Low-viscosity hydroxypropyl silicone oil and preparation method thereof

Abstract

The invention provides a preparation method of low-viscosity hydroxypropyl silicone oil, which comprises the following steps: (1) uniformly stirring and mixing ethylene glycol monoallyl ether and a catalyst to prepare a mixture of ethylene glycol monoallyl ether and the catalyst; (2) adding silicone oil into a reactor, then dropwise adding the mixture of ethylene glycol monoallyl ether and a catalyst into the reactor, carrying out a heat preservation reaction after dropwise adding is finished, and preparing a reaction solution after the reaction is finished; and (3) adding activated carbon into the reaction liquid for adsorption, filtering, and carrying out reduced pressure distillation on the filtrate to obtain the low-viscosity hydroxypropyl silicone oil. The invention also provides the low-viscosity hydroxypropyl silicone oil. The hydroxypropyl silicone oil prepared by the method has the characteristics of narrow molecular weight distribution, no metal catalyst residue and the like, is green and environment-friendly, and is more suitable for industrial production.

Description

Technical Field

[0001] The present invention belongs to the field of polymer materials, and more specifically, relates to a low-viscosity hydroxypropyl silicone oil and a preparation method thereof. Background Art

[0002] Hydroxypropyl silicone oil is a kind of organosilicon compound containing reactive hydroxyl groups. Due to its unique chemical structure and physical properties, it shows wide application potential in many fields. The main characteristics of hydroxypropyl silicone oil include non-toxicity, good hydrophilicity, excellent compatibility and excellent heat resistance, which make it widely used in biomedicine, personal care, industrial coatings, polymer modification and other fields. For example, hydroxypropyl silicone oil is used in the preparation of contact lenses, corrective lenses, intraocular implants, etc. because of its non-toxicity, hydrophilicity and physiological inertness, which meets the requirements of biomedical materials. Hydroxypropyl silicone oil is used as an emollient, conditioner and protective barrier in personal care products, such as shampoo, conditioner, skin cream and lotion formulations, because it can give the product a silky smooth feeling and improve spreadability and absorbency. In the coatings industry, hydroxypropyl silicone oil is used as a matrix for functional silicone coatings such as heat-resistant, radiation-resistant, insulating and light-curing, and is also often used to improve the leveling and defoaming of coatings. Under the action of the catalyst, hydroxypropyl silicone oil can react with the active functional groups in the polymer, such as carboxyl, carbonyl, etc., to achieve the modification of the organic polymer.

[0003] In the existing technology, some raw materials or low molecular weight components often remain in the end-hydrogenated silicone oil during the synthesis process. These residues may cause oil precipitation during use, affecting the stability and application effect of the product. In view of the above problems, the existing technology urgently needs a new preparation process to solve the problems of hydroxypropyl silicone oil in low molecular weight precipitation and poor heat resistance. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a low-viscosity hydroxypropyl silicone oil and a preparation method thereof. The hydroxypropyl silicone oil prepared by the method has the characteristics of narrow molecular weight distribution, no metal catalyst residue, etc., is green and environmentally friendly, and is more suitable for industrial production.

[0005] In order to better solve the above problems, the present invention adopts the following technical solutions:

[0006] A method for preparing low-viscosity hydroxypropyl silicone oil comprises the following steps:

[0007] (1) stirring and mixing ethylene glycol monoallyl ether and a catalyst to uniformly obtain a mixture of ethylene glycol monoallyl ether and the catalyst;

[0008] (2) adding silicone oil into the reactor, then dripping the mixture of ethylene glycol monoallyl ether and the catalyst into the reactor, and keeping the temperature to react after the dripping is completed. After the reaction is completed, a reaction solution is obtained;

[0009] (3) adding activated carbon to the reaction solution for adsorption, filtering, and subjecting the filtrate to reduced pressure distillation to obtain the low-viscosity hydroxypropyl silicone oil.

[0010] As a preferred technical solution, the catalyst is a platinum catalyst.

[0011] As a preferred technical solution, the amount of the catalyst added is 1‰ to 8‰ of the mass of the ethylene glycol monoallyl ether.

[0012] As a preferred technical solution, in step (2), the silicone oil is terminal hydrogen-containing silicone oil with a hydrogen content of 0.10 to 0.15.

[0013] As a preferred technical solution, in step (2), the molar ratio of the ethylene glycol monoallyl ether to the silicone oil is (2-2.5):1.

[0014] As a preferred technical solution, in step (2), the dropwise reaction temperature is 60-90°C.

[0015] As a preferred technical solution, in step (2), the insulation reaction time is 2-5 hours.

[0016] As a preferred technical solution, in step (3), the reduced pressure distillation temperature is 80-110°C.

[0017] As a preferred technical solution, in step (3), the reduced pressure distillation time is 1-3 hours.

[0018] In order to better solve the above technical problems, the present invention also discloses the following technical solutions:

[0019] A low-viscosity hydroxypropyl silicone oil is prepared by any of the methods described above.

[0020] The beneficial effects of the present invention are: by controlling the dripping speed of ethylene glycol monoallyl ether and extending the dripping time, the occurrence of side reactions is effectively reduced, thereby improving the yield of low-viscosity hydroxypropyl silicone oil. By vacuum degassing, unreacted raw materials and low-molecular components are separated from the system to obtain hydroxypropyl silicone oil with a narrow molecular weight distribution. The use of powdered activated carbon to adsorb catalysts and impurities eliminates the influence of platinum catalysts on downstream use, while improving the purity of the product. Due to the improved purity of the product, the heat resistance of hydroxypropyl silicone oil is effectively improved.

[0021] No organic solvents need to be added during the preparation process, and the low-components distilled under reduced pressure are continuously fed back into the reaction without generating wastewater, thus achieving green and environmentally friendly production. Since the step of adding organic solvents is omitted and the recycling of low-components is achieved, the production process is simpler. The prepared hydroxypropyl silicone oil has excellent performance, good compatibility, and is suitable for a variety of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The hydroxypropyl silicone oil TGA of Examples 1-6 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in combination with specific descriptions and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] In order to overcome the deficiencies of the prior art, the present invention provides a low-viscosity hydroxypropyl silicone oil and a preparation method thereof. The method can reduce or eliminate the residue of low molecular weight components, improve the stability and application performance of the product, and can also reduce or eliminate platinum residues, reduce the negative impact on the performance of downstream products, and is more environmentally friendly, meeting increasingly stringent environmental protection requirements. By improving the preparation process, the performance of hydroxypropyl silicone oil can be further improved, its application range in various fields can be broadened, and the market demand for high-performance organosilicon materials can be met.

[0025] The technical solution of the present application includes: a method for preparing low-viscosity hydroxypropyl silicone oil, comprising the following steps:

[0026] (1) stirring and mixing ethylene glycol monoallyl ether and a catalyst to uniformly obtain a mixture of ethylene glycol monoallyl ether and the catalyst;

[0027] (2) adding silicone oil into the reactor, then dripping the mixture of ethylene glycol monoallyl ether and the catalyst into the reactor, and keeping the temperature to react after the dripping is completed. After the reaction is completed, a reaction solution is obtained;

[0028] (3) adding activated carbon to the reaction solution for adsorption, filtering, and subjecting the filtrate to reduced pressure distillation to obtain the low-viscosity hydroxypropyl silicone oil.

[0029] As a preferred technical solution, the ethylene glycol monoallyl ether has a content of ≥99.5% and a water content of ≤100 PPM.

[0030] As a preferred technical solution, the catalyst is a platinum catalyst.

[0031] As a preferred technical solution, the amount of the catalyst added is 1‰ to 8‰ of the mass of the ethylene glycol monoallyl ether.

[0032] As a preferred technical solution, in step (2), the silicone oil is terminal hydrogen-containing silicone oil with a hydrogen content of 0.10 to 0.15.

[0033] As a preferred technical solution, in step (2), the molar ratio of the ethylene glycol monoallyl ether to the silicone oil is (2-2.5):1.

[0034] As a preferred technical solution, in step (2), the dropwise reaction temperature is 60-90°C.

[0035] As a preferred technical solution, in step (2), the dropping time is 5-8 hours.

[0036] As a preferred technical solution, in step (2), the insulation reaction time is 2-5 hours.

[0037] As a preferred technical solution, in step (3), the reduced pressure distillation temperature is 80-110°C.

[0038] As a preferred technical solution, in step (3), the reduced pressure distillation time is 1-3 hours.

[0039] As a preferred technical solution, in step (3), the activated carbon is powdered activated carbon with an iodine value of >1000 Mg / g.

[0040] In order to better solve the above technical problems, the present invention also discloses the following technical solutions:

[0041] A low-viscosity hydroxypropyl silicone oil is prepared by any of the methods described above.

[0042] The technical solution of the present application effectively reduces the occurrence of side reactions by controlling the dripping speed of ethylene glycol monoallyl ether and extending the dripping time, thereby improving the yield of low-viscosity hydroxypropyl silicone oil. By vacuum stripping, unreacted raw materials and low-molecular components are separated from the system to obtain hydroxypropyl silicone oil with a narrow molecular weight distribution. The use of powdered activated carbon to adsorb catalysts and impurities eliminates the impact of platinum catalysts on downstream use and improves the purity of the product. Due to the improved purity of the product, the heat resistance of hydroxypropyl silicone oil has been effectively improved.

[0043] No organic solvents need to be added during the preparation process, and the low-components distilled under reduced pressure are continuously fed back into the reaction without generating wastewater, thus achieving green and environmentally friendly production. Since the step of adding organic solvents is omitted and the recycling of low-components is achieved, the production process is simpler. The prepared hydroxypropyl silicone oil has excellent performance, good compatibility, and is suitable for a variety of application scenarios.

[0044] The technical solution of the present application is further described below in conjunction with the embodiments:

[0045] Unless otherwise specified, the raw materials in the following examples and comparative examples were purchased from commercial sources.

[0046] Example 1

[0047] (1) Add 196 g of ethylene glycol monoallyl ether and 0.2 g of platinum catalyst into a mixer, stir and mix well, and set aside.

[0048] (2) In a reactor equipped with a stirring blade, a thermometer, and a condenser, add 1600g of terminal hydrogenated silicone oil with a hydrogen content of 0.12, start stirring and heat to 60°C, then drop a mixture of ethylene glycol monoallyl ether and a platinum catalyst into the reactor, keep dropping at 60°C, and control the dropping time to be 5 hours. After the dropwise addition is completed, keep the temperature at 60°C for 2 hours. After the insulation is completed, add 8g of powdered activated carbon and adsorb for 2 hours. After the adsorption is completed, filter. The filtrate is heated to 90°C and distilled under reduced pressure to remove low molecular components to obtain the low-viscosity hydroxypropyl silicone oil.

[0049] Example 2

[0050] (1) Add 254.8 g of ethylene glycol monoallyl ether and 0.26 g of platinum catalyst into a mixer, stir and mix well, and set aside.

[0051] (2) In a reactor equipped with a stirring blade, a thermometer, and a condenser, add 2080g of terminal hydrogenated silicone oil with a hydrogen content of 0.12, start stirring and heat to 70°C, then drop a mixture of ethylene glycol monoallyl ether and a platinum catalyst into the reactor, keep dropping at 70°C, and control the dropping time to be 5 hours. After the dropwise addition is completed, keep the temperature at 70°C for 2 hours. After the insulation is completed, add 10.4g of powdered activated carbon and adsorb for 2 hours. After the adsorption is completed, filter. The filtrate is heated to 90°C and distilled under reduced pressure to remove low molecular components to obtain the low-viscosity hydroxypropyl silicone oil.

[0052] Example 3

[0053] (1) Add 220.5 g of ethylene glycol monoallyl ether and 1.35 g of platinum catalyst into a mixer, stir and mix well, and set aside.

[0054] (2) In a reactor equipped with a stirring blade, a thermometer, and a condenser, add 1633.5g of terminal hydrogenated silicone oil with a hydrogen content of 0.12, start stirring and heat to 70°C, then drop a mixture of ethylene glycol monoallyl ether and a platinum catalyst into the reactor, keep dropping at 70°C, and control the dropping time to be 5 hours. After the dropwise addition is completed, keep the temperature at 70°C for 2 hours. After the insulation is completed, add 9g of powdered activated carbon and adsorb for 2 hours. After the adsorption is completed, filter. The filtrate is heated to 90°C and distilled under reduced pressure to remove low molecular components to obtain the low-viscosity hydroxypropyl silicone oil.

[0055] Example 4

[0056] (1) Add 264.6 g of ethylene glycol monoallyl ether and 1.08 g of platinum catalyst into a mixer, stir and mix well, and set aside.

[0057] (2) In a reactor equipped with a stirring blade, a thermometer, and a condenser, add 1960.2g of terminal hydrogenated silicone oil with a hydrogen content of 0.12, start stirring and heat to 80°C, then drop a mixture of ethylene glycol monoallyl ether and a platinum catalyst into the reactor, keep dropping at 80°C, and control the dropping time to be 5 hours. After the dropwise addition is completed, keep the temperature at 80°C for 2 hours. After the insulation is completed, add 16.2g of powdered activated carbon and adsorb for 2 hours. After the adsorption is completed, filter. The filtrate is heated to 90°C and distilled under reduced pressure to remove low molecular components to obtain the low-viscosity hydroxypropyl silicone oil.

[0058] Example 5

[0059] (1) Add 171.5 g of ethylene glycol monoallyl ether and 0.875 g of platinum catalyst into a mixer, stir and mix well, and set aside.

[0060] (2) In a reactor equipped with a stirring blade, a thermometer, and a condenser, add 1330g of terminal hydrogenated silicone oil with a hydrogen content of 0.12, start stirring and heat to 60°C, then drop a mixture of ethylene glycol monoallyl ether and a platinum catalyst into the reactor, keep dropping at 60°C, and control the dropping time to be 5 hours. After the dropwise addition is completed, keep the temperature at 60°C for 2 hours. After the insulation is completed, add 10.5g of powdered activated carbon and adsorb for 2 hours. After the adsorption is completed, filter. The filtrate is heated to 90°C and distilled under reduced pressure to remove low molecular components to obtain the low-viscosity hydroxypropyl silicone oil.

[0061] Example 6

[0062] (1) Add 284.2 g of ethylene glycol monoallyl ether and 1.45 g of platinum catalyst into a mixer, stir and mix well, and set aside.

[0063] (2) In a reactor equipped with a stirring blade, a thermometer, and a condenser, add 2204g of terminal hydrogenated silicone oil with a hydrogen content of 0.12, start stirring and heat to 90°C, then drop a mixture of ethylene glycol monoallyl ether and a platinum catalyst into the reactor, keep dropping at 90°C, and control the dropping time to be 5 hours. After the dropwise addition is completed, keep the temperature at 90°C for 2 hours. After the insulation is completed, add 11.6g of powdered activated carbon and adsorb for 2 hours. After the adsorption is completed, filter. The filtrate is heated to 90°C and distilled under reduced pressure to remove low molecular components to obtain the low-viscosity hydroxypropyl silicone oil.

[0064] Comparative Example 1

[0065] (1) Add 245 g of ethylene glycol monoallyl ether and 1.25 g of platinum catalyst into a mixer, stir and mix well, and set aside.

[0066] (2) In a reactor equipped with a stirring blade, a thermometer, and a condenser, add 1900g of terminal hydrogenated silicone oil with a hydrogen content of 0.12, start stirring and heat to 90°C, then drop a mixture of ethylene glycol monoallyl ether and a platinum catalyst into the reactor, keep dropping at 90°C, and control the dropping time to be 5 hours. After the dropwise addition is completed, keep the temperature at 90°C for 2 hours. After the insulation is completed, add 10g of powdered activated carbon and adsorb for 2 hours. After the adsorption is completed, filter. The low-viscosity hydroxypropyl silicone oil is obtained.

[0067] Comparative Example 2

[0068] (1) Add 264.6 g of ethylene glycol monoallyl ether and 10.8 g of platinum catalyst into a mixer, stir and mix well, and set aside.

[0069] (2) In a reactor equipped with a stirring blade, a thermometer, and a condenser, add 1960.2g of terminal hydrogenated silicone oil with a hydrogen content of 0.12, start stirring and heat to 80°C, then drop a mixture of ethylene glycol monoallyl ether and a platinum catalyst into the reactor, keep dropping at 80°C, and control the dropping time to be 5 hours. After the dropwise addition is completed, keep the temperature at 80°C for 2 hours, and filter after the insulation is completed. The filtrate is heated to 90°C, and distilled under reduced pressure to remove low molecular components to obtain the low-viscosity hydroxypropyl silicone oil.

[0070] The viscosity of the hydroxypropyl silicone oil sample prepared above was tested according to GB / T 265 standard, the appearance was visually inspected, and the volatile matter was tested according to GB / T 28610-2012 standard. The results are shown in Table 1:

[0071] Table 1

[0072] Serial number Appearance Viscosity Volatile Matter Remark Example 1 Colorless clear liquid 51.25 0.11 Example 2 Colorless clear liquid 50.77 0.10 Example 3 Colorless clear liquid 51.02 0.12 Example 4 Colorless clear liquid 51.43 0.13 Example 5 Colorless clear liquid 50.98 0.11 Example 6 Colorless clear liquid 50.67 0.13 Comparative Example 1 Colorless, turbid liquid 47.89 0.32 Comparative Example 2 Light yellow, transparent liquid 50.32 0.12

[0073] It can be seen from the test results in Table 1 that the hydroxypropyl silicone oil prepared by the present invention is a colorless, clear and transparent liquid after desorption and adsorption, while the comparative examples are turbid and light yellow liquids, respectively, and the volatile matter of the comparative example that has not been desorbed is relatively high.

[0074] The hydroxypropyl silicone oil sample prepared above was subjected to a thermal gravimetric test (TGA) under the conditions of nitrogen, 20-700°C, and a heating rate of 20°C / min. The results are shown in Table 2. The test curve is shown in Figure 1 As shown:

[0075] Table 2

[0076]

[0077]

[0078] It can be seen from the test data in Table 2 that the hydroxypropyl silicone oil prepared by the present invention, after degassing, has a 1% weight loss temperature increased from 140°C to 230°C, and a 5% weight loss temperature increased from 258°C to 320°C, and the TGA heat resistance is greatly improved. The improvement of heat resistance effectively improves the yellowing and coking of the material.

[0079] Application Examples

[0080] The hydroxypropyl silicone oils prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were applied to a polypropylene resin system, and the formula was as shown in Table 3. PP140 was used;

[0081] Table 3

[0082] raw material 1# 2# 3# 4# 5# 6# 7# 8# Polypropylene PP140 85 85 85 85 85 85 85 85 Example 1 5 Example 2 5 Example 3 5 Example 4 5 Example 5 5 Example 6 5 Comparative Example 1 5 Comparative Example 2 5 talcum powder 10 10 10 10 10 10 10 10

[0083] The above-mentioned polypropylene PP140 powder, talcum powder and hydroxypropyl silicone oil were mixed in a high-speed mixer for 2 minutes, and the speed of the high-speed mixer was 500 rpm; the mixed raw materials were melt extruded and granulated by a twin-screw extruder with an aspect ratio of 42:1, and the process parameters were: 160°C in zone 1, 180°C in zone 2, 190°C in zone 3, 200°C in zones 4-11, head temperature 200°C, screw speed 400r / min, feeding frequency 20-25Hz, melt pressure 4.0MPa, vacuum degree -0.06MPa. After extrusion granulation, the particles were dried in an oven at 80°C for 4h. Finally, the particles were injection molded into standard test specimens on an injection molding machine.

[0084] The tensile strength is tested according to ASTM D-638. The bending strength is tested according to ASTM D-790. The cantilever beam notched impact strength is tested according to ASTM D-256. The scratch resistance test is tested according to PV3952, with a load of 10N. The scratch resistance is evaluated by measuring the ΔL value (i.e. the change mark of black and white color) on the surface of the scratched sample. The smaller the ΔL value, the better the scratch resistance of the material.

[0085] The performance of the material was compared and evaluated by testing the tensile strength, flexural strength, IZOD notched impact strength, and scratch resistance. The performance test results are shown in Table 4:

[0086] Table 4

[0087]

[0088] It can be seen from Table 4 that the hydroxypropyl silicone oil prepared by the present invention in the polypropylene / talc system has no obvious decline in tensile strength and flexural strength compared with the control group, while the IZOD notched impact strength of the experimental group system is significantly improved compared with the control group, wherein the IZOD notched impact strength is improved by about 15%. Compared with the control group, the effect of the experimental group is more obvious. The reason for this is that since a large amount of low-molecular substances exist in the hydroxypropyl silicone oil that has not been de-thawed, it is easy to migrate to the surface of the PP material, thereby affecting the impact strength of the material; the catalyst platinum remains in the hydroxypropyl silicone oil, and it is easy to undergo a grafting reaction with the components in the material during the application process, resulting in a decrease in impact strength. In the scratch resistance test, hydroxypropyl silicone oil in the polypropylene / talc system has a tendency to migrate to the surface of the material; if low-molecular hydroxypropyl silicone oil is used, the silicone oil is likely to migrate to the surface of the material in large quantities, resulting in poor scratch resistance of the material; in the present invention, after the hydroxypropyl silicone oil after de-lowering treatment migrates to the surface, it is not easy to precipitate and can be stored on the surface of the material for a long time, thereby maintaining good scratch resistance.

[0089] Although particular embodiments of the present invention have been described, many other forms and modifications of the present invention will be apparent to those skilled in the art. It is to be understood that the appended claims and this invention generally cover all such obvious forms and modifications within the true spirit and scope of the present invention.

[0090] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing low-viscosity hydroxypropyl silicone oil, characterized in that: The following steps are involved: (1) stirring and mixing ethylene glycol monoallyl ether and a catalyst to uniformly obtain a mixture of ethylene glycol monoallyl ether and the catalyst; (2) adding silicone oil into the reactor, then dripping the mixture of ethylene glycol monoallyl ether and the catalyst into the reactor, and keeping the temperature to react after the dripping is completed. After the reaction is completed, a reaction solution is obtained; (3) adding activated carbon to the reaction solution for adsorption, filtering, and subjecting the filtrate to reduced pressure distillation to obtain the low-viscosity hydroxypropyl silicone oil.

2. The method for preparing low-viscosity hydroxypropyl silicone oil according to claim 1, characterized in that: The catalyst is a platinum catalyst.

3. The method for preparing low-viscosity hydroxypropyl silicone oil according to claim 1, characterized in that: The added amount of the catalyst is 1‰ to 8‰ of the mass of the ethylene glycol monoallyl ether.

4. The method for preparing low-viscosity hydroxypropyl silicone oil according to claim 1, characterized in that: In step (2), the silicone oil is terminal hydrogen-containing silicone oil, and the hydrogen content is 0.10 to 0.

15.

5. The method for preparing low-viscosity hydroxypropyl silicone oil according to claim 1, characterized in that: In step (2), the molar ratio of the ethylene glycol monoallyl ether to the silicone oil is (2-2.5):

1.

6. The method for preparing low-viscosity hydroxypropyl silicone oil according to claim 1, characterized in that: In step (2), the dropwise reaction temperature is 60-90°C.

7. The method for preparing low-viscosity hydroxypropyl silicone oil according to claim 1, characterized in that: In step (2), the insulation reaction time is 2-5 hours.

8. The method for preparing low-viscosity hydroxypropyl silicone oil according to claim 1, characterized in that: In step (3), the reduced pressure distillation temperature is 80-110°C.

9. The method for preparing low-viscosity hydroxypropyl silicone oil according to claim 1, characterized in that: In step (3), the reduced pressure distillation time is 1-3 hours.

10. A low viscosity hydroxypropyl silicone oil, characterized in that: Prepared by the method described in any one of claims 1 to 9.

Images