JPS5884985A - Cleaning solvent for buffing sludge - Google Patents

Abstract

PURPOSE:To obtain a cleaning solvent for buffing sludge capable of easily removing extremely persistent stains due to buffing sludge by adding a small amount of a lower fatty acid to a solvent contg. chlorine such as perchloroethylene. CONSTITUTION:A cleaning solvent for buffing sludge is obtd. by adding 0.1- 5.0wt% of >=1 kind of lower fatty acid selected from formic acid, acetic acid and propionic acid to a solvent contg. chlorine selected from perchloroethylene, trichloroethylene, 1,1,1-trichloroethane and methylene chloride. By further adding 2-8C ketone or ester to the solvent contg. the added lower fatty acid, the acid odor peculiar to the lower fatty acid can be reduced considerably.

Description

DETAILED DESCRIPTION OF THE INVENTION The present Wf4Fi, perchlorethylene, trichlorethylene, 1,1.1=-)lychloroethane, methylene chloride, and other chlorinated solvents can be prepared by adding a small amount of lower fatty acids. , relates to a good solvent composition that improves the ability to clean puff dregs.

! Various metal daily necessities made from lead, copper, iron, and their alloys such as brass, nickel silver, stainless steel, etc., such as cutlery,
Western tableware, eyeglass frames, outer parts of watches, etc. can be finished to a highly glossy surface using puff polishing.

Traditionally, manual brushing or cleaning agents containing dangerous substances have been used to clean the puff scum after polishing these metal parts. Cleaning with organic solvents other than water-based
Ultrasonic cleaning using trichlorethylene is common.

The abrasive used for puff polishing consists of an oil containing mainly paraffin and fatty acids and abrasive grains.

The content of abrasive grains varies depending on rough polishing and finish polishing, but generally 50 to 70% of abrasive, silica, alkali, chromium oxide, etc. are used.

Puff abrasives are exposed to high temperatures during polishing, undergo various changes, and become extremely soluble, resulting in K<. Furthermore, if the puff residue is left unattended, the oil will solidify and become difficult to clean.

For this reason, a solvent with strong degreasing power, such as trichlorethylene, is generally used to wash the puff dregs.

However, even with trichlorethylene, which is commonly used in the past, it is difficult to completely clean stubborn stains, and after passing it through a cleaning process, it is necessary to re-clean it or perform local correction cleaning. It is.

The present invention provides a puff dregs cleaning agent that improves the dissolving power of a chlorinated solvent that contributes to puff dregs cleaning, and can easily clean even extremely strong puff dregs stains.

That is, the present invention provides a chlorinated solvent selected from perchloroethylene, trichlorethylene, 1,1.1-)9chloroethane, and methylene chloride, and one of the remaining organic acids such as formic acid, acetic acid, and propionic acid, or The present invention relates to a puff scum cleaning solvent characterized by containing two or more kinds of ketones or esters having 3 to 8 carbon atoms.

In operations where workers often come into contact with large amounts of solvent vapor, such as puff scum cleaning operations, it is problematic to use conventionally used relatively highly toxic organic solvents, and less toxic organic solvents such as 1.1. 1-) Attempts to replace it with dichloroethane have also been considered.

However, 1,1.1-) dichloroethane lacks in dissolving power, and there are problems such as an increase in the number of defective products being washed compared to washing with trichlorethylene.

By adding the organic acid according to the present invention to 1,i,1-)dichloroethane, the dissolving power of fi,1,1.1-)dichloroethane for puff dregs can be dramatically improved, thereby improving safety. It has become possible to provide a high-quality puff slag cleaning agent.

The chlorinated solvents, perchloroethylene, trichlorethylene, 1,1.1-)IJ dichlorothane, and methylene chloride referred to in the present invention generally contain a stabilizer.

As stabilizers, radical ethers, nitroparaffins, epoxy compounds, alcohols, amines and the like are conventionally known, and these compounds are used alone or in combination of two or more. In the present invention, these stabilized chlorinated solvents can also be preferably used.

The amount of organic acid selected to be added, such as formic acid, acetic acid, or propionic acid, tends to improve the buff slag cleaning ability to a certain extent, but it depends on factors such as the material of the object to be washed and the difficulty in removing dirt. The amount of organic acid added should be determined.

The preferred range of addition amount is 0 for chlorinated solvents.
．． 1 to 5.0 weight. If it exceeds 5.0 weight, the corrosivity of the metal increases and the odor becomes strong, which is undesirable. do not have.

Propionic acid has a large number of carbon atoms! i-acid, valeric acid, trimethylacetic acid, caproic acid, and kagrylic acid improve the cleaning performance of Matsukasa buff slag, but there is a strong odor in the back, and the cause is unknown, but the solvent is corrosive to metals. This is not preferable because it becomes larger than when the three fats Mt- of the present invention are added.

By adding a ketone or ester having 2 to 8 carbon atoms to the chlorinated solvent according to the present invention to which an organic acid is added, the acid odor characteristic of the organic acid can be alleviated.

Good results are obtained when the amount of ketone or ester added for odor improvement is about the same as the amount of the organic acid added. If the amount of Amabs is too large, the odor of ketones and esters will be too strong and have the opposite effect.

Specific examples of ketones and esters used in the present invention include acetone, methyl ethyl lactone, 2-pentanone, diethyl ketone, methyl n-butyl ketone, methyl isobutyl ketone, 2-heptanone, 4-heptanone, cyclohexanone, acetophenone. -, ethyl formate, propyl formate, butyl formate, isobutyl formate, pentyl formate, methyl acetate, ethyl acetate, -propyl acetate, isopropyl acetate, n-butyl acetate, inbutyl acetate, nibutyl acetate, n-amyl acetate , isoamyl acetate, methylisoamyl acetate, sec-hexyl acetate, acetic acid-
Examples include 2-ethylbutyl.

Hydrocarbons may be further added to the puff scum cleaning solvent of the present invention within a range that does not cause a flash point to the solvent.

Although the addition of hydrocarbons depends on the type of puff dregs, it may improve the ability of the solvent to clean the puff dregs, and may also be useful in removing the odor of the solvent.

Preferred hydrocarbons include n-hexane, isohexane, n-hebutane, cyclohexane, toluene, xylene, petroleum penodine, ligroin, kerosene, and the like.

An example of a cleaning device used in carrying out the present invention is shown in FIG. In the figure, the IFi first cleaning tank, 2 the second washed cypress, 3 the third cleaning cypress, 4 the cooling pipe for condensing the solvent vapor, 5 the water separator, 6 the Fi ultrasonic oscillator, 7 the A heating heater is shown. Furthermore, the arrows in the figure indicate the circulation path of the solvent.

Hereinafter, the present invention will be explained in detail with reference to examples, but it goes without saying that the scope of the present invention is not limited only to these examples.

Example 1 As shown in FIG.
An abrasive 11 shaped into a cube with a side of 10 m and whose weight has been accurately weighed in advance is placed on top and suspended in the test liquid.

Dissolve the abrasive in a quiet device for 50 minutes, measure the weight of the abrasive remaining on the basket to determine the amount of abrasive dissolved, and evaluate the dissolving ability of the abrasive among each test solvent.

The test was conducted while controlling the liquid temperature of the test solvent to Fiso°C. A blue rod was used as the abrasive.

The test results are summarized in Table 1.

Bottle 1 All solvent compositions are expressed in parts by weight.

As shown in this example, adding only 1% fatty acid to a chlorinated solvent greatly improves the dissolution properties compared to dissolving the blue bar in a chlorinated solvent.

Example 2 In order to examine the effect of the amount of fatty acid added, a test similar to Example 1 was conducted using a test solution having the composition shown in Table 2.

The test results are summarized in Table 2.

As shown in Table 2 and above, within this range, the dissolution rate of the blue rod tends to increase as the amount of fatty acid added to the chlorinated solvent increases. However, when the amount of fatty acid added exceeds 5 -, the increase in the dissolution rate of the blue bar becomes less significant, and the power...
If the amount is less than 1%, the effect of adding dill is not significant.

Example 5 A puff slag cleaning test was carried out using the three-tank washer shown in Fig. 1 using the test solutions of the solvents used in Example 1 with the compositions 0), (2), ■, and ■. carried out. Items to be washed include stainless steel men's watch parts (side) that were puff-polished with a blue rod.
was used.

50 watch parts were cleaned with each solvent, and after cleaning, they were inspected in detail under a magnifying glass, and those with no abrasive residue were passed, and the number of passes was 150 x 10. percentage.

For the first cypress, an ultrasonic oscillator with a frequency of 40 kHz for 7 seconds and an output of 600 W was used, and the cleaning liquid temperature was adjusted to 65°C.

The second cypress was bathed in a cold bath, the third cypress in a steam bath, and the items to be washed were washed in the first bath for 111 minutes each.

The cleaning test results are summarized in Table 5.

Table 3 As shown in this washing test, it can be seen that the dissolution rate (Q) measured by the test method of Example 1 is in good agreement with the actual washing results of puff dregs.

As is clear from this example, even when cleaning with trichlorethylene, which is common in puff dregs cleaning, only about 70% could be cleaned, but with the addition of 1.0-formic acid, it was completely cleaned. Further stabilization by adding fatty acids 1,1.
1-) #i#1, which was mostly poorly cleaned with dichloroethane, was completely cleaned with the addition of 1.0% acetic acid.

Example 4 In order to further clarify the effects of the present invention, the same test as in Example 1 was repeated using test solvents having the compositions shown in Table 4.

The results are summarized in Table 4.

Table 4 Test A [phase] - @ Solvents have a suppressed acid odor caused by organic acids compared to solvents ■ - 0, and in a normal washing machine equipped with a condensing tube, λ practically It has no smell.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a cleaning device used in carrying out the present invention, and FIG. 2 is an explanatory diagram showing an aspect of a test in an embodiment of the present invention. Figure 1 2rI! J

Claims (1)

[Claims] 1. Perchlorethylene, trichlorethylene, 1.1
．． 1-) A puff scum cleaning solvent characterized by containing one or more selected organic acids such as formic acid, acetic acid, and propionic acid, or 112111 or more, in a chlorinated solvent such as trichloroethane and methylene chloride. . The puff scum cleaning solvent according to claim 1, wherein the chlorinated solvent is 1.1.1-trichloroethane. 5. Haak's gastric luethylene, trichlorethylene, 1.
1,1-) A chlorinated solvent selected from lychloroethane and methylene chloride, one or more organic acids selected from formic acid, acetic acid, and propionic acid, and a number of atoms S to 8.
0 Ketone Maku is a puff scum cleaning solvent characterized by containing esters. 4. A buff dregs cleaning solvent according to claims 1 to 3, wherein the organic acid content is 0.1 to 5.0% by weight.