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CN-122011768-A - High-temperature-resistant silica gel for gas phase sample inlet spacer and preparation method and application thereof

CN122011768ACN 122011768 ACN122011768 ACN 122011768ACN-122011768-A

Abstract

The invention discloses high-temperature-resistant silica gel for a gas-phase sample inlet spacer and a preparation method and application thereof, and relates to the technical field of gas-phase sample inlet spacer preparation. The low-phenyl silicone rubber comprises 100 parts of low-phenyl silicone rubber, 40-60 parts of filler, 0.6-0.8 part of vulcanizing agent, 1-3 parts of processing aid, 0.5-0.7 part of coupling agent, 0.5-1 part of stabilizer and 3-6 parts of colorant, wherein the filler comprises fumed silica, and the processing aid comprises hydroxyl silicone oil. The gas-phase gasket prepared by the silica gel has excellent high temperature resistance, does not break after being baked at high temperature, maintains the Shore hardness within a reasonable range along with the rise of the temperature, can resist the high temperature of 380-400 ℃, and has excellent sealing property.

Inventors

  • ZHU JIANFENG
  • Tian hengsheng
  • CHEN MENGFEI

Assignees

  • 浙江欧尔赛斯科技有限公司

Dates

Publication Date
20260512
Application Date
20260126

Claims (10)

  1. 1. The silica gel for the high-temperature-resistant gas phase sample inlet spacer is characterized by comprising, by weight, 100 parts of low-phenyl silicone rubber, 40-60 parts of filler, 0.6-0.8 part of vulcanizing agent, 1-3 parts of processing aid, 0.5-0.7 part of coupling agent, 0.5-1 part of stabilizer and 3-6 parts of colorant; wherein the filler comprises fumed silica, and the processing aid comprises hydroxyl silicone oil.
  2. 2. The silica gel for a high temperature resistant gasinlet gasket of claim 1, wherein said vulcanizing agent comprises a bis-di-penta vulcanizing agent.
  3. 3. The silica gel for a high temperature resistant gas phase injection port gasket of claim 1 wherein said coupling agent comprises a titanate.
  4. 4. The silica gel for a high temperature resistant gas phase inlet spacer of claim 1, wherein the stabilizer comprises cerium oxide.
  5. 5. The silica gel for a high temperature resistant gas phase injection port spacer of claim 1, wherein the colorant comprises an inorganic toner, and the inorganic toner comprises at least one of iron oxide red, chrome green, and ultramarine.
  6. 6. The silica gel for a high-temperature-resistant gas-phase sample inlet spacer according to any one of claims 1 to 5, wherein the content of phenyl groups in the low-phenyl silicone rubber is 5% -15%.
  7. 7. The preparation method of the silica gel for the high-temperature-resistant gas phase sample inlet spacer is characterized by comprising the following steps of: Weighing the components according to the component proportion of the silica gel for the high-temperature-resistant gas-phase sample inlet spacer according to any one of claims 1-6; Mixing the low-phenyl silicone rubber, the filler, the vulcanizing agent, the processing aid, the coupling agent, the stabilizer and the colorant to obtain a mixture; and vulcanizing the mixture for three times to obtain the target silica gel.
  8. 8. The method for preparing silica gel for high temperature resistant gas phase injection port spacers as claimed in claim 7, wherein the step of mixing the low phenyl silicone rubber, filler, vulcanizing agent, processing aid, coupling agent, stabilizer, and colorant is performed at a stirring speed of 10rpm-20 rpm.
  9. 9. The method for preparing silica gel for high-temperature-resistant gas-phase sample inlet spacer according to claim 7, wherein the three-time vulcanization is carried out under 20-21Mpa and 180-185 ℃ for 5-8min, then under 0.08-0.09kPa and 150-155 ℃ for 2-2.5h, and finally under 220-230 ℃ for 6-7h.
  10. 10. The use of a silica gel for a high temperature resistant gas inlet spacer according to any one of claims 1 to 6 for the preparation of a gas inlet spacer.

Description

High-temperature-resistant silica gel for gas phase sample inlet spacer and preparation method and application thereof Technical Field The invention relates to the technical field of preparation of gas phase sample inlet spacers, in particular to high-temperature-resistant silica gel for a gas phase sample inlet spacer, and a preparation method and application thereof. Background The sample injection spacer is a key element arranged at a sample injection port in a gas chromatograph, is generally made of a silicon rubber material with high temperature resistance and excellent air tightness, can resist higher temperature and still has good air tightness after sample injection puncture is carried out for a plurality of times. However, the traditional silica gel material has poor high temperature resistance, and the gasket prepared from the silica gel material has high hardness after being baked at high temperature, is easy to crack and cannot maintain the normal shape. Accordingly, the conventional technology is in need of improvement. Disclosure of Invention The invention aims to provide silica gel for a high-temperature-resistant gas-phase sample inlet spacer, application of the silica gel and a preparation method of the spacer, which are used for overcoming the defect that the prepared spacer is easy to crack and cannot maintain normal morphology after being baked at high temperature. The invention provides high-temperature-resistant silica gel for a gas phase sample inlet spacer, which comprises, by weight, 100 parts of low-phenyl silicone rubber, 40-60 parts of a filler, 0.6-0.8 part of a vulcanizing agent, 1-3 parts of a processing aid, 0.5-0.7 part of a coupling agent, 0.5-1 part of a stabilizer and 3-6 parts of a colorant, wherein the filler comprises gas phase white carbon black, and the processing aid comprises hydroxyl silicone oil. Further, the vulcanizing agent comprises a bis-di-pentavulcanizing agent. Further, the coupling agent includes a titanate. Further, the stabilizer includes cerium oxide. Further, the colorant comprises inorganic toner, and the inorganic toner comprises at least one of iron oxide red, chrome green and ultramarine. Further, the content of phenyl groups in the low-phenyl silicone rubber is 5% -15%. In a second aspect, the invention provides a preparation method of silica gel for a high-temperature-resistant gas phase sample inlet spacer, which comprises the following steps: weighing the components according to the component proportion of the silica gel for the high-temperature-resistant gas phase sample inlet spacer; Mixing the low-phenyl silicone rubber, the filler, the vulcanizing agent, the processing aid, the coupling agent, the stabilizer and the colorant to obtain a mixture; and vulcanizing the mixture for three times to obtain the target silica gel. Further, the step of mixing the low-phenyl silicone rubber, the filler, the vulcanizing agent, the processing aid, the coupling agent, the stabilizer, and the colorant is performed at a stirring speed of 10rpm to 20 rpm. Further, the three-time vulcanization is carried out for 5-8min under 20-21Mpa and 180-185 ℃, then for 2-2.5h under 0.08-0.09kPa and 150-155 ℃, and finally for 6-7h under 220-230 ℃. In a third aspect, the invention provides an application of silica gel for a high-temperature-resistant gas-phase sample inlet spacer in preparing the gas-phase sample inlet spacer. In summary, the technical effects achieved by the invention are as follows: Vinyl silicone rubber in the prior art is extremely easy to thermally decompose at high temperature to generate powdery silica fume. In order to improve the heat resistance of silicone rubber, the inventors have introduced a group capable of improving the heat resistance, that is, benzene ring, by changing the molecular structure of silicone rubber, and further used low-phenyl silicone rubber as a main raw material. Reactive Oxygen Species (ROS) such as superoxide radicals (. O 2-), hydroxyl radicals (. OH) and the like are generated when the silica gel is exposed to high temperature conditions. These radicals attack the Si-O-Si backbone and the organic side chains (e.g., methyl groups) of the silica gel, causing the molecular chains to break, thereby yellowing, tackiness, embrittling (i.e., aging) the silica gel. Cerium oxide nanoparticles can rapidly capture and neutralize these free radicals, converting them into harmless substances, interrupting the chain reaction leading to aging. The gas phase method white carbon black has higher specific surface area and porous structure, can effectively absorb heat and inhibit heat conduction, and can effectively improve the stability of the material in a high-temperature environment. Therefore, the precipitation method white carbon black is not used any more, and all the white carbon black is changed into the gas phase method white carbon black. In addition, hydroxyl silicone oil in the formula forms a cross-linking bond through re