the reaction system; more preferably, the neutralizing agent is added in an amount of 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10%, 15% or 20% of the total amount of the reaction system;

[0052] and / or, the additive is added in an amount of 1 to 5000 ppm of the total amount of the reaction system; more preferably, the additive is added in an amount of 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000 or 5000 ppm of the total amount of the reaction system.

[0053] Preferably, the solvent is added in an amount of 20% to 40% of the total amount of the reaction system.

[0054] and / or, the hydrolysis condensation catalyst is added in an amount of 0.5% to 8.0% of the total amount of the reaction system;

[0055] and / or, the neutralizing agent is added in an amount of 0.5% to 8.0% of the total amount of the reaction system;

[0056] and / or, the additive is added in an amount of 100 to 2000 ppm of the total amount of the reaction system.

[0057] Preferably, step one: the end cap M, branched chain T, linear chain D are sequentially added into the dry reactor in a mass ratio, stirred uniformly, then solvent is added and stirred for 0.5-2h, then the mixture of acidic catalyst and water is slowly added into the reactor, the temperature of the reaction system is controlled at 30-100℃, the dropping time is 0.5-5h, after the dropping is completed, the temperature is kept at 30-100℃ for 1-6h, then the stirring is stopped and the layers are separated, the acid water layer is removed, and the branched silicone oil primary polymer S1 is obtained.

[0058] Preferably, step two: the oil layer branched silicone oil primary polymer S1 is added into the reactor, solvent is added for dilution and stirring for 0.5-2h, then the mixture of acidic catalyst and water is slowly added into the reactor, the temperature of the reaction system is controlled at 40-100℃, the dropping time is 0.5-3h, after the dropping is completed, the temperature is kept at 40-100℃ for 1-6h for secondary hydrolysis reaction, then the stirring is stopped and the layers are separated, the acid water layer is removed, the neutralizing agent is added for neutralization, the residual acidic catalyst is removed, then the solvent and water are removed under vacuum at 40-80℃ for 0.5-3h, and the neutral and dry branched silicone oil primary polymer S2 is obtained.

[0059] As preferred, step three: the neutral, dry branched silicone oil prepolymer S2 is added into the dry reactor, then the deep condensation capping agent M' is added, stirred uniformly for 0.5-2h, then the deep condensation catalyst is added, heated while stirring, and the deep condensation is carried out at 50-120°C for 1-8h, then the water produced by the deep condensation and the low components present in the prepolymer are removed under vacuum at 50-120°C for 0.5-5h, and finally the color removal filtration is carried out, to obtain the high-purity branched silicone oil product S3.

[0060] Further, the present application also provides a high-purity branched silicone oil, which is prepared by the method, and the general structure of the high-purity branched silicone oil is as follows:

[0061] (R1R2R3SiO 1 / 2 ) a (R5SiO 3 / 2 ) b ((R7)2SiO 2 / 2 ) c ,

[0062] wherein a=1-100, b=1-2000, c=1-5000, the molecular weight is 1-100000, the viscosity is 1-10000 mPa.s, the total content of Si-OH and Si-alkoxy is less than 0.1 mol%, and the viscosity growth rate under the condition of 80°C heat storage for one month is less than 10%.

[0063] As preferred, a=10-80, b=100-1000, c=100-4000, the molecular weight is 100-80000, and the viscosity is 20-8000 mPa.s.

[0064] As further preferred, a=20-60, b=200-8000, c=150-300, the molecular weight is 500-70000, and the viscosity is 50-5000 mPa.s.

[0065] As further preferred, a is 30, 40, 50, b is 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000, 5000, 6000, 7000, or 8000, c is 150, 200, 250, or 300, the molecular weight is 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000, 5000, 6000, or 7000, and the viscosity is 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000, or 5000 mPa.s.

[0066] Further, the application further provides application of the high-purity branched silicone oil in personal care products, textile treating agents, low-temperature lubricants and LED encapsulating silicone rubbers.

[0067] The application adopts the above technical scheme, and aims at the problem of incomplete hydrolysis of branched silicone oil due to steric hindrance in the hydrolysis and condensation process, which is specifically manifested as the problem that residual Si-OH or Si-alkoxy active groups are difficult to be completely eliminated in an equilibrium state. In view of the problem of residual Si-OH or Si-alkoxy active groups, the application adopts a method combining secondary hydrolysis with deep condensation process to completely eliminate the residual Si-OH or Si-alkoxy active groups. The secondary hydrolysis process aims to eliminate Si-alkoxy groups, break the primary hydrolysis equilibrium, and convert the Si-alkoxy groups into Si-OH or desired Si-O-Si chain segments under the action of an acidic catalyst. The deep condensation process aims to completely remove the residual Si-OH groups, selectively condense Si-OH under the catalysis of an OH condensation catalyst, and convert the Si-OH into desired Si-O-Si chain segments by adding a deep condensation capping agent to provide capping units, so as to reduce the hydroxyl condensation reaction between high polymer molecules and within the molecules, reduce crosslinking and gelation, improve the purity of the product, and obtain high-purity branched silicone oil.

[0068] Compared with the prior art, the application has the following beneficial effects:

[0069] (1) The application adopts the innovative reaction process of “secondary hydrolysis combined with deep condensation”, effectively overcomes the problem of residual Si-OH and Si-alkoxy active groups caused by incomplete hydrolysis due to steric hindrance in the prior art, and the total content of Si-OH and Si-alkoxy in the obtained branched silicone oil product is extremely low, which significantly improves the chemical stability and storage stability of the product, and avoids the phenomena of viscosity increase, appearance turbidity and odor generation during storage and use;

[0070] (2) The application introduces a specific silazane deep condensation capping agent in the deep condensation process, improves the capping efficiency and selectivity, reduces the condensation crosslinking of intramolecular and intermolecular hydroxyl groups, further reduces the risk of gelation, and ensures the good appearance quality and high purity of the branched silicone oil product;

[0071] (3) Compared with the prior art, the branched silicone oil product prepared by the application has more excellent thermal stability and anti-aging performance. After being placed at 80℃ for 1 month, the viscosity growth rate of the product is less than 10%, which is much lower than that of the comparative product prepared without the method of the application (the viscosity growth rate is as high as 40% or more), and the product quality stability is significantly improved, which is more suitable for high-performance and high-reliability applications;

[0072] (4) The preparation method of the application has clear and reasonable steps, mild reaction conditions, simple and easy-to-control process, and easily obtained raw materials in industrialization, greatly improving the industrialization production feasibility of high-purity branched silicone oil, and providing good technical support and economic benefits for the market promotion and application of branched silicone oil products. DETAILED DESCRIPTION

[0073] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the application.

[0074] Embodiment 1

[0075] Step one: hydrolysis and condensation reaction

[0076] Into a dry reactor, 40.5 g of MM, 396 g of phenyltrimethoxysilane (Ph-3M) and 480 g of dimethyldimethoxysilane (MM-2M) were sequentially added and stirred uniformly, then 30% mass fraction of ethanol was added and stirred for 0.5 h, then a mixture of 2% mass fraction of concentrated sulfuric acid and 30% mass fraction of water was slowly added dropwise into the reactor, the temperature of the reaction system was controlled at 60°C, the dropwise adding time was 2 h, after the dropwise adding was completed, the reaction was continued at 60°C for 6 h, then the stirring was stopped and the layers were separated, the acid water layer was removed, and branched silicone oil primary polymer S1 was obtained.

[0077] Step two: secondary hydrolysis reaction

[0078] The branched silicone oil primary polymer S1 in the oil layer was added into a reactor, a solvent was added for dilution and stirring for 0.5 h, then a mixture of an acidic catalyst and water was slowly added dropwise into the reactor, the temperature of the reaction system was controlled at 60°C, the dropwise adding time was 1 h, after the dropwise adding was completed, the temperature was controlled at 60°C and the secondary hydrolysis reaction was continued for 3 h, then the stirring was stopped and the layers were separated, the acid water layer was removed, a neutralizing agent was added into the oil layer for neutralization, the residual acidic catalyst was removed, then the solvent and water were removed under vacuum at 60°C for 3 h for dehydration and drying, and neutral and dry branched silicone oil primary polymer S2 was obtained.

[0079] Step three: deep condensation reaction

[0080] The above-mentioned neutral, dry branched silicone oil prepolymer S2 is added to a dry reactor, then 10% by mass of a deep condensation capping agent (D) hexamethyldisilazane (HMDS) is added, stirred uniformly for 1 h, then 1000 ppm of a deep condensation catalyst (E) dibutyltin dilaurate (DBTL) is added, heated while stirring, and deep condensation is carried out at 80°C for 3 h, then water produced by deep condensation and low components present in the prepolymer are removed under vacuum at 80°C for 5 h, and finally color removal filtration is carried out, to obtain a high-purity branched silicone oil product S3, having a viscosity of 285 mPa.s, a viscosity of 293 mPa.s after being stored hot at 80°C for 1 month, a viscosity increase rate of 3%, and no change in appearance as a colorless transparent viscous liquid.

[0081] Example 2:

[0082] Step one: hydrolysis condensation reaction

[0083] Into a dry reactor, 46.5 g of 1,3-divinyl disiloxane (M Vi M Vi ), 630 g of methyl triethoxysilane (M-3E), and 1110 g of dimethylcyclosiloxane (DMC) are sequentially added, stirred uniformly, then 40% by mass of toluene is added and stirred for 0.5 h, then a mixture of 4% by mass of concentrated hydrochloric acid and 20% by mass of water is slowly added dropwise into the reactor, the temperature of the reaction system is controlled at 80°C, the dropwise addition time is 2 h, after the dropwise addition is completed, the temperature is maintained at 80°C and the reaction is continued for 6 h, then stirring is stopped and the layers are separated, and the acid water layer is removed, to obtain a branched silicone oil prepolymer S1.

[0084] Step two: secondary hydrolysis reaction

[0085] The above-mentioned branched silicone oil prepolymer S1 in the oil layer is added to a reactor, diluted with a solvent, stirred for 0.5 h, then a mixture of an acidic catalyst and water is slowly added dropwise into the reactor, the temperature of the reaction system is controlled at 80°C, the dropwise addition time is 1 h, after the dropwise addition is completed, the temperature is maintained at 80°C and the secondary hydrolysis reaction is continued for 5 h, then stirring is stopped and the layers are separated, the acid water layer is removed, a neutralizing agent is added to the oil layer to neutralize it, the residual acidic catalyst is removed, then the solvent is removed and the water is dried under vacuum at 80°C for 3 h, to obtain a neutral, dry branched silicone oil prepolymer S2.

[0086] Step three: deep condensation reaction

[0087] The above-mentioned neutral, dry branched silicone oil prepolymer S2 is added to a dry reactor, then 15% by mass of a deep condensation capping agent (D) 1,3-divinyl disilazane (HViDS) is added, stirred uniformly for 1 h, then 500 ppm of a deep condensation catalyst (E) triethylamine is added, heated while stirring, and deep condensation is carried out at 60°C for 5 h, then water produced by deep condensation and low components present in the prepolymer are removed under vacuum at 80°C for 5 h, and finally color removal filtration is carried out, to obtain a high-purity branched silicone oil product S3, having a viscosity of 1220 mPa.s, a viscosity of 1250 mPa.s after being stored at 80°C for 1 month, a viscosity increase rate of 2%, and no change in appearance as a colorless transparent viscous liquid.

[0088] Example 3:

[0089] Step one: hydrolysis condensation reaction

[0090] A dry reactor is sequentially charged with 78.5 g of 1,3-diphenyl disiloxane (M Ph M Ph ), 930 g of vinyltrimethoxysilane (Vi-3M), and 1200 g of dimethyldiethoxysilane (MM-2E), stirred uniformly, then 50% by mass of benzene is stirred for 0.5 h, then a mixture of 4% by mass of sulfonic acid and 32% by mass of water is slowly added dropwise to the reactor, the temperature of the reaction system is controlled at 80°C, the dropwise addition time is 2 h, after the dropwise addition is completed, the temperature is maintained at 80°C and the reaction is continued for 6 h, then stirring is stopped and the layers are separated, and the acid water layer is removed, to obtain a branched silicone oil prepolymer S1.

[0091] Step two: secondary hydrolysis reaction

[0092] The above-mentioned branched silicone oil prepolymer S1 in the oil layer is added to a reactor, diluted with a solvent, stirred for 0.5 h, then a mixture of an acidic catalyst and water is slowly added dropwise to the reactor, the temperature of the reaction system is controlled at 80°C, the dropwise addition time is 1 h, after the dropwise addition is completed, the temperature is controlled at 100°C and the secondary hydrolysis reaction is continued for 5 h, then stirring is stopped and the layers are separated, the acid water layer is removed, a neutralizing agent is added to the oil layer to neutralize it, the residual acidic catalyst is removed, then the solvent and water are removed under vacuum at 80°C for 3 h, to obtain a neutral, dry branched silicone oil prepolymer S2.

[0093] Step three: deep condensation reaction

[0094] The above neutral, dry branched silicone oil prepolymer S2 is added to a dry reactor, then 15% by mass of a deep condensation capping agent (D) 1,3-diphenyl disilazane (HPhDS) is added, stirred uniformly for 1 h, then 300 ppm of a deep condensation catalyst (E) bicyclic guanidine catalyst (TBD) is added, heated while stirring, and deep condensation is carried out at 100°C for 4 h, then water produced by deep condensation and low components present in the prepolymer are removed under vacuum at 80°C for 5 h, and finally color removal filtration is carried out, to obtain a high-purity branched silicone oil product S3, having a viscosity of 3210 mPa.s, a viscosity of 3450 mPa.s after being stored at 80°C for 1 month, a viscosity increase rate of 7%, and no change in appearance as a colorless transparent viscous liquid.

[0095] Comparative Example 1-1:

[0096] Step 1: hydrolytic condensation reaction

[0097] To a dry reactor, 40.5 g of MM, 396 g of phenyltrimethoxysilane (Ph-3M), and 480 g of dimethyldimethoxysilane (MM-2M) are sequentially added, stirred uniformly, then 30% by mass of ethanol is added and stirred for 0.5 h, then a mixture of 2% by mass of concentrated sulfuric acid and 30% by mass of water is slowly added dropwise to the reactor, the temperature of the reaction system is controlled at 60°C, the dropwise addition time is 2 h, after the dropwise addition is completed, the temperature is maintained at 60°C and the reaction is continued for 6 h, then stirring is stopped and the layers are separated, the acid water layer is removed, a neutralizing agent is added for neutralization to neutral, then water produced by deep condensation and low components present in the prepolymer are removed under vacuum at 80°C for 5 h, and finally color removal filtration is carried out, to obtain a branched silicone oil product. The viscosity is 258 mPa.s, the viscosity after being stored at 80°C for 1 month is 367 mPa.s, the viscosity increase rate is 42%, and the appearance changes from an initial colorless transparent viscous liquid to turbidity, accompanied by an odor. The reason is that residual Si-OH is deeply condensed intermolecularly and intramolecularly, resulting in viscosity increase, and residual Si-methoxyl is removed to form methanol free in the branched silicone oil, resulting in appearance hazing and turbidity and odor.

[0098] Comparative Example 1-2:

[0099] Step 1: hydrolytic condensation reaction

[0100] To a dry reactor, 40.5 g of MM, 396 g of phenyltrimethoxysilane (Ph-3M), and 480 g of dimethyldimethoxysilane (MM-2M) are sequentially added, stirred uniformly, then 30% by mass of ethanol is added and stirred for 0.5 h, then a mixture of 2% by mass of concentrated sulfuric acid and 30% by mass of water is slowly added dropwise to the reactor, the temperature of the reaction system is controlled at 60°C, the dropwise addition time is 2 h, after the dropwise addition is completed, the temperature is maintained at 60°C and the reaction is continued for 6 h, then stirring is stopped and the layers are separated, the acid water layer is removed, a neutralizing agent is added for neutralization to neutral, then water produced by deep condensation and low components present in the prepolymer are removed under vacuum at 80°C for 5 h, and finally color removal filtration is carried out, to obtain a branched silicone oil product. The viscosity is 258 mPa.s, the viscosity after being stored at 80°C for 1 month is 367 mPa.s, the viscosity increase rate is 42%, and the appearance changes from an initial colorless transparent viscous liquid to turbidity, accompanied by an odor. The reason is that residual Si-OH is deeply condensed intermolecularly and intramolecularly, resulting in viscosity increase, and residual Si-methoxyl is removed to form methanol free in the branched silicone oil, resulting in appearance hazing and turbidity and odor.

[0101] Step two: secondary hydrolysis reaction

[0102] The branched silicone oil prepolymer S1 described above was added to the reactor, solvent was added for dilution, and stirring was performed for 0.5 h. Then, a mixture of acidic catalyst and water was slowly added dropwise into the reactor, the temperature of the reaction system was controlled at 60°C, the dropwise addition time was 1 h, after the dropwise addition was completed, the temperature was controlled at 60°C, and the reaction was continued for 3 h to perform the secondary hydrolysis reaction. Then, stirring was stopped, and layer separation was performed. The acid water layer was removed, a neutralizing agent was added to the oil layer to perform neutralization, the residual acidic catalyst was removed, and then solvent removal and dehydration drying were performed under vacuum at 60°C for 3 h to obtain a neutral and dry branched silicone oil. The viscosity was 266 mPa.s, the viscosity after 1 month of hot storage at 80°C was 399 mPa.s, the viscosity growth rate was 48%, and the appearance was unchanged as a colorless transparent viscous liquid. The reason for the change was that the methoxy groups were basically removed by secondary hydrolysis, and the residual Si-OH caused a large change in viscosity growth due to deep intermolecular and intramolecular condensation.

[0103] Comparative examples 1-3:

[0104] Step one: hydrolysis condensation reaction

[0105] Into a dry reactor, 40.5 g of MM, 396 g of phenyltrimethoxysilane (Ph-3M), and 480 g of dimethyldimethoxysilane (MM-2M) were sequentially added, and stirring was performed until uniform. Then, 30% by mass of ethanol was added and stirring was performed for 0.5 h. Then, a mixture of 2% by mass of concentrated sulfuric acid and 30% by mass of water was slowly added dropwise into the reactor, the temperature of the reaction system was controlled at 60°C, the dropwise addition time was 2 h, after the dropwise addition was completed, the temperature was controlled at 60°C, and the reaction was continued for 6 h, and then stirring was stopped, layer separation was performed, the acid water layer was removed, a neutralizing agent was added to the oil layer to perform neutralization, the residual acidic catalyst was removed, and then solvent removal and dehydration drying were performed under vacuum at 60°C for 3 h to obtain a branched silicone oil prepolymer.

[0106] Step two: deep condensation reaction

[0107] The above-mentioned neutral, dry branched silicone oil prepolymer is added to a dry reactor, then 10% by mass of a deep condensation capping agent (D) hexamethyldisilazane (HMDS) is added, stirred for 1 h, then 1000 ppm of a deep condensation catalyst (E) dibutyltin dilaurate (DBTL) is added, heated while stirring, and deep condensation is carried out at 80°C for 3 h, then water produced by deep condensation and low components present in the prepolymer are removed under vacuum at 80°C for 5 h, and finally color removal filtration is carried out, to obtain a branched silicone oil product, with a viscosity of 278 mPa.s, a viscosity of 320 mPa.s after 1 month of hot storage at 80°C, a viscosity increase rate of 15%, and an appearance that changes from colorless transparent viscous liquid to hazy liquid. The reason is that residual Si-OH is effectively removed and capped by the deep condensation capping agent in the presence of the deep condensation catalyst, so the viscosity increase is relatively small; however, residual Si-methoxyl is removed to form methanol during hot storage, causing secondary condensation to increase the viscosity, and free methanol cannot dissolve the branched silicone oil, causing the branched silicone oil to be wrapped to cause the appearance to become hazy, and accompanied by a solvent odor.

[0108] Comparative Examples 1-4:

[0109] Step one: hydrolysis condensation reaction

[0110] Into a dry reactor, 40.5 g of MM, 396 g of phenyltrimethoxysilane (Ph-3M), and 480 g of dimethyldimethoxysilane (MM-2M) are sequentially added, stirred until uniform, then 30% by mass of ethanol is added and stirred for 0.5 h, then a mixture of 2% by mass of concentrated sulfuric acid and 30% by mass of water is slowly added dropwise into the reactor, the temperature of the reaction system is controlled at 60°C, the dropwise addition time is 2 h, after the dropwise addition is completed, the temperature is maintained at 60°C and the reaction is continued for 6 h, then stirring is stopped and the layers are separated, and the acid water layer is removed, to obtain branched silicone oil prepolymer S1.

[0111] Step two: secondary hydrolysis reaction

[0112] The above-mentioned branched silicone oil prepolymer S1 is added to a reactor, solvent is added for dilution and stirring for 0.5 h, then a mixture of an acidic catalyst and water is slowly added dropwise into the reactor, the temperature of the reaction system is controlled at 60°C, the dropwise addition time is 1 h, after the dropwise addition is completed, the temperature is controlled at 60°C and the secondary hydrolysis reaction is continued for 3 h, then stirring is stopped and the layers are separated, the acid water layer is removed, a neutralizing agent is added to the oil layer for neutralization to remove residual acidic catalyst, then solvent removal and dehydration drying are carried out under vacuum at 60°C for 3 h, to obtain a neutral, dry branched silicone oil prepolymer S2.

[0113] Step three: deep condensation reaction

[0114] The above neutral, dry branched silicone oil prepolymer S2 is added to a dry reactor, then 1000 ppm of a deep condensation catalyst (E) dibutyltin dilaurate (DBTL) is added, heated with stirring, and deep condensation is carried out at 80°C for 3 h, then water produced by deep condensation and low components present in the prepolymer are removed under vacuum at 80°C for 5 h, and finally color removal filtration is carried out, to obtain a high-purity branched silicone oil product S3, having a viscosity of 282 mPa.s, a viscosity of 487 mPa.s after 1 month of hot storage at 80°C, a viscosity growth rate of 73%, and an appearance of partially gelled viscous liquid. The reason for this is that although the branched silicone oil effectively removes residual Si-methoxy groups by secondary hydrolysis, in the absence of a silazane-based capping agent during deep condensation, Si-OH condensation only occurs within and between molecules, resulting in a doubling of the molecular weight of the product, and because the T chain is a crosslinked network structure, gel is easily produced during condensation, resulting in poor product flow.

[0115]

[0116] The above description of the embodiments of the present application is provided to enable one of ordinary skill in the art to make and use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for producing a high purity branched silicone oil, characterized by, The method comprises the following steps: Step one, hydrolysis condensation reaction: the end-capping agent M, branched chain T, linear chain D are added into the reactor in turn and mixed uniformly, after dilution by solvent, hydrolysis condensation catalyst and water are added for the first hydrolysis condensation reaction, the acid water layer is removed, and branched silicone oil primary polymer S1 is obtained; Step two, secondary hydrolysis reaction: the branched silicone oil primary polymer S1 obtained in step one is diluted by solvent again, hydrolysis condensation catalyst and water are added for secondary hydrolysis reaction, the acid water layer is removed, neutralizing agent is added for neutralization, the solvent is removed and dried, and neutral and dry branched silicone oil primary polymer S2 is obtained; Step three, deep condensation reaction: the branched silicone oil primary polymer S2 obtained in step two is added into deep condensation end-capping agent M', and deep condensation catalyst is added for deep condensation reaction; The end-capping agent M is one or more of hexamethyldisiloxane, 1,3-divinyl disiloxane, 1,3-diphenyl disiloxane, 1,3-diethyl disiloxane, trimethylchlorosilane, vinyl dimethylchlorosilane, phenyl dimethylchlorosilane, trimethylmethoxysilane, trimethylethoxysilane, trimethylpropoxysilane, vinyl dimethylmethoxysilane, vinyl diethoxysilane, phenyl dimethylmethoxysilane, phenyl dimethylethoxysilane, ethyl dimethylmethoxysilane and triethylmethoxysilane; The branched chain T is a silane compound represented by general formula R5Si(R6)3; The linear chain D is a cyclic siloxane or a difunctional silane compound represented by general formula (R7)2Si(R8)2; R5 is one of methyl, vinyl, ethyl, propyl and phenyl; R6 is one of trimethylsiloxy, vinyl dimethylsiloxy, phenyl dimethylsiloxy, ethyl dimethylsiloxy, chlorine, bromine, iodine, methoxy, ethoxy, propoxy and butoxy; R7 is one or more of methyl, vinyl, ethyl, propyl and phenyl; R8 is one or more of methyl, vinyl, ethyl, propyl and phenyl, or one of trimethylsiloxy, vinyl dimethylsiloxy, phenyl dimethylsiloxy, ethyl dimethylsiloxy, chlorine, bromine, iodine, methoxy, ethoxy, propoxy and butoxy; The deep condensation end-capping agent M' is one or more of hexamethyldisilazane, 1,3-divinyl disilazane, 1,3-diphenyl disilazane, 1,3-diethyl disilazane; The hydrolysis condensation catalyst is one or more of sulfuric acid, hydrochloric acid, sulfonic acid, phosphoric acid, cation exchange resin in combination; the deep condensation catalyst is dibutyltin dilaurate, stannous octoate, triethylenediamine, triethylamine, hexamethylenetetramine.

2. The method for preparing a high-purity branched silicone oil according to claim 1, characterized in that, The branched chain T is one or more of methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrichlorosilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane; And / or, the linear chain D is one or more of dimethylcyclosiloxane, diethylcyclosiloxane, methyl ethyl cyclosiloxane, methyl phenyl cyclosiloxane, methyl vinyl cyclosiloxane, dimethyl dichlorosilane, dimethyl dimethoxysilane, dimethyl diethoxysilane, methyl vinyl dichlorosilane, methyl vinyl dimethoxysilane, methyl vinyl diethoxysilane, methyl phenyl dichlorosilane, methyl phenyl dimethoxysilane, methyl phenyl diethoxysilane, diphenyl dichlorosilane, diphenyl dimethoxysilane, diphenyl diethoxysilane; And / or, the solvent is one or more of methanol, ethanol, isopropanol, butanol, benzene, toluene, xylene, petroleum ether; And / or, the neutralizing agent is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide.

3. The method for preparing a high-purity branched silicone oil according to claim 1, characterized in that, The end cap M is one or more of hexamethyldisiloxane, 1,3-divinyl disiloxane, 1,3-diphenyl disiloxane, trimethylchlorosilane, vinyl dimethylchlorosilane, trimethylmethoxysilane, vinyl diethoxysilane, phenyl dimethyl methoxysilane; And / or, the branched chain T is one or more of methyltrichlorosilane, methyltrimethoxysilane, vinyl triethoxysilane, phenyl trimethoxysilane, phenyl triethoxysilane; And / or, the linear chain D is one or more of dimethylcyclosiloxane, methyl vinyl cyclosiloxane, methyl phenyl cyclosiloxane, dimethyl dimethoxysilane, dimethyl diethoxysilane, methyl phenyl dimethoxysilane, methyl phenyl diethoxysilane, methyl vinyl dimethoxysilane, methyl vinyl diethoxysilane; And / or, the hydrolysis condensation catalyst is one or more of sulfuric acid, hydrochloric acid, sulfonic acid in combination; And / or, the solvent is one or more of ethanol, isopropanol, benzene, toluene; And / or, the neutralizing agent is one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate.

4. The method for preparing a high-purity branched silicone oil according to claim 1, characterized in that, The solvent addition amount is 1%-50% of the total amount of the reaction system; And / or, the hydrolysis condensation catalyst addition amount is 0.1%-20% of the total amount of the reaction system; And / or, the neutralizing agent addition amount is 0.1%-20% of the total amount of the reaction system.

5. The method for preparing a high-purity branched silicone oil according to claim 1, characterized in that, The solvent addition amount is 20%-40% of the total amount of the reaction system; And / or, the hydrolysis condensation catalyst addition amount is 0.5%-8.0% of the total amount of the reaction system; And / or, the neutralizing agent addition amount is 0.5%-8.0% of the total amount of the reaction system.

6. The method for preparing a high-purity branched silicone oil according to claim 1, characterized in that, The first hydrolysis condensation reaction in step one is as follows: the mixed solution of acid catalyst and water is slowly added into the reactor, the reaction system temperature is controlled at 30-100℃, the dropping time is 0.5-5h, after the dropping is completed, the temperature is kept at 30-100℃ and the reaction is continued for 1-6h; And / or, the second hydrolysis reaction in step two is as follows: the mixed solution of acid catalyst and water is slowly added into the reactor, the reaction system temperature is controlled at 40-100℃, the dropping time is 0.5-3h, after the dropping is completed, the temperature is kept at 40-100℃ and the reaction is continued for 1-6h for the second hydrolysis reaction; And / or, the deep condensation reaction in step three is as follows: after adding the deep condensation catalyst, the mixture is heated and kept at 50-120℃ for 1-8h, and then the water produced in the deep condensation and the low components in the primary polymer are removed under vacuum at 50-120℃ for 0.5-5h.

7. The use of a high purity branched silicone oil prepared by the method of any one of claims 1-6 in personal care products, textile treatment agents, low temperature lubricants, and LED encapsulating silicone rubbers.

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