A liquid composition, containing methylene chloride, can provide phosphate coatings on metal articles. In addition to the methylene chloride, the composition contains a phosphatizing proportion of phosphoric acid and a solubilizing solvent capable of solubilizing phosphoric acid in methylene chloride. Most critically, the composition contains water in an amount exceeding the proportion of phosphoric acid, yet, the water-containing liquid composition maintains liquid phase homogeneity. Phosphatized coatings of desirable water insolubility are thereby obtained.

BACKGROUND OF THE INVENTION 
Phosphatizing operations carried on in water have typically provided 
drawbacks, including sludging and the need for a multi-step operation, to 
achieve dry, coated articles. In an early attempt to overcome such 
problems, as described in U.S. Pat. No. 2,515,934, from 1% to 7% of the 
commercial phosphoric acid 85% syrup was used in an organic mixture, 
rather than in water. Representative of these mixtures was a 50/50 blend 
of acetone and carbon tetrachloride. With the blend, only a few steps were 
needed for phosphatizing. 
A different approach to overcoming the problems that are found in 
water-based phosphatizing systems, was taken in the process of U.S. Pat. 
No. 2,992,146. Therein, by means of special equipment, an aqueous 
phosphatizing solution was sprayed onto a metal article, while the article 
was being maintained in a vapor degreasing zone. The vapor degreasing zone 
contained the vapors from a chlorinated hydrocarbon such as 
trichlorethylene. The operation thereby permitted enhanced drying of 
panels after phosphatizing. 
In subsequently developed phosphatizing operations that relied on using 
chlorinated solvents, the water solution for the phosphatizing was 
altogether eliminated. In typical operations, a metal article for 
phosphatizing might be dipped in a chlorinated hydrocarbon degreasing 
solution, then come in contact with a non-aqueous phosphatizing solution, 
and thereafter be returned to the chlorinated hydrocarbon degreasing 
solution for a final rinse operation. Such operation has been described 
for example in U.S. Pat. Nos. 3,100,728 and 3,197,345. As also discussed 
in the U.S. Pat. No. 3,197,345, it was becoming recognized that there was 
a water-based process, also called an "aqueous" method of phosphatizing 
metal articles, and on the other hand a solvent-based process, which was 
therein noted as the "dry" process. The latter process typically employed 
a solution of phosphoric acid in a chlorinated hydrocarbon solvent. Since 
the compositions of the U.S. Pat. No. 3,197,345 relied on chlorinated 
hydrocarbons, the phosphatizing method used was the "dry" process and the 
useful compositions were substantially water-free compositions. 
As early as in the U.S. Pat. No. 2,515,934, it was recognized that the 
commercial phosphoric acid would introduce a small amount of water into 
organic phosphatizing compositions. In the U.S. Pat. No. 3,197,345 
teachings, it was regarded that substantially all of the water could be 
distilled from the phosphatizing bath as the "dry" treatment progressed. 
Getting away from a dependence on phosphoric acid was also explored. From 
this, it was found that special organic phosphate complexes could be 
useful in the non-aqueous solutions. They had the advantage of providing 
protective coatings of enhanced corrosion resistance. This approach was 
taken in U.S. Pat. No. 3,249,471. Another approach to the dry process, or 
to the "non-aqueous" process as it was also called, and that was employed 
in U.S. Pat. No. 3,297,495, was the use of a high strength acid. In such 
patent, the acid used was preferably one of 96-100% phosphoric acid. This 
concentrated acid presented sludge problems, but these were overcome by 
employing special additives. 
Other techniques, to maintain the non-aqueous phosphatizing process "dry", 
included the use of drying agents such as magnesium sulfate and the use of 
powdered metals. These concepts have been discussed in U.S. Pat. No. 
3,338,754. Therein it was emphasized that small amounts of water are 
detrimental to the phosphate coatings obtained from the non-aqueous 
phosphatizing solutions. It was also early recognized in the U.S. Pat. No. 
2,515,934 that the presence of water in an organic phosphatizing system 
could lead to the formation of two liquid phases, with attendant problems 
developing. Phase separation, and especially with regard to the formation 
of a separate aqueous phase. was discussed in U.S. Pat. No. 3,306,785. It 
is also noted, from the U.S. Pat. No. 3,306,785, that in developing the 
"dry" process with chlorinated hydrocarbons, emphasis was being placed on 
the commercially important trichlorethylene and perchlorethylene solvents. 
SUMMARY OF THE INVENTION 
It has now been found that a chlorinated hydrocarbon phosphatizing 
composition can produce highly desirable coating when such composition is 
maintained in a more "wet" condition. An initial key ingredient for the 
composition is methylene chloride. A further critical ingredient, in 
addition to a phosphatizing proportion of phosphoric acid, is an amount of 
water exceeding such proportion of phosphoric acid. But such water is not 
present in sufficient amount to provide a liquid composition that does not 
retain liquid phase homogeneity. Moreover, it has now been found possible 
to increase the coating weight of the resulting phosphate coating, by 
increasing the water content of the phosphatizing composition well beyond 
a content of just minute amounts. 
A further and most significant discovery, is the achievement of 
phosphatized coatings of extremely reduced water sensitivity. Because of 
this, phosphate coatings are now achieved wherein the coatings can be 
successfully topcoated with water based compositions. Such compositions 
can include aqueous chrome rinses. They can additionally include such 
coatings as water reduced paints and electrocoat primers. With the 
ingredients that are in the phosphatizing composition, including a 
solubilizing solvent capable of solubilizing the phosphoric acid in the 
methylene chloride, it has further been found that a vapor zone can be 
achieved in connection with the phosphating solution, in which zone there 
is obtained enhanced rinsing. For example, with the solubilizing solvent 
methanol, an especially desirable vapor zone can be obtained. 
Liquid blends that can include methylene chloride, methanol and water as a 
portion of the blend have been known heretofore. Further, the methylene 
chloride/methanol and methylene chloride/water azeotropes have been 
recognized to have nearly adjacent boiling points. Such recognition has 
been given for example in U.S. Pat. No. 3,419,477. As in the U.S. Pat. No. 
3,419,477, these phenomena have been previously recognized as useful in 
separation techniques. That is, separation of components can at least be 
initiated by making use of the azeotrope phenomena. Now, however, it has 
been found that in the vapor zone, created through the use of the 
phosphatizing compositions of the present invention, the vapor can provide 
for excellent rinsing of phosphate coated articles. Moreover, on 
condensation, the liquid condensed from the zone will retain complete 
liquid phase homogeneity without phase separation. 
As a corollary, bath rejuvenation, for example, can be accomplished by 
introducing into the phosphatizing bath a uniform liquid. This liquid, in 
constituency, can be equated to the constituency of the vapor zone; it 
thus will be a homogenous blend. The blend is amenable to preparation for 
storage and/or handling, without loss of liquid phase homogeneity, prior 
to use as bath replenishing liquid. 
Broadly, the invention is directed to a methylene-chloride and 
water-containing liquid composition having a continuous and homogenous 
liquid phase. The composition is suitable for phosphatizing metal with a 
water-resistent coating, while the liquid phase contains water in minor 
amount. More particularly, the composition comprises methylene chloride, 
solubilizing solvent capable of solubilizing phosphoric acid in methylene 
chloride, a phosphatizing proportion of phosphoric acid, and water in an 
amount exceeding the proportion of phosphoric acid while being sufficient 
for the composition to provide a phosphatized coating of substantial water 
insolubility, and while retaining liquid phase homogeneity. 
Another aspect to the invention is the process of providing a phosphate 
coating, of the nature described herein above, by contacting a metal 
surface with a composition having a continuous and homogeneous liquid 
phase and containing water in a minor amount, with the composition further 
containing substances as described herein above. Such process may further 
include contacting of the metal surface, before the phosphatizing, with 
vapors containing methylene chloride, and may also include contacting, 
after the phosphatizing, of the coated metal surface with vapors 
containing methylene chloride. 
Additional aspects of the invention include any of the fore-going 
phosphatizing processes followed by an aqueous chromium-containing 
solution treatment of the phosphatized metal surface. Other aspects of the 
invention include a vapor-containing rinse zone, for rinsing phosphate 
coated panels that have been in contact with the phophatizing liquid, with 
such zone comprising a mixture of methylene chloride vapors, solubilizing 
solvent vapors and water vapor. 
A still further aspect of the invention is a composition for sustaining 
phosphatizing from a phosphatizing liquid medium as above described. Such 
rejuvenating composition includes, in a homogeneous liquid blend, 
ingredients also found in the abovedescribed, vapor-containing rinse zone. 
DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The methylene chloride, or the "methylene chloride constituency" as it is 
sometimes referred to herein, is typically comercially available methylene 
chloride, and may contain additional ingredients, although the use of a 
more purified methylene chloride is contemplated. The methylene chloride 
may then contain very minor amounts of stabilizers such as cyclohexane. 
Useful, commercially available methylene chloride may contain very minor 
amounts of additional substances such as other chlorinated hydrocarbons, 
including chloroform and vinylidene chloride. It is further contemplated 
to use as the methylene chloride constituency, methylene chloride blended 
with a minor amount of additional solvent. This would be solvent in 
addition to the organic solvent discussed in greater detail hereinbelow. 
Preferably, the additional solvent will be non-flammable and will form an 
azeotrope with the methylene chloride on heating, e.g., trichloro 
trifluoroethane. Although the methylene chloride constituency will 
generally provide the major amount of the liquid phosphatizing solution 
and will typically provide between about 60 to about 90 weight percent of 
such solution, this is not always the case. Most always, when the 
methylene chloride constituency does not form the major amount of the 
solution, the solubilizing solvent will be the predominant substituent in 
the solution. 
The solubilizing solvent needs to be one or a mixture that is capable of 
solubilizing phosphoric acid in methylene chloride. The solvent can also 
affect other characteristics of the phosphatizing solution, e.g., the 
solvent may have an effect on the solubility of water in the phosphatizing 
solution. It is advantageous that the solubilizing solvent not create a 
readily flammable phosphatizing liquid. It is preferable that it effect 
enhanced solubilization of water in the methylene chloride. It is further 
preferred, for efficient phosphatizing operation, that the solvent have a 
boiling point higher than the boiling point of methylene chloride, or that 
the solvent, on boiling, form an azeotrope with methylene chloride. The 
solvent can be, and on occasion most desirably is, a blend of organic 
substances. Such blends are particularly useful for augmenting the 
solubility of water in the phosphatizing solution. 
Particularly where the phosphatizing solution will be used as a liquid 
phosphatizing bath, at elevated temperature, thereby forming a rinse zone 
immediately above the bath that contains constituents of the bath in vapor 
state, it is desirable that the solubilizing solvent be present in such 
vapor. When phosphatized metal articles are removed from the phosphatizing 
bath into such rinse zone, one ingredient that may be present on the 
article for rinsing is phosphoric acid. Since methylene chloride even as a 
vapor in the rinse zone will exert little solubilizing activity towards 
the phosphoric acid, it is desirable to have solvent vapor also present in 
the rinse zone. 
Most advantageously for efficiency of operation the solubilizing solvent is 
an alcohol having less than six carbon atoms. Alcohols of six carbon atoms 
or more may be used, but should always be present in minor amount with at 
least one less than six carbon atoms alcohol being in major amount. 
Representative alcohols that can be or have been used include methanol, 
ethanol, isopropanol, n-pentanol, n-propanol, n-butanol, allyl alcohol, 
sec-butanol, tert-butanol and their mixtures wherein liquid phase 
homogeneity is maintained when in mixture with methylene chloride. 
However, additional substances, e.g., 2-butoxyethanol, can also be 
serviceable, alone or in combination with alcohol. As mentioned 
hereinabove, useful phosphatizing solutions can be achieved when the 
solvent provides the predominant constituent of the phosphatizing 
composition. Preferably for efficiency and economy the organic solvent is 
methanol. 
As inferred hereinabove, phosphoric acid has only an extremely limited 
solubility in methylene chloride. However, this situation is obviated by 
using the solubilizing solvent. Therefore, although the phosphoric acid is 
a critical ingredient that is generally present in a very minor amount, 
with the solubilizing solvent present in the phosphatizing solution the 
phosphoric acid may be contained in the phosphatizing solution in 
substantial amount. Such amount might be up to 2-3 weight percent or more. 
But, for efficient and economical coating operation, the phosphoric acid 
is generally used in an amount below about one weight percent, basis total 
weight of the phosphatizing composition. A much greater amount than about 
1%, will typically leave a coating on the metal substrate that is tacky to 
the touch. Preferably, for most efficient coating operation, the 
phosphoric acid is present in an amount between about 0.2-0.8 weight 
percent, basis the phosphatizing solution, although an amount below even 
0.1 weight percent can be serviceable. 
If it is contemplated that the phosphatizing solution will be used for the 
coating of metals that have been heretofore recognized as susceptible to 
phosphatizing, i.e., capable of reacting with phosphoric acid. Thus, it is 
contemplated that the phosphatizing solution will be useful for 
phosphatizing aluminum, zinc, cadmium and tin substrates as well as the 
more typical ferruginous metal substrates. The "phosphatizing proportion 
of phosphoric acid", as such term is used herein, may well be a 
"phosphatizing substance", as it might more appropriately be termed. That 
is, the use of such terms herein is not meant to exclude any substances 
that may be, or have been, useful in the solvent phosphatizing art for 
providing a phosphate coating. Such substances might thus include organic 
phosphate substance as well as the more typical acidic substances of 
phosphorous, e.g., the usual orthophosphoric acid. Further, it is 
contemplated that such substance include salts of such acids in 
phosphatizing. Since water is present in the phosphatizing solution in 
amounts greater than the phosphatizing substance, although concentrated 
acids are contemplated, e.g., phospholeum, the resulting solution contains 
the acid in dilution in water. Preferably, for economy, the 
orthophosphoric acid is always the phosphoric substance used in the 
phosphatizing solution. 
As mentioned hereinbefore, the amount of the phosphatizing substance in the 
phosphatizing solution is exceeded by the amount of water present in such 
solution. Water must be present in at least an amount sufficient to 
provide a phosphatized coating on ferrous metal of substantial water 
insolubility. As is discussed in greater detail hereinbelow, this means 
that the coating will be, at most, about 20% water soluble. On the other 
hand, water may typically be present in an amount as great as water 
saturation of the phosphatizing solution, at the temperature of 
phosphatizing. However, saturation is not exceeded as the solution will 
then lose liquid phase homogeniety. Homogeniety as used herein refers to 
solution uniformity free from liquid phase separation. When water 
separates, the separate water phase may attract phosphoric acid into such 
phase, to the detriment of further coating operation. 
For many phosphatizing solutions of the present invention, on one hand 
water insoluble coatings are achieved, coupled with an acceptable coating 
weight, when the water content of the solution reaches about 1.5-2.5 
weight percent. On the other hand, phase separation for many solutions can 
occur when the water content reaches about 5-7 weight percent, basis total 
solution weight. Such is shown in greater detail, by reference to the 
Examples. But, since the solubilizing solvent can affect the ability of a 
phosphatizing solution to solubilize water, then especially those 
solutions wherein the solubilizing solvent predominates, may be solutions 
able to contain substantial amounts of water, for example 10-25 weight 
percent of water might be reached without achieving saturation. But the 
water will always provide a minor weight amount of the phosphatizing 
solution. 
Water in the solution will exert a vapor pressure; the solution water 
content will thereby directly influence the water content of the vapor 
zone associated with the solution. When such zone is over a bath of 
phosphatizing solution, a substantial amount of water vapor may retard the 
drying time of coated metal substrates that are phosphatized in the bath 
and then removed to the vapor zone for drying. Thus attention to the water 
content of a bath, when such might exceed about the 5-10 weight percent 
range is advisable. Since water is present in the phosphatizing solution 
in an amount in excess of phosphoric acid, it will most always be present 
in an amount within the range of about 2-5 weight percent. 
Basic to the "phOsphatizing solution" or "phosphatizing composition" as 
such terms are used herein, are the methylene chloride constituency, 
solubilizing solvent, phosphatizing proportion of phosphoric acid, and the 
water. A further substance that may be present in the phosphatizing 
solution is an aprotic organic substance. Although it is contemplated to 
use aprotic polar organic compounds for such substance, it is preferred 
for efficient coating operation to use dipolar aprotic organic compounds. 
These compounds act in the coating solution to retard the formation of an 
undesirable, grainy coating. The aprotic organic compound can also 
influence the level at which water saturation will occur in the 
phosphatizing compositions containing such compound, particularly when 
they are present in substantial amount. Although it is contemplated that 
such compound will always be present in minor weight amount of the 
phosphatizing solution, and generally present in an amount less than the 
amount of the solubilizing solvent, serviceable phosphatizing solutions 
can be prepared that contain on the order of 10 to 15 weight percent or 
more of such aprotic organic compound. 
It is preferred, for extended retention of the aprotic organic compound in 
the phosphatizing solution during the phosphatizing operation, that such 
compound have a boiling point above the boiling point of the methylene 
chloride. Preferably, for most extended presence in the coating solution, 
such compound boils at least about 20.degree. C higher than the methylene 
chloride. The aprotic organic compound is often a nitrogen-containing 
compound; these plus other useful compounds include N,N-dimethyl 
formamide, dimethyl sulfoxide, acetonitrile, acetone, nitromethane, 
nitrobenzene, tetramethylenesulfone and their inert and homogeneous liquid 
mixtures where such exist. By being inert, it is meant that such mixtures 
do not contain substituents that will chemically react with one another, 
in the phosphatizing solution, at the temperature attained for the 
solution to be at boiling condition. Dimethyl sulfoxide is useful as an 
aprotic organic compound; but, such may further be used as an accelerator 
compound, as is discussed herein below. In such case when the dimethyl 
sulfoxide is present as an accelerator compound, substance other than 
dimethyl sulfoxide is used to supply aprotic organic compound. 
Another substance generally found in the phosphatizing composition is the 
organic accelerator compound. Such compound serves to increase the rate of 
formation of the coating during the phosphatizing process. Acceleration is 
accomplished without deleteriously affecting the nature of the coating, 
e.g., desirable uniform and non-grainy crystal structure for the coating. 
Serviceable compounds typically act in such manner even when present in 
the composition in very minor amount, as for example, in amount much less 
than one weight percent basis total composition weight. Advantageously, 
for efficient operation, the accelerator compound has a boiling point 
greater than the boiling point of methylene chloride. Many of the useful 
accelerator compounds are nitrogen-containing organic compounds. More 
specifically, compounds that can be, or have been, used include urea, 
pyridine, thiourea, dimethyl sulfoxide, dimethylisobutylene amine, 
ethylenediaminetetraacetic acid and dinitrotoluene. 
The use of stabilizers has been taught in the prior art and such are 
contemplated for use herein, such as the hydrogen and hydrogen chloride 
acceptor substituents that can retard the corrosive nature of 
phosphatizing compositions. Stabilizers against oxidation of a 
halohydrocarbon, for example, are also known. These can likewise assist in 
reducing the corrosive nature of the phosphatizing composition. Useful 
substances can include p-benzoquinone, p-tertiaryamyl phenol, thymol, 
hydroquinone and hydroquinone monomethyl ether. 
The methylene chloride containing phosphatizing composition is suitable for 
use with any of the phosphatizing operations that can be, or have been, 
used with solvent phosphatizing. Solvent phosphatizing operations can 
provide, quickly and efficiently, dry, coated metal substrates; and thus, 
such operations will most always provide for quickly achieving same. 
Sequentially, metal articles for phosphatizing may be typically degreased 
in methylene chloride degreasing solution and then immersed in a bath of 
the phosphatizing composition with such bath being most always heated to 
boiling condition. The phosphatized article, upon removal from the bath, 
can then be maintained in the vapor zone above the bath for evaporating 
volatile constituents from the coated article to coating dryness. During 
such maintenance, the article may be subjected to a spray rinse. The 
phosphatizing composition may also be spray applied to a metal article, 
such as in a vapor zone that might be formed and/or replenished by vapor 
from the spray composition. Other contemplated aspects of successful 
operation include initial rinsing of a metal article with warm rinse 
liquid, e.g., immersion rinsing in such liquid, wherein the liquid is 
formed from the constituents of the vapor from the phosphatizing solution. 
Such rinsing is then followed by phosphatizing, and this can be further 
followed by an additional rinse in the warm rinse liquid. For efficiency 
in all operations, the temperature of the phosphatizing composition is 
maintained at boiling condition. At normal atmospheric pressure this will 
typically be at a temperature within the range of about 
100.degree.-105.degree. F. although lower temperatures of operation are 
contemplated. In the ambient atmosphere adjacent to the phosphatizing 
solution, constituents of such solution may be present in the vapor state. 
For convenience, this atmospheric region is thereby termed the "vapor 
zone". 
During phosphatizing, which will take place typically in degreaser 
apparatus, the vapor zone, in addition to containing trace amounts of 
other substances, will be found to contain methylene chloride vapor, vapor 
from the solubilizing solvent that solubilizes the phosphoric acid in 
methylene chloride as well as water vapor. Since such substances are the 
chief ingredients of the vapor zone, they are the chief ingredients of the 
phosphatizing composition that can be expected to be lost from such 
composition as vapor loss. It has therefore been found to be most 
serviceable to formulate a replenishing liquid composition containing 
methylene chloride, solubilizing solvent and water. Further, it has been 
found that such replenishing liquid can be successfully used for 
sustaining the phosphatizing composition, and that such can form a 
homogeneous and storage-stable blend. Thus, for convenience, this liquid 
is often referred to herein as the "sustaining solution." The sustaining 
solution can be prepared ahead, for later use after storage and/or 
shipment. It can be useful for sustaining the formation of water-resistant 
and uniform coatings, especially when used for in-service phosphatizing 
solutions. The coatings from in-service solutions might be exhibiting loss 
of coating uniformity, for example. 
In the make-up of the sustaining solution, the methylene chloride will be 
the predominant ingredient, generally supplying between 70-97 weight 
percent of the solution. In the balance, the solubilizing solvent will 
supply the major amount, being usually present in an amount between about 
2-25 weight percent of the total solution. The water is present in minor 
amount, e.g. 0.5-2 percent or less, and always together with sufficient 
solubilizing solvent to insure solution homogeneity. For the preferred 
solvent methanol, the sustaining solution will preferably contain, for 
best sustaining action, between about 90-96 percent methylene chloride, 
about 2-9 percent methanol and 0.4-4 percent water, with the three 
components totalling 100 weight percent. Preferably, for enhanced 
phosphatizing operation, the water, solubilizing solvent and methylene 
chloride will be combined in the sustaining solution in the equivalent 
proportions of such substances in the phosphatizing medium vapor zone. To 
efficiently prepare a homogeneous sustaining solution, it is preferred to 
first preblend the water with solubilizing solvent. Then the methylene 
chloride is admixed with the preblend to quickly obtain a homogeneous 
sustaining solution. In the preferred method of preparation, and for the 
preferred solubilizing solvent methanol, the weight ratio of the water to 
the alcohol in the preblend is generally maintained at less than 1:6. 
Often, such ratio will be on the order of 1:10-1:12. Also in this 
preferred method of preparation, after the methylene chloride addition, 
additional ingredients, if present, are then generally added. 
These additional ingredients will be present in very minor amounts. 
Typically these are present in combination in an amount less than about 
1-2 weight percent based on the weight of the sustaining solution. Such 
ingredients can include accelerator compound, stabilizer compound, aprotic 
organic compound and phosphoric acid. However, where such sustaining 
composition is prepared for extended storage, the phosphoric acid is 
generally not included to avoid the use of special, acid-resistant 
containers. Preferably, for economy, the additional ingredients are each 
present in an amount less than about 0.1 weight percent. 
For the preferred solvent methanol, in addition to the constituency of the 
sustaining solution being as described above, it is further advantageous 
for most efficient coating action that such solution be added to the 
phosphatizing medium so as to maintain the medium at a specific gravity 
between about 1.14 and about 1.17. At a specific gravity below about 1.14, 
commercially desirable coatings may not be efficiently achieved, while at 
a phosphatizing medium specific gravity greater than about 1.17, when the 
solubilizing solvent is methanol, coating formation can require 
undesirably delicate control. Preferably, for best phosphatizing from a 
methanol containing medium, the sustaining solution is used to maintain 
the medium specific gravity between about 1.15 and about 1.16. 
As a pre-packaged blend, the sustaining solution in addition to being 
useful for sustaining, has further utility in the make-up of a fresh 
phosphatizing composition. When using the sustaining solution for fresh 
solution make-up, it has been found that typical additional ingredients 
for the solution make-up may also be prepared ahead in a storage-stable 
and uniform blend. This additional blend will generally contain, as chief 
ingredients, solubilizing solvent, aprotic organic compound and water. 
Further, such additional blend will often contain accelerator compound and 
stabilizer compound. Such blend is often referred to herein simply as the 
"precursor composition." As a precursor composition to the make-up of a 
fresh bath, substances are generally simply mixed together for preparing 
this precursor composition and then the composition is packaged for 
storage and/or handling. Most usually, the solubilizing solvent will 
comprise the major amount of this precursor composition, and preferably 
will supply between about 55-80 weight percent of the composition. 
Further, the water and aprotic organic compound may be present in 
substantially equivalent amounts. Each ingredient will generally be 
present in an amount between about 10-30 weight percent. Additional 
ingredients, e.g., accelerator compound or stabilizer compound, are each 
often present in an amount less than one weight percent, basis the weight 
of such precursor composition. In a typical fresh bath make-up, the 
precursor composition and the above described sustaining solution, with 
one or both of such generally containing accelerator plus stabilizer, are 
mixed together, often for use in degreasing apparatus, with phosphoric 
acid being added during the blending. Thus, only these two solutions plus 
phosphoric acid need be on hand at the inception of phosphatizing solution 
make-up. 
After coating formation on a metal article, the article can then proceed 
into a vapor zone that will be supplied and replenished by vaporized 
substituents from the phosphatizing composition. As discussed herein 
before, such vapor zone can have a highly desirable make-up of methylene 
chloride vapor, water vapor and solubilizing solvent vapor as chief 
constituents. This vapor blend has been found to be highly suitable as a 
rinsing and drying medium for phosphatized articles. Typically, as in 
immersion phosphatizing, the coated article may be simply removed from the 
phosphatizing bath into the vapor zone, maintained in such zone until dry, 
and then removed for subsequent operation. The constituency of the vapor 
zone, in addition to supplying a desirable rinsing medium, will also form, 
on condensation, a stable, uniform liquid blend. This phenomenon enhances 
the simplicity of recirculation systems, as when coating operation is 
handled in degreaser apparatus. Also, such recirculation systems can be 
adapted to have the recirculating, condensed vapor replenished with fresh 
sustaining solution, which solution has been discussed hereinabove, with 
the replenished liquid then being recirculated to the phosphatizing 
solution medium. 
As such medium in this operation will typically be maintained at a 
temperature at boiling condition, the temperature at the vapor zone will 
typically be within the range of about 100.degree.-105.degree. F. Further, 
the methylene chloride will form the predominant substance in the vapor 
zone. For example, in a phosphatizing composition wherein methanol is the 
solubilizing solvent, the vapor zone can be expected to contain above 90% 
by weight of methylene chloride, exclusive of the ambient air in such 
zone. But, because the vapor zone will also contain methanol vapor, as 
well as water vapor, such combination insures a highly desirable rinse 
vapor. More particularly, with the methanol as solvent, the vapor zone at 
normal pressure may be at a temperature from about 101.degree. F. to about 
104.degree. F. and contain between about 0.6-0.7 weight part water, with 
between about 5.5-6.5 weight parts methanol and the balance methylene 
chloride to provide 100 weight parts. 
The phosphatizing composition will typically provide a desirable phosphate 
coating, i.e., one having a weight of twenty milligrams per square foot or 
more on ferrous metal, in fast operation. Although contact times for 
ferrous metal articles and the phosphatizing composition may be as short 
as fifteen seconds for spray application, it will typically be on the 
order of about forty-five seconds to three minutes for dip coating, and 
may even be longer. The coating weights, in milligrams per square foot, 
can be on the order as low as 10 to 20 to be acceptable, i.e., provide 
incipient corrosion protection with initial enhancement of topcoat 
adhesion, and generally on the order of as great as 100 to 150 although 
much greater weights, e.g., three hundred or so, are contemplated. 
Preferably, for best coating characteristics including augmented topcoat 
adhesion and corrosion protection, the coating will be present in an 
amount between about 20-100 milligrams per square foot. Such coatings are 
readily and consistently produced with desirable coating uniformity. 
The coatings that are obtained on ferrous metal will have at least 
substantial water insolubility, and hence are also termed herein to be 
"water-resistant" coatings. For determining water solubility, the test 
employed is sometimes referred to as the "water soak test". In this test, 
as is also described in connection with the examples, a coated ferruginous 
article is weighed and then immersed in distilled water for ten minutes. 
The water is maintained at room temperature, typically 
65.degree.-75.degree. F, and with no agitation. After this ten minute 
immersion, the article is removed from the water, rinsed in acetone and 
air dried. Subsequently, on re-weighing, the amount of water solubility of 
the coating is shown by any weight loss. This loss is generally expressed 
as a percentage loss of the total original coating. The method used for 
determining the original coating weight has been more specifically 
described in connection with the examples. 
Advantageously, for enhanced corrosion protection, the water solubility of 
the coating will be on the order of less than 20% as determined by the 
water soak test. Such a coating, for convenience, is often termed herein 
as a "phosphatized coating of substantial water insolubility". Preferably, 
for best coating performance, including the ability to receive topcoating 
with water-based topcoat compositions, the water solubility of the coating 
will be less than 5% , basis total weight of the original coating. In 
typical processing, the phosphatizing operation of the present invention 
will provide phosphatized coatings on ferruginous surfaces having 
virtually no water solubility as determined by the water soak test. 
For better determining the nature of the coatings that are obtained on 
ferrous substrates, in addition to physical characteristics, they have 
been subjected to further coating analysis. As detailed more specifically 
in the examples, coatings from the phosphatizing operation that are of the 
iron phosphate type have been subjected to analysis by the Electron 
Spectroscopy for Chemical Analysis (ESCA) technique. Further, such 
coatings have been subjected to Auger Spectroscopy. For convenience, these 
may be referred to simply as "spectroscopic analysis". Such analysis 
confirms that the water insoluble coatings, that are obtained in the 
phosphatizing operation on a ferruginous substrate, contain in their 
make-up, the elements sodium and calcium in trace amounts. The balance of 
the elements is provided by phosphorous, iron, oxygen, carbon and 
nitrogen. Under similar analysis, comparative phosphatized coatings, which 
are water soluble coatings prepared from prior art phosphatizing 
techniques based on chlorinated hydrocarbon phosphatizing methods, fail to 
show such combination of elements in a phosphatized coating. Although all 
of the coatings are complex, because of the nature of the spectroscopic 
analysis techniques used in analyzing the coating, the make-up of the 
coating under analysis is expressed in the form of the elements. That is, 
it is to be understood that the coating is basically and completely 
defined by setting forth the elements. Although the elements will or may 
form various bonding relationships, the coating is defined by the elements 
is not limited to various particular relationships. 
Because of the water resistant nature of the phosphate coating, the 
resulting coated metal substrates are especially adapted for further 
treatment with water based coating and treating systems. For example, the 
coated substrates may be further treated with acidified aqueous solutions 
typically containing a multivalent metal salt or acid in solution. Such 
treating solutions can contain hexavalent-chromium-containing substance, 
including the simplistic rinse solutions of chromic acid and water as 
mentioned in U.S. Pat. Nos. 3,116,178 or 2,882,189, as well as their 
equivalent solutions, for example the molybdic and vanadic acid solutions 
discussed in U.S. Patent 3,351,504. Further these treating solutions may 
be non-aqueous, it being contemplated to use chromic acid solutions such 
as disclosed in U.S. Pat. No. 2,927,046. The treatment can include 
solutions containing additional, reactive ingredients, as for example the 
combination of chromic acid and formaldehyde disclosed in U.S. Pat. No. 
3,063,877. Additional treatments that are contemplated include the complex 
chromic-chromates from solutions typically containing trivalent chromium, 
as has been discussed in U.S. Pat. No. 3,279,958. Further treatments that 
can be used include such as the blended complex chromate salts disclosed 
in U.S. Pat. No. 3,864,175 as well as solutions containing salts of other 
metals, as exemplified in U.S. Pat. No. 3,720,547, wherein salts of 
manganese are employed in treating solutions. All of these treatments will 
generally provide a coating having a weight of from about 2 to about 40 
milligrams per square foot of treated substrate, although such weight may 
be lower, and is often greater, e.g., 100 milligrams per square foot or 
more. For convenience, these treatments and solutions collectively are 
sometimes referred to herein as "non-phosphatizing solutions for treating 
metal substrates". 
The phosphatized coating also lends itself to topcoating from electrically 
deposited primers, such as the electrodeposition of film-forming materials 
in the well known electrocoating processes. Further, the phosphatized 
coatings can form the base coating for a water reducible topcoating. Such 
topcoating compositions typically contain solubilized polymers, similar to 
conventional alkyd, polyester, acrylic and epoxy types, that are typically 
solubilized with smaller amounts of organic amine. Also the resulting 
phosphate coated substrate can be further topcoated with any other 
suitable resin-containing paint or the like, i.e., a paint, primer, 
enamel, varnish or lacquer including a solvent reduced paint. Additional 
suitable paints can include the oil paints and the paint system may be 
applied as a mill finish. 
Before applying the phosphate coating, it is advisable to remove foreign 
matter from the metal surface by cleaning and degreasing. Although 
degreasing may be accomplished with commercial alkaline cleaning agents 
which combine washing and mild abrasive treatments, the cleaning will 
generally include degreasing. Although such degreasing can be accomplished 
with typical degreasing systems, such degreasing can be readily and 
efficiently handled with methylene chloride degreasing solvent. 
The following examples show ways in which the invention has been practiced 
but should not be construed as limiting the invention. In the examples all 
parts are parts by weight unless otherwise specifically stated. In the 
examples the following procedures have been employed. 
PREATION OF TEST PANELS 
Bare steel test panels, typically 6 inches .times. 4 inches or 3 inches by 
4 inches unless otherwise specified, and all being cold rolled, low carbon 
steel panels are typically prepared for phosphatizing by degreasing for 15 
seconds in a commercial, methylene chloride degreasing solution maintained 
at about 104.degree. F. Panels are removed from the solution permitted to 
dry in the vapor above the solution, and are thereafter ready for 
phosphatizing. 
PHOSPHATIZING OF TEST PANELS AND COATING WEIGHT 
In the examples, cleaned and degreased steel panels are phosphatized by 
typically immersing the panels into hot phosphatizing solution maintained 
at its boiling point, for from one to three minutes each. Panels removed 
from the solution pass through the vapor zone above the phosphatizing 
solution until liquid drains from the panel; dry panels are then removed 
from the vapor zone. 
Unless otherwise specified in the examples, the phosphatized coating weight 
for selected panels, expressed as weight per unit of surface area, is 
determined by first weighing the coated panel and then stripping the 
coating by immersing the coated panel in an aqueous solution of 5% chromic 
acid which is heated to 160.degree.-180.degree. F. during immersion. After 
panel immersion in the chromic acid solution for 5 minutes, the stripped 
panel is removed, rinsed first with water, then acetone, and air dried. 
Upon reweighing, coating weight determinations are readily calculated. 
Coating weight data is presented in milligrams per square foot 
(mg/ft.sup.2). 
MANDREL TEST BENDING (ASTM-D 522) 
The conical mandrel test is carried out by the procedure of ASTM D-522. 
Briefly, the testing method consists in deforming a paint-coated metal 
panel by fastening the panel tangentially to the surface of a conical 
steel mandrel and forcing the sheet to conform to the shape of the mandrel 
by means of a roller bearing, rotatable about the long axis of the cone 
and disposed at the angle of the conical surface, the angle of deformation 
or arc travel of the roller bearing being approximately 180.degree.. 
Following the deformation, a strip of glass fiber tape coated with a 
pressure-sensitive adhesive is pressed against the painted surface on the 
deformed portion of the test panel and is then quickly removed. The 
coating is evaluated quantitatively according to the amount of paint 
removed by the adhesive on the tape, in comparison with the condition of a 
standard test panel. 
REVERSE IMT STRENGTH 
In the reverse impact test, a metal ram of specified weight, in pounds, 
with a hemispherical contact surface is allowed to drop from a 
predetermined height in inches onto the test panel. Paint removal is 
measured qualitatively or quantitatively on the convex (reverse) surface. 
In the qualitative measurement the impacted surface is merely observed by 
visual inspection and comparative panels, i.e., those subjected to the 
same impact in inch-pounds, are rated according to a numerical scale 
presented in Example 6 hereinbelow. 
CROSS-HATCH 
This test is conducted by scribing, through the coating to the metal panel 
with a sharp knife, a first set of parallel lines one-eighth inch apart. A 
second, similar set of lines, is then scribed on the panel at right angles 
to the first set. Following this, a strip of glass fiber tape coated with 
a pressure-sensitive adhesive is pressed against the painted surface on 
the scribed portion of the test panel and is then quickly removed. The 
coating is rated in accordance with the numerical scale presented in 
Example 6 hereinbelow, based on the amount of paint removed by the 
adhesive on the tape. 
COIN ADHESION 
A fresh nickel coin is firmly secured in vise-grip pliers; the pliers are 
manually held in a position such that a portion of the rim of the nickel 
coin contacts the coated substrate at about a 45.degree. angle. The nickel 
coin is then drawn down across the panel for about two inches. The type of 
coating flaking and/or chipping is evaluated qualitatively by visual 
observance, and panels are compared with the condition of a standard test 
panel.

EXAMPLE 1 
To 288 parts of methylene chloride there is added, with vigorous agitation, 
102.4 parts methanol, 1.3 parts ortho phosphoric acid, and 15.8 parts 
N,N-dimethyl formamide. These blended ingredients are thereafter boiled 
for one hour using a reflux condenser and the solution is permitted to 
cool. The water content of the resulting boiled solution, provided 
principally by the phosphoric acid, is found to be about 0.1 weight 
percent. This water content is directly determined by gas chromatograph 
analysis of a sample wherein the column packing is Porapak Q manufactured 
by Waters Associates, Inc. The resulting solution is then heated to 
102.degree.-103.degree. F. and panels are phosphatized in the manner 
described hereinabove. 
Some of the resulting coated panels, selected in sets of two with each 
panel in the set being coated under identical conditions, are then 
subjected to testing. One panel in the set is used for coating weight 
determination in the manner described hereinabove. The other panel in the 
set is subjected to the water solubility test. For this test the panel is 
weighed and then immersed in distilled water for ten minutes, the water 
being maintained at ambient temperature and with no agitation. Thereafter, 
the test panel is removed from the water, rinsed in acetone and air dried. 
Subsequently, on reweighing, the amount of water solubility of the coating 
is shown by the weight loss. This loss, basis total original coating 
weight, is reported in the Table below as the percentage or degree, of 
coating loss. 
Coating weights and water solubility of coatings, are determined initially 
for test panels that have been phosphatized in the above-described 
phosphatizing composition. Such data are determined thereafter for 
additional coated panels that have been phosphatized in compositions of 
differing water contents, all as shown in the Table below. These baths of 
varying water content are prepared in step-wise fashion by starting with 
the abovedescribed bath, and then adding about one weight percent water to 
the bath followed by boiling the resulting solution for one hour. This 
procedure is repeated with additional water increments of one weight 
percent, as shown in the Table below. The phosphatizing coating operation 
for each bath of varying water content has been described hereinabove. For 
each phosphatizing bath, water content determinations are made prior to 
phosphatizing by the above-described method. 
TABLE I 
______________________________________ 
Coating Degree of 
Bath Water Panel Coating Solubility of 
Content,Wt. % 
Weight: mg/ft.sup.2 
Coating in Water 
______________________________________ 
0.1 4 60% 
1.1 6 50% 
2.1 10 20% 
3.1 13 &lt;5% 
4.1 24 &lt;5% 
______________________________________ 
The tabulated results demonstrate the enhancement in the degree of water 
insolubility for the phosphate coating as the water content in the 
phosphatizing bath increases. As determined by visual inspection, it is 
also noted that the degree of uniformity of the phosphate coating is 
increasing as the water content of the phosphatizing bath increases. For 
the particular system of this Example, the desirable water content is 
deemed to be between about 2 weight percent and about 5 weight percent. 
Below about 2 weight percent, the degree of water solubility for the 
coated panels is regarded as being excessive. By continuing the step-wise 
water addition discussed hereinabove, this system is found to separate 
free water, i.e., lose liquid phase homogeneity, when the water content 
reaches 5.1 weight percent. 
EXAMPLE 2 
A phosphatizing solution is prepared from 7510 parts of methylene chloride, 
1731 parts methanol, 5 parts ortho phosphoric acid, 374 parts N,N-dimethyl 
formamide, and 7 parts dinitrotoluene. Prior to phosphatizing of steel 
panels the water content of the phosphatizing bath is determined, as 
described in Example 1, to be 373 parts. 
Panels coated in the phosphatizing solution are subjected to the water 
solubility test. Such testing shows the panels to have a degree of 
solubility in water of below 5%. Coating weights for similar panels, but 
phosphatized for different coating times, are determined to be 35 
mg/ft.sup.2 for one panel (lower coating weight) and 60 mg/ft.sup.2 for 
another panel (higher coating weight). 
One of each panel of the lower and the higher coating weight is then 
selected for analysis by the Electron Spectroscopy for Chemical Analysis 
(ESCA) technique. This technique is used to evaluate the surface phenomena 
of the coated panels by providing a determination of the elements present. 
The instrument used is the HP 5950A, a spectrometer system with 
monochromatized X-radiation and manufactured by the Hewlett Packard 
Company. Under such evaluation, the surface of test panels is found to 
contain sodium and calcium in trace amounts and a balance of phosphorus, 
iron, oxygen, carbon and nitrogen. 
Such determination for the principal elements found in the phosphatized 
coating is further evaluated, using similar test panels, with Auger 
spectroscopy. For this analysis the instrument used is the PHI Model 540A 
thin film analyzer manufactured by Physical Electronics Industries, Inc. 
Such analysis confirms the presence at the surface of the test panels of 
the elements phosphorous, iron, oxygen, carbon and nitrogen. 
EXAMPLE 3 
To 380.2 parts of methylene chloride there is added, with vigorous 
agitation, 81 parts methanol, 2.3 parts ortho phosphoric acid, 14.9 parts 
N,N-dimethyl formamide and 0.4 part dinitrotoluene. These blended 
ingredients are thereafter processed in the manner of Example 1 to prepare 
a phosphatizing solution having a water content of about 0.1 weight 
percent. 
Degreased steel panels are then phosphatized in the composition. Additional 
phosphatizing compositions but having differing water contents, as shown 
in the Table below, are prepared as described in Example 1. Phosphatizing 
operation for each bath of varying water content is also as has been 
described hereinbefore. As shown in the Table below, for each 
phosphatizing bath, water content determinations are made prior to 
phosphatizing and coating weights and water solubility testing for 
coatings, are determined for all phosphatized panels. 
TABLE - 
Coating Degree of 
Bath Water Panel Coating Solubility of 
Content, Wt. % 
Weight; mg/ft.sup.2 
Coating in Water 
______________________________________ 
0.1 9 17% 
0.8 9 8% 
2.1 14 &lt;5% 
3.0 22 &lt;5% 
4.2 31 &lt;5% 
______________________________________ 
The tabulated results demonstrate the enhancement in the degree of water 
insolubility of the phosphate coating as the water content in the 
phosphatizing bath increases; also, visual inspection confirms that the 
degree of uniformity of the phosphate coating is increasing as the water 
content of the phosphatizing bath increases. Also the coating weight shows 
a dramatic increase along with the increase in water content of the 
coating bath at a water content level above 2 weight percent. For the 
particular system of this Example, the desirable water content is deemed 
to be between about 2 weight percent and about 5 weight percent. Below 
about 2 weight percent, a desirable coating is not efficiently achieved. 
Coating weight is very small. By further water addition to the bath, this 
system is found to separate free water, i.e., lose liquid phase 
homogeneity, when the water content reaches 5.1 weight percent. 
EXAMPLE 4 
A standard solution was prepared to contain, by weight, 1188 parts of 
methylene chloride, 253 parts methanol, 7.3 parts ortho phosphoric acid, 
60 parts water and 1.0 part dinitrotoluene. These ingredients were blended 
together with vigorous agitation and thereafter aliquot portions of this 
solution were taken. These aliquots each contained 118.8 parts of 
methylene chloride with additional ingredients thus scaled down 
respectively. To each aliquot there was then added an aprotic organic 
compound. 
The aprotic organic substance for each aliquot, together with its 
proportion in each aliquot, are shown in the Table below. Baths for 
phosphatizing were prepared from each aliquot, steel panels were 
phosphatized and the phosphatizing operation was carried on all as has 
been described hereinbefore. For each aliquot the water content is shown 
in the Table below; it was determined as the proportion of the water for 
each aliquot derived from the standard solution. Coating weights were 
determined by visual observation, noting panel color; from experience with 
such technique of noting panel coating weight change with color change, 
the figures in the Table have been given, as typical, a constant degree of 
accuracy of .+-.5 mg/ft.sup.2. 
TABLE III 
______________________________________ 
Coating Panel 
Aprotic Organic Substance 
Bath Water Coating 
Substance Amt.Wt. % Content, Wt. % 
Wt. mg/ft.sup.2 
______________________________________ 
Dimethyl Sulfoxide 
3.5 3.83 35 
Acetonitrile 
2.5 3.87 80 
Acetone 2.6 3.87 25 
Nitromethane 
3.6 3.83 60 
Nitrobenzene 
3.8 3.82 55 
Tetramethylene 
Sulfone 4.2 3.82 35 
______________________________________ 
In all cases, desirable uniform phosphate coatings were noted by visual 
inspection of coated panels. 
EXAMPLE 5 
Solutions in the nature of the aliquots of Example 4 were prepared to 
contain, by weight, 118.8 parts of methylene chloride, 4.7 parts 
N,N-dimethyl formamide, 0.73 part ortho phosphoric acid and 0.1 part 
dinitrotoluene. During the blending of each solution there was added water 
plus a solublizing solvent. 
The solvent for each solution, together with its proportion in each 
solution, are shown in the Table below. The proportion of water in each 
solution is also shown in the Table below. Baths for phosphatizing were 
prepared from each solution in the manner discussed hereinabove. Steel 
panels, these panels being 2 .times. 4 inches cold rolled, low carbon 
steel panels, were then phosphatized. For each panel the coating weight 
was determined, as described in Example 4, and data for this is shown in 
the Table below. 
TABLE IV 
______________________________________ 
Coating 
Organic Solvent Bath Water Panel Coating 
Substance 
Amt.Wt.% Content, Wt.% 
Wt. mg/ft.sup.2 
______________________________________ 
Ethanol 17.9 3.77 45 
n-Propanol 
26.4 3.38 50 
iso-Propanol 
23.4 3.50 40 
Allyl Alcohol 
34.4 3.02 45 
n-Butanol 
41.7 2.68 40 
sec-Butanol 
38.5 2.83 55 
tert-Butanol 
33.9 3.04 25 
n-Pentanol 
49.9 2.30 35 
______________________________________ 
In all cases, desirable uniform phosphate coatings were noted by visual 
inspection of coated panels, including the bath containing the n-pentanol, 
in which bath the methylene chloride does not provide the major amount of 
the bath composition. 
EXAMPLE 6 
In the manner described hereinabove, a phosphatizing solution is prepared 
to contain, by weight, the following ingredients: 60 parts water, 1188 
parts methylene chloride, 253 parts methanol, 7.3 parts ortho phosphoric 
acid, 47.2 parts N,N-dimethyl formamide and 1.0 part dinitrotoluene. 
Hereinafter, for convenience, the resulting phosphatizing solution is 
referred to as the "new organic phosphatizing composition". 
Steel panels were phosphatized in this new organic phosphatizing 
composition. Further, in the manner described hereinbefore, but for 
comparative purposes, panels were phosphatized in a well-known and 
extensively-used commercial phosphatizing bath based on trichloroethylene. 
Hereinafter for convenience, this bath is referred to as the "standard 
organic phosphatizing composition". This standard organic phosphatizing 
composition was prepared by blending together ortho phosphoric acid, with 
two products sold under the tradenames of "Triclene-L" and "Triclene-R", 
to contain a commercially acceptable amount of phosphoric acid in the 
blend. The use of such a commercial phosphatizing bath has been described, 
for example, in U.S. Pat. No. 3,356,540. 
Additional comparative test panels used herein for evaluation are panels 
with an aqueous phosphatizing composition and prepared in accordance with 
specifications that are generally accepted as standards for performance in 
the automotive and household appliance industries. These comparative test 
panels, for convenience, are generally referred to herein as prepared from 
the "comparative aqueous phosphatizing composition". Such composition is a 
solution that can contain zinc acid phsophate, with the test panels being 
dipped in this aqueous solution typically for one minute. Thereafter, the 
test panels are rinsed and then immersed in a dilute solution of chromic 
acid. Such test panels are then dried and are thus provided with a chromic 
acid rinse coating. 
All test panels are painted, before testing, with a commercial enamel 
topcoat. The enal is a commercial white alkyd baking enamel; the enamel 
ostensibly contains a modified alkyd resin based upon a system of 
partially polymerized phthalic acid and glycerin, and has 50 weight 
percent solids. After coating panels with the enamel, the coating is cured 
on all panels by baking in a convection over for 20 minutes at a 
temperature of 320.degree.-325.degree. F. 
Panels are then selected and subjected to the various tests described 
hereinbefore for testing paint film retention and integrity. The tests 
used, and the results obtained, are listed in the Table below. In the 
conical mandrel test, the numbers listed in the Table are centimeters of 
paint removal after taping; the reverse impact test is conducted at 64 
inch-pounds. For the reverse impact test and the conical mandrel test, 
where a range is presented in the Table, such range results from the 
testing of a series of panels. 
In the following Table the efficacy of the total coating obtained on the 
coated parts in the cross hatch and reverse impact tests is quantatively 
evaluated on a numerical scale from 0 to 10. The parts are visually 
inspected and compared with one another and the system is used for 
convenience in the reviewing of results. In the rating system the 
following numbers are used to cover the following results: 
(10) complete retention of film, exceptionally good for the test used; 
(8) some initial coating degradation; 
(6) moderate loss of film integrity; 
(4) significant film loss, unacceptable degradation of film integrity; 
(2) some coating retention only; 
(0) complete film loss. 
TABLE V 
______________________________________ 
Phosphatizing Cross Conical Reverse 
Coin 
Composition Hatch Mandrel Impact Adhesion 
______________________________________ 
New Organic 10 0-1.7 6-9 Good 
Phosphatizing 
Composition 
Standard Organic 
10 0.4-1.9 4-8 Good 
Phosphatizing 
Composition 
Comparative Aqueous 
10 1.9 4-9 Good 
Phosphatizing 
Composition 
______________________________________ 
The above-tabulated results show that the phosphate coating from the new 
organic phosphatizing composition can provide paint adhesion that will 
compare under a variety of tests as the equal of or superior to, 
comparative systems based either on organic commercial baths or aqueous 
compositions. 
In further and related testing, panels from the new organic phosphatizing 
composition are provided with a chrome rinse from a dilute chromic acid 
solution. This is done to equate the nature of the coating on the panels 
with that from the aqueous phosphatizing composition. All test panels are 
topcoated with an alkyd enamel paint system and then panels are subjected 
to a variety of tests. Comparable results, for each specific test, are 
obtained among all tested panels. Such equality of test results is 
achieved even when testing of comparative panels in the standard salt 
spray (fog) test, ASTM B-117-64. 
EXAMPLE 7 
To 356.4 parts of methylene chloride there is added, with vigorous 
agitation, 106.6 parts ethanol, 2.4 parts ortho phosphoric acid and 15.3 
parts N,N-dimethylformamide. These blended ingredients are thereafter 
processed in the manner of Example 1 to prepare a phosphatizing solution 
having a water content of about 0.1 weight percent. 
Degreased steel panels are then phosphatized in the composition. Additional 
phosphatizing compositions, but having differing water contents, as shown 
in the Table below, are prepared as described in Example 1. Phosphatizing 
operation for each bath of varying water content is also as has been 
described hereinbefore. As shown in the Table below, for each 
phosphatizing bath, coating weights and water solubility testing for 
coatings, are determined for phosphatized panels. 
TABLE VI 
______________________________________ 
Coating Degree of 
Bath Water Panel Coating Solubility of 
Content, Wt.% 
Weight; mg/ft.sup.2 
Coating in Water 
______________________________________ 
0.1 14 28% 
1.1 10 30% 
2.1 22 7% 
3.1 27 &lt;5% 
4.1 125 &lt;5% 
______________________________________ 
The tabulated results demonstrate the enhancement in the degree of water 
insolubility of the phosphate coating as the water content in the 
phosphatizing bath increases; also, visual inspection confirms that the 
degree of uniformity of the phosphate coating is increasing as the water 
content of the phosphatizing bath increases. Also, after an initial 
reversal, the coating weight increases right along with the increase in 
water content of the coating bath. For the particular system of this 
Example, the desirable water content is deemed to be greater than 2.1 
weight percent and up to about 5 weight percent. By further water addition 
to the bath, this system is found to separate free water, i.e., lose 
liquid phase homogeneity, when the water content reaches 5.1 weight 
percent. 
For comparative purposes, the "standard organic phosphatizing composition" 
described in Example 6 is used to coat panels and the panels are tested. 
This composition, based on trichlorethylene, has met with commercial 
acceptance as a solvent phosphatizing composition. When the composition 
contains 0.2 weight percent water, all water determinations being by the 
method described in Example 1, the composition provides for a very uniform 
coating of desirable weight. All panel coating is conducted as has been 
described hereinbefore. 
The 0.2 weight percent water content, although not typical for such a 
commercial bath, can be presented and contributed by the other 
substituents in the bath, as for example, when the acid is provided in the 
orthophosphoric form. A test panel from this bath, in water solubility 
testing, exhibits a degree of water solubility of 60%. A duplicate bath, 
except that it is in equilibrium with 0.5 weight percent water, supplied 
by water addition, also yields uniform coatings of desirable weight. 
At the 0.5 weight percent level, the coating has a degree of water 
solubility of 28%. This approaches the minimum degree of coatings from 
such bath, since upon further water addition, the bath is found to lose 
homogeneity at only 0.6 weight percent water. 
EXAMPLE 8 
A standard solution was prepared to contain, by volume, 900 parts of 
methylene chloride, 320 parts methanol, 50 parts N,N-dimethylformamide, 
4.5 parts ortho phosphoric acid and 60 parts water. These ingredients were 
blended together with vigorous agitation and thereafter aliquote portions 
of this solution were taken. These aliquots each contained 90 parts of 
methylene chloride with additional ingredients thus scaled down 
respectively. To each aliquot there was then added 0.064 weight percent of 
organic accelerator compound, with the exception of one aliquot that was 
kept free from accelerator compound for comparative purposes. 
The particular organic accelerator substance for each aliquot is shown in 
the Table below. Baths for phosphatizing were prepared from each aliquot, 
steel panels were phosphatized and the phosphatizing operation was carried 
on all as has been described hereinbefore, with all panels being coated 
for an equal time. Coating weights were determined as described 
hereinbefore and are shown in the Table below. Relative coating weights 
for coatings from each aliquot, basis a given weight of 1.00 for the 
coatings weight from the aliquot that was maintained free from accelerator 
compound, are also shown in the Table. 
TABLE VII 
______________________________________ 
Panel 
Coating Relative Panel 
Organic Accelerator Substance 
Wt. mg/ft.sup.2 
Coating Weight 
______________________________________ 
None 45 1.00 
Ethylenediaminetetraacetic acid* 
48 1.07 
Dinitrotoluene 55 1.22 
Dimethyl Isobutylene Amine 
56 1.24 
Dimethyl Sulfoxide 
62 1.38 
Thiourea 63 1.40 
Pyridine 71 1.58 
Urea 78 1.73 
______________________________________ 
*Disodium salt. 
In all cases, desirable phosphate coatings were noted. 
EXAMPLE 9 
A phosphatizing bath is prepared in the manner of Example 1 to contain, on 
a basis of 100 parts of prepared bath: 46.47 parts methylene chloride, 
48.96 parts 2-butoxyethanol, 2.34 parts water, 1.84 part 
N,N-dimethylformamide, 0.35 part phosphoric acid and 0.04 part 
dinitrototuene. Steel test panels are then phosphatized and are thereafter 
subjected to visual inspection for interpretation of coating results. By 
such inspection the phosphatized panels are viewed to have a desirably 
uniform coating of sufficient weight deemed to be acceptable for 
commercial purposes. This results is achieved with the 2-butoxyethanol 
being present as the organic solvent and with the methylene chloride not 
being present in major amount. 
EXAMPLE 10 
A composition for sustaining phsophatizing by addition to a depleted 
phosphatizing bath is prepared by blending together 93.28 parts methylene 
chloride, 5.99 parts methanol, 0.71 part water, 0.01 part p-tertiaryamyl 
phenol and 0.01 part p-benzoquinone. Hereinafter, the resulting 
homogeneous, stable solution is referred to as the "bath-sustaining 
solution". 
There is separately prepared, by blending together into a homogeneous 
solution, 62.75 parts methanol, 17.57 parts water, 19.13 parts 
N,N-dimethylformamide, 0.38 part dinitrotoluene, 0.12 part p-tertiaryamyl 
phenol, and 0.044 part p-benzoquinone. One part by volume of this 
resulting uniform solution is then blended with three parts by volume of 
the bath-sustaining solution. To this resulting homogeneous blend there is 
then added sufficient orthophosphoric acid to provide about 0.22%, by 
volume, of the orthophosphoric acid in the resulting blend. 
The phosphatizing bath thereby prepared is subsequently used to phosphatize 
degreased 3 .times. 4 inches steel panels. These phosphatized panels are 
referred to hereinafter as the "initially-phosphatized panels". Following 
this initial working of the bath, the bath is subjected to heat-induced 
vapor loss. From the working and the subsequent vapor loss, the bath 
experiences about a 31% loss, by volume. This is deemed to be a loss that 
would otherwise be observed following very frequent, extended use of the 
bath as a phosphatizing bath. 
After this contraction in the bath, additional panels, being degreased 3 
.times. 3 inches steel panels for reconciliation with the volume of the 
bath, are coated. These coated panels are referred to hereinafter as the 
"depleted bath panels". 
The resulting depleted bath is then permitted to cool, and the cool bath is 
restored to its original volume by adding the bath-sustaining solution. 
After addition, the bath is then heated, as described in Example 1, and 
additional 3 .times. 4 steel panels are coated. Resulting coated panels 
are referred to as the "restored bath panels". 
The quality of the coating on the panels, from the both the new bath panels 
and the restored bath panels, is deemed to be of a quality acceptable for 
commercial purposes. Such quality is judged by visual inspection of 
coating uniformity as well as determination of coating weight, which 
determination is conducted as has been described hereinbefore. On the 
other hand, the depleted bath panels can be seen from visual inspection to 
have non-uniform coatings that are judged to be commercially unacceptable. 
Thus, the worked bath of contracted volume that provides commercially 
unacceptable panels, can be successfully rejuvenated with the 
bath-sustaining solution, as is evidenced by coatings achieved on 
resulting coated panels. 
EXAMPLE 11 
To 82.5 parts of methylene chloride there is added, with vigorous 
agitation, 17.0 parts methanol and 0.5 part ortho phosphoric acid. The 
resulting phosphatizing solution has a water content of about 0.1 weight 
percent, at least principally contributed by the acid. A degreased steel 
panel is then phosphatized in the composition. Additional phosphatizing 
compositions, but having differing water contents, are prepared as 
described in Example 1, and panels are phosphatized in such compositions. 
All phosphatizing operations are as have been described hereinbefore. 
Coating weights and water solubility testing for coatings, are determined 
for selected phosphatized panels. As the bath water content goes from 3% 
to 4%, the coating weight goes from 20 to 97 mg/ft.sup.2 respectively. 
However, with a bath at the 3.2 percent water level, the most desirable 
coating, at a weight of about 35 mg/ft.sup.2 and having less than 5% water 
solubility, is achieved. This result is obtained although the bath 
contains no aprotic polar organic compound.