Liquid silicone rubber based on silicone oil mixing and preparation method thereof
Preparing modified inhibitors through esterification solves the problem of early curing of inhibitors in liquid silicone rubber that is prone to volatilization, achieves the effect of extending storage time and improving product stability, and provides versatile benefits.
Patent Information
- Application Number
- CN202510014873.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-06
- Publication Date
- 2025-03-28
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Alkynol inhibitors commonly used in existing liquid silicone rubbers are easily volatile, causing liquid silicone rubber to cure early, affecting storage time and product quality.
Using modification inhibitors, 2-methyl-3-butyne-2-ol and white erucic acid are prepared in a specific proportion of esterification, increasing molecular weight and reducing volatility, while improving compatibility in the silicone system through polar groups.
It extends the storage and use time of liquid silicone rubber, improves its stability and mass consistency, reduces surface defects and mechanical strength losses caused by volatility, and provides multifunctional effects such as antioxidant and antibacterial.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of silicone rubber, and in particular to a liquid silicone rubber based on silicone oil mixing and a preparation method thereof. Background Art
[0002] Liquid silicone rubber, also known as two-component addition silicone rubber, is a type of organic silicone relative to mixed semi-solid silicone rubber and common room temperature vulcanized single-component silicone. It has good fluidity, fast vulcanization speed, castability and injection molding, and has been widely used in many fields. Liquid silicone rubber is mainly divided into two categories: self-adhesive and non-self-adhesive, and can be made into varieties with different viscosities, different curing speeds, different colors and different mechanical strengths according to needs. In addition, it can also be cured at room temperature or high temperature, and high temperature curing can complete the curing process within seconds. These properties enable it to easily cope with the production of molds with complex shapes and fine structures, and it has an irreplaceable position in many industries.
[0003] In order to ensure that liquid silicone rubber has a certain storage time, inhibitors are usually used to extend its service life. However, although commonly used acetylene alcohol inhibitors have good inhibitory effects, they have small molecular weights and are easy to volatilize, causing the inhibitors to fail, prompting the liquid silicone rubber to cure prematurely and resulting in product scrapping. In view of this, we propose a liquid silicone rubber based on silicone oil mixing and a preparation method thereof. Summary of the invention
[0004] The object of the present invention is to provide a liquid silicone rubber based on silicone oil mixing and a preparation method thereof, so as to solve the problems raised in the above background technology.
[0005] To achieve the above object, the present invention provides a liquid silicone rubber based on silicone oil mixing, comprising the following components: 0.5-0.7 parts by weight of a modified inhibitor, 67-75 parts by weight of vinyl-terminated polydimethylsiloxane, 11-13 parts by weight of vinyl silicone oil, 12-18 parts by weight of hydrogen-containing silicone oil, 0.1-0.5 parts by weight of a Karstedt catalyst, 10-15 parts by weight of fumed silica, 0.1-0.3 parts by weight of 2,6-di-tert-butyl-p-cresol, 0.6-1.4 parts by weight of titanium dioxide, 3-7 parts by weight of polydimethylsiloxane and 0.07-0.09 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:5-7.
[0006] Preferably, the preparation method of the modified inhibitor is as follows: 2-Methyl-3-butyn-2-ol and erucic acid are added to a round-bottom flask equipped with a magnetic stirrer, added to a mixed solvent of toluene and ethanol, stirred and heated to 60-70°C to completely dissolve the reactants, p-toluenesulfonic acid is added to the reaction mixture, and the reaction mixture is heated to a reflux temperature of 110-120°C under magnetic stirring, and maintained at reflux for 4-6 hours. After the reaction is completed, it is naturally cooled to room temperature, poured into a separatory funnel, and the reaction mixture is washed with a saturated sodium bicarbonate solution, and the separatory funnel is shaken to fully mix the organic phase and the aqueous phase, and the layers are allowed to stand for separation, and the organic phase is separated, and anhydrous sodium sulfate is added and stirred for 5-10 minutes, and the reaction mixture is allowed to stand for precipitation and then filtered to obtain a modified inhibitor.
[0007] 2-Methyl-3-butyn-2-ol is a commonly used inhibitor for liquid silicone rubber, but it has a small molecular weight, is extremely volatile and highly toxic, and has poor compatibility with the silicone system, which can easily cause the storage stability of the rubber to be greatly reduced, so it needs to be modified.
[0008] Erucic acid is a compound widely distributed in the plant kingdom, existing in spices, fruits, vegetables, grains and oil crops. The carboxyl group (-COOH) of erucic acid can undergo esterification reaction with the hydroxyl group (-OH) of 2-methyl-3-butyn-2-ol to generate esters, and ester compounds can reduce the acute toxicity of 2-methyl-3-butyn-2-ol. At the same time, erucic acid can interact with 2-methyl-3-butyn-2-ol through hydrogen bonds or other non-covalent interactions, further reducing its toxicity and significantly improving the safety of products made of liquid silicone rubber. In addition, the molecular weight of 2-methyl-3-butyn-2-ol after esterification increases, which effectively improves the problem of its volatility due to its small molecular weight, and can avoid surface defects and mechanical strength loss of products caused by volatiles, thereby improving production efficiency and product quality. In addition, erucic acid also contains polar groups such as hydroxyl groups, which can increase the polarity of 2-methyl-3-butyne-2-ol and effectively improve its compatibility in the silicone system through hydrogen bonds or van der Waals forces, thereby promoting the stable existence of 2-methyl-3-butyne-2-ol in the silicone system, which is beneficial to improving the quality consistency of the final product. On the one hand, it can further reduce the volatility of 2-methyl-3-butyne-2-ol, and on the other hand, it can promote the stability of the silicone system and prevent the occurrence of phase separation. In addition, compared with other chemical reagent modifications, erucic acid is a natural component, and phenolic hydroxyl groups can neutralize harmful oxygen free radicals in the human body, so it has good antioxidant, antibacterial, anti-inflammatory, anti-anxiety and environmental friendliness. Introducing erucic acid into liquid silicone rubber can achieve green environmental protection while providing multifunctional effects.
[0009] Preferably, in the mixed solvent of toluene and ethanol, the volume ratio of toluene to ethanol is 8:2-4.
[0010] Preferably, the added amount of p-toluenesulfonic acid is 1.8-2.2% of the mass of erucic acid.
[0011] Preferably, the added amount of the saturated sodium bicarbonate solution accounts for 8-13% of the mass of the mixed solvent of toluene and ethanol.
[0012] Preferably, the anhydrous sodium sulfate accounts for 1-5% of the mass of the mixed solvent of toluene and ethanol.
[0013] On the other hand, the present invention provides a method for preparing liquid silicone rubber based on silicone oil mixing, which is used for any one of the liquid silicone rubber based on silicone oil mixing described above, comprising the following steps: The vinyl-terminated polydimethylsiloxane, vinyl silicone oil, fumed silica, 2,6-di-tert-butyl-p-cresol, titanium dioxide and polydimethylsiloxane are fully dispersed by a three-roll mill, and then placed in a vacuum degassing device to remove air bubbles, and the degassed mixture is sealed and stored to obtain component A; the hydrogen-containing silicone oil and the Karstedt catalyst are uniformly mixed under the action of a stirrer at a low speed of 400-700RPM, and then the modified inhibitor is added to the mixture, and stirring is continued until it is completely dispersed, and finally dibutyltin dilaurate is added and stirred for 5-10 minutes, and the stirring speed is increased to 1000-2000RPM, and the high-speed stirring time is 10-15 minutes, and then the mixed components are placed in a vacuum degassing device to remove air bubbles, and sealed and stored to obtain component B; the liquid silicone rubber based on silicone oil mixing is prepared from component A and component B.
[0014] Preferably, the hydrogen content of the hydrogen-containing silicone oil is 2-3%.
[0015] Preferably, the vinyl content of the vinyl silicone oil is 0.01-0.1% by mass.
[0016] Preferably, in the liquid silicone rubber based on silicone oil mixing, the mixing mass ratio of component A to component B is 10:1-5.
[0017] Compared with the prior art, the present invention has the following beneficial effects: In the liquid silicone rubber based on silicone oil mixing and the preparation method thereof, a modified inhibitor prepared by 2-methyl-3-butyne-2-ol and erucic acid is used to esterify 2-methyl-3-butyne-2-ol, thereby reducing the toxicity of 2-methyl-3-butyne-2-ol and expanding its application scope. The molecular weight of 2-methyl-3-butyne-2-ol is increased by erucic acid, its volatility is reduced, and the inhibitory effect of 2-methyl-3-butyne-2-ol is improved, thereby extending the storage and use time of the liquid silicone rubber. The introduced polar groups can form hydrogen bonds and van der Waals forces, thereby increasing the interaction between molecules and improving the compatibility of 2-methyl-3-butyne-2-ol in the liquid silicone rubber system, thereby increasing the consistency of the liquid silicone rubber system and ensuring the stability of the liquid silicone rubber. In addition, compared with the modification of other chemical reagents, the use of the natural component erucic acid not only has good environmental friendliness, but also provides multifunctional effects. DETAILED DESCRIPTION
[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0019] The liquid silicone rubber based on silicone oil mixing of the present invention comprises the following components: 0.5-0.7 parts by weight of a modified inhibitor, 67-75 parts by weight of vinyl-terminated polydimethylsiloxane, 11-13 parts by weight of vinyl silicone oil, 12-18 parts by weight of hydrogen-containing silicone oil, 0.1-0.5 parts by weight of a Karstedt catalyst, 10-15 parts by weight of fumed silica, 0.1-0.3 parts by weight of 2,6-di-tert-butyl-p-cresol, 0.6-1.4 parts by weight of titanium dioxide, 3-7 parts by weight of polydimethylsiloxane and 0.07-0.09 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:5-7.
[0020] Embodiment 1: A liquid silicone rubber based on silicone oil mixing and a preparation method thereof, comprising the following steps: Prepare components: 0.7 parts by weight of modified inhibitor, 75 parts by weight of vinyl-terminated polydimethylsiloxane, 13 parts by weight of vinyl silicone oil, 18 parts by weight of hydrogen-containing silicone oil, 0.5 parts by weight of Karstedt catalyst, 15 parts by weight of fumed silica, 0.3 parts by weight of 2,6-di-tert-butyl-p-cresol, 1.4 parts by weight of titanium dioxide, 7 parts by weight of polydimethylsiloxane, and 0.09 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:5; in a mixed solvent of toluene and ethanol, the volume ratio of toluene to ethanol is 8:4; the amount of p-toluenesulfonic acid added is 2.2% of the mass of erucic acid; the amount of saturated sodium bicarbonate solution added is 13% of the mass of the mixed solvent of toluene and ethanol; anhydrous sodium sulfate is 5% of the mass of the mixed solvent of toluene and ethanol; the hydrogen content of hydrogen-containing silicone oil is 3%; the mass percentage of vinyl in vinyl silicone oil is 0.1%; in the liquid silicone rubber based on silicone oil mixing, the mixing mass ratio of component A and component B is 10:5; 2-Methyl-3-butyn-2-ol and erucic acid were added to a round-bottom flask equipped with a magnetic stirrer, and then added to a mixed solvent of toluene and ethanol, stirred and heated to 70°C to completely dissolve the reactants, and p-toluenesulfonic acid was added to the reaction mixture. Under magnetic stirring, the reaction mixture was heated to a reflux temperature of 120°C and kept in a reflux state for 4 hours. After the reaction was completed, it was naturally cooled to room temperature, and the reaction mixture was poured into a separatory funnel. The reaction mixture was washed with a saturated sodium bicarbonate solution, and the separatory funnel was shaken to fully mix the organic phase and the aqueous phase, and the mixture was allowed to stand for stratification, and the organic phase was separated, and then anhydrous sodium sulfate was added and stirred for 5 minutes, and the mixture was allowed to stand for precipitation and then filtered to obtain a modified inhibitor; The vinyl-terminated polydimethylsiloxane, vinyl silicone oil, fumed silica, 2,6-di-tert-butyl-p-cresol, titanium dioxide and polydimethylsiloxane are fully dispersed by a three-roll mill, and then placed in a vacuum degassing device to remove air bubbles by vacuuming, and the degassed mixture is sealed and stored to obtain component A; the hydrogen-containing silicone oil and the Karstedt catalyst are mixed evenly under the action of a stirrer at a low speed of 500RPM, and then the modified inhibitor is added to the mixture, and stirring is continued until it is completely dispersed, and finally dibutyltin dilaurate is added and stirred for 10 minutes, and the stirring speed is increased to 2000RPM, and the high-speed stirring time is 15 minutes, and then the mixed components are placed in a vacuum degassing device to remove air bubbles, and sealed and stored to obtain component B; the liquid silicone rubber based on silicone oil mixing is prepared from components A and B.
[0021] Embodiment 2: A liquid silicone rubber based on silicone oil mixing and a preparation method thereof, comprising the following steps: Prepare components: 0.7 parts by weight of modified inhibitor, 75 parts by weight of vinyl-terminated polydimethylsiloxane, 13 parts by weight of vinyl silicone oil, 18 parts by weight of hydrogen-containing silicone oil, 0.5 parts by weight of Karstedt catalyst, 15 parts by weight of fumed silica, 0.3 parts by weight of 2,6-di-tert-butyl-p-cresol, 1.4 parts by weight of titanium dioxide, 7 parts by weight of polydimethylsiloxane, and 0.09 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:6; in a mixed solvent of toluene and ethanol, the volume ratio of toluene to ethanol is 8:4; the amount of p-toluenesulfonic acid added is 2.2% of the mass of erucic acid; the amount of saturated sodium bicarbonate solution added is 13% of the mass of the mixed solvent of toluene and ethanol; anhydrous sodium sulfate is 5% of the mass of the mixed solvent of toluene and ethanol; the hydrogen content of hydrogen-containing silicone oil is 3%; the mass percentage of vinyl in vinyl silicone oil is 0.1%; in the liquid silicone rubber based on silicone oil mixing, the mixing mass ratio of component A and component B is 10:5; 2-Methyl-3-butyn-2-ol and erucic acid were added to a round-bottom flask equipped with a magnetic stirrer, and then added to a mixed solvent of toluene and ethanol, stirred and heated to 70°C to completely dissolve the reactants, and p-toluenesulfonic acid was added to the reaction mixture. Under magnetic stirring, the reaction mixture was heated to a reflux temperature of 120°C and kept in a reflux state for 4 hours. After the reaction was completed, it was naturally cooled to room temperature, and the reaction mixture was poured into a separatory funnel. The reaction mixture was washed with a saturated sodium bicarbonate solution, and the separatory funnel was shaken to fully mix the organic phase and the aqueous phase, and the mixture was allowed to stand for stratification, and the organic phase was separated, and then anhydrous sodium sulfate was added and stirred for 5 minutes, and the mixture was allowed to stand for precipitation and then filtered to obtain a modified inhibitor; The vinyl-terminated polydimethylsiloxane, vinyl silicone oil, fumed silica, 2,6-di-tert-butyl-p-cresol, titanium dioxide and polydimethylsiloxane are fully dispersed by a three-roll mill, and then placed in a vacuum degassing device to remove air bubbles by vacuuming, and the degassed mixture is sealed and stored to obtain component A; the hydrogen-containing silicone oil and the Karstedt catalyst are mixed evenly under the action of a stirrer at a low speed of 500RPM, and then the modified inhibitor is added to the mixture, and stirring is continued until it is completely dispersed, and finally dibutyltin dilaurate is added and stirred for 10 minutes, and the stirring speed is increased to 2000RPM, and the high-speed stirring time is 15 minutes, and then the mixed components are placed in a vacuum degassing device to remove air bubbles, and sealed and stored to obtain component B; the liquid silicone rubber based on silicone oil mixing is prepared from components A and B.
[0022] Embodiment 3: A liquid silicone rubber based on silicone oil mixing and a preparation method thereof, comprising the following steps: Prepare components: 0.7 parts by weight of modified inhibitor, 75 parts by weight of vinyl-terminated polydimethylsiloxane, 13 parts by weight of vinyl silicone oil, 18 parts by weight of hydrogen-containing silicone oil, 0.5 parts by weight of Karstedt catalyst, 15 parts by weight of fumed silica, 0.3 parts by weight of 2,6-di-tert-butyl-p-cresol, 1.4 parts by weight of titanium dioxide, 7 parts by weight of polydimethylsiloxane, and 0.09 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:7; in a mixed solvent of toluene and ethanol, the volume ratio of toluene to ethanol is 8:4; the amount of p-toluenesulfonic acid added is 2.2% of the mass of erucic acid; the amount of saturated sodium bicarbonate solution added is 13% of the mass of the mixed solvent of toluene and ethanol; anhydrous sodium sulfate is 5% of the mass of the mixed solvent of toluene and ethanol; the hydrogen content of hydrogen-containing silicone oil is 3%; the mass percentage of vinyl in vinyl silicone oil is 0.1%; in the liquid silicone rubber based on silicone oil mixing, the mixing mass ratio of component A and component B is 10:5; 2-Methyl-3-butyn-2-ol and erucic acid were added to a round-bottom flask equipped with a magnetic stirrer, and then added to a mixed solvent of toluene and ethanol, stirred and heated to 70°C to completely dissolve the reactants, and p-toluenesulfonic acid was added to the reaction mixture. Under magnetic stirring, the reaction mixture was heated to a reflux temperature of 120°C and kept in a reflux state for 4 hours. After the reaction was completed, it was naturally cooled to room temperature, and the reaction mixture was poured into a separatory funnel. The reaction mixture was washed with a saturated sodium bicarbonate solution, and the separatory funnel was shaken to fully mix the organic phase and the aqueous phase, and the mixture was allowed to stand for stratification, and the organic phase was separated, and then anhydrous sodium sulfate was added and stirred for 5 minutes, and the mixture was allowed to stand for precipitation and then filtered to obtain a modified inhibitor; The vinyl-terminated polydimethylsiloxane, vinyl silicone oil, fumed silica, 2,6-di-tert-butyl-p-cresol, titanium dioxide and polydimethylsiloxane are fully dispersed by a three-roll mill, and then placed in a vacuum degassing device to remove air bubbles, and the degassed mixture is sealed and stored to obtain component A; the hydrogen-containing silicone oil and the Karstedt catalyst are mixed evenly under the action of a stirrer at a low speed of 500RPM, and then the modified inhibitor is added to the mixture, and stirring is continued until it is completely dispersed, and finally dibutyltin dilaurate is added and stirred for 10 minutes, the stirring speed is increased to 2000RPM, and the high-speed stirring time is 15 minutes, and then the mixed components are placed in a vacuum degassing device to remove air bubbles, and sealed and stored to obtain component B; the liquid silicone rubber based on silicone oil mixing is prepared from component A and component B Embodiment 4: A liquid silicone rubber based on silicone oil mixing and a preparation method thereof, comprising the following steps: Prepare components: 0.7 parts by weight of modified inhibitor, 67 parts by weight of vinyl-terminated polydimethylsiloxane, 11 parts by weight of vinyl silicone oil, 12 parts by weight of hydrogen-containing silicone oil, 0.1 parts by weight of Karstedt catalyst, 10 parts by weight of fumed silica, 0.1 parts by weight of 2,6-di-tert-butyl-p-cresol, 0.6 parts by weight of titanium dioxide, 3 parts by weight of polydimethylsiloxane, and 0.07 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:7; in a mixed solvent of toluene and ethanol, the volume ratio of toluene to ethanol is 8:4; the amount of p-toluenesulfonic acid added is 2.2% of the mass of erucic acid; the amount of saturated sodium bicarbonate solution added is 13% of the mass of the mixed solvent of toluene and ethanol; anhydrous sodium sulfate is 5% of the mass of the mixed solvent of toluene and ethanol; the hydrogen content of hydrogen-containing silicone oil is 3%; the mass percentage of vinyl in vinyl silicone oil is 0.1%; in the liquid silicone rubber based on silicone oil mixing, the mixing mass ratio of component A and component B is 10:5; 2-Methyl-3-butyn-2-ol and erucic acid were added to a round-bottom flask equipped with a magnetic stirrer, and then added to a mixed solvent of toluene and ethanol, stirred and heated to 70°C to completely dissolve the reactants, and p-toluenesulfonic acid was added to the reaction mixture. Under magnetic stirring, the reaction mixture was heated to a reflux temperature of 120°C and kept in a reflux state for 4 hours. After the reaction was completed, it was naturally cooled to room temperature, and the reaction mixture was poured into a separatory funnel. The reaction mixture was washed with a saturated sodium bicarbonate solution, and the separatory funnel was shaken to fully mix the organic phase and the aqueous phase, and the mixture was allowed to stand for stratification, and the organic phase was separated, and then anhydrous sodium sulfate was added and stirred for 5 minutes, and the mixture was allowed to stand for precipitation and then filtered to obtain a modified inhibitor; The vinyl-terminated polydimethylsiloxane, vinyl silicone oil, fumed silica, 2,6-di-tert-butyl-p-cresol, titanium dioxide and polydimethylsiloxane are fully dispersed by a three-roll mill, and then placed in a vacuum degassing device to remove air bubbles by vacuuming, and the degassed mixture is sealed and stored to obtain component A; the hydrogen-containing silicone oil and the Karstedt catalyst are mixed evenly under the action of a stirrer at a low speed of 500RPM, and then the modified inhibitor is added to the mixture, and stirring is continued until it is completely dispersed, and finally dibutyltin dilaurate is added and stirred for 10 minutes, and the stirring speed is increased to 2000RPM, and the high-speed stirring time is 15 minutes, and then the mixed components are placed in a vacuum degassing device to remove air bubbles, and sealed and stored to obtain component B; the liquid silicone rubber based on silicone oil mixing is prepared from components A and B.
[0023] Embodiment 5: A liquid silicone rubber based on silicone oil mixing and a preparation method thereof, comprising the following steps: Prepare components: 0.5 parts by weight of modified inhibitor, 75 parts by weight of vinyl-terminated polydimethylsiloxane, 13 parts by weight of vinyl silicone oil, 18 parts by weight of hydrogen-containing silicone oil, 0.5 parts by weight of Karstedt catalyst, 15 parts by weight of fumed silica, 0.3 parts by weight of 2,6-di-tert-butyl-p-cresol, 1.4 parts by weight of titanium dioxide, 7 parts by weight of polydimethylsiloxane, and 0.09 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:7; in a mixed solvent of toluene and ethanol, the volume ratio of toluene to ethanol is 8:4; the amount of p-toluenesulfonic acid added is 2.2% of the mass of erucic acid; the amount of saturated sodium bicarbonate solution added is 13% of the mass of the mixed solvent of toluene and ethanol; anhydrous sodium sulfate is 5% of the mass of the mixed solvent of toluene and ethanol; the hydrogen content of hydrogen-containing silicone oil is 3%; the mass percentage of vinyl in vinyl silicone oil is 0.1%; in the liquid silicone rubber based on silicone oil mixing, the mixing mass ratio of component A and component B is 10:5; 2-Methyl-3-butyn-2-ol and erucic acid were added to a round-bottom flask equipped with a magnetic stirrer, and then added to a mixed solvent of toluene and ethanol, stirred and heated to 70°C to completely dissolve the reactants, and p-toluenesulfonic acid was added to the reaction mixture. Under magnetic stirring, the reaction mixture was heated to a reflux temperature of 120°C and kept in a reflux state for 4 hours. After the reaction was completed, it was naturally cooled to room temperature, and the reaction mixture was poured into a separatory funnel. The reaction mixture was washed with a saturated sodium bicarbonate solution, and the separatory funnel was shaken to fully mix the organic phase and the aqueous phase, and the mixture was allowed to stand for stratification, and the organic phase was separated, and then anhydrous sodium sulfate was added and stirred for 5 minutes, and the mixture was allowed to stand for precipitation and then filtered to obtain a modified inhibitor; The vinyl-terminated polydimethylsiloxane, vinyl silicone oil, fumed silica, 2,6-di-tert-butyl-p-cresol, titanium dioxide and polydimethylsiloxane are fully dispersed by a three-roll mill, and then placed in a vacuum degassing device to remove air bubbles by vacuuming, and the degassed mixture is sealed and stored to obtain component A; the hydrogen-containing silicone oil and the Karstedt catalyst are mixed evenly under the action of a stirrer at a low speed of 500RPM, and then the modified inhibitor is added to the mixture, and stirring is continued until it is completely dispersed, and finally dibutyltin dilaurate is added and stirred for 10 minutes, and the stirring speed is increased to 2000RPM, and the high-speed stirring time is 15 minutes, and then the mixed components are placed in a vacuum degassing device to remove air bubbles, and sealed and stored to obtain component B; the liquid silicone rubber based on silicone oil mixing is prepared from components A and B.
[0024] Embodiment 6: A liquid silicone rubber based on silicone oil mixing and a preparation method thereof, comprising the following steps: Prepare components: 0.6 parts by weight of modified inhibitor, 75 parts by weight of vinyl-terminated polydimethylsiloxane, 13 parts by weight of vinyl silicone oil, 18 parts by weight of hydrogen-containing silicone oil, 0.5 parts by weight of Karstedt catalyst, 15 parts by weight of fumed silica, 0.3 parts by weight of 2,6-di-tert-butyl-p-cresol, 1.4 parts by weight of titanium dioxide, 7 parts by weight of polydimethylsiloxane, and 0.09 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:7; in a mixed solvent of toluene and ethanol, the volume ratio of toluene to ethanol is 8:4; the amount of p-toluenesulfonic acid added is 2.2% of the mass of erucic acid; the amount of saturated sodium bicarbonate solution added is 13% of the mass of the mixed solvent of toluene and ethanol; anhydrous sodium sulfate is 5% of the mass of the mixed solvent of toluene and ethanol; the hydrogen content of hydrogen-containing silicone oil is 3%; the mass percentage of vinyl in vinyl silicone oil is 0.1%; in the liquid silicone rubber based on silicone oil mixing, the mixing mass ratio of component A and component B is 10:5; 2-Methyl-3-butyn-2-ol and erucic acid were added to a round-bottom flask equipped with a magnetic stirrer, and then added to a mixed solvent of toluene and ethanol, stirred and heated to 70°C to completely dissolve the reactants, and p-toluenesulfonic acid was added to the reaction mixture. Under magnetic stirring, the reaction mixture was heated to a reflux temperature of 120°C and kept in a reflux state for 4 hours. After the reaction was completed, it was naturally cooled to room temperature, and the reaction mixture was poured into a separatory funnel. The reaction mixture was washed with a saturated sodium bicarbonate solution, and the separatory funnel was shaken to fully mix the organic phase and the aqueous phase, and the mixture was allowed to stand for stratification, and the organic phase was separated, and then anhydrous sodium sulfate was added and stirred for 5 minutes, and the mixture was allowed to stand for precipitation and then filtered to obtain a modified inhibitor; The vinyl-terminated polydimethylsiloxane, vinyl silicone oil, fumed silica, 2,6-di-tert-butyl-p-cresol, titanium dioxide and polydimethylsiloxane are fully dispersed by a three-roll mill, and then placed in a vacuum degassing device to remove air bubbles by vacuuming, and the degassed mixture is sealed and stored to obtain component A; the hydrogen-containing silicone oil and the Karstedt catalyst are mixed evenly under the action of a stirrer at a low speed of 500RPM, and then the modified inhibitor is added to the mixture, and stirring is continued until it is completely dispersed, and finally dibutyltin dilaurate is added and stirred for 10 minutes, and the stirring speed is increased to 2000RPM, and the high-speed stirring time is 15 minutes, and then the mixed components are placed in a vacuum degassing device to remove air bubbles, and sealed and stored to obtain component B; the liquid silicone rubber based on silicone oil mixing is prepared from components A and B.
[0025] Comparative Example 1: The method of Example 3 was adopted without adding a modification inhibitor.
[0026] Comparative Example 2: The method of Example 3 was adopted, and 2-methyl-3-butyn-2-ol was directly used without modifying 2-methyl-3-butyn-2-ol by erucic acid.
[0027] The present invention adopts the modified inhibitor to prepare the liquid silicone rubber based on silicone oil mixing, wherein the performance index inspection items and inspection standards of the liquid silicone rubber based on silicone oil mixing are as follows: Add component B to component A in a stirrer already filled with component A, wherein component A and component B are mixed in a mass ratio of 10:1, and a low-speed stirrer is used for preliminary mixing at a stirring speed of 500RPM for 10 minutes, then the stirring speed is increased to 3000RPM, and stirring is continued for 15 minutes. The mixed liquid silicone rubber is placed in a vacuum degassing device to remove bubbles generated during the mixing process, and then poured into a mold, and the mold is placed in an oven for curing. The curing time of the liquid silicone rubber at a curing temperature of 80°C is recorded to reflect the inhibitory effect of the inhibitor, and the tensile strength, elongation at break and tear strength of the cured sample are tested to reflect the mechanical performance of the final product and characterize the stability of the liquid silicone rubber system; component B containing the inhibitor is placed in a constant temperature drying oven at 25°C, and the mass change after 24 hours is tested to indirectly react to the volatility of the inhibitor and calculate the mass loss rate.
[0028] According to the above standards, the liquid silicone rubber prepared by the above Examples 1-6 and Comparative Examples 1-2 based on silicone oil mixing was tested, and the obtained data are shown in Table 1: Table 1 Performance data of Examples 1-6 and Comparative Examples 1-2
[0029] The above data fully show that compared with Comparative Examples 1-2, Examples 1-6 can fully show the role of the modified inhibitor in the inhibition effect and stability performance of the liquid silicone rubber based on silicone oil mixing.
[0030] Since the present invention adopts a modified inhibitor to prepare the liquid silicone rubber based on silicone oil mixing, the performance of the liquid silicone rubber based on silicone oil mixing is effectively improved by the modified inhibitor, as follows: It can be seen from Examples 1-3 that with the continuous increase in the proportion of the modified inhibitor component, the inhibitory effect and stability of the liquid silicone rubber are significantly improved, indicating that the inhibitor after esterification can more effectively exert the inhibitory effect. The increase in the proportion of erucic acid also means the presence of more polar groups, which helps to reduce phase separation and maintain the uniformity of the system, thereby improving the overall stability of the liquid silicone rubber. At the same time, the antioxidant properties of erucic acid itself also help to protect the system from oxidative degradation, further improving the long-term stability of the material.
[0031] It can be seen from Examples 3 and 4 that with the continuous change of the content of other components, the inhibitory effect and stability performance of the liquid silicone rubber do not change significantly, indicating that small changes in other components within a certain range are not enough to significantly affect the inhibitory effect and stability performance of the liquid silicone rubber, and therefore there is no obvious change.
[0032] It can be seen from Examples 3, 5 and 6 that the inhibitory effect and stability of the liquid silicone rubber change continuously with the changing content of the modified inhibitor, which indicates that the esterification product obtained by the esterification reaction of 2-methyl-3-butyn-2-ol and erucic acid has low volatility and toxicity, while retaining the inhibitory ability to the Karstedt catalyst. When the proportion of the modified inhibitor increases, it can more effectively control the rate of the platinum-catalyzed addition crosslinking reaction, thereby significantly improving the operating window and storage stability of the liquid silicone rubber. The compound formed after esterification has a large molecular weight and is not easy to volatilize, which reduces the surface defects and mechanical strength loss of the rubber caused by the volatilization of the inhibitor. The polar group improves the dispersibility and compatibility of the inhibitor in the silicone system, maintains the consistency of the system, and enhances the comprehensive performance of the liquid silicone rubber.
[0033] According to the above test experiments, the liquid silicone rubber based on silicone oil mixing prepared according to Example 3 has the best performance, so Example 3 is taken as the best example; By comparing Example 3 with Comparative Examples 1-2, it can be seen that: In Comparative Example 1, no modified inhibitor was added, and the inhibition effect and stabilization performance effect of the liquid silicone rubber were worse. The activity of the Karstedt catalyst in the liquid silicone rubber was not effectively controlled, which promoted the occurrence of the cross-linking reaction, the rubber compound cured quickly, the operating window became narrower, and the reaction was violent, resulting in a large amount of heat and bubbles generated during the reaction, forming defects, affecting its appearance and performance, causing stress concentration inside the silicone rubber matrix, and reducing its mechanical strength.
[0034] Comparative Example 2 uses unmodified 2-methyl-3-butyn-2-ol, and the inhibition effect and stability performance of the liquid silicone rubber are poor. Since 2-methyl-3-butyn-2-ol is highly volatile, this means that its concentration in the rubber will decrease over time, resulting in a weakened inhibition effect, causing the storage stability of the rubber to decrease, and affecting the surface quality of the rubber and the loss of mechanical strength, which cannot meet the requirements of high-quality liquid silicone rubber. It also verifies the positive role of erucic acid in improving the volatility and compatibility of 2-methyl-3-butyn-2-ol, as well as the effect of improving the stability of the liquid silicone rubber system.
[0035] In summary, the inhibitory effect and stability of liquid silicone rubber can be significantly improved by modifying the inhibitor. Erucic acid can reduce the toxicity of 2-methyl-3-butyn-2-ol through esterification reaction and increase the molecular weight of 2-methyl-3-butyn-2-ol, thereby reducing volatility, reducing product surface defects and mechanical strength loss caused by inhibitor volatilization, and improving product safety and the safety of the operating environment. The polar groups of erucic acid can interact with other components in the silicone system through hydrogen bonds or van der Waals forces, enhancing the dispersibility and compatibility of the modified inhibitor in the system, maintaining the uniformity of the rubber, improving storage stability, and reducing problems in the processing process. At the same time, the stability of the modified inhibitor can also effectively extend the operating time, provide a wider operating window, and facilitate processing and molding. In addition, erucic acid itself has antioxidant and antibacterial properties, which also gives the product additional functional advantages.
[0036] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only preferred examples of the present invention, and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.
Claims
1. A liquid silicone rubber based on silicone oil mixing, characterized in that: The invention comprises the following components: 0.5-0.7 parts by weight of a modified inhibitor, 67-75 parts by weight of vinyl-terminated polydimethylsiloxane, 11-13 parts by weight of vinyl silicone oil, 12-18 parts by weight of hydrogen-containing silicone oil, 0.1-0.5 parts by weight of a Karstedt catalyst, 10-15 parts by weight of fumed silica, 0.1-0.3 parts by weight of 2,6-di-tert-butyl-p-cresol, 0.6-1.4 parts by weight of titanium dioxide, 3-7 parts by weight of polydimethylsiloxane and 0.07-0.09 parts by weight of dibutyltin dilaurate; The modified inhibitor is prepared from 2-methyl-3-butyn-2-ol and erucic acid in a mass ratio of 2:5-7.
2. The liquid silicone rubber based on silicone oil mixing according to claim 1, characterized in that: The preparation method of the modified inhibitor is as follows: 2-Methyl-3-butyn-2-ol and erucic acid are added to a round-bottom flask equipped with a magnetic stirrer, added to a mixed solvent of toluene and ethanol, stirred and heated to 60-70°C to completely dissolve the reactants, p-toluenesulfonic acid is added to the reaction mixture, and the reaction mixture is heated to a reflux temperature of 110-120°C under magnetic stirring, and the reflux state is maintained for 4-6 hours. After the reaction is completed, it is naturally cooled to room temperature, poured into a separatory funnel, and the reaction mixture is washed with a saturated sodium bicarbonate solution. The separatory funnel is shaken to fully mix the organic phase and the aqueous phase, and the layers are allowed to stand for separation, and the organic phase is separated, and anhydrous sodium sulfate is added and stirred for 5-10 minutes. After standing for precipitation, it is filtered to obtain a modified inhibitor.
3. The liquid silicone rubber based on silicone oil mixing according to claim 2, characterized in that: In the mixed solvent of toluene and ethanol, the volume ratio of toluene to ethanol is 8:2-4.
4. The liquid silicone rubber based on silicone oil mixing according to claim 2, characterized in that: The added amount of the p-toluenesulfonic acid is 1.8-2.2% of the mass of erucic acid.
5. The liquid silicone rubber based on silicone oil mixing according to claim 2, characterized in that: The added amount of the saturated sodium bicarbonate solution accounts for 8-13% of the mass of the mixed solvent of toluene and ethanol.
6. The liquid silicone rubber based on silicone oil mixing according to claim 2, characterized in that: The anhydrous sodium sulfate accounts for 1-5% of the mass of the mixed solvent of toluene and ethanol.
7. A method for preparing liquid silicone rubber based on silicone oil mixing, used for preparing the liquid silicone rubber based on silicone oil mixing according to any one of claims 1 to 6, characterized in that: The steps include: The vinyl-terminated polydimethylsiloxane, vinyl silicone oil, fumed silica, 2,6-di-tert-butyl-p-cresol, titanium dioxide and polydimethylsiloxane are fully dispersed by a three-roll mill, and then placed in a vacuum degassing device to remove air bubbles, and the degassed mixture is sealed and stored to obtain component A; the hydrogen-containing silicone oil and the Karstedt catalyst are uniformly mixed under the action of a stirrer at a low speed of 400-700RPM, and then the modified inhibitor is added to the mixture, and stirring is continued until it is completely dispersed, and finally dibutyltin dilaurate is added and stirred for 5-10 minutes, and the stirring speed is increased to 1000-2000RPM, and the high-speed stirring time is 10-15 minutes, and then the mixed components are placed in a vacuum degassing device to remove air bubbles, and sealed and stored to obtain component B; the liquid silicone rubber based on silicone oil mixing is prepared from component A and component B.
8. The method for preparing liquid silicone rubber based on silicone oil mixing according to claim 7, characterized in that: The hydrogen content of the hydrogen-containing silicone oil is 2-3%.
9. The method for preparing liquid silicone rubber based on silicone oil mixing according to claim 7, characterized in that: The vinyl silicone oil has a vinyl content of 0.01-0.1% by mass.
10. The method for preparing liquid silicone rubber based on silicone oil mixing according to claim 7, characterized in that: In the liquid silicone rubber mixed with silicone oil, the mixing mass ratio of component A to component B is 10:1-5.