Single-end functional group silicone oil for spandex spinning oil and preparation method and application thereof

Abstract

The present invention relates to the technical field of spandex spinning oil, and in particular to a single-end functional group silicone oil for spandex spinning oil, a preparation method and an application thereof. The single-end functional group silicone oil is: 1 , R 2 , R 3 Each is independently selected from ‑Me or ‑H, and X is selected from any one of C1 to C3 alkane groups. The preparation method is: in an inert gas atmosphere, in an organic solvent system, dry hexamethylcyclotrisiloxane reacts with an organic lithium initiator under heating conditions; then trimethylchlorosilane is added for reaction; then an initiation promoter, a molecular weight regulator and an inhibitor are added for reaction; after the reaction is completed, low-boiling substances are removed by reduced pressure distillation; a capping agent and a catalyst acetic acid are added to the reaction system for reaction; and post-treatment and purification are performed to obtain the single-end functional group silicone oil. The single-end functional group silicone oil has high operability, can give the spandex spinning oil excellent dispersibility, low dosage and thixotropic value, and long service life.

Description

Technical Field

[0001] The invention relates to single-end functional group silicone oil for spandex spinning oil, a preparation method and application thereof, and belongs to the technical field of spandex spinning oil. Background Art

[0002] Spandex is the abbreviation of polyurethane fiber. Polyurethane fiber is highly elastic and can be stretched 6 to 7 times. It is currently a widely used engineering fiber and is constantly expanding into aerospace, military, and special civilian fields.

[0003] In the process of spandex spinning production, oiling agent is needed to oil the spandex. With the increasing demand for spandex production, the demand for spandex spinning oil agent is also increasing. The main oil agent manufacturers on the market include Takemoto, Matsumoto, American Golston, etc. The oil agents provided by these companies use dimethyl silicone oil as the main raw material. For example, US patent application US4999120A discloses an aqueous emulsion topcoat containing polydimethylsiloxane and ethoxylated long-chain alkanol for spandex fiber treatment. The main component of the spandex spinning oil agent disclosed in the patent is dimethyl silicone oil. However, because the methyl group in the molecular weight of dimethyl silicone oil is an inert group, the dispersion effect of dimethyl silicone oil in the spandex spinning oil agent is poor, resulting in uneven dispersion of the spandex oil agent. When used in spandex spinning, it will affect the feel, antistatic properties, antibacterial properties, etc. of the spandex product. Therefore, the development of a single-end functional group silicone oil for spandex spinning oil agent has important economic value in the field of spandex spinning oil agent. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a single-end functional group silicone oil for spandex spinning oil, a preparation method and an application thereof. The end group of the single-end functional group silicone oil carries an active functional group, so that the single-end photoactive group silicone oil is easier to emulsify and disperse, and the spandex spinning oil used therein is more uniform, so that the spandex has a good hand feel, excellent antistatic performance, and good antibacterial properties.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: a single-end functional group silicone oil for spandex spinning oil, wherein the structure of the single-end functional group silicone oil is as follows:

[0006] Formula I;

[0007] In Formula I, R 1 , R 2 , R 3 Each is independently selected from -Me or -H, X is selected from any one of C1 to C3 alkane groups; n is a natural number, 20≤n≤300.

[0008] Further, the X is selected from -Me, -Et, -CH=CH 2 、-CH=CH-CH 3 Any one of .

[0009] Furthermore, the single-end functional group silicone oil is selected from any one of the following structures:

[0010] .

[0011] The present invention also discloses a method for preparing a single-end functional group silicone oil for a spandex spinning oil, the preparation method comprising:

[0012] S1. In an inert gas atmosphere, in an organic solvent system, dry hexamethylcyclotrisiloxane reacts with an organic lithium initiator under heating conditions;

[0013] S2, adding trimethylsilyl chloride to the system after the reaction in step S1 to carry out a reaction;

[0014] S3, adding an initiator, a molecular weight regulator and an inhibitor to the system after the reaction in step S2 to react;

[0015] After the reaction in step S4 and step S3 is completed, low boiling points are removed by distillation under reduced pressure;

[0016] S5, adding a capping agent and a catalyst, acetic acid, to the reaction system for reaction;

[0017] S6, post-processing and purification to obtain the single-end functional group silicone oil.

[0018] Furthermore, in step S1, the organic solvent is any one of toluene, xylene, and n-heptane;

[0019] In step S1, the organic lithium initiator is at least one of methyl lithium, n-butyl lithium, and sec-butyl lithium;

[0020] In step S3, the initiator is any one of tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide, and trimethyl urea;

[0021] In step S3, the molecular weight regulator is any one of trimethylsilanol and dimethylvinylsilanol;

[0022] In step S3, the inhibitor is any one of acetonitrile and diethyl ether.

[0023] Furthermore, in step S5, the end-capping agent is any one of tetramethoxysilane, vinyltrimethoxysilane, and tetraethoxysilane.

[0024] Further, in step S1, the reaction temperature is 30-40°C and the reaction time is 10-30min;

[0025] In step S2, the reaction temperature is 30-40°C and the reaction time is 30-60min;

[0026] In step S3, the reaction temperature is 10-50°C and the reaction time is 3-8h;

[0027] In step S4, the temperature of the reduced pressure distillation is 90-120°C and the pressure is -100~-90kPa;

[0028] In step S5, the reaction temperature is 90-135°C and the reaction time is 3-6h;

[0029] In step S6, low-boiling substances other than the single-end functional group silicone oil are removed by vacuum distillation, the pressure of the vacuum distillation is -100 to -90 kPa, and the temperature is 95-155°C.

[0030] Further, the mass ratio of hexamethylcyclotrisiloxane to the organic solvent is 1:(0.8-1);

[0031] The molar ratio of hexamethylcyclotrisiloxane to the organic lithium initiator is (90-230): 1;

[0032] The molar ratio of hexamethylcyclotrisiloxane to trimethylchlorosilane is (14-62):1;

[0033] The molar ratio of hexamethylcyclotrisiloxane to the initiator is 1:(0.35-1.05);

[0034] The molar ratio of hexamethylcyclotrisiloxane to the inhibitor is 1:(1.5-5.2);

[0035] The molar ratio of the molecular weight regulator to the organic lithium initiator is (5.5-26.5): 1;

[0036] The molar ratio of the hexamethylcyclotrisiloxane to the end-capping agent is 1:(0.7-1.25).

[0037] Furthermore, before performing step S1, the hexamethylcyclotrisiloxane is dried, and the preparation method of the dried hexamethylcyclotrisiloxane is as follows:

[0038] Dissolve hexamethylcyclotrisiloxane in an organic solvent, heat to reflux, remove water with a water separator, and observe that the reflux liquid of the water separator becomes clear;

[0039] When the system temperature drops to 0-20°C, the air in the system is extracted, and the pressure in the system is -99kPa±1kPa. Then, inert gas is injected into the system to replace all the air in the system with inert gas.

[0040] Finally, heating is performed and an organic lithium initiator is added to carry out the reaction in step S1.

[0041] The invention also discloses an application of a single-end functional group silicone oil for a spandex spinning oil, wherein the single-end functional group silicone oil is applied to the spandex spinning oil.

[0042] The beneficial effects of the present invention are:

[0043] The single-end functional group silicone oil of the present invention, the active functional group carried by the end group makes the silicone oil easier to emulsify and disperse, so that the prepared spandex oil agent is more uniform, and the application in spandex spinning will make the spandex feel good, have excellent antistatic properties, and have good antibacterial properties. Moreover, the single-end functional group silicone oil of the present invention is a green, environmentally friendly, non-toxic and harmless silicone oil, and its preparation yield is high, the product performance is excellent, and it has flame retardancy. The spandex oil agent with flame retardant effect is effectively wrapped on the surface of the spandex fiber through dry spinning, which will not reduce or reduce the mechanical properties of the spandex fiber itself, and can also ensure that the spandex fiber has a high flame retardant effect and good thermal stability, and does not pollute the environment during the flame retardant process, does not affect the color of the fabric, and meets most of the use scenarios. The single-end functional group silicone oil for spandex spinning oil agent described herein has high operability, can give the spandex oil agent excellent dispersibility, low dosage and thixotropic value, and long service life.

[0044] Silicone oils with different molecular weights and different numbers of chain links can be customized, with n between 20-300. Silicone oils with different chain links can be prepared according to different usage environments.

[0045] The single-end functional group silicone oil and preparation method for spandex spinning oil of the present invention can customize single-end functional group silicone oils with different functional groups as required, and can be applied to different types of spandex spinning oil fields. The advantages of the present invention over the traditional dimethyl silicone oil for spandex spinning oil are: the structure and molecular weight can be directionally regulated according to different use environments, and the advantage of one end of the structure being inert and the other end being active can be used to achieve directional combination with other oil materials as a dispersant and emulsifier, and the low molecular weight polysiloxane product can easily penetrate the matrix material, making the surface treatment more integrated with the matrix material. The spandex exhibits higher hydrophilicity and lipophilicity and wear resistance.

[0046] The present invention discloses a method for preparing a single-end functional group silicone oil for a spandex spinning oil, using D3 as a raw material, organic lithium as an initiator, adopting an anionic ring-opening polymerization reaction mechanism, rationally adding a molecular weight regulator, a reaction accelerator, a side reaction inhibitor and a reaction terminator, exploring suitable reaction conditions and temperatures, rationally adopting a strategy of replacing air with an inert gas, and improving the reaction yield. Therefore, the single-end functional group silicone oil prepared by the method of the present invention has the advantages of high purity, high yield (reaction yield ≥ 95%), narrow molecular weight distribution (PDI < 1.5), etc. DETAILED DESCRIPTION

[0047] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0049] The single-end functional group silicone oil for spandex spinning oil has a structure as follows:

[0050] Formula I;

[0051] In Formula I, R 1 , R 2 , R 3 Each is independently selected from -Me or -H, X is selected from any one of C1 to C3 alkane groups; n is a natural number, 20≤n≤300.

[0052] Specifically, the X is selected from -Me, -Et, -CH=CH 2 、-CH=CH-CH 3 Any of the above.

[0053] More specifically, the single-end functional group silicone oil is selected from any one of the following structures:

[0054] .

[0055] A method for preparing a single-end functional group silicone oil for a spandex spinning oil, the preparation method comprising:

[0056] S1. In an inert gas atmosphere, in an organic solvent system, dry hexamethylcyclotrisiloxane (D3) reacts with an organic lithium initiator under heating conditions;

[0057] S2, adding trimethylsilyl chloride to the system after the reaction in step S1 to carry out a reaction; trimethylsilyl chloride is used as an alkylating agent to treat Si-OH in D3, and an inert gas is passed through the whole process;

[0058] S3, adding an initiator, a molecular weight regulator and an inhibitor to the system after the reaction in step S2 to carry out a reaction, and the process is also protected by an inert gas throughout the process;

[0059] After the reaction in step S4 and step S3 is completed, low boiling points are removed by distillation under reduced pressure;

[0060] S5, adding a capping agent and a catalyst, acetic acid, to the reaction system for reaction;

[0061] S6, post-processing and purification to obtain the single-end functional group silicone oil.

[0062] Specifically, in step S1, the organic solvent is any one of toluene, xylene, and n-heptane;

[0063] In step S1, the organic lithium initiator is at least one of methyl lithium, n-butyl lithium, and sec-butyl lithium;

[0064] In step S3, the initiator is any one of tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide, and trimethyl urea;

[0065] In step S3, the molecular weight regulator is any one of trimethylsilanol and dimethylvinylsilanol;

[0066] In step S3, the inhibitor is any one of acetonitrile and diethyl ether.

[0067] Specifically, in step S5, the end-capping agent is any one of tetramethoxysilane, vinyltrimethoxysilane, and tetraethoxysilane.

[0068] Specifically, in step S1, the reaction temperature is 30-40°C and the reaction time is 10-30min;

[0069] In step S2, the reaction temperature is 30-40°C and the reaction time is 30-60min;

[0070] In step S3, the reaction temperature is 10-50°C and the reaction time is 3-8h;

[0071] In step S4, the temperature of the reduced pressure distillation is 90-120°C and the pressure is -100~-90kPa;

[0072] In step S5, the reaction temperature is 90-135°C and the reaction time is 3-6h;

[0073] In step S6, low-boiling substances other than the single-end functional group silicone oil are removed by vacuum distillation, the pressure of the vacuum distillation is -100 to -90 kPa, and the temperature is 95-155°C.

[0074] Specifically, the mass ratio of hexamethylcyclotrisiloxane to the organic solvent is 1:(0.8-1);

[0075] The molar ratio of hexamethylcyclotrisiloxane to the organic lithium initiator is (90-230): 1;

[0076] The molar ratio of hexamethylcyclotrisiloxane to trimethylchlorosilane is (14-62):1;

[0077] The molar ratio of hexamethylcyclotrisiloxane to the initiator is 1:(0.35-1.05);

[0078] The molar ratio of hexamethylcyclotrisiloxane to the inhibitor is 1:(1.5-5.2);

[0079] The molar ratio of the molecular weight regulator to the organic lithium initiator is (5.5-26.5): 1;

[0080] The molar ratio of the hexamethylcyclotrisiloxane to the end-capping agent is 1:(0.7-1.25).

[0081] Specifically, before performing step S1, the hexamethylcyclotrisiloxane is dried. The preparation method of the dried hexamethylcyclotrisiloxane is as follows:

[0082] Dissolve hexamethylcyclotrisiloxane in an organic solvent, heat to reflux, remove water with a water separator, and observe that the reflux liquid of the water separator becomes clear (water content ≤ 0.03%);

[0083] When the system temperature drops to 0-20°C, the air in the system is extracted, and the pressure in the system is -99kPa±1kPa. Then, inert gas is injected into the system to replace all the air in the system with inert gas (the control operation in the system is replaced by inert gas, and the operation is repeated at least 5 times);

[0084] Finally, heating is performed and an organic lithium initiator is added to carry out the reaction in step S1, and the whole process is protected by an inert gas.

[0085] More specifically, the inert gas used in the embodiment of the present invention is nitrogen with a purity of 99.999%, which can also be replaced by inert gases such as argon and helium.

[0086] The invention discloses an application of a single-end functional group silicone oil for a spandex spinning oil. The single-end functional group silicone oil is applied to the spandex spinning oil.

[0087] More specifically, the main components of the spandex spinning oil include industrial grade white oil, organosilicon quaternary ammonium salt, antistatic agent, organic complex salt, and the single-end functional group silicone oil of the present invention.

[0088] 1. Silicone Oil Preparation Example

[0089] Example 1

[0090] Preparation of single-end functional group silicone oil products: , the specific preparation method is:

[0091] (1) Weigh 19 kg of hexamethylcyclotrisiloxane (D3) and 16 kg of toluene and put them into a 100 L glass reactor. Heat to reflux and start the dehydration operation. Observe the appearance of the liquid separated by the water separator. When the appearance is clear and transparent, the dehydration operation can be stopped. The dehydration time is 4 hours from the beginning of the distillation. After the dehydration is completed, start cooling. When cooling, put in a slightly positive pressure of nitrogen and seal the entire equipment to prevent water vapor in the air from entering the equipment. After vacuuming, use N 2 Replace the air for 5 times. Heat the oil and set the oil temperature to 40°C. When the material temperature rises to 35°C, add 470 mL of n-butyl lithium (2.0 mol / L) into the reactor and react at 40°C for 15 minutes.

[0092] (2) Add 0.15 kg of trimethylsilyl chloride into the reactor and react at 40°C for 30 min.

[0093] (3) Add 0.85 kg trimethylsilanol, 5.54 kg acetonitrile and 2.5 kg DMF mixed solution into the reactor and keep N 2 Gas was introduced into the reactor and the reaction was carried out at 35°C for 7h.

[0094] (4) Add 0.56 kg of anhydrous acetic acid from the feed port, stir for 1 hour, set the heating temperature to 98°C, use negative pressure to remove low-boiling substances, first use a vacuum water pump, and when less solvent is removed, replace the vacuum oil pump to continue removing the low-boiling substances. When the material in the kettle rises to 95°C and no solvent is removed, stop removing low-boiling substances.

[0095] (5) Weigh 15.6 kg of methyl orthosilicate and 0.68 kg of anhydrous acetic acid, add them into the reactor from the feed port, and carry out end-capping reaction at 135°C. The reaction is completed after 4 hours.

[0096] (6) Heating: Set the oil temperature to 135°C and increase the oil temperature according to the discharge speed. The oil temperature is increased by 5-10°C each time. Use the vacuum water pump first. When the solvent is less removed, replace the vacuum oil pump and continue to remove the low-boiling substances. When the material in the reactor rises to 155°C and no solvent is removed, stop removing the low-boiling substances and filter to obtain the finished product.

[0097] In this embodiment, the yield of the single-end functional group silicone oil is 97.61%, the PDI is 1.35, and the viscosity is 32 mm 2 / s.

[0098] Example 2

[0099] Preparation of single-end functional group silicone oil products: , the specific preparation method is:

[0100] (1) Weigh 316.5 g of D3 and 253.2 g of toluene, add them into a 1 L four-necked flask, heat to reflux, N 2 The reaction mixture was azeotropically dehydrated for 1.5 h. The mixture was cooled to 5°C and the air in the reaction system was removed by evacuating the mixture with nitrogen using a double row tube. 3.15 mL of n-butyl lithium was added to the reaction system using a syringe and stirred at 30°C for 10 min.

[0101] (2) Add 10.5 g of trimethylsilyl chloride and stir at 30 °C for 30 min.

[0102] (3) Mix 15 g of trimethylsilanol, 108 g of DMF and 302 g of acetonitrile and add them into the reaction system using a syringe. React at 30 °C for 6.5 h.

[0103] (4) Add 3.2 g of acetic acid to terminate the reaction, and stir at 30°C for 30 min. Control the temperature at 95°C, use a water pump to remove the solvent for 30 min, and then use an oil pump to remove the solvent for 30 min (pressure is -100 to -90 kPa).

[0104] (5) Add 158 g of tetramethoxysilane and 12.3 g of acetic acid to the reaction system and react at 120 °C for 4 h.

[0105] (6) Control the temperature to 95°C, use a water pump to remove the solvent for 30 minutes, then control the temperature to 150°C, use an oil pump to remove the solvent for 30 minutes. Finally, cool to room temperature, filter out the salt with a sand core funnel to obtain the final product.

[0106] In this embodiment, the yield of the single-end functional group silicone oil is 95.9%, the PDI is 1.42, and the viscosity is 51 mm 2 / s.

[0107] Example 3

[0108] Preparation of single-end functional group silicone oil products: , the specific preparation method is:

[0109] (1) Weigh 15kg D3 and 12.5kg toluene and put them into a 100L glass reactor. Heat to reflux and start the dehydration operation. Observe the appearance of the liquid separated by the water separator. When the appearance is clear and transparent, the dehydration operation can be stopped. The dehydration time is 4 hours from the beginning of the distillation. After the dehydration is completed, the temperature is lowered. When cooling, a slightly positive pressure of nitrogen can be added and the entire equipment can be sealed to prevent water vapor in the air from entering the equipment. After vacuuming, use N 2 The air was replaced for 5 times. Then the oil temperature was set to 40°C. When the material temperature rose to 35°C, 354 mL of n-butyl lithium was added to the reactor and the reaction was carried out at 40°C for 15 minutes.

[0110] (2) Add 0.12 kg of trimethylsilyl chloride into the reactor and react at 40°C for 30 min.

[0111] (3) Add 0.64 kg of dimethylvinylsilanol, 4.21 kg of acetonitrile and 1.84 kg of DMF into the reactor and keep N 2 Pour into the kettle and react at 35°C for 7h.

[0112] (4) Add 0.36 kg of acetic acid from the feed port and stir for 1 hour. Heat and set the oil temperature to 98°C. Use negative pressure to remove low-boiling substances. Use a vacuum water pump first. When less solvent is removed, replace the vacuum oil pump and continue to remove the solvent. When the material in the kettle rises to 95°C and no solvent is removed, stop removing low-boiling substances.

[0113] (5) Weigh 12.8 kg of methyl orthosilicate and 0.42 kg of anhydrous acetic acid and add them from the feed port. Heat and perform the end-capping reaction at 135°C. The reaction is completed after 4 hours.

[0114] (6) Heating, set the oil temperature to 135℃, increase the oil temperature according to the speed of discharging, and increase the oil temperature by 5-10℃ each time. Use the vacuum water pump first, and replace the vacuum oil pump when the solvent is less removed to continue to remove the solvent. When the material in the reactor rises to 155℃ and no solvent is removed, stop removing the low-boiling point substances. Filter to obtain the finished product.

[0115] In this embodiment, the yield of the single-end functional group silicone oil is 96.35%, the PDI is 1.41, and the viscosity is 27 mm 2 / s, vinyl content is 0.138%.

[0116] Example 4

[0117] Preparation of single-end functional group silicone oil products: , the specific preparation method is:

[0118] (1) Weigh 19 kg of hexamethylcyclotrisiloxane (D3) and 19 kg of o-xylene and put them into a 100 L glass reactor. Heat to reflux and start the dehydration operation. Observe the appearance of the liquid separated by the water separator. When the appearance is clear and transparent, the dehydration operation can be stopped. The dehydration time is 4 hours from the beginning of the distillation. After the dehydration is completed, start cooling. When cooling, put in a slightly positive pressure of nitrogen and seal the entire equipment to prevent water vapor in the air from entering the equipment. After vacuuming, use N 2 Replace the air for 5 times. Heat until the material temperature rises to 35°C, add 0.6 mol of methyl lithium into the reactor, and react at 35°C for 30 minutes.

[0119] (2) Add 0.1 kg of trimethylsilyl chloride into the reactor and react at 35 °C for 60 min.

[0120] (3) Add 0.54 kg trimethylsilanol, 19 kg ether, and 4.9 kg tetrahydrofuran mixed solution into the reactor and keep N 2 Gas was introduced into the reactor and the reaction was carried out at 10°C for 8 h.

[0121] (4) Add 0.56 kg of anhydrous acetic acid from the feed port, stir for 1 hour, set the heating temperature to 98°C, use negative pressure to remove low-boiling substances, first use a vacuum water pump, and when less solvent is removed, replace the vacuum oil pump to continue removing the low-boiling substances. When the material in the kettle rises to 95°C and no solvent is removed, stop removing low-boiling substances.

[0122] (5) Weigh 12.98 kg of tetramethoxysilane and 0.68 kg of anhydrous acetic acid, add them into the reactor from the feed port, and carry out the end-capping reaction at 90°C. The reaction is completed after 6 hours.

[0123] (6) Heating: Set the oil temperature to 135°C and increase the oil temperature according to the discharge speed. The oil temperature is increased by 5-10°C each time. Use the vacuum water pump first. When the solvent is less removed, replace the vacuum oil pump and continue to remove the low-boiling substances. When the material in the reactor rises to 155°C and no solvent is removed, stop removing the low-boiling substances and filter to obtain the finished product.

[0124] In this embodiment, the yield of the single-end functional group silicone oil is 97.32%, the PDI is 1.38, and the viscosity is 34 mm 2 / s.

[0125] Comparative Example 1

[0126] The single-end functional group silicone oil was prepared by the same method as in Example 1, except that the raw material D3 was replaced by the same molar amount of D4 (octamethylcyclotetrasiloxane), and the n-butyl lithium was replaced by the same molar amount of metal oxide (specifically titanium chloride).

[0127] The PDI of the single-end functional group silicone oil obtained in this comparative example is 2.0.

[0128] Comparative Example 2

[0129] The single-end functional group silicone oil was prepared by the same method as in Example 1, except that in step (1), no water removal operation was performed on the hexamethylcyclotrisiloxane (D3).

[0130] The reaction system of this comparative example contains water, and a viscous silicone oil product cannot be formed.

[0131] Comparative Example 3

[0132] The single-end functional group silicone oil was prepared by the same method as in Example 1, except that the reaction temperature in step (1) was 80° C. (higher than the temperature condition specified in the present invention).

[0133] In this comparative example, implosion occurred during the reaction, the reaction product was in a solid state, and no silicone oil product could be obtained.

[0134] Comparative Example 4

[0135] The single-end functional group silicone oil was prepared by the same method as in Example 1, except that the end-capping reaction in step (5) was not performed in this comparative example 4.

[0136] The yield of the silicone oil obtained in this comparative example is 97.23%, the PDI is 1.45, and the viscosity is 40 mm 2 / s.

[0137] Comparative Example 5

[0138] The single-end functional group silicone oil was prepared by the same method as in Example 1, except that the reaction temperature in step (5) was 150° C. (higher than the reaction temperature specified in the present invention).

[0139] The yield of the silicone oil obtained in this comparative example is 95.67%, the PDI is 1.65, and the viscosity is 43 mm 2 / s.

[0140] 2. Application examples of spandex spinning oil

[0141] The silicone oils prepared in the above examples and comparative examples were respectively formulated into spandex spinning oils, wherein the composition of the spandex spinning oils is as follows: The composition of the spandex spinning oils prepared in the following application examples is as follows: 45 parts of silicone oil, 45 parts of industrial grade white oil, 8 parts of organosilicon quaternary ammonium salt (gemini silicon quaternary ammonium salt), 1 part of antistatic agent (sodium alkyl sulfonate), 1 part of organic complex salt (magnesium stearate)

[0142] The spandex spinning oil is prepared according to the above formula composition. The difference in the formula composition in each application example is only that different silicone oils are used.

[0143] The silicone oil used in the preparation of spandex spinning oil in Application Examples 1 to 4 is the single-end functional group silicone oil prepared in Examples 1 to 4.

[0144] The silicone oil used in the preparation of spandex spinning oil in Application Comparative Example 1 to Application Comparative Example 5 is the single-end functional group silicone oil prepared in Comparative Example 1 to Comparative Example 5.

[0145] The silicone oil used in the preparation of the spandex spinning oil in Comparative Example 6 is dimethyl silicone oil.

[0146] The spandex spinning oils prepared in the application examples and the comparative examples were tested for performance indicators, and these spandex spinning oils were applied to the spandex spinning process to measure the relevant properties of the spandex fibers. The specific performance test results are shown in Table 1 below, where the test methods involved are:

[0147] Mechanical properties: According to GB1040-92 and GB1043-932 standards, the tensile strength α and impact strength β of the unnotched spandex cured sample were tested on a WDML-3 microcomputer-controlled slow tensile testing machine and impact testing machine.

[0148] Flame retardant properties: Spandex fibers were tested in accordance with "FZT50006-2013" and "GBT5451-1997".

[0149] Table 1 Performance index test results

[0150]

[0151] It can be seen from the above example data and table data that the silicone oil obtained by the preparation method of the present invention in Example 1-Example 4 has a high yield and a narrow molecular weight distribution. Application Example 1-Application Example 4 uses the spandex spinning oil prepared with the silicone oil of the present invention. The oil is a uniform liquid and has fluidity, a small thixotropic value, and a material with a small thixotropic coefficient exhibits more stable fluidity, which is suitable for occasions requiring stable fluidity. Application Example 1-Application Example 4 uses the spandex spinning oil prepared with the silicone oil of the present invention, which has strong tensile strength and impact strength, low static electricity, and experimental results show that it has a good flame retardant effect. When applied to spandex fibers, it exhibits excellent properties such as good hand feel, good molding, antibacterial and antistatic properties, which improves the defects of the narrow application range and poor performance of traditional oils, and is significantly better than the effect of using conventional dimethyl silicone oil in Application Comparative Example 6. Moreover, by comparing Example 1, Example 2, and Example 3, it can be seen that Example 1 and Examples 3-4 are prepared in a 100L pilot reactor, and Example 2 is prepared in a laboratory test. The preparation method of the present invention can meet the process requirements of small tests, pilot tests, and large-scale production, and the prepared silicone oils are all green, environmentally friendly, non-toxic and harmless silicone oils with high yields and excellent product performance, which meet most usage scenarios.

[0152] The difference between Example 1 and Example 2 is that the number of chain links in Example 1 is 24, and the number of chain links in Example 2 is 50. The silicone oil prepared in Example 1 is applied to a dispersion system with a lower viscosity, and Example 2 is applied to a dispersion system with a higher viscosity. The difference between Example 3 and Example 1 is only that the X group in Example 3 is a vinyl group, and the single-end functional silicone oil carrying a vinyl group will make the filler more compliant, and the vinyl group can also react with the characteristic group in the filler to improve the processing ability of the treating agent. The single-end functional silicone oil described in this article has high operability, can give the spandex spinning oil excellent dispersibility, low dosage and thixotropic value, and long service life.

[0153] From the comparison of the experimental data of Comparative Example 1 and Example 1, it can be seen that if conventional D4 is used as a raw material, the molecular weight distribution of the prepared silicone oil is relatively wide. From the oil agent indicators and application effects of Comparative Example 1 and Application Example 1, it can be seen that the oil agent prepared with silicone oil obtained by using D4 as a raw material has a large thixotropic value, resulting in poor stable fluidity, and low tensile strength and impact strength, resulting in the phenomenon that spandex fibers are prone to breakage, and the antistatic performance and flame retardant performance are also worse than those of the examples. This is because the functional groups carried by the end groups of Example 1 can form chemical bonds with spandex fibers, better adhere to the surface of spandex fibers, and modify the spandex fibers.

[0154] From the experimental comparison between Comparative Example 2 and Example 1, it can be seen that when hexamethylcyclotrisiloxane (D3) is used as a raw material to prepare silicone oil, it is necessary to control the anhydrous dry state of the reaction system in order to obtain silicone oil with excellent performance.

[0155] From the experimental comparison between Comparative Example 3 and Example 1, it can be seen that if the polymerization reaction temperature in step (1) is too high, implosion will occur during the reaction, and the reaction product will be in a solid state, and no silicone oil product can be obtained. Therefore, the polymerization reaction temperature defined in the present invention is more conducive to obtaining a silicone oil product with excellent performance, and finally obtaining a spandex spinning oil with excellent use effect.

[0156] From the experimental comparison between Comparative Example 4 and Example 1, it can be seen that if the small molecule group of the end-capping agent described in the present invention is not introduced during the preparation of silicone oil, the end group of the silicone oil will not be able to carry active functional groups, and the prepared silicone oil is similar to traditional dimethyl silicone oil, but its performance is slightly better than dimethyl silicone oil, and its performance is far inferior to the single-end functional group silicone oil introduced with the small molecule group of the end-capping agent described in the present invention. From the relevant performance test results and indications, the tensile strength and impact strength of Comparative Example 4 are smaller than those of Example 1, the thixotropy value is larger than that of Example 1, and the electrostatic value is also larger than that of Example 1, indicating that the flow stability of Comparative Example 4 is poor, and the antistatic performance and fiber strength are both worse than those of Example 1. The above results show that if the small molecule group of the end-capping agent described in the present invention is not introduced during the preparation of silicone oil, the performance of the prepared spandex oil agent will be worse than that of the oil agent introduced with the end group small molecule.

[0157] From the experimental comparison between Comparative Example 5 and Example 1, it can be seen that if the end-capping reaction temperature in step (5) is higher than the reaction temperature specified in the present invention, it will cause mutual polymerization reaction between the small molecule group end-capping agents, and ultimately make it difficult to separate the silicone oil and the products produced by the small molecule polymerization, thereby affecting the quality of the silicone oil. When applied to the spandex spinning oil, the spandex oil will be unevenly mixed and difficult to disperse evenly, which will seriously affect the feel and related mechanical properties of the spandex oil.

[0158] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0159] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. A method for preparing a single-end functional group silicone oil for a spandex spinning oil, characterized in that: The preparation method is: S1. In an inert gas atmosphere, in an organic solvent system, dry hexamethylcyclotrisiloxane reacts with an organic lithium initiator under heating conditions; S2, adding trimethylsilyl chloride to the system after the reaction in step S1 to carry out a reaction; S3, adding an initiator, a molecular weight regulator and an inhibitor to the system after the reaction in step S2 to react; After the reaction in step S4 and step S3 is completed, low boiling points are removed by distillation under reduced pressure; S5, adding a capping agent and a catalyst, acetic acid, to the reaction system for reaction; S6, post-processing and purification to obtain the single-end functional group silicone oil; In step S3, the molecular weight regulator is any one of trimethylsilanol and dimethylvinylsilanol; In step S5, the end-capping agent is tetramethoxysilane; In step S1, the reaction temperature is 30-40°C and the reaction time is 10-30min; In step S2, the reaction temperature is 30-40°C and the reaction time is 30-60min; In step S3, the reaction temperature is 10-50°C and the reaction time is 3-8h; In step S4, the temperature of the reduced pressure distillation is 90-120°C and the pressure is -100~-90kPa; In step S5, the reaction temperature is 90-135°C and the reaction time is 3-6h; In step S6, low-boiling substances other than the single-end functional group silicone oil are removed by vacuum distillation, the pressure of the vacuum distillation is -100 to -90 kPa, and the temperature is 95-155° C.; The molar ratio of hexamethylcyclotrisiloxane to the organic lithium initiator is (90-230): 1; The molar ratio of hexamethylcyclotrisiloxane to trimethylchlorosilane is (14-62):1; The molar ratio of the molecular weight regulator to the organic lithium initiator is (5.5-26.5): 1; The molar ratio of the hexamethylcyclotrisiloxane to the end-capping agent is 1:(0.7-1.25).

2. The method for preparing the single-end functional group silicone oil for spandex spinning oil according to claim 1, characterized in that: In step S1, the organic solvent is any one of toluene, xylene, and n-heptane; In step S1, the organic lithium initiator is at least one of methyl lithium, n-butyl lithium, and sec-butyl lithium; In step S3, the initiator is any one of tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide, and trimethyl urea; In step S3, the inhibitor is any one of acetonitrile and diethyl ether.

3. The method for preparing the single-end functional group silicone oil for spandex spinning oil according to claim 1, characterized in that: The mass ratio of hexamethylcyclotrisiloxane to the organic solvent is 1:(0.8-1); The molar ratio of hexamethylcyclotrisiloxane to the initiator is 1:(0.35-1.05); The molar ratio of the hexamethylcyclotrisiloxane to the inhibitor is 1:(1.5-5.2).

4. The method for preparing the single-end functional group silicone oil for spandex spinning oil according to claim 1, characterized in that: Before performing step S1, the hexamethylcyclotrisiloxane is first dried. The preparation method of the dried hexamethylcyclotrisiloxane is as follows: Dissolve hexamethylcyclotrisiloxane in an organic solvent, heat to reflux, remove water with a water separator, and observe that the reflux liquid of the water separator becomes clear; When the system temperature drops to 0-20°C, the air in the system is extracted, and the pressure in the system is -99kPa±1kPa. Then, inert gas is injected into the system to replace all the air in the system with inert gas. Finally, heating is performed and an organic lithium initiator is added to carry out the reaction in step S1.

5. An application of a single-end functional group silicone oil for spandex spinning oil prepared by the preparation method according to any one of claims 1 to 4, characterized in that: The single-end functional group silicone oil is applied to spandex spinning oil.

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