CN-117702127-B - Cleaning liquid for stainless steel equipment for producing G4-level solvent and application of cleaning liquid

Abstract

The invention relates to a cleaning solution for stainless steel equipment, in particular to a cleaning solution for stainless steel equipment for producing a G4-level solvent. According to the technical scheme, the cleaning solution for the stainless steel equipment for producing the G4-level solvent is prepared by only mixing four common acids such as acetic acid, oxalic acid, nitric acid and phosphoric acid with deionized water according to a certain proportion. The cleaning solution for the stainless steel equipment for producing the G4-level solvent provided by the invention is used for cleaning the equipment before the stainless steel equipment is used, and the soluble metal ions can be fully dissolved in advance in the cleaning process, so that excessive metal ions are not separated out (the metal ion separating amount is controlled to be less than 100 ppt) in the process of producing, processing, storing and using the solvent of the cleaned stainless steel equipment, the metal ions of the product are ensured to meet the requirements, and the G4 level is reached. The cleaning liquid for the stainless steel equipment for producing the G4-grade solvent can greatly improve the production efficiency and quality and reduce the production cost and energy consumption.

Inventors

• CUI WENTAO
• LIN QIUYU
• SHEN JUN

Assignees

• 福建钰融科技有限公司

Dates

Publication Date

20260505

Application Date

20231213

Claims (6)

1. 1. A cleaning solution for a stainless steel apparatus for producing G4 grade solvent, comprising, in mass percent: acetic acid 0.5% to 3.0%; oxalic acid 0.5% to 3.0%; nitric acid 0.5% to 5.0%; phosphoric acid 1.0% to 3.0%; the balance of deionized water.
2. 2. The method for preparing a cleaning liquid for a stainless steel apparatus for producing a G4 grade solvent according to claim 1, comprising the steps of: Acetic acid 0.5 to 3.0%, oxalic acid 0.5 to 3.0%, nitric acid 0.5 to 5.0% and phosphoric acid 1.0 to 3.0% are added to deionized water based on the total mass percentage of the cleaning solution of the stainless steel apparatus for producing the G4 grade solvent.
3. 3. A method of cleaning a stainless steel apparatus for producing a G4 grade solvent according to claim 1, comprising the steps of: filling the stainless steel equipment with the cleaning solution for producing the G4-grade solvent, standing the cleaning solution for producing the G4-grade solvent in the stainless steel equipment, and fully infiltrating the cleaning solution with the stainless steel equipment to obtain a first cleaning solution; And (3) detecting metal ions and judging whether to continue cleaning, if the metal ion content of the first washing liquid is more than 2000ppt, replacing the cleaning liquid of the stainless steel equipment for producing the G4-level solvent, and then, carrying out the first cleaning again, if the metal ion content of the first washing liquid is 1000 ppt-2000 ppt, continuing to stand for 3-5h, marking the cleaning liquid in the stainless steel equipment as the first cleaning liquid, if the metal ion content of the first cleaning liquid exceeds the metal ion content of the first washing liquid by more than or equal to 5%, repeating the second cleaning, and if the metal ion content of the first cleaning liquid exceeds the metal ion content of the first washing liquid by less than 5%, finishing the cleaning.
4. 4. A method according to claim 3, wherein the stainless steel apparatus comprises a stainless steel rectification apparatus, a stainless steel storage tank and a stainless steel transport tank.
5. 5. The method according to claim 4, wherein, when the stainless steel apparatus is a stainless steel rectifying apparatus, the cleaning liquid of the stainless steel apparatus for producing the G4 grade solvent is filled in the stainless steel rectifying apparatus set in the first cleaning, and circulated using a circulation pump.
6. 6. The method of claim 5, wherein the circulating is performed for 3-5 hours using a circulating pump.

Description

Cleaning liquid for stainless steel equipment for producing G4-level solvent and application of cleaning liquid Technical Field The invention relates to a cleaning solution for stainless steel equipment, in particular to a cleaning solution for stainless steel equipment for producing a G4-level solvent. Background The G4-grade solvent is an organic solvent with high purity and low evaporation rate, has the characteristics of low volatility, low toxicity, low corrosiveness and the like, and is widely applied to the fields of precision cleaning, surface treatment, electronic chemicals and the like. The specific composition of the G4 grade solvent may vary from manufacturer to manufacturer and from application to application, but is typically a mixture comprising a plurality of organic compounds. These compounds may include alcohols, ketones, esters, aromatics, etc., but they all have a relatively high boiling point and a relatively low vapor pressure. The G4 class solvent can be used for precision cleaning and surface treatment to remove oxides, grease and other contaminants from metal surfaces to ensure quality and performance of electronic components and semiconductors, and thus, the G4 class solvent plays an important role in the electronics and semiconductor manufacturing industries. The semiconductor industry has extremely high requirements on metal ions, and the concentration of the metal ions in a common solvent generally needs to reach ppt level, so that the equipment for producing the solvent is required to have extremely low metal ion and impurity particle leaching amounts during processing, storage and use. Semiconductors often require the use of large amounts of organic solvents for cleaning, as well as particularly high requirements for the metal ions of these organic solvents, typically to the ppt level. However, some organic solvents used for semiconductors have high boiling points and large usage amounts, such as PMA, NMP and the like, and the rectification process needs steam heating and negative pressure and high temperature. Fluoroplastic equipment cannot meet the strength requirement, can fall off or deform at high temperature, and can only be used as equipment with smaller volume. Stainless steel equipment has proper strength, but the stainless steel equipment inevitably has metal ions dissolved in the rectification process, however, the existing cleaning liquid often cannot effectively dissolve the soluble metal ions in advance, so that excessive metal ions still precipitate in the production process of the cleaned stainless steel equipment, the product cannot meet the requirement of semiconductor chemicals on G4 solvents, and the product quality is affected. Disclosure of Invention In view of the above problems, the present application provides a cleaning liquid for a stainless steel apparatus for producing a G4 grade solvent and a method of cleaning a stainless steel apparatus in order to sufficiently clean the stainless steel distillation apparatus to a clean state, so that the stainless steel distillation apparatus does not precipitate metal ions or the precipitated metal ions are small, less than 100ppt, and do not adversely affect the quality of the produced G4 grade solvent product when the solvent distillation operation is performed. To achieve the above object, the present inventors have provided a cleaning liquid for stainless steel equipment for producing a G4 grade solvent, comprising, in mass percent: acetic acid 0.0% to 6.0%; oxalic acid 0.0% to 6.0%; nitric acid 0.0% to 6.0%; phosphoric acid 0.0% to 6.0%; the balance of deionized water. The cleaning liquid provided by the invention comprises acetic acid, oxalic acid, nitric acid and phosphoric acid, and can be subjected to chemical reaction with metal ions under a certain proportioning condition, so that the soluble metal ions can be effectively dissolved. Specifically, acetic acid, oxalic acid, nitric acid and phosphoric acid have acidity and can react with metal ions, and the chemical reactions can promote the dissolution of the metal ions, so that the content of the metal ions in the stainless steel equipment after cleaning is reduced. In addition, deionized water with larger content ratio in the cleaning liquid can not chemically react with metal ions, but can play a role in dilution, so that the concentration of the cleaning liquid is more uniform, and the dissolution of the metal ions is better promoted. Therefore, the cleaning liquid can effectively dissolve the soluble metal ions in advance, reduce the content of the metal ions in the stainless steel equipment after cleaning, and improve the quality and efficiency in the production process. Preferably, the cleaning liquid of the stainless steel equipment for producing the G4 grade solvent comprises the following components in percentage by mass: acetic acid 0.0% to 3.0%; oxalic acid 0.0% to 3.0%; nitric acid 0.5% to 5.0%; Phosphoric acid 0.0% to 3.0%; the balance o