CN1445352A - Cleaning agent for electronics equipments - Google Patents

Abstract

The invention provides a cleaning agent for electronic equipment, which is composed of 50-95% dichloropentafluoropropane and 5-20% _C5 - _C15 alkane mixture (percentage by weight), and 0-20% Trifluoroethanol, 0-10% alcohol ether, and 0-10% chlorinated olefin form a solvent-based cleaning agent. The cleaning agent for electronic equipment has low ozone depletion potential and has moderate solubility and volatilization rate, and is suitable for cleaning electronic equipment, especially for cleaning electronic equipment in a running state or a charged state.

Description

A cleaning agent for electronic equipment

Technical field

The invention relates to a composition, in particular to a solvent composition for cleaning electronic equipment.

Background technique

With the rapid development of the output of electronics, electrical machinery, precision machinery, resin processing and precision optics, cleaning agents with excellent performance have also been widely used. The solvents mainly used for cleaning are chemical substances such as 1,1,2-trifluorotrichloroethane (hereinafter referred to as CFC-113), 1,1,1-trichloroethane and carbon tetrachloride, but such artificial The synthetic "chlorofluorocarbons" have been proved by research to cause the decomposition and disappearance of ozone in the atmosphere. The international community recognizes that ozone-depleting substances have caused serious damage to the ozone layer and the importance of the ozone layer to the earth's ecological environment. Most countries, including my country, have signed and acceded to the "Vienna Convention for the Protection of the Ozone Layer", which compulsorily phases out the use of ozone-depleting substances.

The ability of substances to destroy ozone is characterized by the ozone depletion potential (hereinafter referred to as ODP) index. The higher the ODP value, the greater the ability to destroy ozone.

At present, among the cleaning agents to be eliminated in my country's cleaning industry, CFC-113 is the most used and widely used in industry, such as cleaning of electronic components, cleaning of precision equipment, cleaning of metal materials and as a drying solvent. Because CFC-113 has the characteristics of non-combustibility, low toxicity, low corrosion, chemical and thermal stability, etc., the cleaning operation is very safe, and because CFC-113 is used as a cleaning solvent, it has moderate solubility, good selectivity, low viscosity, Low surface tension, high permeability, quick drying, etc., make CFC-113 have many advantages as a cleaning agent. However, the ODP value of CFC-113 is very high, reaching 0.8. Due to its damage to the ozone layer, developed countries banned its use on January 1, 1996. Completely phase out CFC-113 in 2019.

The usual method is to choose a solvent with a lower ODP value to replace CFC-113, such as hydrofluorochlorocarbons, hydrofluorocarbons, perfluorocarbons, hydrofluoroethers, chlorinated hydrocarbons, hydrobromohydrocarbons, etc. . Dichloropentafluoropropane (hereinafter referred to as HCFC-225) has some properties similar to CFC-113, its ODP value is very low, 0.03, and hardly destroys the ozone layer, so it is selected as a substitute for CFC-113, but it is used alone When HCFC-225 is used, acid will be generated under aqueous conditions, which will cause corrosion to metals. Moreover, for different cleaning requirements, cleaning methods and cleaning environments, it is difficult for a single component to achieve the ideal cleaning effect, so it needs to be mixed with other solvents with different characteristics to form a composition to meet various cleaning requirements.

Chinese patent application 91101212.5 discloses an azeotropic solvent composition, an azeotropic solvent composition containing dichloropentafluoropropane and fluoroalcohol. The composition is excellent in terms of cleaning power (especially cleaning flux), nonflammability, chemical stability and selective solvency, and has a liquid composition with low boiling point, high solubility and easy solvent control and easy recovery and reuse Etc.

Chinese invention patent ZL91101481.0 specification discloses a ternary azeotropic composition of dichloropentafluoropropane, trans-1,2-dichloroethylene and methanol or ethanol or isopropanol. The azeotropic solvent composition is used as an electronic cleaning agent, mainly as a solvent for removing flux and flux residues from printed circuit boards.

The azeotropic composition containing dichloropentafluoropropane disclosed in the above two inventions is mainly used for cleaning flux and flux residues in a closed cleaning environment. It requires easy control of the liquid composition of the solvent, easy recovery and reuse of the solvent, and also requires a mixed solvent It can be applied to steam cleaning. Therefore, this type of mixed solvent must be an azeotropic mixture with a low boiling point and is volatile, and has strict requirements on the proportioning of each component, and the cost is high. Due to the absorption of heat during volatilization, the moisture in the surrounding air will condense on the surface to be cleaned, thereby causing the occurrence of electrical conduction. The use of this type of azeotropic composition as a cleaning agent for electronic equipment has certain limitations. Cleaning requirements for removing oil, salt, dust particles, water, etc. on the surface of the equipment in the operating state or charged state, in an open cleaning environment.

Contents of the invention

The invention provides a cleaning agent for electronic equipment, which has low ozone depletion potential and moderate solubility and volatilization rate, and is suitable for cleaning electronic equipment, especially for cleaning electronic equipment in a running state or a charged state.

As a cleaning agent for electronic equipment, especially when the electronic equipment is cleaned in a running state or a charged state, it is very important to have a suitable volatilization rate. If the volatilization rate is too fast, the heat required for volatilization will cause the surface to be cleaned to cool down rapidly, and the water vapor in the air will condense or even frost on the cold surface, which is very dangerous in a live working environment. On the contrary, too slow volatilization rate means that the cleaning agent stays on the surface of the workpiece for a long time, which is not only a manifestation of insufficient cleaning ability, but also directly affects the working state of the workpiece.

HCFC-225 used in the present invention is 3,3-dichloro-1,1,1,2,2-pentafluoropropane and isomer 1,3-dichloro-1,1,2,2, The main characteristics of the mixture of 3-pentafluoropropane as a cleaning solvent are: 1. Moderate volatilization rate; 2. Relatively weak solubility of CFC-113; 3. Poor storage stability; 4. High price. Therefore, an appropriate amount of high boiling point solvent must be added to adjust the volatilization rate, and other solvents can also be added to improve its solubility, stability and cost reduction. Since the applicable conditions of the present invention do not need to be recovered and reused, there is no requirement to form an azeotrope, so the requirements for the ratio between the two isomers of HCFC-225 are not very strict.

Research has found that a certain amount of C ₅ -C ₁₅ alkane mixture is compatible with HCFC-225, which can easily control the volatilization rate of the cleaning agent and reach the volatilization level of the original CFC-113 cleaning agent. The compounded composition not only has strong dissolving ability, but also has a suitable volatilization rate, which meets the requirements of cleaning agents for electronic equipment.

C ₅ -C ₁₅ alkanes mixtures refer to straight-chain alkanes, branched-chain alkanes, cycloalkanes or mixtures thereof, which do not deplete ozone.

With the increase of C ₅ ~ C ₁₅ alkane mixture in HCFC-225, the volatilization rate of the formed composition decreases, and prevents the condensation of water vapor on the surface of the equipment during the volatilization of the cleaning agent, and also helps the cleaning agent itself The moisture contained in it evaporates, but the cleaning ability gradually decreases and the stability is slightly worse. Research has found that when 50-95% of HCFC-225 is compatible with 5-20% of C ₅ -C ₁₅ alkane mixture, its volatilization rate and cleaning ability can reach a comparable level of the original CFC-113 cleaning agent.

Trifluoroethanol is a fluoroalcohol with a molecular formula of CF ₃ CH ₂ OH. This compound does not deplete ozone. Studies have proved that the presence of a certain amount of trifluoroethanol makes HCFC-225 not easy to decompose and produce acid even under water-containing conditions, which increases stability and does not corrode metals. At the same time, trifluoroethanol, as a polar solvent, increases the cleaning ability for polar dirt. Adding 0-20% trifluoroethanol to the mixture of the present invention can improve the stability of the composition and increase the cleaning ability.

Alcohol ether solvents have strong dissolving ability, moderate volatilization rate, good cleaning ability for organic oil stains, and these substances do not deplete ozone. Adding 0-10% alcohol ether in the mixture of the present invention helps to improve the cleaning ability of the composition and adapt to the cleaning requirements of different materials to be cleaned.

Described alcohol ether is ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol butyl ether, ethylene glycol isobutyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether , propylene glycol isobutyl ether or their mixtures.

Chlorinated olefins are often used as cleaning agents due to their strong solvency, and these compounds do not deplete ozone. Adding 0-10% of chlorinated olefins to the mixture of the present invention helps to improve the cleaning ability of the composition, and is suitable for cleaning heavily polluted occasions.

The chlorinated olefin is 1,2-dichloroethylene, 1,1-dichloroethylene, trichloroethylene, tetrachloroethylene or their mixtures.

In order to improve the smell of the cleaning agent of the present invention, a small amount of completely volatilized moisture-free essence, such as lemon essence, sweet orange essence, etc., can be added in the present invention.

The cleaning composition is characterized by low ozone depletion value (ODP), which can replace CFC-113 cleaning agent as an electronic equipment cleaning agent, low surface tension, high cleaning efficiency, moderate volatilization speed, high or no flash point, and voltage resistance. High value, good compatibility with materials, no corrosion to metal, glass, ceramics, polycarbonate, polyphenylene ether, nylon, epoxy resin, polyethylene, and all parameters can match CFC-113 cleaning agent.

The cleaning mixture can be used to clean the surface of inorganic and organic substances, including metal, glass, ceramics, polymers (such as polycarbonate, polyphenylene ether, nylon, epoxy resin, polyethylene, etc.) after being compatible with different components. , can effectively remove oil stains, salt, dust particles, water, etc. attached to the surface. Appropriate cleaning methods include ultrasonic cleaning, liquid solvent spraying, especially the cleaning of electronic equipment in a running state or a charged state has a good effect.

Description of drawings

Fig. 1 is the test result of embodiment 1 cleaning agent, CFC-113 cleaning agent, HCFC-225 volatilization rate;

Fig. 2 is the test result of water content change in the volatilization process of embodiment 1 cleaning agent;

Fig. 3 is the test result that embodiment 1 cleaning agent changes in surface resistance during volatilization;

Table 1 is the compatibility test result of embodiment 1 cleaning agent to various materials;

Table 2 is the cleaning ability test result of embodiment 1 cleaning agent, CFC-113 cleaning agent;

Table 3 is the surface tension test result of embodiment 1 cleaning agent, CFC-113 cleaning agent;

Table 4 is the measurement result of the volatilization rate, stability, cleaning ability of embodiment 2-14 cleaning agent;

Table 5 shows the stability test results of the CFC-113 cleaning agent, the cleaning agent of Example 1, the cleaning agent of Example 8, and the cleaning agent of Example 13.

Detailed ways

Example 1:

Measure HCFC-225 and C ₅ -C ₁₅ linear alkanes at a weight ratio of 95:5, mix them uniformly to form a mixture, and conduct various index tests on the cleaning agent.

1. Comparison of the volatilization rate of the cleaning agent, HCFC-225, and CFC-113 cleaning agent. The measurement results are shown in Figure 1. The addition of C ₅ -C ₁₅ alkane mixture reduces the volatilization rate of the cleaning agent and reaches the level of the original CFC-113 cleaning agent.

2. Determination of water content in the process of cleaning agent volatilization. The measurement results are shown in Figure 2. It can be seen that the addition of the C ₅ -C ₁₅ alkane mixture prevents the condensation of water vapor on the surface of the equipment during the volatilization of the cleaning agent, and also helps the volatilization of the water contained in the cleaning agent itself.

3. Conductive safety evaluation of cleaning agent during volatilization. In view of the fact that the cleaning agent of the present invention is not an absolute azeotrope, the chemical composition will change during the volatilization process, so the change of the surface resistance of the cleaning agent during the volatilization process is measured to ensure the safety of use. The test results are shown in Figure 3. It can be seen from the figure that as the cleaning agent volatilizes, the surface resistance of the cleaning agent itself increases, which is safer for cleaning electronic equipment when it is running or charged.

4. Compatibility between cleaning agent and material. The test results are shown in Table 1. It can be seen that the cleaning agent of this embodiment has no swelling and no corrosion to commonly used materials.

5. Evaluation of cleaning ability of cleaning agent. The cleaning ability of the cleaning agent to silicone grease, natural oil, and sodium chloride was measured by conventional methods, and the results are shown in Table 2. It can be seen that the cleaning ability of this embodiment is equivalent to that of CFC-113 cleaning agent. In addition, the surface tension of the cleaning agent was measured, and the results are shown in Table 3, indicating that its ability to penetrate, wet and clean complex surfaces is stronger than that of CFC-113 cleaning agent.

6. Stability test of cleaning agent. By measuring the chloride ion content of the cleaning agent of this embodiment at different times, the results are shown in Table 5, and its storage stability is slightly worse than that of the CFC-113 cleaning agent.

Example 2:

After measuring HCFC-225 and C ₅ ~ C ₁₅ linear alkanes at a weight ratio of 75:25, mix them uniformly to form a mixture, test the volatilization rate and cleaning ability of the cleaning agent, and the results are shown in Table 4 .

Example 3-14: After measuring HCFC-225, alkanes, trifluoroethanol, alcohol ethers, and chlorinated olefins in different weight ratios, they were mixed uniformly to form a mixture, and the cleaning agent was tested for its volatilization rate and cleaning ability. The test results are shown in Table 4.

Embodiment 3-8: Element Composition (% by weight) Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 HCFC-225 50 57 64 78 85 92 C ₅ ~C ₁₅ branched alkanes 14 10 9.5 8 5 6 Trifluoroethanol 20 15 17.2 6 2 Ethylene glycol propyl ether 4.5 Ethylene glycol butyl ether 9 Propylene Glycol Ether 5.5 2 Propylene Glycol Propyl Ether 6 2 1,2-Dichloroethylene 10 9 tetrachlorethylene 3.8 7.5 2

Embodiment 9-14: Element Composition (% by weight) Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 HCFC-225 78 88 64 50 85 57 C ₅ ~C ₁₅ branched alkanes 8 5 9.5 14 5 10 Trifluoroethanol 7 17.2 20 6 17 Ethylene glycol propyl ether 4.5 Ethylene glycol isobutyl ether 7 Propylene Glycol Ether 5.6 3 1 Propylene Glycol Propyl Ether 2 2 1,2-Dichloroethylene 10 3 9 Trichlorethylene 7.5 3.7 essence 1

The cleaning agents prepared in each embodiment have no swelling and no corrosion to commonly used materials after testing.

The measurement results of the volatilization rate and cleaning ability of each cleaning agent are shown in Table 4.

Choose embodiment 8 and embodiment 13, do stability test. By measuring the chloride ion content of the cleaning agent at different times, the results are shown in Table 5, which shows that the addition of trifluoroethanol and alcohol ether can improve the storage stability of the cleaning agent.

Claims (5)

1. cleaning agent for electronics equipments comprises following component (weight percent):

Dichloro pentafluoropropane 50-95%

C ₅～C ₁₅Paraffins mixture 5-20%

2. cleaning agent for electronics equipments according to claim 1 is characterized in that: described C ₅～C ₁₅Paraffins mixture be straight-chain paraffin, branched paraffin, naphthenic hydrocarbon or their mixture.

3. cleaning agent for electronics equipments according to claim 1 and 2 comprises following component (weight percent):

Dichloro pentafluoropropane 50-95%

C ₅～C ₁₅Paraffins mixture 5-20%

Trifluoroethanol 0-20%

Alcohol ether 0-10%

Chloro-alkenes 0-10%

4. cleaning agent for electronics equipments according to claim 3 is characterized in that: described alcohol ether is ethylene glycol monomethyl ether, ethylene glycol ethyl ether, glycol propyl ether, butyl glycol ether, ethylene glycol ethyl isobutyl ether, propylene glycol monomethyl ether, propylene-glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, propylene glycol ethyl isobutyl ether or their mixture.

5. cleaning agent for electronics equipments according to claim 3 is characterized in that: described chloro-alkenes is 1,2-dichloroethene, vinylidene chloride, trieline, zellon or their mixture.

Images