CA1071240A - Stabilized perchloroethylene - Google Patents
Stabilized perchloroethyleneInfo
- Publication number
- CA1071240A CA1071240A CA272,627A CA272627A CA1071240A CA 1071240 A CA1071240 A CA 1071240A CA 272627 A CA272627 A CA 272627A CA 1071240 A CA1071240 A CA 1071240A
- Authority
- CA
- Canada
- Prior art keywords
- solvent
- tbge
- degreaser
- perchloroethylene
- sump
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
- C11D3/0005—Other compounding ingredients characterised by their effect
- C11D3/0084—Antioxidants; Free-radical scavengers
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/38—Separation; Purification; Stabilisation; Use of additives
- C07C17/42—Use of additives, e.g. for stabilisation
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
- C23G5/02—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents
- C23G5/028—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing halogenated hydrocarbons
- C23G5/02854—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing halogenated hydrocarbons characterised by the stabilising or corrosion inhibiting additives
- C23G5/02861—Oxygen-containing compounds
- C23G5/0288—Epoxy compounds
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Wood Science & Technology (AREA)
- Biochemistry (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Detergent Compositions (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Epoxy Compounds (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
Abstract of the Disclosure Perchloroethylene is stabilized against degradation in the presence of hydrogen chloride and metals by the addition of l-tertiary butoxy-2,3-epoxy propane (tertiary butyl glycidyl ether) as the essential acid acceptor.
Description
10~240 Perchloroethylene (1,1,2,2-tetrachloroethylene) is a well known chlorinated solvent widely used by industry to clean metals and fabrics. It, like methyl chloroform (l,l,l-trichloroethane), has been gaining wide spread usage in areas previously employing trichloroethylene (1,1,2-trichloroethylene) because of the publicity of the alleged unfavorable ecological impact on the atmosphere of this latter solvent. The increased use of perchloroethylene and l,l,l-trichloroethane in the metal cleaning fields previously employing trichloroethylene has ~ubjected these solvents to unusual conditions which often results in solvent decomposition, generating hydrogen chloride which then reacts with the metals to produce metal chloride, a reaction product which causes the decomposition of the solvent thus producing more hydrogen chloride. Also, these same degradation products and me,tal halides attach or catalyze the decomposition of chain fatty acids and oils, causing the production of compounds having a disagreeable odor.
The art has attempted to meet these problems as they arise by resorting to known stabilizers such as, for example, epichlorohydrin, epibromohydrin, butylene oxide, and cyclo-hexane oxide, alone or in combination with various other well known inhibitors such as dioxane, dioxolane, trioxane, nitromethane, nitroethane, and the nitriles. While these known combinations give satisfactory results under well regulated and careful clean housekeeping of the solvent and the equipment, unfortunately, many operations are not well run from the housekeeping standpoint. This results in excessive corrosion of equipment, metal parts being cleaned, and decomposition of the solvent and polishing .' 17,952-F -l-~07~Z~O
and grinding compounds dissolved in the solvent. Once the inhibitor level of a solvent is decreased without decrease of the contaminating components, corrosion and decomposition are accelerated.
The present invention resides in perchloroethy-lene stabilized against degradation in the presence of hydrogen chloride and metals and containing from 0.1 to 5.0 weight percent of tertiary butyl glycidyl ether.
The present invention further resides in a process for stabilizing perchloroethylene against degra-dation in the presence of hydrogen chloride and metals comprising adding to the perchloroethylene from 0.1 to 5.0 weight percent of tertiary butyl glycidyl ether.
The tertiary butyl glycidyl ether is the principal and essential mineral acid acceptor when this solvent is used as vapor degreasing solvent and substan-tially eliminates degradation of the solvent and corrosion of the metals in contact therewith. l-Tertiary butoxy
The art has attempted to meet these problems as they arise by resorting to known stabilizers such as, for example, epichlorohydrin, epibromohydrin, butylene oxide, and cyclo-hexane oxide, alone or in combination with various other well known inhibitors such as dioxane, dioxolane, trioxane, nitromethane, nitroethane, and the nitriles. While these known combinations give satisfactory results under well regulated and careful clean housekeeping of the solvent and the equipment, unfortunately, many operations are not well run from the housekeeping standpoint. This results in excessive corrosion of equipment, metal parts being cleaned, and decomposition of the solvent and polishing .' 17,952-F -l-~07~Z~O
and grinding compounds dissolved in the solvent. Once the inhibitor level of a solvent is decreased without decrease of the contaminating components, corrosion and decomposition are accelerated.
The present invention resides in perchloroethy-lene stabilized against degradation in the presence of hydrogen chloride and metals and containing from 0.1 to 5.0 weight percent of tertiary butyl glycidyl ether.
The present invention further resides in a process for stabilizing perchloroethylene against degra-dation in the presence of hydrogen chloride and metals comprising adding to the perchloroethylene from 0.1 to 5.0 weight percent of tertiary butyl glycidyl ether.
The tertiary butyl glycidyl ether is the principal and essential mineral acid acceptor when this solvent is used as vapor degreasing solvent and substan-tially eliminates degradation of the solvent and corrosion of the metals in contact therewith. l-Tertiary butoxy
2,3-epoxypropane (hereafter called TBGE) has the formula H3C-C-O-CH2-C~-~CH2 CH3 o The use of TBGE to maintain the solvent substantially free of mineral acids is unique because numerous reac-tions occur under the use condition which result in the acid acceptance of the compound being greater than the expected value of 1. The following equations illustrate the reactions and products found in the solvent under use conditions.
*Acid acceptors.
17,952-F -2-.
1~712~0 " .
C~H \H H+ ~ C/H \H + / CH3 :
OtBu ~I) (II) (III) :: .
(I) * or M Cl > ClCH2CHOH - (III) - > ClCH2CH-OH :~
X yCH20tBu CH2H
(IV) (V) (I)* H20 3 HOCH2CHOH-(III) > HOCH2CH-OH
,, CH2otBu CH2H
~ (VI) (VII) , . .
(I)* Act ve Hydrogen? -(CH2CHO)- -(III) ~ -(CH2CHO)x (H20 or ROH) CH20tBu 2 ; ~VIII) (IX) , . . .
I)* ZnCl or FeCl > CH3CCH20tBu -(III) > CH3CCH20H (XI) 2 ll ;., Rearrangement enol H2o > CH2=CH=CH20tBu (X) (XII) CH3 CH3* CH3*
CH C H20 ~ HO-C-CH3 + HC-CH20H
*Acid acceptors.
17,952-F -2-.
1~712~0 " .
C~H \H H+ ~ C/H \H + / CH3 :
OtBu ~I) (II) (III) :: .
(I) * or M Cl > ClCH2CHOH - (III) - > ClCH2CH-OH :~
X yCH20tBu CH2H
(IV) (V) (I)* H20 3 HOCH2CHOH-(III) > HOCH2CH-OH
,, CH2otBu CH2H
~ (VI) (VII) , . .
(I)* Act ve Hydrogen? -(CH2CHO)- -(III) ~ -(CH2CHO)x (H20 or ROH) CH20tBu 2 ; ~VIII) (IX) , . . .
I)* ZnCl or FeCl > CH3CCH20tBu -(III) > CH3CCH20H (XI) 2 ll ;., Rearrangement enol H2o > CH2=CH=CH20tBu (X) (XII) CH3 CH3* CH3*
CH C H20 ~ HO-C-CH3 + HC-CH20H
3 CH3 CH3 ~, (III) (XIII) (XIV) 17,952-F _3_ . , .
`` ~, , . ' , ~
.:. . : - .- --(III) HCl~ Cl-C-CH + HC-CH2Cl CH3 C~13 (XV) (XVI) C~3 CH3 (III) ~ > CH3-C-CH2-C=CH2 (XVII) /0\ ~ CH3 (III) (o) > CH -C H20 > HO-C-CH20H
, CH3 CH3 (XVIII)* (XIX) (XVIII)* HCl ~ Cl-C-CH20H
.,.
(XX) It i8 thus seen that TBGE has unique properties not pos-sessed by the conventional acid acceptors, e.g. epichloro-hydrin, cyclohexane oxide and butylene oxide or by methyl glycidyl ether or isopropyl glycidyl ether. The unique property is its ability to react with the hydrogen chloride, metal chlorides and water to produce intermediate reaction products which are capable of further reaction with these same reactants, i.e. the reaction products of the expected reaction have labile groups reactive with hydrogen chloride, metal chlorides and water. This unique property makes the TBGE unexpectedly superior to the prior art acid acceptors.
:, 17, 952-F -4-.
l 071Z40 TBGE has a favorable partitioning factor, i.e.
; the volume ratio of the amount of TBGE which goes to the vapor from a boiling solvent to the amount of TBGE which stays in the liquid. This factor varies from about 1 to 1.4 to 1 to 2 respectively, depending on the oils and con-taminants present in the boiling solvent. It is advantageous that such a partitioning factor exists since the metal chips accumulate in the liquid and the metal chlorides are formed in the liquid. The favorable partitioning assures that there is adequate TBGE in the liquid to tie-up the chlorides and remove them from this reactive state. The additions of make-up solvent containing the TBG~ in the abo~e-noted ranges will provide adequate ~BGE in the liquid and vapor under use conditions. Further, the partitioning actor also allows only a slow accumulation of TBGE in the sump and still so that while some increase or build-up occurs in the sump and still, excessive build-up does not occur, thus limiting losses from the unit during solvent purification in the sludge or still bottoms.
The amount of tertiary butyl glycidyl ether employed to achieve the improved stability under the acid generating conditions is from about 0.1 to about 5 and preferably between about 0.25 and about 1.5 percent by weight based on the weight of the total composition. It i6, o course, understood that while quantities greater than 1.5 weight percent i.e. up to about 5 percent can be employed, unless extremely severe conditions exist it is uneconomical to employ these quantities greater than about 1.5 weight percent. It is further to be understood that best results are obtained when there is also added 17,592-F -5~
:` , , ' .:
` - ~ .: ,' ' :
: 1071Z40 ' from 10 to 500 ppm of an antioxidant, i.e. an amine such as N-methyl morpholine, or a phenolic, since perchloro-ethylene undergoes oxidation in the presence of heat, light, and oxygen.
Example 1 A 2' x 5 1/2' x 5' (0.61 x 1.68 x 1.52 m.) two--chamber open top vapor degreaser was used in the test.
Perchloroethylene containing about 0.~5 weight percent -TBGE and 50 ppm by weight M-methyl morpholine was used in the test. The degreaser was heated with a two-deck heat exchanger at 45-48 psi (3.18-3.38 kg./cm. ) steam pressure.
Cooling was provided by means of perimeter water coils and a freeboard water jacket. Solvent from the degreaser boiling sump was pumped by a transfer pump to a steam heated still equipped with an automatic level control.
Condensate solvent in the degreacer was routed through a water cooled water separator into a warm dip chamber which overflowed into a boiling sump compartment.
The still condensate was also routed back into the warm dip chamber.
Working Volumes of the Degreaser-Still .~
Degreaser sump - 25.25 U.S. gallons (95.5 liters) Degreaser warm dip - 31.17 U.S. gallonc (113 liters) Still during operation 29.38 U.S. gallons (111 liters) Test Procedure Ater the initial solvent fill, the system was put into operation for three days prior to any solvent sampling. Sampling was commenced on the third day of operation with samples taken from the sump, warm dip, still condenser and still bottom.
17,952-F -6-`'' 1~71Z40 All solvent samples were analyzed by vapor phase chromatography (VPC) determination of inhibitor levels and were taken prior to any sol~ent make up addi-tions or oil additions.
Three sets of eight 0.032" x 4" x 8!' (1.25mm. x 1.58cm. x 3.16cm.) 1010 steel panels were placed in the degreaser at various positions:
Coupon Locations in Degreaser Coupon # Position Vapor Liq.
1 A-trough sumpside x 2 B-trough sumpside x 3 C-liquid sumpside x
`` ~, , . ' , ~
.:. . : - .- --(III) HCl~ Cl-C-CH + HC-CH2Cl CH3 C~13 (XV) (XVI) C~3 CH3 (III) ~ > CH3-C-CH2-C=CH2 (XVII) /0\ ~ CH3 (III) (o) > CH -C H20 > HO-C-CH20H
, CH3 CH3 (XVIII)* (XIX) (XVIII)* HCl ~ Cl-C-CH20H
.,.
(XX) It i8 thus seen that TBGE has unique properties not pos-sessed by the conventional acid acceptors, e.g. epichloro-hydrin, cyclohexane oxide and butylene oxide or by methyl glycidyl ether or isopropyl glycidyl ether. The unique property is its ability to react with the hydrogen chloride, metal chlorides and water to produce intermediate reaction products which are capable of further reaction with these same reactants, i.e. the reaction products of the expected reaction have labile groups reactive with hydrogen chloride, metal chlorides and water. This unique property makes the TBGE unexpectedly superior to the prior art acid acceptors.
:, 17, 952-F -4-.
l 071Z40 TBGE has a favorable partitioning factor, i.e.
; the volume ratio of the amount of TBGE which goes to the vapor from a boiling solvent to the amount of TBGE which stays in the liquid. This factor varies from about 1 to 1.4 to 1 to 2 respectively, depending on the oils and con-taminants present in the boiling solvent. It is advantageous that such a partitioning factor exists since the metal chips accumulate in the liquid and the metal chlorides are formed in the liquid. The favorable partitioning assures that there is adequate TBGE in the liquid to tie-up the chlorides and remove them from this reactive state. The additions of make-up solvent containing the TBG~ in the abo~e-noted ranges will provide adequate ~BGE in the liquid and vapor under use conditions. Further, the partitioning actor also allows only a slow accumulation of TBGE in the sump and still so that while some increase or build-up occurs in the sump and still, excessive build-up does not occur, thus limiting losses from the unit during solvent purification in the sludge or still bottoms.
The amount of tertiary butyl glycidyl ether employed to achieve the improved stability under the acid generating conditions is from about 0.1 to about 5 and preferably between about 0.25 and about 1.5 percent by weight based on the weight of the total composition. It i6, o course, understood that while quantities greater than 1.5 weight percent i.e. up to about 5 percent can be employed, unless extremely severe conditions exist it is uneconomical to employ these quantities greater than about 1.5 weight percent. It is further to be understood that best results are obtained when there is also added 17,592-F -5~
:` , , ' .:
` - ~ .: ,' ' :
: 1071Z40 ' from 10 to 500 ppm of an antioxidant, i.e. an amine such as N-methyl morpholine, or a phenolic, since perchloro-ethylene undergoes oxidation in the presence of heat, light, and oxygen.
Example 1 A 2' x 5 1/2' x 5' (0.61 x 1.68 x 1.52 m.) two--chamber open top vapor degreaser was used in the test.
Perchloroethylene containing about 0.~5 weight percent -TBGE and 50 ppm by weight M-methyl morpholine was used in the test. The degreaser was heated with a two-deck heat exchanger at 45-48 psi (3.18-3.38 kg./cm. ) steam pressure.
Cooling was provided by means of perimeter water coils and a freeboard water jacket. Solvent from the degreaser boiling sump was pumped by a transfer pump to a steam heated still equipped with an automatic level control.
Condensate solvent in the degreacer was routed through a water cooled water separator into a warm dip chamber which overflowed into a boiling sump compartment.
The still condensate was also routed back into the warm dip chamber.
Working Volumes of the Degreaser-Still .~
Degreaser sump - 25.25 U.S. gallons (95.5 liters) Degreaser warm dip - 31.17 U.S. gallonc (113 liters) Still during operation 29.38 U.S. gallons (111 liters) Test Procedure Ater the initial solvent fill, the system was put into operation for three days prior to any solvent sampling. Sampling was commenced on the third day of operation with samples taken from the sump, warm dip, still condenser and still bottom.
17,952-F -6-`'' 1~71Z40 All solvent samples were analyzed by vapor phase chromatography (VPC) determination of inhibitor levels and were taken prior to any sol~ent make up addi-tions or oil additions.
Three sets of eight 0.032" x 4" x 8!' (1.25mm. x 1.58cm. x 3.16cm.) 1010 steel panels were placed in the degreaser at various positions:
Coupon Locations in Degreaser Coupon # Position Vapor Liq.
1 A-trough sumpside x 2 B-trough sumpside x 3 C-liquid sumpside x
4 D-trough warm dipside x E-liquid warm dipside x 6 F-below trough on sumpside near trough x 7 G-below trough on sumpside in center of sumpside x 8 H-between trough and liquid on warm dipside x Average inhibitor partitioning during the 25-day test were as follows:
Ratio Sump % TBGE to Vapor Degreaser Sump 0.449% 1.4 Degreaser Warm Dip 0.317% 1.0 Still Conden~ate 0.456% 1.4 Still Sump 0.768% 2.4 At the end of the 25-day test the degreaser was shut down and the solvent in the warm dip chamber pumped into a tared 55 U.S. gallon (208 liters) drum. At this point there was a 25 percent oil content in the still pump. The contents of the degreaser sump were then routed through the still and distillate collected in the warm dip chamber.
17,952-F -7-- ~)71240 The amounts and analysis of the recovered solvent are tab-ulated in Tables I and II. Nine U.S. gallons (34.0 liters) ~:
. of solvent were recovered from the degreaser sump below ,.: the still transfer line, referred to as still bottoms below.
TABLE I
. Solvent . Wt. in U.S. Gallons % TBGE
Solvent Source Lbs. (Kg.) ~Liters) in Solvent 1) Warm dip at 373 ~169)27.69 ~105) 0.33 shut down .- 2) Distillate 289 ~131)21.46 ~81.4) 0.55 from still ; ~first batch) 3) Distillate 215 ~97.6) 15.96 ~60.2) 0.56 :~ from still !' ~second batch) 4) Residue solvent 123 ~56.0) 9.13 ~34.5) 0.504 ; from degreaser sump , TOTALS 1000 ~453.6) 74.24 ~281.1) Still Bottom8* 160 15.89 1.394 *Note: Still.bottoms contain 56% oil and 44% solvent, there-fore 6.99 gallons (26.4 liters) of the still bottoms are perchloroethylene with 1.394% wt. TBGE. Still bottoms also contain 0.213% of the chlorohydrin product ~CH3)3C-OCH2-CH-CH2Cl OH
.~ 17,952-F -8-.
,~ ~
10~1240 .
TABLE II
, Material Balance for TBGE Inhibitor Solvent Wt. inU.S. Gallons % TBGE
Solvent Source Lbs. (Kg.)(Liters) in Solvent 1) Solvent for 1965.3 (881)145.9 (551) 0.445 test 2) Recovered from still boil down1000.0 (453.6) 74.24 ~271) 0.4654 3) Still bottoms contain 44 perchloro (0.44 x 15.89) 94.1~ (42.8) 6.99 (26.4) 1.394 Total Recovered (2 and 3)1094.16 (496.4)81.24 (297.4) 0.545 -(Calcd) Comsumed*
(1 - (2+3))871.14 (384.6)64.67 (253.6) 0.296 :~ (Calcd) *Note: 0.458 U.S. gallons (1.73 liters) of T~GE inhibitor is accounted for by the 81.23 U.S. gallons (297 liters) of total recovered solvent lincluded 0.0149 U.S. gallons (0.560) of TBGE for chlorohydrin product in still bottoms).
Substracting 0.458 from the 0.6493 U.S. gallons (2.54 liters) TBGE in the original solvent gives 0.1914 U.S. gallons (0.72 liters) TBGE lost iwth the 64.67 U.S. gallons of consumed solvent.
Therefore the percent of TBGE in the consumed (by vapor losses and reaction with metal chlorides) solvent is 0.1914 x 100 = 0.2960% TBGE.
64.67 This figure of 0.2960% TBGE is very close to the average warm dip inhibitor content during the test period of 0.311%
TBGE laverage of 9 determinations).
Normal degreaser-still operation involves dumping and subsequent discarding of the boiled down still bottoms.
; 25 Accordingly, the amount of TBGE that would be lost is calculated by dividing the amount of TBGE in the boiled down still bottoms, i.e. 6.99 gal (25.4 liters) x 1.394% TBGE
by the amount of TBGE in the original solvent, 0.6493 gal.
17,952-F -9-',` ' .. .
(2.46 liters), or original would be lost. This loss is not excessive as seen by the fact that the 74.24 U.S.
gallons (281 liters) of recovered solvent had an average ; 0.465% TBGE inhibitor content while the original solvent had a 0.445~ inhibitor content.
The solvent comsu~ption in the idling degreaser during the 25-day test was calculated as follows:
~, Cross section area of degreaser - 9.5 ft.2 (0.88 m.2) - 871.14 lbs (396 kg.) solvent = 91.70 lbs/f~.
9.5 ft. ~0.88 m. ) (449 kg./m. ) for 25 days 600 hours in 25-day test 91 70 1bs/ft.2 (449 kg-/m- ) = 0.153 lbs/ft- /hr-600 hrs. ~0.748 kg./m.2/hr.
,, There was no rusting observed on any of the three sets of 1010 steel coupons removed from the degreaser and stored in the office. None of the removed coupons has exhibited any post rusting after removal from the degreaser, (20 days).
Example 2 A vapor degreasing grade of perchloroethylene was used having the following composition:
0.005% ~Wt.) N-Methyl Morpholine 0.40% (Wt.) Tertiary Butylglycidyl ether Balance - Perchloroethylene A six-week degreaser test was undertaken to study the ability of this formulation to withstand the stresses commonly occurring in vapor degreasing operations. The secondary purpose of this test was to look at the inhibitor distribution in both the degreaser ~ump and .~
17,952-F -10-~ 1071Z40 condensate over an extended period of time, and to deter-mine if this solvent exhibited stability and consistency under simulated field conditions Procedure The degreaser used for this experiment was elec-trically heated and measured 2' x 3' x 5' (0.61 x 0.92 x ,~ 1.52 m.). After the initial fill, the degreaser ran for a period of 45 days with additional solvent being added , intermittently as needed. Samples were taken every two .7 10 days from both the degreaser sump and warm dip to deter-mine if there was decomposition occurring with either the perchloroethylene or TBGE. These samples were tested by gas chromatography (GC) analysis which showed the changes in inhibitor levels and also whether or not decomposition products were present. During the test an effort was made to create in the degreaser the variety of adverse conditions that can occur during cleaning operations.
Consequently, there were added to the degreaser over the 45-day period 0.5 U.S. gallon (1.89 liter) of water, 1.25 U.S. gallons (4.73 liters) of commercial cutting oils, 0.5 lb. (0.23 kg.) steel chips, 0.5 lb. (0.23 kg.) zinc chips.
Results The solvent showed no significant loss of inhi-bitor in either the warm dip or degreaser sump during the course of this six-week degreaser test. The inhibitor partitioning of TBGE started out at a ratio 2-sump, l-warm dip and remained that way consistently throughout the 45-day period. Neither of the above additions (oil or chips) appeared to alter the condition of the solvent ~ ' , 17,952-F -11-~. , .
107~Z40 ' significantly from a stability standpoint. The GG analysis of samples taken during the study show no decomposition products of the solvent present but did show the chlorohydrin that occurs as a result of the reaction of HCl with TBGE.
The presence of one chlorohydrin shows that the inhibitor was performing adequately as an acid acceptor. The average TBGE concentration in the warm-dip was about 0.31 wt. percent and in the sump was bout 0.6 wt. percent.
Example 3 A field degreaser trial was started to evaluate the performance of the TBGE form~lation under field oper-' ating conditions. Perchloroethylene with 0.4% of TBGE
and containing 50 ppm of N-methyl morpholine, based on total composition, was used in the test. Steel panels were suspended in the vapor zone to enable visual obser-vation of rust formation during or after removal from the degreaser.
Procedure and Test -A one chamber, open top degreaser with a spray lance was used in the test. The degreaser was gas heated with cooling being done by a free-board water jacket.
Initially, the degreaser was charged with 155 U.S
gallons ~585 liters) of the formulation with approximately 55 U.S. gallons (208 liters) of make-up being added weekly.
This rate of make-up ls essentially the same as it was for the perchloroethylene used previously.
For the first week samples were taken daily.
After that, samples were taken weekly. The samples were analyzed at two locations for acid acceptance levels and whether degradation of the perchloroethylene and/or TBG~
17,952-F -12-, 1~71240 was occurring. Analysis of the samples were done using GB, the industry standard Acid ~cceptance Test Method, and I.R.
After one month, four (4) sets of three 4" x 8"
(10.2 x 20.4 cm.) 1010 steel panels were placed in the degreaser's vapor zone. The panels were exposed to the vapors for varying periods of time.
~posure of 1010 Steel Panels Panel Position Length of Exposure A vapor zone 1 week B vapor zone 2 weeks C vapor zone 3 weeks D vapor zone 4 weeks At the end of the exposure times no appreciable 15 rusting or corrosion of the panels was observed. Acid acceptance readings remained at an acceptable level ~ during the test.
,; ACID ACCEPTANCE DURING TEST
Source Acid Acceptance~2) Time Drum~l) 0.108 0 hrs Sump 0.140 24 hrs Sump 0.150 48 hrs Sump 0.165 8 days Sump 0.187 20 days Sump 0.187 28 days Sump 0.215 34 days Condensate 0.100 3 days Condensate 0.105 8 days Condensate 0.127 20 days Condensate 0.130 28 days Condensate 0.135 34 days . ~
~, 17,952-F -13-~` - .
.~! . .
~ lQ~7~240 .
(1) Sample was t~ken from formulation drun.
(2) Acid acceptance as ~ NaOH.
Samples generally were taken bef~re addition of ~, make-up solvent. The greatest increase occurred between 0 and 20 days. TBGE partition's at a rate of approximately 1.4 to 1 to condensate.
PARTI TI ONING TBC E TRIAL
Partitioning Wt. ~ Wt. % Factor TimeTBGE Sump CondensateSump/Cond.
2 days 0.44 - ~
3 days 0.46 - -
Ratio Sump % TBGE to Vapor Degreaser Sump 0.449% 1.4 Degreaser Warm Dip 0.317% 1.0 Still Conden~ate 0.456% 1.4 Still Sump 0.768% 2.4 At the end of the 25-day test the degreaser was shut down and the solvent in the warm dip chamber pumped into a tared 55 U.S. gallon (208 liters) drum. At this point there was a 25 percent oil content in the still pump. The contents of the degreaser sump were then routed through the still and distillate collected in the warm dip chamber.
17,952-F -7-- ~)71240 The amounts and analysis of the recovered solvent are tab-ulated in Tables I and II. Nine U.S. gallons (34.0 liters) ~:
. of solvent were recovered from the degreaser sump below ,.: the still transfer line, referred to as still bottoms below.
TABLE I
. Solvent . Wt. in U.S. Gallons % TBGE
Solvent Source Lbs. (Kg.) ~Liters) in Solvent 1) Warm dip at 373 ~169)27.69 ~105) 0.33 shut down .- 2) Distillate 289 ~131)21.46 ~81.4) 0.55 from still ; ~first batch) 3) Distillate 215 ~97.6) 15.96 ~60.2) 0.56 :~ from still !' ~second batch) 4) Residue solvent 123 ~56.0) 9.13 ~34.5) 0.504 ; from degreaser sump , TOTALS 1000 ~453.6) 74.24 ~281.1) Still Bottom8* 160 15.89 1.394 *Note: Still.bottoms contain 56% oil and 44% solvent, there-fore 6.99 gallons (26.4 liters) of the still bottoms are perchloroethylene with 1.394% wt. TBGE. Still bottoms also contain 0.213% of the chlorohydrin product ~CH3)3C-OCH2-CH-CH2Cl OH
.~ 17,952-F -8-.
,~ ~
10~1240 .
TABLE II
, Material Balance for TBGE Inhibitor Solvent Wt. inU.S. Gallons % TBGE
Solvent Source Lbs. (Kg.)(Liters) in Solvent 1) Solvent for 1965.3 (881)145.9 (551) 0.445 test 2) Recovered from still boil down1000.0 (453.6) 74.24 ~271) 0.4654 3) Still bottoms contain 44 perchloro (0.44 x 15.89) 94.1~ (42.8) 6.99 (26.4) 1.394 Total Recovered (2 and 3)1094.16 (496.4)81.24 (297.4) 0.545 -(Calcd) Comsumed*
(1 - (2+3))871.14 (384.6)64.67 (253.6) 0.296 :~ (Calcd) *Note: 0.458 U.S. gallons (1.73 liters) of T~GE inhibitor is accounted for by the 81.23 U.S. gallons (297 liters) of total recovered solvent lincluded 0.0149 U.S. gallons (0.560) of TBGE for chlorohydrin product in still bottoms).
Substracting 0.458 from the 0.6493 U.S. gallons (2.54 liters) TBGE in the original solvent gives 0.1914 U.S. gallons (0.72 liters) TBGE lost iwth the 64.67 U.S. gallons of consumed solvent.
Therefore the percent of TBGE in the consumed (by vapor losses and reaction with metal chlorides) solvent is 0.1914 x 100 = 0.2960% TBGE.
64.67 This figure of 0.2960% TBGE is very close to the average warm dip inhibitor content during the test period of 0.311%
TBGE laverage of 9 determinations).
Normal degreaser-still operation involves dumping and subsequent discarding of the boiled down still bottoms.
; 25 Accordingly, the amount of TBGE that would be lost is calculated by dividing the amount of TBGE in the boiled down still bottoms, i.e. 6.99 gal (25.4 liters) x 1.394% TBGE
by the amount of TBGE in the original solvent, 0.6493 gal.
17,952-F -9-',` ' .. .
(2.46 liters), or original would be lost. This loss is not excessive as seen by the fact that the 74.24 U.S.
gallons (281 liters) of recovered solvent had an average ; 0.465% TBGE inhibitor content while the original solvent had a 0.445~ inhibitor content.
The solvent comsu~ption in the idling degreaser during the 25-day test was calculated as follows:
~, Cross section area of degreaser - 9.5 ft.2 (0.88 m.2) - 871.14 lbs (396 kg.) solvent = 91.70 lbs/f~.
9.5 ft. ~0.88 m. ) (449 kg./m. ) for 25 days 600 hours in 25-day test 91 70 1bs/ft.2 (449 kg-/m- ) = 0.153 lbs/ft- /hr-600 hrs. ~0.748 kg./m.2/hr.
,, There was no rusting observed on any of the three sets of 1010 steel coupons removed from the degreaser and stored in the office. None of the removed coupons has exhibited any post rusting after removal from the degreaser, (20 days).
Example 2 A vapor degreasing grade of perchloroethylene was used having the following composition:
0.005% ~Wt.) N-Methyl Morpholine 0.40% (Wt.) Tertiary Butylglycidyl ether Balance - Perchloroethylene A six-week degreaser test was undertaken to study the ability of this formulation to withstand the stresses commonly occurring in vapor degreasing operations. The secondary purpose of this test was to look at the inhibitor distribution in both the degreaser ~ump and .~
17,952-F -10-~ 1071Z40 condensate over an extended period of time, and to deter-mine if this solvent exhibited stability and consistency under simulated field conditions Procedure The degreaser used for this experiment was elec-trically heated and measured 2' x 3' x 5' (0.61 x 0.92 x ,~ 1.52 m.). After the initial fill, the degreaser ran for a period of 45 days with additional solvent being added , intermittently as needed. Samples were taken every two .7 10 days from both the degreaser sump and warm dip to deter-mine if there was decomposition occurring with either the perchloroethylene or TBGE. These samples were tested by gas chromatography (GC) analysis which showed the changes in inhibitor levels and also whether or not decomposition products were present. During the test an effort was made to create in the degreaser the variety of adverse conditions that can occur during cleaning operations.
Consequently, there were added to the degreaser over the 45-day period 0.5 U.S. gallon (1.89 liter) of water, 1.25 U.S. gallons (4.73 liters) of commercial cutting oils, 0.5 lb. (0.23 kg.) steel chips, 0.5 lb. (0.23 kg.) zinc chips.
Results The solvent showed no significant loss of inhi-bitor in either the warm dip or degreaser sump during the course of this six-week degreaser test. The inhibitor partitioning of TBGE started out at a ratio 2-sump, l-warm dip and remained that way consistently throughout the 45-day period. Neither of the above additions (oil or chips) appeared to alter the condition of the solvent ~ ' , 17,952-F -11-~. , .
107~Z40 ' significantly from a stability standpoint. The GG analysis of samples taken during the study show no decomposition products of the solvent present but did show the chlorohydrin that occurs as a result of the reaction of HCl with TBGE.
The presence of one chlorohydrin shows that the inhibitor was performing adequately as an acid acceptor. The average TBGE concentration in the warm-dip was about 0.31 wt. percent and in the sump was bout 0.6 wt. percent.
Example 3 A field degreaser trial was started to evaluate the performance of the TBGE form~lation under field oper-' ating conditions. Perchloroethylene with 0.4% of TBGE
and containing 50 ppm of N-methyl morpholine, based on total composition, was used in the test. Steel panels were suspended in the vapor zone to enable visual obser-vation of rust formation during or after removal from the degreaser.
Procedure and Test -A one chamber, open top degreaser with a spray lance was used in the test. The degreaser was gas heated with cooling being done by a free-board water jacket.
Initially, the degreaser was charged with 155 U.S
gallons ~585 liters) of the formulation with approximately 55 U.S. gallons (208 liters) of make-up being added weekly.
This rate of make-up ls essentially the same as it was for the perchloroethylene used previously.
For the first week samples were taken daily.
After that, samples were taken weekly. The samples were analyzed at two locations for acid acceptance levels and whether degradation of the perchloroethylene and/or TBG~
17,952-F -12-, 1~71240 was occurring. Analysis of the samples were done using GB, the industry standard Acid ~cceptance Test Method, and I.R.
After one month, four (4) sets of three 4" x 8"
(10.2 x 20.4 cm.) 1010 steel panels were placed in the degreaser's vapor zone. The panels were exposed to the vapors for varying periods of time.
~posure of 1010 Steel Panels Panel Position Length of Exposure A vapor zone 1 week B vapor zone 2 weeks C vapor zone 3 weeks D vapor zone 4 weeks At the end of the exposure times no appreciable 15 rusting or corrosion of the panels was observed. Acid acceptance readings remained at an acceptable level ~ during the test.
,; ACID ACCEPTANCE DURING TEST
Source Acid Acceptance~2) Time Drum~l) 0.108 0 hrs Sump 0.140 24 hrs Sump 0.150 48 hrs Sump 0.165 8 days Sump 0.187 20 days Sump 0.187 28 days Sump 0.215 34 days Condensate 0.100 3 days Condensate 0.105 8 days Condensate 0.127 20 days Condensate 0.130 28 days Condensate 0.135 34 days . ~
~, 17,952-F -13-~` - .
.~! . .
~ lQ~7~240 .
(1) Sample was t~ken from formulation drun.
(2) Acid acceptance as ~ NaOH.
Samples generally were taken bef~re addition of ~, make-up solvent. The greatest increase occurred between 0 and 20 days. TBGE partition's at a rate of approximately 1.4 to 1 to condensate.
PARTI TI ONING TBC E TRIAL
Partitioning Wt. ~ Wt. % Factor TimeTBGE Sump CondensateSump/Cond.
2 days 0.44 - ~
3 days 0.46 - -
5 days - 0.31 1.45/1 10 days 0.51 0.33 1.54/1 22 days ~.57 0.39 1.46/1 30 days 0.57 0.40 1.42/1 37 days l).66 0.43 1.53/1 45 days ).76 0.52 1.46/1 17,952-F -14-~, , . , ,
Claims (8)
1. Perchloroethylene stabilized against degradation in the presence of hydrogen chloride and metals andcontaining from 0.1 to 5.0 weight percent of tertiary butyl glycidyl ether.
2. The composition of Claim 1 and containing in addition to the tertiary butyl glycidyl ether, 10 to 500 parts per million parts by weight of composition of an antioxidant.
3. The composition of Claim 2 wherein said antioxidant is N-methyl morpholine.
4. The composition of Claim 3 wherein the tertiary butyl glycidyl ether is present in the amount of from 0.25 to 1.5 weight percent.
5. The composition of Claim 4 wherein the N-methyl morpholine is present in the amount of 50 ppm by weight, based on the total composition.
6. A process for stabilizing perchloroethylene against degradation in the presence of hydrogen chloride and metals comprising adding to the perchloroethylene from 0.1 to 5.0 weight percent of tertiary butyl glycidyl ether.
7. A process as in Claim 6 wherein there is also added to the perchloroethylene from 10 to 500 parts per million parts of composition of an antioxidant.
8. A proces as in Claim 7 wherein the antioxidant is N-methyl morpholine.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US66479076A | 1976-03-08 | 1976-03-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071240A true CA1071240A (en) | 1980-02-05 |
Family
ID=24667452
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA272,627A Expired CA1071240A (en) | 1976-03-08 | 1977-02-24 | Stabilized perchloroethylene |
Country Status (13)
| Country | Link |
|---|---|
| JP (1) | JPS52108910A (en) |
| AT (1) | AT352693B (en) |
| AU (1) | AU506145B2 (en) |
| BE (1) | BE852214A (en) |
| CA (1) | CA1071240A (en) |
| CH (1) | CH629734A5 (en) |
| DE (1) | DE2710088C2 (en) |
| ES (1) | ES456597A1 (en) |
| FR (1) | FR2343710A1 (en) |
| GB (1) | GB1570939A (en) |
| IT (1) | IT1115839B (en) |
| NL (1) | NL7702488A (en) |
| SE (1) | SE431978B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2554710B1 (en) * | 1983-11-14 | 1987-09-25 | Medicalex | OSTEOSYNTHESIS MATERIAL FOR THE TREATMENT OF FEMUR FRACTURES |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5028929A (en) * | 1973-07-13 | 1975-03-24 |
-
1977
- 1977-02-24 CA CA272,627A patent/CA1071240A/en not_active Expired
- 1977-03-02 AU AU22848/77A patent/AU506145B2/en not_active Expired
- 1977-03-07 FR FR7706658A patent/FR2343710A1/en active Granted
- 1977-03-07 ES ES456597A patent/ES456597A1/en not_active Expired
- 1977-03-07 IT IT4833777A patent/IT1115839B/en active
- 1977-03-07 GB GB954977A patent/GB1570939A/en not_active Expired
- 1977-03-08 JP JP2536877A patent/JPS52108910A/en active Granted
- 1977-03-08 DE DE19772710088 patent/DE2710088C2/en not_active Expired
- 1977-03-08 NL NL7702488A patent/NL7702488A/en unknown
- 1977-03-08 BE BE175584A patent/BE852214A/en not_active IP Right Cessation
- 1977-03-08 CH CH288977A patent/CH629734A5/en not_active IP Right Cessation
- 1977-03-08 AT AT155277A patent/AT352693B/en not_active IP Right Cessation
- 1977-03-08 SE SE7702611A patent/SE431978B/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| CH629734A5 (en) | 1982-05-14 |
| DE2710088A1 (en) | 1977-09-22 |
| FR2343710B1 (en) | 1978-10-20 |
| BE852214A (en) | 1977-09-08 |
| FR2343710A1 (en) | 1977-10-07 |
| DE2710088C2 (en) | 1983-05-26 |
| GB1570939A (en) | 1980-07-09 |
| AT352693B (en) | 1979-10-10 |
| SE7702611L (en) | 1977-09-09 |
| SE431978B (en) | 1984-03-12 |
| ES456597A1 (en) | 1978-07-16 |
| JPS572694B2 (en) | 1982-01-18 |
| JPS52108910A (en) | 1977-09-12 |
| IT1115839B (en) | 1986-02-10 |
| AU506145B2 (en) | 1979-12-13 |
| NL7702488A (en) | 1977-09-12 |
| ATA155277A (en) | 1979-03-15 |
| AU2284877A (en) | 1978-09-07 |
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