Method for directly preparing 107 glue at low temperature by using organic silicon hydrolysis material

Abstract

The invention belongs to the field of organic silicon, and relates to a preparation method of room temperature vulcanized silicone rubber (107 rubber for short), in particular to a method for directly preparing the 107 rubber at low temperature by utilizing an organic silicon hydrolysis material. The method comprises the following steps: carrying out vacuum devolatilization on an organic silicon hydrolysis material; breaking the vacuum after the vacuum devolatilization is finished, adding a catalyst, and uniformly stirring; then carrying out a reaction under a vacuum condition; after the reaction is finished, vacuum is broken, an acid solution is added for neutralization, and then secondary vacuum low-temperature removal is performed to obtain the 107 glue. According to the preparation method provided by the invention, temperature parameters under a vacuum condition are accurately regulated and controlled, a line body and a ring body do not need to be separated, preparation is directly carried out, the ring body is fully converted, and the utilization rate of raw materials and the yield of 107 glue are improved; according to the method, vacuum temperature control is adopted, so that the raw materials can be subjected to polymerization reaction at the temperature of 130 DEG C or below, and a large amount of energy consumption is reduced; meanwhile, side reactions can be effectively inhibited, generation of impurities is reduced, the prepared 107 glue is excellent in performance, the stability of the product is improved, and remarkable industrial application value is achieved.

Description

Technical Field

[0001] This invention belongs to the field of organosilicon and relates to a method for preparing room temperature vulcanizing silicone rubber (referred to as 107 rubber), specifically a method for directly preparing 107 rubber at low temperature using organosilicon hydrolysate. Background Technology

[0002] Organosilicon hydrolysate refers to a mixture of linear and cyclic oligomeric siloxanes obtained through the hydrolysis of organochlorosilanes. The ratio of linear to cyclic oligomeric siloxanes is approximately 0.55-0.6:0.4-0.45. Industrial organosilicon hydrolysate generally contains a certain amount of moisture and other impurities. Organosilicon hydrolysate is a core intermediate in the organosilicon industry, and its important role lies in being the basic raw material for the production of almost all bulk organosilicon products.

[0003] Currently, there are two main ways to utilize organosilicon hydrolysate: one is to pyrolyze the hydrolysate to prepare DMC, and then use the DMC to prepare products such as 107 glue; the other is to separate linear and cyclic oligomeric siloxanes through a linear-ring separation system, then use the linear material to prepare 107 glue, and use the separated cyclic material to prepare 110 glue or other products.

[0004] Existing methods for processing organosilicon hydrolysate significantly increase the production cycle and cost of 107 adhesive, and the reaction temperatures are all above 150℃, requiring a large amount of energy to provide heat. Summary of the Invention

[0005] To overcome the above problems, this invention provides a method for directly preparing 107 glue using organosilicon hydrolysate through temperature-controlled and reduced-pressure polymerization. The raw materials can react at temperatures below 130°C, resulting in milder reaction conditions, reduced production costs, increased safety, and a 107 glue yield of >90%.

[0006] To achieve the above technical objectives, the present invention adopts the following technical solution: This invention provides a method for directly preparing 107 adhesive at low temperature using organosilicon hydrolysate, comprising the following steps: (1) Vacuum descaling of the organosilicon hydrolysate; (2) After the vacuum de-lowering is completed, the vacuum is broken, the catalyst is added and stirred evenly; then the reaction is carried out under vacuum conditions; (3) After the reaction is complete, the vacuum is broken, an acidic solution is added for neutralization, and then a second vacuum is performed to remove the 107 gel.

[0007] Preferably, in step (1), the organosilicon hydrolysate is composed of 55-60% linear material and 40-45% cyclic material; the vacuum descaling is carried out under reduced pressure distillation for 30-40 minutes at 90-120°C and a vacuum degree of -0.09 MPa.

[0008] Preferably, in step (2), the catalyst is a potassium hydroxide alcohol solution with a mass fraction of 0.75% (the alcohol solvent includes, but is not limited to, methanol, ethanol, etc.); 17.5-18 ppm of catalyst (calculated based on the amount of KOH) is added to every 750g of organosilicon hydrolysate; and the stirring time is 15-20min.

[0009] The preferred solvent for the potassium hydroxide alcohol solution is ethanol.

[0010] Preferably, in step (2), the reaction is carried out under a vacuum of -0.09 MPa, with the heating rate controlled at 5°C / 15 min, and the temperature is raised to 125-140°C for 10-60 min.

[0011] Preferably, in step (3), the acidic solution is a phosphoric acid solution with a mass fraction of 0.9%; 21 ppm of phosphoric acid is added to every 750g of organosilicon hydrolysate.

[0012] Preferably, in step (3), the secondary vacuum de-lowering is to raise the temperature to 170-180℃, maintain the vacuum degree at -0.075Mpa, and de-lower the vacuum for 1h.

[0013] Compared with the prior art, the advantages of this invention are: (1) The present invention utilizes cheaper organosilicon hydrolysate to directly prepare 107 glue without pretreatment, thereby reducing the production cycle and cost of 107 glue.

[0014] (2) The preparation method provided by the present invention can directly prepare the filament and the ring by precisely controlling the temperature parameters under vacuum conditions without separating the filament and the ring. The ring is fully converted, which improves the utilization rate of raw materials and the yield of 107 glue. (3) The present invention adopts vacuum temperature control, which enables the raw materials to polymerize at temperatures below 130°C, thus reducing a large amount of energy consumption. At the same time, it can effectively suppress the occurrence of side reactions and reduce the generation of impurities, resulting in the excellent performance of the prepared 107 glue, improving the stability of the product, and having significant industrial application value.

[0015] (4) The present invention uses potassium hydroxide alcohol solution as catalyst. Compared with traditional potassium hydroxide aqueous solution, the interaction between OH⁻ and solvent is weakened, and the "basic activity" (nucleophilic attack) is enhanced, making the cyclic transformation in the hydrolysate more thorough, further improving the raw material utilization rate and the yield of 107 glue, and making it easier to remove. Detailed Implementation

[0016] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0017] The organosilicon hydrolysate provided by this invention is mainly composed of 55%-60% linear material and 40%-45% cyclic material. It is clear and transparent in appearance and has no odor.

[0018] The method for determining the surface curing time of the 107 adhesive prepared in this invention is as follows: Weigh about 50g of sample into a glass petri dish, add 3% dibutyltin dilaurate and 6% tetraethyl orthosilicate (by sample mass), mix evenly, and place in an environment with a temperature of (23±2)℃ and a relative humidity of 60%~70%. Use a glass rod to lightly touch the surface of the adhesive from time to time, starting from the beginning of mixing the adhesive until no adhesive sticks to the glass rod.

[0019] In the following examples and comparative examples, the mass ratio of the organosilicon hydrolysate used was: linear: cyclic = 0.55: 0.45.

[0020] Example 1 Take 750g of organosilicon hydrolysate and put it into a vacuum distillation apparatus. After heating the apparatus to 100℃, adjust the vacuum degree to -0.09Mpa and dehydrate the hydrolysate for 30min.

[0021] After vacuum degradation is completed, the vacuum is broken, and then 17.5 ppm of catalyst (calculated as KOH) is added in the form of a 0.75% potassium hydroxide ethanol solution. Stirring is continued for 15 min to ensure that the catalyst and organosilicon hydrolysate are fully mixed. Then, maintain the vacuum at -0.09 MPa again, control the heating rate at 5℃ / 15min, and heat to 125℃ and hold for 13min.

[0022] After the reaction was completed, the vacuum was removed, and then 21 ppm of phosphoric acid was added in the form of a 0.9% phosphoric acid aqueous solution. The mixture was stirred for 30 minutes to neutralize the phosphoric acid with the catalyst in the material and to adjust the colloidal viscosity.

[0023] The system was heated to 180℃ and the vacuum degree was maintained at -0.08Mpa for 1 hour to obtain 107 glue. The yield of 107 glue was greater than 90%, the viscosity was 46484mPa.s, the surface curing time was 16min, and it was clear, transparent and free of impurities, with good quality.

[0024] Example 2 Take 750g of organosilicon hydrolysate and put it into a vacuum distillation apparatus. After heating the apparatus to 100℃, adjust the vacuum degree to -0.09Mpa and dehydrate the hydrolysate for 30min.

[0025] After vacuum degradation is completed, the vacuum is broken, and then 17.5 ppm KOH is added in the form of a 0.75% potassium hydroxide ethanol solution. Stirring is continued for 15 minutes to ensure that the catalyst and organosilicon hydrolysate are fully mixed.

[0026] Then, maintain the vacuum at -0.09 MPa again, control the heating rate at 5℃ / 15min, and heat to 130℃ and hold for 10min.

[0027] After the reaction was completed, the vacuum was removed, and then 21 ppm of phosphoric acid was added in the form of a 0.9% phosphoric acid aqueous solution. The mixture was stirred for 30 minutes to neutralize the phosphoric acid with the catalyst in the material and to adjust the colloidal viscosity.

[0028] The system was heated to 180℃ and the vacuum degree was maintained at -0.08Mpa for 1 hour to obtain 107 glue. The yield of 107 glue was greater than 90%, the viscosity was 63344mPa.s, the surface curing time was 15min, and it was clear, transparent and free of impurities, with good quality.

[0029] Example 3 Take 750g of organosilicon hydrolysate and put it into a vacuum distillation apparatus. After heating the apparatus to 100℃, adjust the vacuum degree to -0.09Mpa and dehydrate the hydrolysate for 30min.

[0030] After vacuum degradation is completed, the vacuum is broken, and then 17.5 ppm KOH is added in the form of a 0.75% potassium hydroxide ethanol solution. Stirring is continued for 15 minutes to ensure that the catalyst and organosilicon hydrolysate are fully mixed.

[0031] Then, maintain the vacuum at -0.09 MPa again, control the heating rate at 5-10℃ / 15min, and heat to 140℃ and hold for 27min.

[0032] After the reaction was completed, the vacuum was removed, and then 21 ppm of phosphoric acid was added in the form of a 0.9% phosphoric acid aqueous solution. The mixture was stirred for 30 minutes to neutralize the phosphoric acid with the catalyst in the material and to adjust the colloidal viscosity.

[0033] The system was heated to 180℃ and the vacuum degree was maintained at -0.08Mpa for 1 hour to obtain 107 glue. The yield of 107 glue was greater than 90%, the viscosity was 143544mPa.s, the surface curing time was 14min, and it was clear, transparent and free of impurities, with good quality.

[0034] Comparative Example 1 Take 750g of organosilicon hydrolysate and put it into a vacuum distillation apparatus. After heating the apparatus to 100℃, adjust the vacuum degree to -0.09Mpa and dehydrate the hydrolysate for 30min.

[0035] After vacuum degradation is completed, the vacuum is broken, and then 17.5 ppm KOH is added in the form of a 0.75% potassium hydroxide ethanol solution. Stirring is continued for 15 minutes to ensure that the catalyst and organosilicon hydrolysate are fully mixed. Then control the heating rate at 5℃ / 15min, and heat to 125℃ and hold for 13min.

[0036] After the reaction was completed, 21 ppm of phosphoric acid was added in the form of a 0.9% phosphoric acid aqueous solution, and stirring was continued for 30 min to neutralize the phosphoric acid with the catalyst in the material.

[0037] The system was heated to 180℃ and the vacuum degree was maintained at -0.08Mpa for 1 hour to obtain the final product. The product had no viscosity and could not be used to prepare 107 glue.

[0038] Comparative Example 2 Take 750g of organosilicon hydrolysate and put it into a vacuum distillation apparatus. After heating the apparatus to 100℃, adjust the vacuum degree to -0.09Mpa and dehydrate the hydrolysate for 30min.

[0039] After vacuum degradation is completed, the vacuum is broken, and then 17.5 ppm KOH is added in the form of a 0.75% potassium hydroxide ethanol solution. Stirring is continued for 15 minutes to ensure that the catalyst and organosilicon hydrolysate are fully mixed. Then, maintain the vacuum at -0.09 MPa again, control the heating rate at 5℃ / 10min, and heat to 125℃ and hold for 13min.

[0040] After the reaction was completed, the vacuum was removed, and then 21 ppm of phosphoric acid was added in the form of a 0.9% phosphoric acid aqueous solution. The mixture was stirred for 30 minutes to neutralize the phosphoric acid with the catalyst in the material and to adjust the colloidal viscosity.

[0041] The system was heated to 180℃ and the vacuum degree was maintained at -0.08Mpa for 1 hour to obtain 107 glue. The yield of 107 glue was 50%, the viscosity was 46484mPa.s, the surface curing time was 16min, and it was clear, transparent and free of impurities, with good quality.

[0042] Comparative Example 3 Take 750g of organosilicon hydrolysate and put it into a vacuum distillation apparatus. After heating the apparatus to 100℃, adjust the vacuum degree to -0.09Mpa and dehydrate the hydrolysate for 30min.

[0043] After vacuum degradation is completed, the vacuum is broken, and then 17.5 ppm KOH is added in the form of a 0.75% potassium hydroxide ethanol solution. Stirring is continued for 15 minutes to ensure that the catalyst and organosilicon hydrolysate are fully mixed. Then, maintain the vacuum at -0.09 MPa again, control the heating rate at 5℃ / 15min, and heat to 145℃ and hold for 13min.

[0044] After the reaction was completed, the vacuum was removed, and then 21 ppm of phosphoric acid was added in the form of a 0.9% phosphoric acid aqueous solution. The mixture was stirred for 30 minutes to neutralize the phosphoric acid with the catalyst in the material and to adjust the colloidal viscosity.

[0045] When the reaction temperature is 145℃ or higher, it is difficult to control the target viscosity of the prepared 107 adhesive.

[0046] Comparative Example 4 Take 750g of organosilicon hydrolysate and put it into a vacuum distillation apparatus. After heating the apparatus to 100℃, adjust the vacuum degree to -0.09Mpa and dehydrate the hydrolysate for 30min.

[0047] After vacuum descaling is completed, the vacuum is broken, and then 17.5 ppm of catalyst (calculated as KOH) is added in the form of a 0.75% potassium hydroxide aqueous solution. Stirring is continued for 15 min to ensure that the catalyst and the organosilicon hydrolysate are fully mixed. Then, maintain the vacuum at -0.09 MPa again, control the heating rate at 5℃ / 15min, and heat to 125℃ and hold for 13min.

[0048] After the reaction was completed, the vacuum was removed, and then 21 ppm of phosphoric acid was added in the form of a 0.9% phosphoric acid aqueous solution. The mixture was stirred for 30 minutes to neutralize the phosphoric acid with the catalyst in the material and to adjust the colloidal viscosity.

[0049] The system was heated to 180℃ and the vacuum degree was maintained at -0.08Mpa for 1 hour to obtain 107 glue. The yield of 107 glue was 83%, the viscosity was 42367mPa.s, the surface curing time was 16min, and it was clear, transparent and free of impurities, with good quality.

Claims

1. A method for directly preparing 107 adhesive at low temperature using organosilicon hydrolysate, characterized in that, Includes the following steps: (1) Vacuum descaling of the organosilicon hydrolysate; (2) After the vacuum de-lowering is completed, the vacuum is broken, the catalyst is added and stirred evenly; then the reaction is carried out under vacuum conditions; (3) After the reaction is complete, the vacuum is broken, an acidic solution is added for neutralization, and then a second vacuum is performed to remove the 107 gel.

2. The method according to claim 1, characterized in that, In step (1), the organosilicon hydrolysate is composed of 55-60% linear material and 40-45% cyclic material; the vacuum descaling is carried out under reduced pressure distillation for 30-40 minutes at 90-120℃ and a vacuum degree of -0.09Mpa.

3. The method according to claim 1 or 2, characterized in that, In step (2), the catalyst is a potassium hydroxide alcohol solution with a mass fraction of 0.75%; 17.5-18 ppm of catalyst is added to every 750g of organosilicon hydrolysate, calculated based on the amount of KOH; the stirring time is 15-20min.

4. The method according to claim 3, characterized in that, In the potassium hydroxide alcohol solution, the alcohol solvent includes, but is not limited to, methanol and ethanol.

5. The method according to claim 1, 3, or 4, characterized in that, In step (2), the reaction is carried out under a vacuum of -0.09 MPa, with the heating rate controlled at 5℃ / 15min, and the temperature is raised to 125-140℃ for 10-60min.

6. The method according to claim 1, characterized in that, In step (3), the acidic solution is a phosphoric acid solution with a mass fraction of 0.9%; 21 ppm of phosphoric acid is added to every 750g of organosilicon hydrolysate.

7. The method according to claim 1 or 6, characterized in that, In step (3), the secondary vacuum de-lowering involves heating to 170-180℃, maintaining a vacuum level of -0.075Mpa, and vacuum de-lowering for 1 hour.