JPS62115099A - Methylchloroform composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a methyl chloroform composition for cleaning silver or silver-containing materials such as silver-plated materials.

(Prior art) Methyl chloroform has a high dissolving power for oil and grease, is nonflammable, and has low toxicity compared to solvents such as trichlorethylene and perchlorethylene, and is useful for degreasing metals. It is widely used for cleaning, developing printed circuit board dry film, 7lux cleaning, and as a diluting solvent for aerosol products. however,
Methyl chloroform alone is relatively unstable and is a metal,
In particular, the presence of aluminum has the disadvantage that decomposition is significantly accelerated. Once this decomposition reaction starts, it proceeds as a chain reaction while generating hydrogen chloride, and the liquid becomes colored and eventually turns into tar-like, black carbide.

In order to suppress this decomposition reaction and prevent corrosion of metals, stabilization of methyl chloroform is an essential requirement. Many proposals have been made to add the following, either singly or in combination.

Currently commercially available industrial grade methyl chloroform, stabilized with the stabilizers mentioned above, can be used without problems for cleaning many common metals, including aluminum, iron, zinc, brass, etc. can do.

(Problem to be solved by the invention) However, silver plating materials used as contact materials for electronic components are extremely susceptible to discoloration, and even the conventionally known stabilized methyl chloroform can completely suppress discoloration. That was difficult. There is a method to suppress this discoloration by adding certain amines to methyl chloroform, but in this case, the stability of the amine itself makes it impossible to use it for a long time and is not practical. . Therefore, the reality is that methyl chloroform is rarely used for cleaning metal materials containing silver.

(Means for Solving the Problems) In order to improve the stability of methyl chloroform against silver, the inventors of the present invention have conducted repeated research and have added amines and antioxidants to methyl chloroform. Furthermore, by adding one or more substances selected from cyclic ethers, nitroalkanes, and epoxides, silver or silver-containing materials such as silver plating can be washed by immersion cleaning and steam cleaning. The present inventors have discovered a practically stable methyl chloroform composition that does not have a discolored or corroded surface, and based on this knowledge, the present invention has been completed.

That is, the present invention is characterized in that it contains methyl chloroform as a main component, contains amines and antioxidants, and is composed of one or more substances selected from cyclic ethers, nitroalkanes, and epoxides. The present invention provides a silver-stabilized methyl chloroform composition characterized by:

Conventionally known stabilizers, namely cyclic ethers,
By adding amines and antioxidants to nitroalkanes and epoxides, we have achieved long-term liquid stability that could not be obtained when amines were added alone.
Furthermore, the sustainability of the stabilizing effect on silver is improved. Also, among amines.

Even for substances such as pyridine, which did not have a stabilizing effect on silver when added alone, a significant improvement in the stabilizing effect can be seen when used in combination with an antioxidant.

Therefore, by using amines and antioxidants together with cyclic ethers, nitroalkanes, and epoxides, it is possible to improve the stability against silver, which has not been achieved conventionally, and to improve the sustainability of the effect. It became clear.

Examples of the stabilizer of the present invention include amines such as diethylamine, p-butylamine, n-amylamine, N-methylmorpholine, inbutylamine, cyclohexylamine, dicyclohexylamine, N,N-
Dimethylamine, 1,2-diaminocyclohexane, n
-propylamine, ethylenediamine, piperidine, 2
- Methylpiperidine, N-methylpiperidine, piperazine, pyridine, etc., as antioxidants 2,6-di-t-butyl-4-methyl-phenol, 2,4.6-)limethylphenol, p-t-butylcatechol etc., cyclic ethers such as 1,3-dioxane, 1,4-dioxane, 1,3-dioxolane, etc., nitroalkanes such as nitromethane, nitroethane, nitrobutane, etc., and epoxides such as 1,2-butylene oxide, 2,3- Examples include butylene oxide and propylene oxide.

The addition ratio of each stabilizer component in the second aspect of the present invention can be changed depending on the amount of impurities in methyl chloroform, the surface condition of the silver or silver-plated object to be washed, the cleaning method, the cleaning conditions, etc. The addition ratio of each stabilizer component to the total amount of the methyl chloroform composition is preferably within the following range.

Amines 0.0001 to 0.5% by weight Antioxidants 0.001 to O,S weight Cyclic ethers 1.0 to 15.0 weight:! t-tinitroalkanes 0.1 to 10.0 weight i% epoxides
0.1 to 10.0 wt% The composition of the present invention maintains sufficient stability against metals, especially silver, even when used for long periods of time, and even in the presence of water or moisture. Surfaces of silver-plated materials and structures! -In that it is less likely to discolor or corrode,
A great improvement over conventional compositions.

In recent years, it has become extremely valuable industrially as a cleaning solvent for silver or silver-containing materials such as silver-plated products, which are widely used as immersed electrical contact materials in the electronic and electrical industries, including the semiconductor and IC fields. It's expensive.

(Example) The effects of the present invention will be specifically explained below using Examples and Comparative Examples. The discoloration test method and judgment method shown in Examples and Comparative Examples are as follows. Note that the weight percentages are based on the total amount of the methyl chloroform composition.

Discoloration test method Prepare three hard glass cleaning containers (&l,,%2.A3) each equipped with a cooling tube with a capacity of 1000 cc. Use as a tank. Cut the sample (methyl chloroform composition) 1. 700α each in &2, 300cc in Ya3, Fa1
, A3 is heated to a boiling state and Black 2 is held at about 20C. A copper plate with a thickness of 0.51111 is plated with nickel and copper,
Furthermore, the surface of the washed object was plated with silver to a thickness of 1 to 3 μm and pressed into a rectangular shape (311IImx133+I).
1 m) were sequentially placed in IG 1 , 42 , and IG 5 cleaning containers, and each tank was cleaned for 10 minutes. For items to be washed, the degree of discoloration is inspected by visually observing the appearance of the silver-plated surface.

The degree of discoloration is ranked 1 based on the following criteria.
Almost no discoloration.

Rank 2: There is a slight discoloration, but it is very slight.

Rank 3: Significant discoloration.

Rank 4: Significant discoloration.

, Rank 5: Significant discoloration and partially burnt blackening.

(Discoloration effect confirmation test) Example 1 0.5% by weight of 1.2-butylene oxide, 2.5% by weight of 1,4-dioxide, 0.3% by weight of nitromethane,
Pyridine 0.02 fold f, 2.6-di-t-butyl-4
A color change test was conducted on tr-methyl chloroform containing 0.01% by weight of -methyl-phenol.

The results are shown in Table 1.

Actually, layer side 2 1.2-butylene oxide 0.5% by weight, 1.4-dioxide 2.5% by weight, nitromethane 0.3% by weight,
A color change test was carried out on methyl chloroform containing 0.022% by weight of formula-butylamine and 0.01% by weight of 2.6-di-tert-phthyl-4-methyl-phenol. The results are shown in Table 1.

Example 3 1.2-butylene oxide 0.5% by weight, 1,4-dioxide 2.5% by weight, nitromethane 0.3% by weight,
N-methylmorpholine 0.022% by weight 2.6-di-t
A color change test was carried out on methyl chloroform containing 0.01% by weight of -butyl-4-methyl-phenol. The results are shown in Table 1.

Example 4 0.5% by weight of 1.2-butylene oxide, 2.5% by weight of 1.4-dioxide, 0.5Mt of nido-o)tan,
Isobutylamine 0.02 weight 1t%, 2,6-di-t-
A color change test was conducted on methyl chloroform containing 0.011% by weight of butyl-4-methyl-phenol. The results are shown in No. 18.

Example 5 1.2-butylene oxide 0.5 weight + & weight, 1,4-
2.5% by weight of siloxide, 0.3it of nido crmethane
J Yu, 2-methylpiperidine 0. '02 heavy-i1%, 2
．． 6-di-t-butyl-4-methyl-phenol 0.0
A color change test was conducted on methyl chloroform containing 11% by weight. The results are shown in Table 1.

Comparative Examples 1 to 5 From the compositions of Examples 1 to 5, 2,6-di-t-
A color change test was conducted on the sample excluding butyl-4-methyl-phenol. The results are shown in Table 1.

Comparative Example 6 1.2-butylene oxide 0.5% by weight, 1,4-dioxide 2.5% by weight, 2) lomethane 0.3% by weight,
2.6-di-t-butyl-4-methyl-phenol 0.
A color change test was conducted on methyl chloroform containing 0.02% by weight. The results are shown in Table 1.

Table 1 Discoloration effect confirmation test (discoloration effect persistence test) Example 6 1.2-butylene oxide 0.5% by weight, 1.4-dioxide 2.5% by weight, nitromethane 0.5% by weight,
Methyl chloroform containing 0.01% by weight of ethylenediamine, 0.01 TfI amount of 2,6-di-t-butyl-4-methyl-phenol f 100 C, 1 e'J per week
It was refluxed under the following conditions. A color change test was conducted on the liquid before and after reflux. The results are shown in Table 2.

Example 7 0.5% by weight of 1.2-butylene oxide, 2.5% by weight of 1,4-siloxide, 0.3% by weight of Nido 0177,
N-methylpiperidine 0.01 wt%, 2.6-di-t
The mixture was refluxed under conditions of between 1100C1IJ1 of methylchloroform containing 0.01 it of -butyl-4-methyl-phenol. A color change test was conducted on the liquid before and after reflux. The results are shown in Table 2.

Comparative Example 7.8 2,6-di-tert-butyl-4-methyl-
A sample excluding phenol was refluxed under the same conditions. A color change test was conducted on the liquid before and after reflux. The results are shown in Table 2.

Table 2 Discoloration Effect Sustainability Test (Effects of the Invention) As is clear from Tables 1 and 2, the methyl chloroform composition of the present invention maintains the surface even after washing silver or silver plated objects at high temperatures. There is very little discoloration, and the stability effect is extremely long-lasting. It is also a clear improvement over methyl chloroform compositions that do not contain the substances of the invention.

Procedural amendment January 6, 1986

Claims (1)

[Claims] Silver or silver containing methyl chloroform as a main component, containing amines and antioxidants, and one or more substances selected from cyclic ethers, nitroalkanes, and epoxides. Methyl chloroform composition for cleaning silver-containing materials such as silver-plated items.