US2031144A

US2031144A - Nonflammable cleaning solvent

Info

Publication number: US2031144A
Application number: US467997A
Authority: US
Inventors: Merrill A Youtz
Original assignee: Standard Oil Co
Current assignee: Standard Oil Co
Priority date: 1930-07-14
Filing date: 1930-07-14
Publication date: 1936-02-18
Anticipated expiration: 1953-02-18

Description

Patented Feb. 18, 1936 PATENT OFFICE 2.031.144 w v NONFLAMMABLE CLEANING SOLVENT Merrill A. Youtz, Hammond, Ind., assixllor to Standard Oil Company (Indiana), Chicago, 111., a corporation of Indiana No Drawing. Application my 14, 1930,

Serial No. 457,991

'1 Claim.

This invention relatesto cleaning solvents and it pertains more particularly to non-flammable mixtures of light hydrocarbons and halogenated solvents.

The object of my invention is to provide a cleaning solvent containing a large amount of flammable light hydrocarbons protected by chlorinated solvents, so that when the cleaning solvent is evaporated both the vapors and the residual liquids are non-flammable.

Light hydrocarbons. such as benzine, petroleum naphtha, etc, are excellent solvents and are relatively inexpensive, but they are dangerous because of their flammable and explosive nature. Nonflammable solvents, such as carbon tetrachloride, are non-explosive, but are expen sive and are objectionable because they dissolve too much oil from furs, woolen goods; etc. Carbon tetrachloride has been added to relatively heavy naphthas for rendering the evaporated vapors non-explosive, and attempts have been made to render the naphtha non-volatile by the addition of waxy bodies. In suchcases, when the initial mixture is on the verge of flammability, the residual solvent very soon becomes flammable and such mixtures are therefore objectionable and dangerous.

I have discovered that by proceeding directly contrary-to the above practice, both the evaporated vapors and residual liquids may contain high percentages of light' hydrocarbon solvents explosive. naphtha instead of a non-volatile naphtha and I select flammable and non-flammable solvents (such as petroleum naphtha) and still be non- I use a relatively volatile petroleum V of substantially the same volatility for my mixture. Such a mixture may be evaporated to any degree and still maintain the same ratio of flammable solvent to non-flammable solvent, both in the evolved vapors and in the residual liquid.

In other words, I provide a mixture which cannot 'readilybe fractionated by distillation.

As a specific example of my cleaning solvent this'solvent is usedas a dry cleaner and a large amount of it is evaporated, the gaseous or vapor phase will always be non-flammable because it will always contain about 60 to 65% carbon tetrachloride. Likewise the liquid phase will be nonflammable because it will always contain the same proportion of non-flammable solvent. There no tendency for the naphtha to concentrate in the residual solvent. Consequently I am enabled to employ larger proportions of naphtha in the" mixture than has heretofore been possible with-. out danger of flammability. a

As another example of my invention I may use a heavier mixture. I may use acetylene tetrachloride with petroleum naphtha, whose boiling l5 range is about 290 to 325 F. In fact, I may use any mixture of flammable hydrocarbon solvents with non-flammable solvents as long as the volatility'of one is substantially the same as the volatility of the other so that there will be no tendency of the mixture to fractionate or separate into different components by distillation or evaporation.

By departingfrom prior usage and employing a flammable solvent of substantially the same volatility as the non-flammable solvent, I have produced several noteworthyresults. The 501- vent mixture is as safe to use under any conditions as carbon tetrachloride, but at the same I time it is less expensive than carbon tetrachloride, it-does not have as great a tendency to remove natural oils from furs, woolens, etc.,' and it combines the properties of hydrocarbon solvents with chlorinated solvents.

While I have described preferred embodiments i of my invention in detail, I do not limit myself tosaid details except as defined by the following claim.

A dry cleaning solvent comprising a mixture of, petroleum naphtha having a boiling range of about Hill-220 F. with carbon tetrachloride in proportions of about 35 to 40 parts by volume of petroleum naphtha to about 65 to '60 parts by volume of carbon tetrachloride whereby the drycleaning fluid is substantially non-flammable, its vapors are substantiallynon-flammable. and it leaves a substantially non-flammable residue'upon evaporation.