Preparation method of low volatile matter side hydrogen-containing silicone oil

Abstract

The invention discloses a preparation method of low-volatile-matter side hydrogen-containing silicone oil, and belongs to the technical field of silicone oil production. The preparation method of the hydrogen-containing silicone oil comprises the following steps: (1) adding a hydroxyl-terminated polydimethylsiloxane oligomer (linear body) and a phosphonitrile chloride composite catalyst into a reaction kettle, stirring, vacuumizing, and heating for reaction; (2) detecting the viscosity on line, when the viscosity reaches the specified viscosity, recovering the normal pressure, adding the high-hydrogen silicone oil, hexamethyldisiloxane and phosphonitrile chloride composite catalyst, and reacting at low temperature; and (3) adding a terminator to finish the reaction, and filtering to obtain the hydrogen-containing silicone oil. The hydrogen-containing silicone oil is prepared by adopting the linear body, the high-hydrogen-content silicone oil and the high-catalytic-activity phosphonitrile chloride as raw materials, no obvious cyclosiloxane is generated in the reaction process, the content of low-boiling-point substances is extremely low, the cost of the raw materials is reduced, the problem that a large amount of solid waste is generated in a neutralization reaction in a traditional acid equilibrium catalysis process is solved, and environmental pollution is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of silicone oil production, and in particular relates to a method for preparing low-volatile hydrogen-containing silicone oil. Background Art

[0002] Hydrogenated silicone oil is an important silicon-based functional material, widely used in cosmetics, personal care products, textiles, coatings and plastics. In the field of cosmetics and personal care products, hydrogenated silicone oil is widely used due to its excellent skin-friendliness, antioxidant and moisturizing properties, which can give the product good smoothness and silky texture. In the field of textiles, hydrogenated silicone oil can be used as a softener and waterproofing agent to give fabrics soft, skin-friendly and moisture-proof properties. In the field of coatings and plastics, hydrogenated silicone oil can be used as a leveling agent, toughening agent and antistatic agent to improve the leveling, flexibility and antistatic properties of the product.

[0003] At present, the industrial preparation of hydrogenated silicone oil mainly adopts the strong acid method, such as using trifluoromethanesulfonic acid or sulfuric acid as a catalyst for polymerization, but this method has problems such as cumbersome handling, many by-products, and serious environmental pollution. Therefore, it is of great significance to develop a new green and environmentally friendly hydrogenated silicone oil preparation technology. The preparation of hydrogenated silicone oil by terminal hydroxyl polydimethylsiloxane oligomer (linear body) is an emerging green preparation technology. Through the reaction of linear bodies with silicon hydrogen compounds, hydrogenated silicone oil can be prepared with high selectivity under mild conditions, reducing the generation of by-products, which is in line with the concept of green chemistry.

[0004] The linear preparation technology of hydrogenated silicone oil has the following characteristics and challenges: 1. The reaction conditions are mild, and no high temperature or high pressure is required, which is beneficial to energy saving and consumption reduction. However, the reaction conditions need to be precisely controlled to avoid side reactions.

[0005] 2. The sources of raw materials are wide, and the types of linear bodies and silicon hydrogen compounds are diverse, which provides a broad space for the molecular design of hydrogen-containing silicone oil; but it is necessary to reasonably select the raw material combination to obtain the ideal product structure.

[0006] 3. The reaction is highly selective and produces few by-products, which reduces the difficulty of subsequent separation and purification; however, the catalyst system still needs to be optimized to further improve the reaction selectivity.

[0007] 4. It complies with the concept of green chemistry, does not involve heavy metals and strong acids and alkalis, and reduces environmental pollution; however, it is necessary to evaluate the green environmental protection of the entire process to ensure that clean production is truly achieved.

[0008] 5. The product structure is controllable, and the molecular weight and functional group types of hydrogen-containing silicone oil are easy to adjust; however, in-depth research on the structure-performance relationship is required to design hydrogen-containing silicone oil that meets specific application requirements. Summary of the invention

[0009] In order to overcome the deficiencies in the prior art, the main purpose of the present invention is to provide a method for preparing a low-volatile side hydrogen-containing silicone oil. The present invention uses a terminal hydroxyl polydimethylsiloxane oligomer (linear body) as a reaction monomer, performs a polymerization reaction under the action of a chlorophosphazene composite catalyst, and then undergoes secondary polymerization with a high hydrogen-containing silicone oil, a high hydrogen-containing silicone oil and hexamethyldisiloxane. After the reaction is completed, the reaction is terminated, and the side hydrogen-containing silicone oil is obtained by post-processing. The present invention uses chlorophosphazene as the main catalyst, effectively improves the product yield, reduces the amount of catalyst used, and also reduces the cost of the later termination reaction.

[0010] To achieve the above purpose, the technical solution adopted by the present invention is: A method for preparing low-volatile hydrogen-containing silicone oil comprises the following steps: S1. Add the linear body and the chlorophosphazene composite catalyst into the reaction kettle, stir and mix evenly, evacuate the air, and heat to react; S2, online viscosity detection, when the specified viscosity is reached, normal pressure is restored, high hydrogen silicone oil, hexamethyldisiloxane and chlorophosphazene composite catalyst are added, and the temperature is lowered for reaction; S3, adding a terminator to terminate the reaction, filtering, and obtaining the hydrogen-containing silicone oil.

[0011] In step S1 of the present invention, the chlorophosphazene composite catalyst is diluted and pretreated with an inert solvent before being added, and the amount of the chlorophosphazene composite catalyst is 0.5 to 5 ppm, for example, 0.5 ppm, 1 ppm, 2 ppm, 3 ppm, 4 ppm, 5 ppm.

[0012] Preferably, in step S1, the inert solvent is one or more of toluene, ethanol, and isopropanol.

[0013] More preferably, in step S1, the amount of the chlorophosphazene composite catalyst used is 0.5-4 ppm.

[0014] In step S1 of the present invention, the vacuum degree is -70~-100kPa, for example, -70kPa, -80kPa, -90kPa, -95kPa or -100kPa; the reaction temperature is 60~100°C, for example, 60°C, 70°C, 75°C, 80°C, 85°C, 90°C or 100°C; and the reaction time is 1~4h, for example, 1h, 2h, 2.5h, 3h or 4h.

[0015] Preferably, in step S1, the vacuum degree is -80~-100 kPa.

[0016] Preferably, in step S1, the reaction temperature is 70-90°C.

[0017] Preferably, in step S1, the reaction time is 1 to 3 hours.

[0018] In step S2 of the present invention, in order to reduce the content of hydroxyl groups in the system, the specified viscosity is greater than 50,000 cp.

[0019] Preferably, the specified viscosity in step S2 is greater than 100,000 cp.

[0020] In step S2 of the present invention, during the viscosity reduction process, the amount of the chlorophosphazene composite catalyst added is 1-20 ppm.

[0021] Preferably, in step S2, the amount of the chlorophosphazene composite catalyst added is 1-10 ppm.

[0022] In step S2 of the present invention, the reaction temperature is 30-70°C, for example, 30°C, 40°C, 45°C, 50°C, 55°C, 60°C; the reaction time is 2-5h, for example, 2h, 3h, 3.5h, 4h, 5h.

[0023] Preferably, in step S2, the reaction temperature is 40-60°C.

[0024] Preferably, in step S2, the reaction time is 2 to 4 hours.

[0025] In step S3 of the present invention, the amount of the terminator added is 5 to 100 times the total amount of the chlorophosphazene composite catalyst added.

[0026] Preferably, in step S3, the amount of the terminator added is 5 to 50 times the total amount of the chlorophosphazene composite catalyst added.

[0027] In step S3 of the present invention, the reaction temperature of the termination reaction process is 10-60° C. and the reaction time is 2-6 hours.

[0028] Preferably, in step S3, the reaction temperature is 10-40° C., and the reaction time is 2-4 h.

[0029] Compared with the prior art, the present invention has the following beneficial effects: 1. The amount of chlorophosphazene catalyst used in the present invention is extremely small, which effectively reduces the production cost.

[0030] 2. The preparation method of the present invention greatly simplifies the synthesis process of hydrogen-containing silicone oil, shortens the reaction time, and does not generate a large amount of solid waste, thereby reducing environmental pollution.

[0031] 3. The preparation method of the present invention does not produce obvious cyclosiloxane, the content of low-boiling substances is extremely low, and the hydrogen-containing silicone oil is very active. The hydrogen content of the hydrogen-containing silicone oil is 0.18% to 0.75%, the volatile matter is as low as 0.72%, and the yield is as high as 99.6%. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0033] Embodiment 1: A method for preparing low-volatile hydrogen-containing silicone oil comprises the following steps: S1. Add 110 parts of linear body and 1 ppm of chlorophosphazene composite catalyst into the reactor, wherein the chlorophosphazene composite catalyst is diluted with toluene, stir and mix the reactants evenly, maintain a vacuum environment of -90 kPa, raise the temperature to 80° C., keep the temperature for 2 hours, and carry out polycondensation reaction; S2. Monitor the viscosity change in real time by an online viscometer. When the viscosity is 100,000 cp, restore the normal pressure, cool to 50° C., add 100 parts of high hydrogen silicone oil, 4.6 parts of hexamethyldisiloxane and 5 ppm of chlorophosphazene composite catalyst, and carry out secondary polymerization for 4 hours. S3. Cool the system temperature to 30°C, add 160 ppm of terminator and react for 3 hours, filter, and obtain colorless and odorless hydrogenated silicone oil.

[0034] After testing, the hydrogen content of the side hydrogen-containing silicone oil is 0.75% and the molecular weight is 4000, which meets the design molecular weight requirements.

[0035] Embodiment 2: A method for preparing low-volatile hydrogen-containing silicone oil comprises the following steps: S1. Add 110 parts of linear body and 1 ppm of chlorophosphazene composite catalyst into the reactor, wherein the chlorophosphazene composite catalyst is diluted with ethanol, stir and mix the reactants evenly, maintain a vacuum environment of -90 kPa, raise the temperature to 80° C., keep the temperature for 2 hours, and carry out polycondensation reaction; S2. Monitor the viscosity change in real time by an online viscometer. When the viscosity is 100,000 cp, restore the normal pressure, cool to 50° C., add 100 parts of high hydrogen silicone oil, 4.6 parts of hexamethyldisiloxane and 7 ppm of chlorophosphazene composite catalyst, and carry out secondary polymerization for 4 hours. S3. Cool the system temperature to 30°C, add 160 ppm of terminator and react for 3 hours, filter, and obtain colorless and odorless hydrogenated silicone oil.

[0036] After testing, the hydrogen content of the side hydrogen-containing silicone oil is 0.75% and the molecular weight is 4000, which meets the design molecular weight requirements.

[0037] Embodiment 3: A method for preparing low-volatile hydrogen-containing silicone oil comprises the following steps: S1. Add 110 parts of linear body and 3 ppm of chlorophosphazene composite catalyst into the reactor, wherein the chlorophosphazene composite catalyst is diluted with ethanol, stir and mix the reactants evenly, maintain a vacuum environment of -80 kPa, raise the temperature to 80° C., keep the temperature for 3 hours, and carry out polycondensation reaction; S2. Monitor the viscosity change in real time by an online viscometer. When the viscosity is 200,000 cp, restore the normal pressure, cool to 40° C., add 100 parts of high hydrogen silicone oil, 4.6 parts of hexamethyldisiloxane and 7 ppm of chlorophosphazene composite catalyst, and carry out secondary polymerization for 3 hours. S3. Cool the system temperature to 20°C, add 160 ppm of terminator and react for 3 hours, filter, and obtain colorless and odorless hydrogenated silicone oil.

[0038] After testing, the hydrogen content of the side hydrogen-containing silicone oil is 0.75% and the molecular weight is 4000, which meets the design molecular weight requirements.

[0039] Embodiment 4: A method for preparing low-volatile hydrogen-containing silicone oil comprises the following steps: S1. Add 790 parts of linear body and 3 ppm of chlorophosphazene composite catalyst into the reactor, wherein the chlorophosphazene composite catalyst is diluted with toluene, stir and mix the reactants evenly, maintain a vacuum environment of -90 kPa, raise the temperature to 80° C., keep the temperature for 1.5 hours, and carry out polycondensation reaction; S2. Monitor the viscosity change in real time by an online viscometer. When the viscosity is 100,000 cp, restore the normal pressure, cool to 50° C., add 100 parts of high hydrogen silicone oil, 19 parts of hexamethyldisiloxane and 5 ppm of chlorophosphazene composite catalyst, and carry out secondary polymerization for 3 hours. S3. Cool the system temperature to 30°C, add 160 ppm of terminator and react for 4 hours, filter, and obtain colorless and odorless hydrogenated silicone oil.

[0040] After testing, the hydrogen content of the side hydrogen-containing silicone oil is 0.18% and the molecular weight is 6400, which meets the design molecular weight requirements.

[0041] Embodiment 5: A method for preparing low-volatile hydrogen-containing silicone oil comprises the following steps: S1. Add 790 parts of linear body and 3 ppm of chlorophosphazene composite catalyst into the reactor, wherein the chlorophosphazene composite catalyst is diluted with isopropanol, stir and mix the reactants evenly, maintain a vacuum environment of -90 kPa, raise the temperature to 80° C., keep the temperature for 2 hours, and carry out polycondensation reaction; S2. Monitor the viscosity change in real time by an online viscometer. When the viscosity is 100,000 cp, restore the normal pressure, cool to 50° C., add 100 parts of high hydrogen silicone oil, 19 parts of hexamethyldisiloxane and 8 ppm of chlorophosphazene composite catalyst, and carry out secondary polymerization for 2 hours. S3. Cool the system temperature to 30°C, add 220 ppm of terminator and react for 4 hours, filter, and obtain colorless and odorless hydrogenated silicone oil.

[0042] After testing, the hydrogen content of the side hydrogen-containing silicone oil is 0.18% and the molecular weight is 6400, which meets the design molecular weight requirements.

[0043] Comparative Example 1: A method for preparing low-volatile hydrogen-containing silicone oil comprises the following steps: S1. Under nitrogen protection, the raw materials dimethylcyclosiloxane mixture, hexamethyldisiloxane, high hydrogen silicone oil and trifluoromethanesulfonic acid were subjected to ring opening and equilibrium reaction at 25°C for 6 hours; Among them, 109 parts of dimethylcyclosiloxane mixture, 4.6 parts of hexamethyldisiloxane, 100 parts of high hydrogen silicone oil, and the addition amount of trifluoromethanesulfonic acid is 0.3%; S2, using Na2CO3 as a neutralizing agent, neutralizing at 30°C for 6 hours, filtering to obtain a filtrate, wherein the amount of Na2CO3 added is 3 times that of trifluoromethanesulfonic acid; S3. The filtrate is heated to 150°C under a pressure of -0.1 MPa, and low-boiling substances below 150°C are removed by reduced pressure distillation to finally obtain a colorless transparent liquid, which is the side hydrogenated silicone oil.

[0044] After testing, the hydrogen content of the side hydrogen-containing silicone oil is 0.75% and the molecular weight is 4000, which meets the design molecular weight requirements.

[0045] Comparative Example 2: A method for preparing low-volatile hydrogen-containing silicone oil comprises the following steps: S1. Under nitrogen protection, the raw materials dimethylcyclosiloxane mixture, hexamethyldisiloxane, high hydrogen silicone oil and trifluoromethanesulfonic acid were subjected to ring opening and equilibrium reaction at 25°C for 6 hours; Among them, 790 parts of dimethylcyclosiloxane mixture, 19 parts of hexamethyldisiloxane, 100 parts of high hydrogen silicone oil, and the addition amount of trifluoromethanesulfonic acid is 0.3%; S2, using Na2CO3 as a neutralizing agent, neutralizing at 30°C for 6 hours, filtering to obtain a filtrate, wherein the amount of Na2CO3 added is 3 times that of trifluoromethanesulfonic acid; S3. The filtrate is heated to 150°C under a pressure of -0.1 MPa, and low-boiling substances below 150°C are removed by reduced pressure distillation to finally obtain a colorless transparent liquid, which is the side hydrogenated silicone oil.

[0046] After testing, the hydrogen content of the side hydrogen-containing silicone oil is 0.18% and the molecular weight is 6400, which meets the design molecular weight requirements.

[0047] Comparative Example 3: The side hydrogenated silicone oil was prepared by the same method as in Example 3, except that in step S2, the polymerization endpoint viscosity was controlled to be 20000 cp.

[0048] After testing, the hydrogen content of the side hydrogen-containing silicone oil was 0.15%, and the molecular weight was 7000. The product molecular weight did not meet the design value.

[0049] Comparative Example 4: The side hydrogen-containing silicone oil was prepared by the same method as in Example 3, except that in step S2, the amount of chlorophosphazene catalyst used was 30 ppm.

[0050] After testing, the hydrogen content of the side hydrogen-containing silicone oil was 0.18%, and the molecular weight was 5600. The product molecular weight did not meet the design value.

[0051] The viscosity and volatile matter of the hydrogen-containing silicone oil prepared in Examples 1-5 and Comparative Examples 1-2 were respectively measured, and the yield was calculated; and the time required for filtering the same mass of hydrogen-containing silicone oil S2 in Examples 1-5 and Comparative Examples 1-2 was recorded. The measurement results are shown in Table 1.

[0052] Table 1 Test results of embodiments and comparative examples

[0053] In summary, the hydrogen-containing silicone oil prepared by the present invention does not require desulfurization treatment, and the volatile matter can be as low as 0.72%; moreover, the filtering time of the prepared hydrogen-containing silicone oil is short, the amount of chlorophosphazene composite catalyst used is small, the production cost is reduced, and the product yield is improved, and the yield is as high as 99.6%.

[0054] The above embodiments are only preferred technical solutions of the present invention and should not be regarded as limiting the present invention. The protection scope of the present invention shall be the technical solutions recorded in the claims, including equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A method for preparing low-volatile hydrogen-containing silicone oil, characterized in that: The steps include: S1, adding hydroxyl-terminated polydimethylsiloxane oligomer and chlorophosphazene composite catalyst into a reaction kettle, stirring and mixing evenly, evacuating, and heating to react; S2, online viscosity detection, when the specified viscosity is reached, normal pressure is restored, high hydrogen silicone oil, hexamethyldisiloxane and chlorophosphazene composite catalyst are added, and the temperature is lowered for reaction; S3, adding a terminator to terminate the reaction, filtering, and obtaining the hydrogen-containing silicone oil.

2. The method for preparing low-volatile side hydrogen-containing silicone oil according to claim 1, characterized in that: In step S1, the amount of the chlorophosphazene composite catalyst used is 0.5-5 ppm.

3. The method for preparing low-volatile side hydrogen-containing silicone oil according to claim 1, characterized in that: In step S1, the chlorophosphazene composite catalyst is diluted and pre-treated with an inert solvent before being added.

4. The method for preparing low-volatile hydrogen-containing silicone oil according to claim 1, characterized in that: In step S1, the vacuum degree of the reaction is -70~-100 kPa, the temperature is 60~90°C, and the time is 1~3 hours.

5. The method for preparing low-volatile side hydrogen-containing silicone oil according to claim 1, characterized in that: In step S2, the specified viscosity is greater than 50000 cp.

6. The method for preparing low-volatile hydrogen-containing silicone oil according to claim 1, characterized in that: In step S2, the amount of the chlorophosphazene composite catalyst used is 1-20 ppm, and the mixture is stirred and mixed and cooled.

7. The method for preparing low-volatile hydrogen-containing silicone oil according to claim 1, characterized in that: In step S2, the reaction temperature is 30-70° C. and the reaction time is 2-5 h.

8. The method for preparing low-volatile hydrogen-containing silicone oil according to claim 1, characterized in that: In step S3, the amount of the terminator added is 5 to 100 times the total amount of the chlorophosphazene composite catalyst.

9. The method for preparing low-volatile hydrogen-containing silicone oil according to claim 1, characterized in that: In step S3, the reaction temperature is 10-60° C. and the reaction time is 2-6 h.

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