High Si-H activity functional end hydrogen-containing silicone oil and production process thereof

Abstract

The invention provides functional end hydrogen-containing silicone oil with high Si-H activity and a production process of the functional end hydrogen-containing silicone oil. The hydrogen-terminated silicone oil is prepared from the following components: 78 to 85 percent of octamethylcyclotetrasiloxane, 0.15 to 0.45 percent of a metal organic framework loaded diacid catalyst, 4 to 8 percent of an amino functionalized hydrogen-containing end-capping reagent, 2.5 to 6 percent of a polyether-siloxane block regulator, 1 to 3 percent of hexamethyldisiloxane, 1.5 to 4 percent of absolute ethyl alcohol and 0.3 to 0.8 percent of a weakly alkaline adsorbent. According to the invention, the hydrogen-terminated silicone oil is based on octamethylcyclotetrasiloxane, has a stable polydimethylsiloxane main chain skeleton, has a controllable molecular chain length, contains amino groups which can react with carboxyl and epoxy groups, and has wide functions and application scenes; the molecular weight distribution is easy to regulate and control, the polyether-containing chain segment has good hydrophilicity, and the block structure improves the high and low temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of organosilicon softener technology, specifically to a highly Si-H active functionalized hydrogen-containing silicone oil and its production process. Background Technology

[0002] In the textile industry, hydrogen-terminated silicone oils are key finishing agents for fabrics. They can combine with textile materials through hydrosilylation reactions, imparting softness, smoothness, and wash resistance to the fabric. Currently, the mainstream preparation process for hydrogen-terminated silicone oils typically uses octamethylcyclotetrasiloxane as the base monomer, combined with common hydrogen-containing double-ended monomers (such as tetramethyldihydrodisiloxane), and produces them through catalytic ring-opening polymerization. However, as high-end textile fabrics demand higher performance from finishing agents, existing technologies are gradually showing limitations, failing to meet the requirements for environmental friendliness and functional compatibility.

[0003] Existing preparation technologies have significant shortcomings: On the one hand, the catalytic systems mostly use concentrated sulfuric acid or ordinary supported monoacid catalysts, which not only cannot be recycled and reused, but also require complex neutralization of residual acidic substances, increasing environmental costs; moreover, the catalysts lack shape selectivity, leading to uncontrolled growth of the octamethylcyclotetrasiloxane ring-opening polymerization molecular chain, resulting in a wide molecular weight distribution of the product and batch-to-batch fluctuations in the fabric finishing performance. On the other hand, ordinary hydrogen-containing double-ended caps can only control the molecular chain length and cannot introduce additional active groups. However, carboxyl-modified fibers and epoxy-based finishing agents commonly used in the textile industry require additional modification with hydrogen-containing silicone oils to bind, which prolongs the production process and reduces the activity of Si-H bonds, affecting the durability of the fabric finishing effect. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a high Si-H active functionalized hydrogen-containing silicone oil and its production process, which enables the high Si-H active functionalized hydrogen-containing silicone oil to have advantages such as narrow molecular weight distribution, high Si-H bond content and retention rate, good hydrophilicity, excellent high and low temperature resistance and thermal stability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This application discloses a high Si-H activity functionalized hydrogen-containing silicone oil. By weight percentage, the high Si-H activity functionalized hydrogen-containing silicone oil comprises the following components: 78-85% octamethylcyclotetrasiloxane, 0.15-0.45% metal-organic framework supported bis-acid catalyst, 4-8% amino-functionalized hydrogen-containing end-capping agent, 2.5-6% polyether-siloxane block modifier, 1-3% hexamethyldisiloxane, 1.5-4% anhydrous ethanol, and 0.3-0.8% weakly basic adsorbent.

[0006] By setting up the above technical solutions, octamethylcyclotetrasiloxane, as the basic monomer, can provide the polydimethylsiloxane backbone structure for highly Si-H active functionalized hydrogen-containing silicone oils, laying the foundation for the basic product framework; the metal-organic framework supported on the bis-acid catalyst can play a catalytic role, promoting the efficient ring-opening polymerization reaction of octamethylcyclotetrasiloxane, and due to the characteristics of the metal-organic framework, it may have certain shape selectivity and recyclability potential, helping to improve reaction efficiency and environmental friendliness; the amine-functionalized hydrogen-containing end-capping agent can not only provide end-group Si-H bonds to control the molecular chain length, but its contained amine groups can also endow the product with the ability to react directly with carboxyl, epoxy, and other materials, expanding the product's functions and downstream application scenarios; polyether - Siloxane block modifiers can participate in regulating the molecular weight distribution of products, while introducing polyether segments to improve the hydrophilicity of products. They can also form block structures with the siloxane backbone, which helps to improve the product's high and low temperature resistance. Hexamethyldisiloxane can be used as an auxiliary modifier to help fine-tune the molecular chain length of products and optimize product viscosity and other properties. Anhydrous ethanol can promote the dispersion of metal-organic framework-supported dual-acid catalysts in the system, avoid catalyst agglomeration leading to uneven local reactions, and ensure stable reaction. Weakly basic adsorbents can neutralize residual acidic substances in the system, prevent the hydrolysis of Si-H bonds due to the acidic environment during subsequent storage, and adsorb trace impurities, improving product purity and storage stability.

[0007] Preferably, by weight percentage, the high Si-H activity functionalized hydrogen-containing silicone oil comprises the following components: 84.3% octamethylcyclotetrasiloxane, 0.2% metal-organic framework supported diacid catalyst, 6% amine functionalized hydrogen-containing end-capping agent, 4% polyether-siloxane block modifier, 2% hexamethyldisiloxane, 3% anhydrous ethanol and 0.5% weakly basic adsorbent.

[0008] By setting up the above technical solutions, the high Si-H active functionalized end-hydrogen-containing silicone oil has the advantages of narrow molecular weight distribution, high Si-H bond content and retention rate, good hydrophilicity, excellent high and low temperature resistance and thermal stability, and the product has high purity and stable viscosity.

[0009] Preferably, the weakly alkaline adsorbent is alkali-modified diatomaceous earth.

[0010] By setting up the above technical solution, the weak alkalinity of alkali-modified diatomaceous earth can specifically neutralize the acidic substances remaining in the synthesis system of highly Si-H active functionalized hydrogen-containing silicone oil (such as the acidic active sites remaining in the metal-organic framework supported dual acid catalyst), avoiding the accelerated hydrolysis of Si-H bonds due to the acidic environment, thereby ensuring the stability of Si-H bonds and reducing the performance degradation caused by Si-H bond degradation during product storage.

[0011] The preferred method for preparing the metal-organic framework supported dual-acid catalyst is as follows: 1) Dissolve 10-15 mmol of ZrCl4 and 10-15 mmol of terephthalic acid in 100-150 mL of N,N-dimethylformamide, add 0.5-0.7 mmol of acetic acid, and ultrasonically disperse at 200-300 W and 30-40 kHz for 30-35 min. Then transfer to a reaction vessel and hydrothermally react at 115-120 °C for 24 h. After cooling, filter, wash three times with DMF, and then vacuum dry at 75-80 °C for 12-13 h to obtain metal-organic framework material powder. 2) Disperse 5-8g of metal-organic framework material powder in 100-110mL of ethanol, add 1.5-2g of salicylic acid and 2.0-2.5g of phosphotungstic acid, stir and impregnate at 58-60℃ and 150-250r / min for 7-8h, then raise the temperature to 75-80℃ and dry under vacuum conditions of -0.08 to -0.09MPa for 9-10h to obtain the final product.

[0012] By setting up the above technical solution, metal-organic framework material powder provides a stable support with a suitable pore structure for subsequent loading of dual acids. After salicylic acid and phosphotungstic acid are loaded onto the metal-organic framework support material, the final metal-organic framework-supported dual acid catalyst can fully disperse the active sites of dual acids by relying on the support characteristics of the metal-organic framework. At the same time, the synergistic effect of salicylic acid and phosphotungstic acid can ensure catalytic activity, providing an efficient catalytic basis for the polymerization reaction in the subsequent synthesis of high Si-H activity functionalized end-hydrogen-containing silicone oil.

[0013] The preferred method for preparing the amino-functionalized hydrogen-containing end-capping agent is as follows: a. Under nitrogen protection, 10-15 mol of methyldichlorosilane and 10-15 mol of allylamine were added to a reaction vessel, and the mixture was cooled to 0-5°C in an ice bath. While stirring, 0.1-0.15 mol of triethylamine was added dropwise. After the addition was completed, the mixture was heated to 40-42°C and reacted for 3-3.5 h to obtain chloroaminosilane. b. Add 5-8 mol of tetramethyldihydrodisiloxane and 0.05-0.08 mol of zinc chloride to chloroaminosilane, heat to 68-70℃ and react for 5-5.5 h. Finally, remove low-boiling substances by vacuum distillation at 80℃ and -0.09 to -0.095 MPa to obtain the product.

[0014] By employing the aforementioned technical solution, the resulting amino-functionalized hydrogen-containing end-capping agent contains Si-H bonds. This retains the terminal Si-H bonds that control the molecular chain length, and the introduction of amino groups enables the end-capping agent to react with other materials containing carboxyl and epoxy groups. Simultaneously, the vacuum distillation process helps improve product purity, ensuring the end-capping effect and functional expansion of the amino-functionalized hydrogen-containing end-capping agent in the subsequent synthesis of highly Si-H-active functionalized hydrogen-containing silicone oils.

[0015] Preferably, the preparation method of the polyether-siloxane block regulator is as follows: 10-15 mol of polyethylene glycol monomethyl ether is added to a reaction vessel and dehydrated for 1.5-2 h under vacuum conditions of 108-110℃ and -0.08 to -0.09 MPa. After cooling to 60℃, 5-8 mol of octamethylcyclotetrasiloxane, 1.5-2 mol of hexamethyldisiloxane and 0.015-0.02 mol of trifluoromethanesulfonic acid are added, and the reaction is carried out under nitrogen protection at 85℃ for 3.5-4 h. Finally, the pH of the system is neutralized to 7 using triethylamine, and low-boiling substances are removed by vacuum distillation to obtain the product.

[0016] By setting up the above technical solution, dehydration under vacuum conditions can effectively remove water from polyethylene glycol monomethyl ether, avoiding interference from water in subsequent polymerization reactions and ensuring the smooth progress of the reaction. After cooling, octamethylcyclotetrasiloxane, hexamethyldisiloxane, and trifluoromethanesulfonic acid are added, and the reaction is carried out under nitrogen protection and at a specific temperature. This can promote the block copolymerization of polyethylene glycol monomethyl ether and siloxane monomers, forming a block structure that combines polyether segments and siloxane segments. Finally, the system is neutralized to neutral with triethylamine and low-boiling substances are removed by vacuum distillation. This can terminate the reaction to avoid overpolymerization and improve the purity of the product. The resulting polyether-siloxane block regulator can play a role in regulating molecular weight distribution and improving the hydrophilicity and high and low temperature resistance of the product in the subsequent synthesis of high Si-H active functionalized end-hydrogen-containing silicone oils based on its block structure.

[0017] Preferably, the conditions for vacuum distillation are: temperature 120-122℃, pressure -0.09 to -0.095MPa.

[0018] By setting the above technical solution, this temperature can effectively promote the volatilization of residual unreacted small molecule monomers (such as octamethylcyclotetrasiloxane and hexamethyldisiloxane) and possible trace solvents in the system, while avoiding high temperature damage to the formed polyether-siloxane block structure and ensuring the structural integrity of the regulator. At the same time, the negative pressure environment of -0.09 to -0.095 MPa can lower the boiling point of low-boiling substances, making them easier to remove completely at this temperature and reducing impurity residues. Meanwhile, this negative pressure intensity will not cause the regulator itself to be lost due to excessive volatilization, ultimately improving the purity of the polyether-siloxane block regulator and ensuring that it can stably play its role in regulating molecular weight distribution, improving hydrophilicity and high and low temperature resistance in the subsequent synthesis of high Si-H active functionalized end-hydrogen-containing silicone oil.

[0019] This application also discloses a production process for a highly Si-H active functionalized hydrogen-containing silicone oil, comprising the following steps: S1. Add octamethylcyclotetrasiloxane and anhydrous ethanol to a reaction vessel, stir at 200-300 r / min, heat to 70-75℃, and dehydrate under a vacuum of -0.08 to -0.09 MPa for 30-45 min until the water content of the system is ≤0.05%; S2. Add the metal-organic framework supported diacid catalyst and amine-functionalized hydrogen-containing end-capping agent to the mixture obtained in S1, heat to 70-80℃ under nitrogen protection, and stir the reaction at 300-400r / min for 2-3h. S3. Add hexamethyldisiloxane and polyether-siloxane block modifier to the mixture obtained in S2, heat to 95-105℃, and stir at 400-500r / min for 3-5h. S4. Cool the S3 system to 55-58℃, add a weakly basic adsorbent, stir at 200-250 r / min for 25-30 min, and then filter through a 0.2-0.22 μm filter membrane to recover the metal-organic framework supported dual acid catalyst. S5. Transfer the filtrate obtained in S4 to a devolatilization vessel, heat it to 120-140℃, increase the vacuum to -0.098MPa, treat it for 2-3 hours, cool it to 30-35℃, and then filter it with a 0.05-0.1μm filter membrane to obtain high Si-H activity functionalized end-hydrogen-containing silicone oil.

[0020] By setting up the above technical solution, the final high Si-H activity functionalized hydrogen-containing silicone oil has high purity, suitable molecular weight distribution, good Si-H bond stability, good hydrophilicity and high and low temperature resistance, and the catalyst can be recycled, making it more environmentally friendly.

[0021] Preferably, in step S3, the Si-H content is sampled and detected every 0.5 hours.

[0022] By setting up the above technical solution, the generation and retention of Si-H bonds during the reaction process can be monitored in real time. This allows for timely understanding of the capping effect of the amine-functionalized hydrogen-containing capping agent and changes in the Si-H active sites in the reaction system. It avoids insufficient Si-H bond generation and inadequate capping due to insufficient reaction time, or excessive Si-H bond reaction (such as hydrolysis and breakage) due to excessive reaction time, which would lead to reduced activity. This allows for precise control of the reaction endpoint in the S3 stage, ensuring that the final high-Si-H activity functionalized hydrogen-containing silicone oil has a stable Si-H content that meets the requirements, laying the foundation for its activity and performance stability in subsequent applications such as hydrosilylation.

[0023] Preferably, in step S4, the catalyst recovered by filtration is washed with ethanol 2-3 times.

[0024] By setting up the above technical solution, the residual reaction mixture adhering to the catalyst surface can be effectively removed, preventing these impurities from clogging the active sites of the catalyst or occupying the pore structure of the metal-organic framework, ensuring the exposure of the active sites of the catalyst and the recovery of catalytic performance, and ensuring that the recovered catalyst can maintain a stable catalytic efficiency in subsequent recycling, thus providing support for the continuity and environmental protection of the high Si-H activity functionalized end-hydrogen-containing silicone oil synthesis process.

[0025] The beneficial effects of this invention are as follows: Octamethylcyclotetrasiloxane, as a basic monomer, provides the polydimethylsiloxane backbone structure for highly Si-H active functionalized hydrogen-containing silicone oils, laying the foundation for the product's basic framework. Metal-organic framework-supported diacid catalysts can exert catalytic activity, promoting the efficient ring-opening polymerization of octamethylcyclotetrasiloxane. Furthermore, the characteristics of metal-organic frameworks may possess certain shape selectivity and recyclability potential, contributing to improved reaction efficiency and environmental friendliness. Amine-functionalized hydrogen-containing end-capping agents can provide terminal Si-H bonds to control the molecular chain length, and their contained amine groups can also endow the product with the ability to directly react with carboxyl, epoxy, and other materials, expanding product functionality and downstream application scenarios. Polyether-siloxane intercalation... Segment regulators can participate in controlling the molecular weight distribution of products, while introducing polyether segments to improve the hydrophilicity of products and forming block structures with siloxane backbones, which helps to improve the product's high and low temperature resistance. Hexamethyldisiloxane can be used as an auxiliary regulator to help fine-tune the molecular chain length of products and optimize product viscosity and other properties. Anhydrous ethanol can promote the dispersion of metal-organic framework-supported diacid catalysts in the system, avoid catalyst agglomeration leading to uneven local reactions, and ensure stable reaction. Weakly basic adsorbents can neutralize residual acidic substances in the system, prevent the hydrolysis of Si-H bonds due to acidic environment during subsequent storage, and adsorb trace impurities, improving product purity and storage stability.

[0026] Metal-organic framework (MOF) powder provides a stable support with suitable pore structure for subsequent loading of dual acids. After salicylic acid and phosphotungstic acid are loaded onto the MOF support material, the resulting MOF-supported dual acid catalyst can fully disperse the active sites of the dual acids by relying on the support characteristics of the MOF. At the same time, the synergistic effect of salicylic acid and phosphotungstic acid can ensure catalytic activity, providing an efficient catalytic basis for the polymerization reaction in the subsequent synthesis of highly Si-H functionalized end-hydrogen-containing silicone oil.

[0027] The prepared amino-functionalized hydrogen-containing end-capping agent contains Si-H bonds, which not only retain the terminal Si-H bonds that control the molecular chain length, but also enable the end-capping agent to react with other materials containing carboxyl and epoxy groups due to the introduction of amino groups. Meanwhile, the vacuum distillation process helps improve product purity, ensuring the end-capping effect and functional expansion of the amino-functionalized hydrogen-containing end-capping agent in the subsequent synthesis of highly Si-H active functionalized hydrogen-containing silicone oils. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: This example discloses a high Si-H activity functionalized hydrogen-containing silicone oil. By weight percentage, the high Si-H activity functionalized hydrogen-containing silicone oil comprises the following components: 85% octamethylcyclotetrasiloxane, 0.15% metal-organic framework supported bis-acid catalyst, 8% amino-functionalized hydrogen-containing end-capping agent, 4.05% polyether-siloxane block modifier, 1% hexamethyldisiloxane, 1.5% anhydrous ethanol, and 0.3% alkali-modified diatomaceous earth.

[0030] The preparation method of metal-organic framework supported dual-acid catalyst is as follows: 1) Dissolve 10 mmol of ZrCl4 and 10 mmol of terephthalic acid in 100 mL of N,N-dimethylformamide, add 0.5 mmol of acetic acid, and sonicate at 200 W and 30 kHz for 30 min. Then transfer to a reaction vessel and hydrothermally react at 115 °C for 24 h. After cooling, filter, wash three times with DMF, and then vacuum dry at 75 °C for 12 h to obtain metal-organic framework material powder. 2) Disperse 5g of metal-organic framework material powder in 100mL of ethanol, add 1.5g of salicylic acid and 2.0g of phosphotungstic acid, stir and impregnate at 58℃ and 150r / min for 7h, then raise the temperature to 75℃ and dry under vacuum conditions of -0.08MPa for 9h to obtain the final product.

[0031] The preparation method of amino-functionalized hydrogen-containing end-capping agents is as follows: a. Under nitrogen protection, 10 mol of methyldichlorosilane and 10 mol of allylamine were added to a reaction vessel, cooled to 0°C in an ice bath, and 0.1 mol of triethylamine was added dropwise while stirring. After the addition was completed, the temperature was raised to 40°C and reacted for 3 hours to obtain chloroaminosilane. b. Add 5 mol of tetramethyldihydrodisiloxane and 0.05 mol of zinc chloride to chloroaminosilane, heat to 68℃ and react for 5 h. Finally, remove low-boiling substances by vacuum distillation at 80℃ and -0.09 MPa to obtain the product.

[0032] The preparation method of polyether-siloxane block regulator is as follows: 10 mol of polyethylene glycol monomethyl ether is added to a reaction vessel and dehydrated for 1.5 h under vacuum conditions of 108 °C and -0.08 MPa. After cooling to 60 °C, 5 mol of octamethylcyclotetrasiloxane, 1.5 mol of hexamethyldisiloxane and 0.015 mol of trifluoromethanesulfonic acid are added, and the reaction is carried out for 3.5 h under nitrogen protection at 85 °C. Finally, the pH of the system is neutralized to 7 using triethylamine, and low-boiling substances are removed by vacuum distillation at 120 °C and -0.09 MPa to obtain the product.

[0033] This embodiment also discloses a production process for a highly Si-H active functionalized hydrogen-containing silicone oil, comprising the following steps: S1. Add octamethylcyclotetrasiloxane and anhydrous ethanol to a reaction vessel, stir at 200 r / min, heat to 70℃, and dehydrate under a vacuum of -0.08 MPa for 30 min until the water content of the system is ≤0.05%; S2. Add the metal-organic framework supported diacid catalyst and amine-functionalized hydrogen-containing end-capping agent to the mixture obtained in S1, heat to 70°C under nitrogen protection, and stir the mixture at 300 r / min for 2 h. S3. Add hexamethyldisiloxane and polyether-siloxane block modifier to the mixture obtained in S2, heat to 95°C, and stir at 400 r / min for 3 h. During this period, take samples every 0.5 h to detect the Si-H content. S4. Cool the S3 system to 55℃, add a weakly basic adsorbent, stir at 200r / min for 25min, and then filter through a 0.2μm filter membrane to recover the metal-organic framework supported dual acid catalyst. The filtered and recovered catalyst is washed twice with ethanol. S5. Transfer the filtrate obtained in S4 to a devolatilization vessel, heat it to 120°C, increase the vacuum to -0.098MPa, treat it for 2 hours, cool it to 30°C, and then filter it with a 0.05μm filter membrane to obtain high Si-H activity functionalized end-hydrogen-containing silicone oil.

[0034] Example 2: This example discloses a high Si-H activity functionalized hydrogen-containing silicone oil. By weight percentage, the high Si-H activity functionalized hydrogen-containing silicone oil comprises the following components: 78% octamethylcyclotetrasiloxane, 0.45% metal-organic framework supported bis-acid catalyst, 8% amino-functionalized hydrogen-containing end-capping agent, 6% polyether-siloxane block modifier, 3% hexamethyldisiloxane, 3.75% anhydrous ethanol, and 0.8% alkali-modified diatomaceous earth.

[0035] The preparation method of metal-organic framework supported dual-acid catalyst is as follows: 1) Dissolve 15 mmol of ZrCl4 and 15 mmol of terephthalic acid in 150 mL of N,N-dimethylformamide, add 0.7 mmol of acetic acid, and sonicate at 300 W and 40 kHz for 35 min. Then transfer to a reaction vessel and hydrothermally react at 120 °C for 24 h. After cooling, filter, wash three times with DMF, and then vacuum dry at 80 °C for 13 h to obtain metal-organic framework material powder. 2) Disperse 8g of metal-organic framework material powder in 110mL of ethanol, add 2g of salicylic acid and 2.5g of phosphotungstic acid, stir and impregnate at 250r / min at 60℃ for 8h, then raise the temperature to 80℃ and dry under vacuum conditions of -0.09MPa for 10h to obtain the product.

[0036] The preparation method of amino-functionalized hydrogen-containing end-capping agents is as follows: a. Under nitrogen protection, 15 mol of methyldichlorosilane and 15 mol of allylamine were added to a reaction vessel, cooled to 5°C in an ice bath, and 0.15 mol of triethylamine was added dropwise while stirring. After the addition was completed, the temperature was raised to 42°C and reacted for 3.5 h to obtain chloroaminosilane. b. Add 8 mol of tetramethyldihydrodisiloxane and 0.08 mol of zinc chloride to chloroaminosilane, heat to 70℃ and react for 5.5 h. Finally, remove low-boiling substances by vacuum distillation at 80℃ and -0.095 MPa to obtain the product.

[0037] The preparation method of polyether-siloxane block regulator is as follows: 15 mol of polyethylene glycol monomethyl ether is added to a reaction vessel and dehydrated for 2 h under vacuum conditions of 110℃ and -0.09 MPa. After cooling to 60℃, 8 mol of octamethylcyclotetrasiloxane, 2 mol of hexamethyldisiloxane and 0.02 mol of trifluoromethanesulfonic acid are added, and the reaction is carried out for 4 h under nitrogen protection at 85℃. Finally, the pH of the system is neutralized to 7 using triethylamine, and low-boiling substances are removed by vacuum distillation at 122℃ and -0.095 MPa to obtain the product.

[0038] This embodiment also discloses a production process for a highly Si-H active functionalized hydrogen-containing silicone oil, comprising the following steps: S1. Add octamethylcyclotetrasiloxane and anhydrous ethanol to a reaction vessel, stir at 300 r / min, heat to 75℃, and dehydrate under a vacuum of -0.09 MPa for 45 min until the water content of the system is ≤0.05%; S2. Add the metal-organic framework supported diacid catalyst and amine-functionalized hydrogen-containing end-capping agent to the mixture obtained in S1, heat to 80°C under nitrogen protection, and stir the mixture at 400 r / min for 3 h. S3. Add hexamethyldisiloxane and polyether-siloxane block modifier to the mixture obtained in S2, heat to 105℃, stir at 500r / min for 5h, and take samples every 0.5h to detect the Si-H content. S4. Cool the S3 system to 58℃, add a weakly basic adsorbent, stir at 250r / min for 30min, and then filter through a 0.22μm filter membrane to recover the metal-organic framework supported dual acid catalyst. The filtered and recovered catalyst is washed three times with ethanol. S5. Transfer the filtrate obtained in S4 to a devolatilization vessel, heat it to 140℃, increase the vacuum to -0.098MPa, treat it for 3 hours, cool it to 35℃, and then filter it with a 0.1μm filter membrane to obtain high Si-H activity functionalized end-hydrogen-containing silicone oil.

[0039] Example 3: This example discloses a high Si-H activity functionalized hydrogen-containing silicone oil. By weight percentage, the high Si-H activity functionalized hydrogen-containing silicone oil comprises the following components: 84.3% octamethylcyclotetrasiloxane, 0.2% metal-organic framework supported bis-acid catalyst, 6% amino-functionalized hydrogen-containing end-capping agent, 4% polyether-siloxane block modifier, 2% hexamethyldisiloxane, 3% anhydrous ethanol, and 0.5% alkali-modified diatomaceous earth.

[0040] The preparation method of metal-organic framework supported dual-acid catalyst is as follows: 1) Dissolve 12 mmol of ZrCl4 and 12 mmol of terephthalic acid in 120 mL of N,N-dimethylformamide, add 0.6 mmol of acetic acid, and sonicate at 250 W and 35 kHz for 32 min. Then transfer to a reaction vessel and hydrothermally react at 117 °C for 24 h. After cooling, filter, wash three times with DMF, and then vacuum dry at 77 °C for 12.5 h to obtain metal-organic framework material powder. 2) Disperse 6g of metal-organic framework material powder in 105mL of ethanol, add 1.7g of salicylic acid and 2.2g of phosphotungstic acid, stir and impregnate at 59℃ and 200r / min for 7.5h, then raise the temperature to 77℃ and dry under vacuum conditions of -0.085MPa for 9.5h to obtain the product.

[0041] The preparation method of amino-functionalized hydrogen-containing end-capping agents is as follows: a. Under nitrogen protection, 12 mol of methyldichlorosilane and 12 mol of allylamine were added to a reaction vessel, cooled to 2°C in an ice bath, and 0.12 mol of triethylamine was added dropwise while stirring. After the addition was completed, the temperature was raised to 41°C and reacted for 3.2 h to obtain chloroaminosilane. b. Add 6 mol of tetramethyldihydrodisiloxane and 0.06 mol of zinc chloride to chloroaminosilane, heat to 69℃ and react for 5.5 h. Finally, remove low-boiling substances by vacuum distillation at 80℃ and -0.095 MPa to obtain the product.

[0042] The preparation method of polyether-siloxane block regulator is as follows: 12 mol of polyethylene glycol monomethyl ether is added to a reaction vessel and dehydrated for 1.7 h under vacuum conditions of 109 °C and -0.085 MPa. After cooling to 60 °C, 6.5 mol of octamethylcyclotetrasiloxane, 1.7 mol of hexamethyldisiloxane and 0.017 mol of trifluoromethanesulfonic acid are added, and the reaction is carried out for 4 h under nitrogen protection at 85 °C. Finally, the pH of the system is neutralized to 7 using triethylamine, and low-boiling substances are removed by vacuum distillation at 121 °C and -0.095 MPa to obtain the product.

[0043] This embodiment also discloses a production process for a highly Si-H active functionalized hydrogen-containing silicone oil, comprising the following steps: S1. Add octamethylcyclotetrasiloxane and anhydrous ethanol to a reaction vessel, stir at 250 r / min, heat to 72℃, and dehydrate under a vacuum of -0.085 MPa for 32 min until the water content of the system is ≤0.05%; S2. Add the metal-organic framework supported dual acid catalyst and amine-functionalized hydrogen-containing end-capping agent to the mixture obtained in S1, heat to 75°C under nitrogen protection, and stir the mixture at 350 r / min for 2.5 h. S3. Add hexamethyldisiloxane and polyether-siloxane block modifier to the mixture obtained in S2, heat to 100℃, stir at 450r / min for 4h, and take samples every 0.5h to detect the Si-H content. S4. Cool the S3 system to 56℃, add a weakly basic adsorbent, stir at 225r / min for 27min, and then filter through a 0.21μm filter membrane to recover the metal-organic framework supported dual acid catalyst. The filtered and recovered catalyst is washed three times with ethanol. S5. Transfer the filtrate obtained in S4 to a devolatilization vessel, heat it to 130℃, increase the vacuum to -0.098MPa, treat it for 2.5h, cool it to 32℃, and then filter it with a 0.05μm filter membrane to obtain high Si-H activity functionalized end-hydrogen-containing silicone oil.

[0044] Comparative Example 1: A high Si-H activity functionalized end-hydrogen-containing silicone oil differs from Example 3 only in that it uses conventional concentrated sulfuric acid (0.3%) instead of a metal-organic framework-supported dual-acid catalyst.

[0045] Comparative Example 2: A high Si-H activity functionalized hydrogen-containing silicone oil differs from Example 3 only in that ordinary tetramethyldihydrodisiloxane is used instead of the amino-functionalized hydrogen-containing capping agent.

[0046] Comparative Example 3: A high Si-H activity functionalized end-hydrogen-containing silicone oil differs from Example 3 only in that no polyether-siloxane block modifier is added.

[0047] Comparative Example 4: A high Si-H activity functionalized end-hydrogen-containing silicone oil, which differs from Example 3 only in that the catalyst is MOF-801@PTA (MOF-801 is a Zr-based metal-organic framework, PTA is terephthalic acid, and only phosphotungstic acid is supported, without salicylic acid).

[0048] Comparative Example 5: A highly Si-H active functionalized end-hydrogen-containing silicone oil differs from Example 3 only in that the catalyst is a mixture of salicylic acid and phosphotungstic acid (a metal-organic framework carrier material).

[0049] Comparative Example 6: The only difference between this highly Si-H active functionalized hydrogen-containing silicone oil and Example 3 is that the reaction of the highly Si-H active functionalized hydrogen-containing silicone oil is carried out at a constant temperature of 90°C throughout (without segmented temperature control).

[0050] Comparative Example 7: The only difference between this highly Si-H active functionalized hydrogen-containing silicone oil and Example 3 is that the preparation process of the highly Si-H active functionalized hydrogen-containing silicone oil does not involve vacuum devolatilization (only atmospheric distillation).

[0051] Comparative Example 8: A high Si-H activity functionalized end-hydrogen-containing silicone oil differs from Example 3 only in that: no modified diatomaceous earth was added (no neutralization step).

[0052] Comparative Example 9: A high Si-H activity functionalized hydrogen-containing silicone oil differs from Example 3 only in that the amount of amine-functionalized hydrogen-containing capping agent is 2.0% (lower than the lower limit of this application).

[0053] Comparative Example 10: A high Si-H activity functionalized end-hydrogen-containing silicone oil differs from Example 3 only in that the amount of polyether-siloxane block modifier is 8.0% (higher than the upper limit of this application).

[0054] Comparative Example 11: A highly Si-H active functionalized end-hydrogen-containing silicone oil differs from Example 3 only in that it uses a recycled and unwashed metal-organic framework supported on a dual-acid catalyst.

[0055] Comparative Example 12: The high Si-H activity functionalized end-hydrogen silicone oil is used in the prior art, such as the end-hydrogen silicone oil prepared by announcement number CN103145990B.

[0056] The hydrogen-containing silicone oils obtained in Examples 1-3 and Comparative Examples 1-12 were subjected to performance tests for Si-H content (mmol / g), molecular weight and distribution (PDI), viscosity (25℃, mPa·s), thermal decomposition temperature (Td, ℃), Si-H bond retention rate (%), low-temperature fluidity, hydrophilicity (contact angle, °), catalyst recovery rate (%), hydrosilylation reaction efficiency (gel time, min), and low molecular weight cyclic content (%). The testing steps for each property are as follows: 1. Si-H content (mmol / g): According to GB / T16632-2008 "Determination of Si-H group content in hydrolysates and pyrolysis products of organosilicon materials by iodometric titration", weigh 0.5g of sample, add 10mL of carbon tetrachloride, 5mL of acetic acid and 2mL of potassium bromide solution, place in the dark for 10min, titrate with 0.1mol / L sodium thiosulfate until pale yellow, add starch indicator and continue titrating until the blue color disappears, and calculate the Si-H content.

[0057] 2. Molecular weight and distribution (PDI): Referring to GB / T36214.4-2018 "Plastic Polysiloxane Materials - Part 4: Determination of Molecular Weight and Distribution - Gel Permeation Chromatography (GPC)", tetrahydrofuran was used as the mobile phase (flow rate 1.0 mL / min), column temperature 35℃, and polystyrene was used as the standard. The number-average molecular weight (Mn), weight-average molecular weight (Mw), and PDI (Mw / Mn) were calculated.

[0058] 3. Viscosity (25℃, mPa·s): Refer to GB / T2794-2013 "Determination of viscosity of adhesives", use a rotational viscometer (NDJ-8S) at 25±0.1℃, and take the average value of three parallel measurements.

[0059] 4. Thermal decomposition temperature (Td, °C): Referring to ISO 11358-1 "Plastics - Thermogravimetric analysis (TGA) - Part 1: General principles", under a nitrogen atmosphere, the temperature at which 5% weight loss occurs is recorded as Td5% by increasing the temperature from room temperature to 500 °C at a rate of 10 °C / min. This temperature is used as the evaluation index for the onset of thermal decomposition.

[0060] 5. Si-H bond retention rate (%): Refer to the stability test method in GB / T2363-1992 "Organosilicon Emulsions". Place the sample in a 100℃ oven and store it in a sealed container for 24 hours. Measure the Si-H content before and after storage. Calculate the retention rate as "(Si-H content after storage / Si-H content before storage) × 100%". The higher the retention rate, the better the stability of the Si-H bond.

[0061] 6. Low-temperature flowability: Refer to GB / T19977-2005 "Determination of Low-Temperature Viscosity of Hydraulic Fluids (Brockfield Viscometer Method)", place the sample in a -60℃ low-temperature chamber for 2 hours, and immediately measure the viscosity with a rotational viscometer after removal. If the viscosity is ≤1000mPa·s and there is no stratification or solidification, it is judged as "good flow"; if the viscosity is >1000mPa·s or solidification occurs, it is judged as "poor flow".

[0062] 7. Hydrophilicity (contact angle, °): Referring to GB / T24368-2009 "Detection of Hydrophobic Contaminants on Glass Surface - Contact Angle Measurement Method", a contact angle measuring instrument (DSA100) was used. The sample was uniformly coated on a clean glass slide (film thickness 50μm), 5μL of deionized water was added, and the contact angle between the water droplet and the sample surface was measured. Five parallel measurements were taken and the average value was taken. The smaller the contact angle, the better the hydrophilicity.

[0063] 8. Catalyst recovery rate (%): After filtering and recovering the catalyst, wash it twice with anhydrous ethanol (10 mL each time), dry it under vacuum at 80℃ for 4 h, weigh and record the mass of the recovered catalyst, and calculate the recovery rate according to "(mass of recovered catalyst / mass of initial added catalyst) × 100%" to evaluate the recycling performance of the catalyst.

[0064] 9. Hydrosilylation efficiency (gel time, min): Referring to the gel time test principle in HG / T4858-2015 "Addition-type Liquid Silicone Rubber", a hydrosilylation reaction system adapted to end-hydrogen silicone oil and vinyl silicone oil was prepared. The end-hydrogen silicone oil and vinyl silicone oil (molar ratio 1:1) and platinum catalyst (10 ppm) were mixed uniformly and placed in an 80℃ constant temperature water bath. The time from the start of mixing until the system viscosity reached 10000 mPa·s (gel time) was recorded. The shorter the time, the higher the hydrosilylation efficiency.

[0065] 10. Low molecular weight cyclic content (%): Refer to GB / T30304-2013 "Determination of low molecular weight cyclic content in organosilicon products by gas chromatography", using an FFAP capillary column (30m×0.32mm×0.25μm), column temperature program: 80℃ for 2 min, then increase to 250℃ at 10℃ / min and hold for 5 min, FID detector, external standard method to calculate the total content of low molecular weight cyclic compounds D3-D10, the content ≤0.5% is qualified.

[0066] The results are shown in Table 1.

[0067] Table 1 Performance parameters of the hydrogen-containing silicone oils obtained in Examples 1-3 and Comparative Examples 1-12

[0068] As shown in Table 1, compared with Example 3: Comparative Example 1 showed a 24.1% decrease in Si-H content (1.45 vs 1.91 mmol / g), a 59.1% increase in PDI (1.75 vs 1.10), a 17.6% decrease in thermal decomposition temperature (295 vs 358 °C), a 64.5% increase in contact angle (102 vs 62 °C), a 216.7% increase in gel time (38 vs 12 min), a 560.7% increase in low-molecular-weight cyclic content (1.85 vs 0.28%), and a catalyst recovery rate of 0 (compared to 96.2% in Example 3). The significant fluctuations in the data are primarily due to the following reasons: The shape-selective microporous structure of concentrated sulfuric acid, lacking a metal-organic framework, cannot restrict the random growth of molecular chains, leading to a substantial increase in PDI. Its strong acidity directly attacks Si-H bonds, initiating hydrolysis (Si-H + H₂O → Si-OH + H₂↑), resulting in a decrease in Si-H content and retention. Simultaneously, the strong acid accelerates the breaking of Si-O bonds in the main chain, generating a large number of low-molecular-weight cyclic compounds (such as octamethylcyclotetrasiloxane), leading to a decrease in thermal decomposition temperature and a surge in the content of low-molecular-weight cyclic compounds. Furthermore, concentrated sulfuric acid cannot be recovered, and the lack of amine groups to synergistically improve hydrophilicity results in a significantly increased contact angle. In the hydrosilylation reaction, the absence of amine groups to "guide" the matching of Si-H bonds with vinyl groups leads to a substantial extension of gelation time.

[0069] Comparative Example 2 showed a 17.3% decrease in Si-H content (1.58 vs 1.91 mmol / g), a 13.6% increase in PDI (1.25 vs 1.10), a 13.4% decrease in thermal decomposition temperature (310 vs 358℃), a 61.3% increase in contact angle (100 vs 62°), a 133.3% increase in gel time (28 vs 12 min), and a change in low-temperature flowability from "good flow" to "poor flow". The difference stems from the fact that tetramethyldihydrodisiloxane is a traditional petroleum-based end-capping agent, providing only Si-H bonds and lacking the amine (-NH2) function of amine-functionalized hydrogen-containing end-capping agents. On the one hand, the absence of amine groups prevents the formation of hydrogen bonds with the polyether segments of the polyether-siloxane block modifier, causing the molecular chains to easily aggregate at -60°C due to the lack of a "flexible buffer," resulting in deteriorated low-temperature fluidity. On the other hand, amine groups cannot improve hydrophilicity, and the contact angle rises back to the hydrophobic range (>90°). At the same time, the "protective effect" of amine groups on Si-H bonds (hydrogen bonds stabilize Si-H bonds) disappears, and some Si-H bonds are hydrolyzed during the reaction, leading to a decrease in content and thermal stability. In the hydrosilylation reaction, the lack of amine group "positioning" effect results in low reaction site matching efficiency and prolonged gelation time.

[0070] Comparative Example 3 showed a 65.5% increase in PDI (1.82 vs 1.10), a 46.2% increase in viscosity (950 vs 650 mPa·s), a 10.6% decrease in thermal decomposition temperature (320 vs 358 °C), a 58.1% increase in contact angle (98 vs 62 °C), a 108.3% increase in gel time (25 vs 12 min), and a change in low-temperature flowability to "poor flowability". The key reason is the lack of block structure in polyether-siloxane block modifiers: their polyether segments (PEO) can "break" the regular arrangement of the siloxane backbone, reducing molecular chain entanglement. Without polyether segments, excessive molecular chain entanglement leads to a surge in viscosity. At the same time, the hydrophilicity of the polyether segments disappears, and the contact angle increases. More importantly, the "chain transfer-buffering" effect of polyether-siloxane block modifiers is missing. After the ring-opening of octamethylcyclotetrasiloxane, the molecular chain growth is uncontrolled, and the molecular weight distribution is out of control (PDI widens from 1.10 to 1.82). At low temperatures, the lack of flexible segment regulation by polyether segments hinders molecular chain movement and deteriorates fluidity. The wide molecular weight distribution leads to decreased thermal stability (low molecular weight components are easily decomposed at high temperatures). In the hydrosilylation reaction, the molecular chain length is uneven, the reaction rate varies greatly, and the gelation time is prolonged.

[0071] In Comparative Example 4, the Si-H content decreased by 20.4% (1.52 vs 1.91 mmol / g), PDI increased by 34.5% (1.48 vs 1.10), viscosity increased by 10.8% (720 vs 650 mPa·s), thermal decomposition temperature decreased by 14.8% (305 vs 358℃), Si-H bond retention decreased by 5.5% (93.8% vs 99.3%), low-molecular-weight cyclic content increased by 203.6% (0.85% vs 0.28%), and low-temperature fluidity became "poor flowability." The core problem is the lack of acid-regulating effect from salicylic acid: phosphotungstic acid is a strong Bronsted acid, and without salicylic acid, the acidity is too strong, which will accelerate the hydrolysis of Si-H bonds (Si-H + H+). + →Si + +H2↑) leads to a decrease in Si-H content and retention rate; on the other hand, excessive acidity triggers a cyclization side reaction after the ring-opening of octamethylcyclotetrasiloxane (Si-O bonds in the molecular chain rearrange to form cyclic bodies), and the content of low molecular weight cyclic bodies soars; at the same time, strong acidity leads to uneven distribution of active sites on the surface of metal-organic framework carriers, fast local polymerization rate, and broadening of PDI; at low temperature, Si-OH generated by the hydrolysis of Si-H bonds is prone to form hydrogen bonds, molecular chain aggregation, and deterioration of fluidity.

[0072] Comparative Example 5 showed a 27.7% decrease in Si-H content (1.38 vs 1.91 mmol / g), a 50.0% increase in PDI (1.65 vs 1.10), a 61.5% increase in viscosity (1050 vs 650 mPa·s), a 19.6% decrease in thermal decomposition temperature (288 vs 358 °C), a 21.5% decrease in catalyst recovery (75.5 vs 96.2%), a 250.0% increase in gel time (42 vs 12 min), and a 650.0% increase in low-molecular-weight cyclic content (2.10 vs 0.28%). The reasons lie in the "triple effect" of the lack of metal-organic framework (MOF) support: First, the high specific surface area (≥1200 m² / g) of the MOF is missing, making salicylic acid-phosphotungstic acid prone to aggregation, resulting in uneven dispersion of active sites and excessively rapid local polymerization, which leads to PDI widening and viscosity spikes. Second, the shape-selective micropores (0.8-1.0 nm) of the MOF disappear, making it impossible to limit excessive molecular chain growth and cyclization side reactions, resulting in a surge in the content of low-molecular-weight rings and a decrease in thermal stability. Third, the lack of structural support from the MOF makes salicylic acid-phosphotungstic acid easily lost with low-molecular-weight impurities during the reaction, significantly reducing catalyst recovery. At the same time, uneven active sites lead to low Si-H bond formation efficiency and decreased content, resulting in chaotic reaction site matching during hydrosilylation and a significantly prolonged gelation time.

[0073] Comparative Example 6 showed a 38.2% increase in PDI (1.52 vs 1.10), a 35.4% increase in viscosity (880 vs 650 mPa·s), a 12.0% decrease in thermal decomposition temperature (315 vs 358 °C), a 5.3% decrease in Si-H bond retention (94.0 vs 99.3%), an 83.3% increase in gel time (22 vs 12 min), and a 157.1% increase in low-molecular-weight cyclic content (0.72 vs 0.28%). The core function of segmented temperature control is to "regulate the reaction priority in stages": the low-temperature stage (70-80℃) mainly catalyzes the ring-opening of octamethylcyclotetrasiloxane (low activation energy), while the high-temperature stage (95-105℃) mainly catalyzes block and end-capping (high activation energy); at a constant temperature of 90℃, the low-temperature ring-opening is insufficient, and the high-temperature stage is prone to simultaneous ring-opening, polymerization, and cyclization side reactions, resulting in uneven molecular chain growth (PDI broadening) and an increase in low-molecular-weight rings (cyclization side reactions); at the same time, local overheating occurs during the reaction, some Si-H bonds are oxidized, and the retention rate decreases; the wide molecular weight distribution leads to increased viscosity, and the thermal stability is reduced due to low-molecular-weight impurities; the large difference in molecular chain length in the hydrosilylation reaction prolongs the gelation time.

[0074] Comparative Example 7 showed a 346.4% increase in low molecular weight cyclic content (1.25 vs 0.28%), a 7.8% decrease in thermal decomposition temperature (330 vs 358 °C), and a 3.5% decrease in Si-H bond retention (95.8 vs 99.3%). Other indicators were similar to those of Example 3 (PDI 1.15 vs 1.10, contact angle 64 vs 62°). The reason is that low molecular weight cyclic compounds (such as octamethylcyclotetrasiloxane, boiling point 175-210℃) are difficult to completely remove under normal pressure. The residual low molecular weight cyclic compounds decompose preferentially at high temperatures (such as thermal decomposition tests), resulting in a decrease in thermal decomposition temperature. At the same time, the residual low molecular weight cyclic compounds contain trace amounts of acidic impurities, which will slowly catalyze the hydrolysis of Si-H bonds, resulting in a decrease in retention rate. Since PDI, hydrophilicity, etc. are mainly determined by the synergistic effect of components and have a low correlation with the devolatilization process, these indicators change relatively little. However, the surge in the content of low molecular weight cyclic compounds directly affects the application safety of products in high-end fields (such as electronic packaging) (low molecular weight cyclic compounds are prone to migration, leading to performance failure).

[0075] The Si-H bond retention rate of Comparative Example 8 decreased by 14.1% (85.3% vs 99.3%), the thermal decomposition temperature decreased by 16.8% (298% vs 358%), and the gelation time increased by 50.0% (18% vs 12 minutes). Other indicators changed little (PDI 1.14% vs 1.10, contact angle 65% vs 62%). The core issue is the lack of neutralization of residual acidic catalysts: after the reaction, the metal-organic framework-supported dual-acid catalyst still retains trace amounts of acidic sites (-OH of phosphotungstic acid). When neutralized with unmodified diatomaceous earth (weakly alkaline, pH 8-9), these acidic sites continue to catalyze the hydrolysis of Si-H bonds (Si-H + H2O → Si-OH + H2↑), leading to a significant decrease in Si-H bond retention. Simultaneously, the generated Si-OH is prone to condensation reactions at high temperatures (Si-OH + Si-OH → Si-O-Si + H2O), causing main chain breakage and a decrease in thermal decomposition temperature. In the hydrosilylation reaction, some Si-H bonds have already been hydrolyzed into Si-OH, reducing active sites and prolonging gelation time. However, PDI, hydrophilicity, and other properties are determined synergistically by the components during the reaction process, and the neutralization step does not affect the initial reaction results, so these indicators show relatively little change.

[0076] Comparative Example 9 showed a 29.3% decrease in Si-H content (1.35 vs 1.91 mmol / g) and a 150.0% increase in gel time (30 vs 12 min), with other indicators showing minimal changes (PDI 1.22 vs 1.10, thermal decomposition temperature 325 vs 358℃). The core function of the amine-functionalized hydrogen-containing end-capping agent is to provide end-group Si-H bonds and guide the amine group: insufficient dosage reduces the amount of end-group Si-H bond formation, directly leading to a decrease in Si-H content; simultaneously, if the amine concentration is too low, its "guiding" effect on the matching of Si-H bonds with vinyl groups is weakened, resulting in low collision efficiency of reaction sites in the hydrosilylation reaction and a significant increase in gel time; since PDI is mainly synergistically regulated by polyether-siloxane block modifiers and catalysts, and its thermal stability is determined by the molecular backbone structure, insufficient dosage of the amine-functionalized hydrogen-containing end-capping agent has a relatively small impact on these indicators, but the reduction in end-group activity directly limits the application of the product in the field of crosslinking agents (insufficient active sites lead to low crosslinking density).

[0077] The PDI of Comparative Example 10 increased by 25.5% (1.38 vs 1.10), and the viscosity increased by 84.6% (1200 vs 650 mPa·s). The other indicators were not significantly different from those of Example 3 (Si-H content 1.85 vs 1.91 mmol / g, contact angle 60 vs 62°). When the amount of polyether-siloxane block modifier is too high, the proportion of polyether segments (PEO) in the system is too large. On the one hand, it will excessively "break" the regularity of the siloxane backbone, resulting in chaotic molecular chain entanglement and a broadened molecular weight distribution (PDI increases from 1.10 to 1.38). On the other hand, the excessive hydrophilicity of the polyether segments enhances the intermolecular hydrogen bonding, leading to a surge in viscosity. Since the Si-H content is mainly controlled by the amine-functionalized hydrogen-containing end-capping agent, the contact angle decreases slightly due to the increase in polyether segments, so these indicators change little. However, excessively high viscosity will make the product difficult to process (such as difficult to mix with other components), and the broadened PDI will affect the uniformity of the performance of downstream products.

[0078] Compared to Comparative Example 11, the PDI increased by 29.1% (1.42 vs 1.10), the Si-H bond retention decreased by 6.5% (92.8% vs 99.3%), the catalyst recovery decreased by 7.9% (88.5% vs 96.2%), the low-molecular-weight cyclic content increased by 239.3% (0.95% vs 0.28%), and the gelation time prolonged by 116.7% (26 min vs 12 min). This is because residual low-molecular-weight impurities (such as unreacted octamethylcyclotetrasiloxane and low-molecular-weight cyclic compounds) remain on the surface of the recovered catalyst. These impurities clog the microporous structure of the metal-organic framework, disrupting the shape-selective effect and leading to uneven molecular chain growth (widening of PDI). Simultaneously, trace amounts of acidic substances in the impurities catalyze the hydrolysis of Si-H bonds, reducing retention. The active sites on the catalyst surface are covered by impurities, reducing catalytic efficiency, increasing the amount of low-molecular-weight cyclic compounds, resulting in insufficient active sites in the hydrosilylation reaction and prolonged gelation time. Impurities also increase the risk of catalyst aggregation, leading to a decrease in recovery rate.

[0079] Comparative Example 12 showed a 26.7% decrease in Si-H content (1.40 vs 1.91 mmol / g), a 52.7% increase in PDI (1.68 vs 1.10), a 15.6% decrease in thermal decomposition temperature (302 vs 358 °C), a 53.2% increase in contact angle (95 vs 62 °C), a catalyst recovery rate of 0 (compared to 96.2% in Example 3), a 191.7% increase in gel time (35 vs 12 min), and a 453.6% increase in low molecular weight cyclic content (1.55 vs 0.28%). Existing technologies employ traditional sulfuric acid catalysis combined with conventional tetramethyldihydrodisiloxane end-capping, lacking polyether-siloxane block modifiers. The core difference between these technologies and our proposed solution lies in the absence of a synergistic innovation system: sulfuric acid lacks shape selectivity and recyclability, leading to broadened PDI, unrecoverable catalyst, and an increase in low-molecular-weight rings; tetramethyldihydrodisiloxane lacks amine function, resulting in poor hydrophilicity and low Si-H bond stability; and the absence of polyether-siloxane block modifiers leads to uncontrolled molecular weight distribution and decreased thermal stability.

[0080] In summary, the synergistic innovation of "metal-organic framework supported dual-acid catalyst, amine-functionalized hydrogen-containing end-capping agent, and polyether-siloxane block modifier" in this application, combined with optimized processes such as segmented temperature control and vacuum devolatilization, has achieved breakthroughs in hydrogen-containing silicone oil in terms of narrow molecular weight distribution (PDI≤1.14), high Si-H activity (≥1.72mmol / g), excellent thermal stability (Td5%≥342℃), and environmental friendliness (catalyst recovery rate≥94.5%).

[0081] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high Si-H activity functionalized end-hydrogen silicone oil characterized in that, The end-hydrogen silicone oil includes the following components by weight percentage: octamethylcyclotetrasiloxane 78-85%, metal organic framework supported dual acid catalyst 0.15-0.45%, amine functionalized hydrogen-terminated end-capping agent 4-8%, polyether-siloxane block modifier 2.5-6%, hexamethyldisiloxane 1-3%, anhydrous ethanol 1.5-4%, and weakly basic adsorbent 0.3-0.8%.

2. The high Si-H activity functionalized end-hydrogenated silicone oil according to claim 1, characterized in that, The high Si-H activity functionalized end-hydrogen silicone oil includes the following components by weight percentage: octamethylcyclotetrasiloxane 84.3%, metal organic framework supported dual acid catalyst 0.2%, amine functionalized hydrogen-terminated end-capping agent 6%, polyether-siloxane block modifier 4%, hexamethyldisiloxane 2%, anhydrous ethanol 3%, and weakly basic adsorbent 0.5%.

3. The high Si-H activity functionalized end-hydrogenated silicone oil according to claim 1 or 2, characterized in that, The weakly basic adsorbent is alkali-modified diatomite.

4. The high Si-H activity functionalized end-hydrogenated silicone oil according to claim 1 or 2, characterized in that, The preparation method of the metal organic framework supported dual acid catalyst is as follows: 1) 10-15 mmol of ZrCl4 and 10-15 mmol of terephthalic acid are dissolved in 100-150 mL of N,N-dimethylformamide, 0.5-0.7 mmol of acetic acid is added, and after ultrasonic dispersion at 200-300 W and 30-40 kHz for 30-35 min, it is transferred to a reaction kettle, hydrothermal reaction is carried out at 115-120 °C for 24 h, after cooling, it is filtered, washed with DMF for 3 times, and then vacuum dried at 75-80 °C for 12-13 h to obtain a metal organic framework material powder; 2) 5-8 g of the metal organic framework material powder is dispersed in 100-110 mL of ethanol, 1.5-2 g of salicylic acid and 2.0-2.5 g of phosphotungstic acid are added, and after stirring at 150-250 r / min at 58-60 °C for 7-8 h, the temperature is increased to 75-80 °C, and then dried under the condition of -0.08 to -0.09 MPa vacuum for 9-10 h.

5. The high Si-H activity functionalized end-hydrogenated silicone oil according to claim 1 or 2, characterized in that, The preparation method of the amine functionalized hydrogen-terminated end-capping agent is as follows: a. Under nitrogen protection, 10-15 mol of methylhydrogen dichlorosilane and 10-15 mol of allylamine are added to a reaction kettle, ice bath cooling is carried out to 0-5 °C, 0.1-0.15 mol of triethylamine is added dropwise while stirring, after the dropwise addition is completed, the temperature is increased to 40-42 °C, and reaction is carried out for 3-3.5 h to obtain chloroamine silane; b. 5-8 mol of tetramethyldihydrodisiloxane and 0.05-0.08 mol of zinc chloride are added to the chloroamine silane, the temperature is increased to 68-70 °C, and reaction is carried out for 5-5.5 h, finally, low boiling point substances are removed by vacuum distillation under the condition of 80 °C and -0.09 to -0.095 MPa.

6. The high Si-H activity functionalized end-hydrogenated silicone oil according to claim 1 or 2, characterized in that, The preparation method of the polyether-siloxane block regulator is as follows: 10-15 mol of polyethylene glycol monomethyl ether is added into a reaction kettle, and dehydrated at 108-110 DEG C under the condition of vacuum of-0.08 to-0.09 MPa for 1.5-2 h, and after cooling to 60 DEG C, 5-8 mol of octamethylcyclotetrasiloxane, 1.5-2 mol of hexamethyldisiloxane and 0.015-0.02 mol of trifluoromethanesulfonic acid are added, and reacted at 85 DEG C under nitrogen protection for 3.5-4 h, and finally the pH of the system is neutralized to 7 by using triethylamine, and low boiling point substances are removed by vacuum distillation, and the polyether-siloxane block regulator is obtained.

7. The high Si-H activity functionalized end-hydrogenated silicone oil according to claim 6, characterized in that, The conditions of the vacuum distillation are as follows: temperature 120-122 DEG C, pressure-0.09 to-0.095 MPa.

8. A process for the production of a high Si-H activity functionalized end-hydrogenated silicone oil according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1, octamethylcyclotetrasiloxane and anhydrous ethanol are added into a reaction kettle, and stirred at a speed of 200-300 r / min, and heated to 70-75 DEG C, and dehydrated under vacuum of-0.08 to-0.09 MPa for 30-45 min, until the water content of the system is≤0.05%; S2, the metal-organic framework supported bimetallic acid catalyst and the amine group functionalized hydrogen-terminated agent are added into the mixture obtained in S1, and heated to 70-80 DEG C under nitrogen protection, and stirred at a speed of 300-400 r / min for 2-3 h; S3, hexamethyldisiloxane and the polyether-siloxane block regulator are added into the mixture obtained in S2, and heated to 95-105 DEG C, and stirred at a speed of 400-500 r / min for 3-5 h; S4, the system in S3 is cooled to 55-58 DEG C, and a weak alkaline adsorbent is added, and stirred at a speed of 200-250 r / min for 25-30 min, and then filtered through a filter membrane with a pore size of 0.2-0.22 μm, and the metal-organic framework supported bimetallic acid catalyst is recovered; S5, the filtrate obtained in S4 is transferred into a devolatilization kettle, and heated to 120-140 DEG C, and the vacuum degree is increased to-0.098 MPa, and treated for 2-3 h, and then cooled to 30-35 DEG C, and filtered again through a filter membrane with a pore size of 0.05-0.1 μm, and the high Si-H activity functionalized hydrogen-terminated silicone oil is obtained.

9. The process for producing a high Si-H activity functionalized end-hydrogenated silicone oil according to claim 8, characterized in that, In step S3, the Si-H content is detected by sampling every 0.5 h.

10. The process for producing a high Si-H activity functionalized end-hydrogenated silicone oil according to claim 8, characterized in that, In step S4, the recovered catalyst is washed with ethanol for 2-3 times.

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