Leather with fluorochemical finish

Fluorochemical aliphatic carboxylic acids, and water dispersible salts thereof, having fluoroaliphatic radicals and urylene and/or carbamato radicals, are used to impart oil and water repellency to fibrous substrates such as tanned leather.

This invention relates to finishing tanned leather with fluorochemical 
compounds and to the so prepared finished leather. In another aspect, it 
relates to such fluorochemical compounds and to their preparation. 
Leather has a combination of properties which has long made it useful and 
desirable for many applications requiring protection, comfort, durability, 
and esthetics, e.g. footwear, garments, and upholstery. Such properties 
include long term flexibility, toughness, breathability, insulation, 
conformability, and such esthetic properties as soft feel and luxurious 
appearance. However, due to its porous, fibrous structure, leather absorbs 
water and oil, and the consequent unsightly water spotting and stains 
detract from its usefulness and appearance. There has been considerable 
effort expended to overcome these drawbacks of leather. See Kirk-Othmer, 
Encycl. of Chem. Tech., Vol. 22, 1970, John Wiley & Sons, p. 150, 151. 
Certain fluorochemicals have been proposed or used as means to impart water 
and oil repellency to leather. Those fluorochemicals disclosed in the 
patent literature include fluoropolymers of fluorinated acrylate monomers 
(U.S. Pat. No 3,524,760), fluorinated carboxylic acids (U.S. Pat. No. 
3,382,097), perfluoroalkyl alkylene thiocarboxylic acids (U.S. Pat. No. 
3,471,518), chromium complexes of fluorinated carboxylic acids(U.S. Pat. 
Nos. 2,934,450, 3,651,105, 3,907,576, and 3,574,518), and carbamates of 
fluorocarbon alcohols (U.S. Pat. No. 3,657,320). Those fluorochemicals 
disclosed in other literature include the chromium complex of a 
fluorinated carboxylic acid (Hopkins, W. J. et al., J. Amer. Leather Chem. 
Assn., 67 552-4 (1972)), fluoropolymers of fluorinated acrylate monomers 
(Grueber, A. L., Report No. 59 (1979), Wool Research Organization of New 
Zealand, Inc.), and perfluorobutyl acrylate, fluoroalkylsiloxane polymers, 
polyfluoroalkyl phosphates, and fluoro compounds (Nagabhushanam, T. et 
al., Leather Science, 22 229-234 (1975)). 
Only a few of these prior art fluorochemicals have been found to be 
commercially useful in leather finishing, and even then, on a limited 
basis. For example, the chromium complexes, due to the green color they 
impart to the leather, are limited in use generally to the finishing of 
dark leather. 
The fluorochemicals used in this invention confer durable water and oil 
repellency to leather while not adversely affecting the appearance, feel, 
hand, and other desirable qualities of the leather. And the 
fluorochemicals and their aqueous dispersions are generally colorless. 
The fluorochemical compositions useful in the leather finishing process of 
this invention comprise fluorochemical compounds which are normally solid, 
water insoluble, fluoroaliphatic radical-containing and ureylene 
(--NHCONH--), carbamato(--OCONH--), carbonamido(--CONH--), and/or 
carbonyloxy(--OCO--)radical-containing aliphatic carboxylic acids, and the 
salts of said acids which are self-dispersible in water. (The term 
"aliphatic carboxylic acid" refers to an organic compound having a 
carboxyl group, --COOH, the carbon atom of which is bonded to a carbon 
atom which is part of an aliphatic moiety, e.g. --CH.sub.2 --, as 
distinguished from a ring carbon atom in an aromatic nucleus.) 
The aforementioned three types of radicals or moieties--the fluoroaliphatic 
radical, the carboxylic acid group, and the four different 
carbonyl-containing radicals (i.e., the ureylene, carbamato, carbonamido, 
and/or carbonyloxy)--are covalently bonded together in the same molecule 
by organic linkages which are of a non-interfering nature (as described in 
detail below). Those three types of radicals or moieties and the organic 
linkages are the essential parts of the fluorochemicals of this invention. 
The number of each of them in a particular fluorochemical compound can 
vary, but generally such a compound will have one or two fluoroaliphatic 
radicals (commonly symbolized as "R.sub.f "), one aliphatic carboxyl 
group, and 1 to 4 of said carbonyl-containing radicals ("A") of preferably 
no more than two types. Where the fluorochemical compound has only one 
carbonyl-containing radical, A, it will generally be a urylene or 
carbamato radical. 
Those fluorochemical compounds of this invention with relatively low 
softening or melting points, e.g. less than 100.degree. C., preferably 
less than 70.degree. C., will generally impart better oil repellency to 
the tanned leather and are thus preferred. 
A class of said fluorochemical compounds can be represented by the formula: 
EQU [R --Q--A--Q'--].sub.m (Q).sub.n COOM I 
where 
R is a fluoroaliphatic radical (R.sub.f) or an aliphatic radical (R.sub.h), 
Q is an organic linkage, 
Q' is Q or Q--A--Q, 
A is a carbonyl-containing radical selected from the group consisting of 
--NHCONH--, --CONH--, --OCO--, and --OCONH--, 
M is a hydrogen atom or an alkali metal, ammonium, or organoammonium ion, 
m is 1 or 2, with the provisos that if m is 1, then R is said R.sub.f and 
if m is 2, then at least one R is said R.sub.f, and 
n is zero or 1. 
Subclasses of fluorochemical compounds within the scope of formula I supra 
include those represented by formulas II, III, and IV below. 
EQU [R.sub.f --Q--A--Q'].sub.2 QCOOM II 
where R.sub.f, Q, A, Q', and M are as defined for formula I, though A 
preferably is carbamato. 
EQU R.sub.f --Q--A--Q'--COOM III 
where R.sub.f, Q, A, Q', and M are as defined for formula I, though A 
preferably is urylene carbamato and Q' contains said aliphatic radical 
R.sub.h. 
##STR1## 
where R.sub.f, Q, A, Q', and M defined for formula I, though A preferably 
is urylene or carbamato and R.sub.h is said aliphatic radical as defined 
for formula III. 
The fluoroaliphatic radical (R.sub.f) is a fluorinated, preferably 
saturated, monovalent, non-aromatic, aliphatic radical of at least three 
fully fluorinated carbon atoms. The chain in the radical may be straight, 
branched, or, if sufficiently large, cyclic, and may be interrupted by 
divalent oxygen atoms or trivalent nitrogen atoms bonded only to carbon 
atoms. A fully fluorinated aliphatic radical is preferred, but hydrogen or 
chlorine atoms may be present as substituents in the radical provided that 
not more than one atom of either is present in the radical for every two 
carbon atoms, and the radical must at least contain a terminal 
perfluoromethyl group. Preferably, the fluorinated aliphatic radical 
contains not more than 20 carbon atoms because such a large radical 
results in inefficient use of the fluorine content. The fluorochemicals 
preferably contain at least 20 weight percent, preferably 25 to 50 weight 
percent, fluorine in the form of said fluoroaliphatic radical. 
The aliphatic radical (R.sub.h) is an essentially fluorine-free radical 
preferably having at least 5 catenary carbon atoms and as many as 18 or 
even 24 such atoms. In a sense, it is the fluorine-free analog of the 
fluoroaliphatic radical, though it can be polyvalent or monovalent. 
The organic linkages, Q, can have a wide variety of structures, serving as 
they do as the function of bonding together in the same molecule the R, A, 
and COOM moieties. However, the COOM moiety is bonded to an aliphatic 
carbon atom of the vicinal Q linkage, and the A moieties are bonded only 
to carbon atoms (aromatic or aliphatic) of the vicinal Q linkages. And, 
furthermore, the Q linkages must be free of interferring moieties, 
particularly hydrophilic groups, such as acidic functional groups and 
salts thereof, e.g. --COOH and --COONa, polyoxyethylene, 
polyethyleneimine, and aliphatic hydroxyl groups, which would interfere 
with the ability of the fluorochemical compound to impart the desired oil 
and water repellency to the substrate treated therewith in accordance with 
this invention. Bearing in mind the above-described function of the Qs and 
constraints thereon, Q can comprise such representative moieties as 
aliphatic moieties, e.g. --CH.sub.2 --, --CH.sub.2 CH.sub.2 
----CH.dbd.CH--, and cyclohexylene, aromatic moieties, e.g., phenylene, 
and combinations thereof, e.g. methylene diphenylene and tolylene, or 
combinations of such moieties with such hetero-atom-containing moieties as 
oxy, thio, aza, carbonyl, sulfone, sulfoxy, sulfonamido, carbonamido 
urylene carbamato, and imino, e.g. combinations such as 
sulfonamidoalkylene, carbonaminoalkylene, alkyleneoxyalkylene, 
iminoalkylene, alkylenecarbamato, and sulfonyloxyphenylene. The Qs for a 
specific fluorochemical compound useful in this invention will be dictated 
by the ease of preparation of such compound and the availability of the 
necessasry precursors thereof. From the above description of Q, it is 
apparent that these linkages can have a wide variety of structures. 
However large Q is, and regardless of how many Qs there are in such 
compounds, the fluorine content (the locus of which is R.sub.f) of the 
compounds is at least 20 weight percent of the compounds. 
In order for the fluorochemical compounds to disperse well in water, for 
example in the aqueous medium used in the wet end drumming treatment of 
tanned leather (after splitting and shaving in the case of cattlehide), 
the compounds are in the form of their water-dispersible salts, i.e., M in 
formula I is an alkali metal, ammonium, or organoammonium ion, e.g., Na, 
K, NH.sub.4, NH.sub.2 (C.sub.2 H.sub.5).sub.2, HN(CH.sub.3).sub.3, H.sub.2 
N(C.sub.2 H.sub.4 OH).sub.2, HN(CH.sub.3).sub.2 C.sub.2 H.sub.4 OH, and 
morpholinoammonium. Such salts are made by neutralizing the carboxylic 
acid precursor (i.e., compounds of formula I where M is H) with the 
appropriate aqueous base, e.g. ammonium hydroxide. 
The fluorochemical compounds of this invention can be prepared by reacting 
selected organic reagents with fluoroaliphatic radical-containing 
intermediates (that is, precursors containing R.sub.f, which generally are 
commercially made by electro-chemical fluorination of organic acids or 
halides thereof or by telomerization of tetrafluoroethylene, followed by 
known reactions to form said intermediates). Such reactions are carried 
out neat or in the presence of polar non-reactive solvents, such as ethyl 
acetate, at moderate temperatures, such as 50.degree. to 130.degree. C. 
Because of the nature of such intermediates and such reactions, the 
fluorochemicals so prepared and useful in this invention will often be 
mixtures of isomers and homologs. 
Suitable R.sub.f precursors for this purpose include the following 
representative compounds: 
C.sub.8 F.sub.17 SO.sub.2 N(C.sub.2 H.sub.5)C.sub.2 H.sub.4 OH 
C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)C.sub.4 H.sub.8 OH 
C.sub.7 F.sub.15 CH.sub.2 OH 
C.sub.6 F.sub.13 CH.sub.2 CH.sub.2 OH 
C.sub.8 F.sub.17 C.sub.2 H.sub.4 SC.sub.2 H.sub.4 OH 
##STR2## 
(CF.sub.3).sub.2 CFOC.sub.2 F.sub.4 C.sub.2 H.sub.4 OH C.sub.6 F.sub.13 
C.sub.2 H.sub.4 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4 OH 
C.sub.7 F.sub.15 CON(CH.sub.3)C.sub.2 H.sub.4 OH 
##STR3## 
C.sub.10 F.sub.19 OC.sub.6 H.sub.4 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4 OH 
C.sub.8 F.sub.17 C.sub.2 H.sub.4 N(CH.sub.3)C.sub.2 H.sub.4 OH 
C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)H 
C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4 OCOCH.dbd.CH.sub.2 
C.sub.8 F.sub.17 C.sub.2 H.sub.4 OCOCH.dbd.CH.sub.2 
C.sub.8 F.sub.17 SO.sub.2 F 
C.sub.9 F.sub.19 CH.sub.2 NCO 
C.sub.8 F.sub.17 SO.sub.2 NHC.sub.2 H.sub.4 NH.sub.2 
C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4 OCH.sub.2 
CH(OH)CH.sub.2 Cl 
C.sub.8 F.sub.17 SO.sub.3 C.sub.6 H.sub.4 NCO. 
The organic reagents which are reacted with the appropriate R.sub.f 
precursors to prepare the fluorochemical treating agents of this invention 
include the following representative organic polyisocyanates: 
tolylene-2,4-diisocyanate 
hexamethylenediisocyanate 
methylenebis(4-cyclohexylisocyanate) 
methylenebis(4-phenylisocyanate) 
1,3,3-trimethyl-5-isocyanatocyclohexyl-1-methylisocyanate 
p-xylylenediisocyanate 
2,2,5-trimethylhexyl-1,6-diisocyanate 
dimethylenetriphenyltriisocyanate 
the following representative aliphatic dicarboxylic acid anhydrides: 
succinic anhydride 
glutaric anhydride 
itaconic anhydride 
maleic anhydride 
azelaic polyanhydride 
the following representative hydroxy- or amino-substituted carboxylic 
acids: 
(HOCH.sub.2).sub.2 C(CH.sub.3)COOH 
C.sub.6 H.sub.13 CH(OH)(CH.sub.2).sub.10 COOH 
C.sub.6 H.sub.13 CH(OH)CH.sub.2 CH.dbd.CH(CH.sub.2).sub.7 COOH 
HO(CH.sub.2).sub.5 COOH 
HO(CH.sub.2).sub.3 COOH 
HO(CH.sub.2).sub.2 COOH 
HOCH.sub.2 COOH 
H.sub.2 NCH.sub.2 COOH 
H.sub.2 N(CH.sub.2).sub.3 COOH 
H.sub.2 N(CH.sub.2).sub.10 COOH 
H.sub.2 N(CH.sub.2).sub.5 COOH. 
In general, the fluorochemical carboxylic acids having carbomato and/or 
urylene radicals can be prepared by reacting R.sub.f -isocyanate with a 
hydroxy- or aminoaliphatic carboxylic acid. For the fluorochemical 
carboxylic acid having carbonyloxy radical, a R.sub.f -containing 
electrophilic olefin can be reacted with an amino-aliphatic carboxylic 
acid. For the fluorochemical carboxylic acids having carbonamido or 
carbonyloxy radicals, a R.sub.f -amine or R.sub.f -alcohol can be reacted 
with an aliphatic carboxylic acid anhydride. The salts of the 
above-described three general types of fluorochemical aliphatic carboxylic 
acids can be prepared by neutralizing such acids with appropriate 
salt-forming bases. Where the fluorochemical product desirably has a 
monovalent aliphatic group, R.sub.h, as in formula IV supra, an R.sub.h 
-alcohol, -isocyanate, or -amine can be used in place of a portion of the 
corresponding R.sub.f -precursor. 
The preferred anionic fluorochemical urethane compounds used in this 
invention generally can be prepared by reacting a fluoroaliphatic alcohol 
(as an R.sub.f percursor) with a diisocyanate and the hydroxy-substituted 
carboxylic acid in appropriate molar ratios by refluxing the reactants in 
a polar, non-reactive organic solvent, such as ethyl acetate at a 
concentration of about 60 to 70 percent solids. An equivalent amount of an 
aqueous base is added to neutralize the acid function, the water used 
being sufficient to yield about a 20 to 25 weight percent aqueous 
dispersion of the fluorochemical carboxylate product (after distilling off 
the organic solvent). 
Other fluorochemical compounds used in this invention can be prepared by 
known organic reactions, representative synthetic routes for some of these 
being outlined in the following reaction schemes, where R.sub.f, Q, and m 
are as defined above, and R.sup.2 comprises an aliphatic moiety having a 
carbon atom bonded to the depicted carboxylic radical. 
##STR4## 
Representative fluorochemical compounds useful in the practice of this 
invention are those represented by the formulas (which are numbered for 
later reference) in Table 1. The fluorochemical compounds of formulas 
1-12, 23, 25 can be made by following Scheme 1, those of formulas 13, 14, 
15, 20, 22 by following Scheme 2, those of formulas 18, 19, 21 by 
following Scheme 6, and those of formulas 16, 24, 17 by following Schemes 
3, 4, 5, respectively. 
TABLE 1 
__________________________________________________________________________ 
Formula 
No. Structure of fluorochemical (FC) 
__________________________________________________________________________ 
##STR5## 
##STR6## 
##STR7## 
##STR8## 
##STR9## 
##STR10## 
##STR11## 
##STR12## 
##STR13## 
10. 
##STR14## 
##STR15## 
##STR16## 
##STR17## 
##STR18## 
##STR19## 
16. [C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4 OCOCH.sub.2 
CH.sub.2 ].sub.2 N(CH.sub.2).sub.10 COONH.sub.4 
17. C.sub.8 F.sub.17 SO.sub.2 N(C.sub.2 H.sub.5)C.sub.2 H.sub.4 OCOCH.sub 
.2 CH.sub.2 COOK 
##STR20## 
##STR21## 
20. C.sub.7 F.sub.15 CH.sub.2 NHCONH(CH.sub.2).sub.10 COONH.sub.4 
##STR22## 
##STR23## 
##STR24## 
24. C.sub.8 F.sub.17 SO.sub.2 NHC.sub.2 H.sub.4 NHCOC.sub.3 H.sub.6 
COONH.sub.4 
##STR25## 
__________________________________________________________________________ 
Mixtures of the fluorochemical compounds can be used in this invention. In 
fact, where said Schemes 1 and 2 are used to prepare compounds 1, 2, 5, 
6-15, 23, 25 isomers of those compounds will be present in admixture with 
them; in the case of compounds 1, 2, 6-13, 15, 23, 25 these compounds will 
be produced in admixture with isomers where the aromatic methyl 
substituent is in the 5-position of the ring; in the case of compounds 5 
and 14, these compounds will be produced in admixture with isomers where 
the gem methyl groups on the hexylene chain are in the 5-position and the 
third methyl group is in the 2-position. 
Since the fluorochemicals of this invention are preferably applied to 
tanned leather in conjunction with the wet processing thereof, the 
fluorochemicals are preferably used for this purpose in the form of their 
salts, such salts being self-dispersible in water. Thus, aqueous 
dispersions of such one or a mixture of such salts, with the concentration 
of the salts in the dispersion being such as to provide the appropriate 
treating level, can advantageously be added to the tanning drum commonly 
used in the wet processing of tanned leather. Such wet processing 
operation normally entails steps of re-tanning, dyeing, and fatliquoring, 
with water rinsing usually following these steps, the operation then being 
normally followed by dry operations. (For a review article on leather and 
its preparation, see for example Kirk-Othmer, Encycl. of Chem. Tech., 3rd 
Ed., Vol. 14, John Wiley & Sons, New York, 1981, pp. 200-224.) 
Advantageously, the fluorochemical treatment or finishing of leather in 
accordance with this invention can be carried out in conjunction with the 
normal post-tanning, wet processing operation without requiring 
significant alteration thereof other than accommodating addition of the 
aqueous fluorochemical dispersion (by itself or in admixture with any of 
the normal post-tanning agents,) to the wet processing drum. Preferably, 
the aqueous dispersion is added by itself to the aqueous 
medium-leather-containing drum before the fatliquoring step or after the 
fatliquoring step without draining the fatliquor-bath before addition of 
the dispersion. After allowing sufficient time for impregnation or 
penetration of the fluorochemical salt into the leather being tumbled in 
the drum, e.g. 20 minutes, the bath in the drum is acidified with an 
organic acid, such as formic acid, to a pH of about 4. Advantageously, 
fluorochemicals of this invention applied by this process are 
substantially completely exhausted from the fatliquor bath onto the tanned 
leather. 
Other methods of applying or contacting tanned leather with the 
fluorochemicals of this invention can be used, such as spraying, brushing, 
or padding the tanned leather with an aqueous dispersion of the salt form 
of the fluorochemical or with an organic solvent solution of the acid form 
of the fluorochemical. For example, a 50% butoxyethoxyethyl acetate 
solution of the fluorochemical acid or its water-dispersible salt, e.g. 
ammonium salt, can be made up and further diluted with water to an 
appropriate treatment level and applied to the leather as a sprayable 
aqueous dispersion. If an organic solvent solution of the fluorochemical 
is to be applied, solvents such as chlorinated hydrocarbons, e.g. 
tetrachloroethylene and trichloroethylene, can be used to dissolve the 
fluorochemical acid. 
The amount of the fluorochemical deposited on the tanned leather can vary, 
but functionally stated that amount will be sufficient to impart oil and 
water repellency to the leather. Generally that amount will be about 0.2 
to 4, preferably 0.5 to 3, weight percent based on the weight of the 
tanned leather after it is dried at the temperatures, e.g. 
40.degree.-60.degree. C., encountered in the normal drying operation of 
leather finishing. With such amounts of fluorochemical deposited on the 
tanned leather, the finished leather will have oil and water repellency 
that is durable, that is, the repellency will last a long time during 
active use of the article made from such finished leather, the 
fluorochemical penetrating to a significant depth into the leather. Such 
durable repellency is obtained without adversely affecting the appearance, 
feel, hand, flexibility, breathability, or other desirable properties of 
leather. And such desirable properties are obtained not only by treating 
tanned cattlehide in accordance with this invention but other tanned hides 
and skins, such as sheepskin and pigskin. 
The tanned leather finished in accordance with this invention can be used 
to fabricate or manufacture in the customary way such leather articles as 
shoe uppers, garments, gloves, luggage, handbags, upholstery, and the 
like. 
Though the fluorochemicals of this invention are especially useful in the 
treatment of tanned leather (a collagen type, porous matrix in sheet 
form), as illustrated herein, they can be used to treat other fibrous 
substrates to impart oil and water repellency thereto.

Objects and advantages of this invention are shown in the following 
examples, Examples 1-17 illustrating the preparation of various 
fluorochemicals of this invention and Examples 18-59 illustrating the use 
of various fluorochemicals in the treatment of leather. 
EXAMPLE 1 
In a 2-liter, 3-neck, borosilicate glass flask fitted with condenser, 
thermometer, stirrer, and electric heating mantle, were placed 1108 g (2.0 
moles) N-ethyl(perfluorooctane)sulfonamidoethyl alcohol, 348 g (2.0 moles) 
tolylene-2,4-diisocyanate, 134 g (1.0 mole) finely pulverized 
2,2-bis(hydroxymethyl) propionic acid, 0.9 g dibutyltindilaurate urethane 
catalyst, and 575 g ethyl acetate solvent. The resulting reaction mixture 
was stirred and refluxed at 80.degree. C. for about 6 hours to complete 
the reaction, as indicated by attainment of a clear solution and absence 
of --NCO groups as measured by infared absorption analysis. 
The resulting product solution contained the fluorochemical acid 
represented by formula 1A. 
##STR26## 
About 33 percent of said product solution was placed in a 2-liter, 3-neck 
flask equipped as described above. To the flask were then added with 
stirring an aqueous KOH solution containing 0.33 mole base and 1700 g 
water. The flask was adapted for distillation and the contents heated to 
80.degree.-95.degree. C. to remove ethyl acetate solvent. Water lost 
during this solvent removal process was replaced, resulting in a 25 weight 
percent solids aqueous dispersion of the fluorochemical acid potassium 
salt represented by formula 1 in Table 1 supra. 
EXAMPLE 2 
To about 33 percent of the ethyl acetate solution of the fluorochemical 
acid 1A of Example 1 in a 2-liter, 3-neck flask equipped as described 
above, there were added with stirring an aqueous solution containing 0.36 
mole (a 10 percent excess) NH.sub.4 OH and 1700 g water. The flask was 
adapted for distillation and the mixture heated to 80.degree.-95.degree. 
C. to remove ethyl acetate solvent. Water lost during this process was 
replaced, resulting in a 25 weight percent solids aqueous dispersion of 
the fluorochemical acid ammonium salt represented by formula 2 of Table 1 
supra. 
EXAMPLE 3-12 
Following the general procedures of Examples 1 and 2 and using the 
appropriate or corresponding precursor fluorochemical alcohol, isocyanate, 
hydroxy carboxylic acid, and aqueous base, all in the appropriate molar 
ratios, there were prepared carbamate-ester-containing fluorochemical acid 
and acid salts represented by the formulas 3-12 of Table 1 supra. 
EXAMPLE 13-15 
A modification of the procedure of Example 1 can be used to prepare the 
fluorochemical compounds of formulas 13-15 of Table 1 supra, which contain 
urylene link in addition to the carbamato moiety. 
In the preparation of these compounds, the fluorochemical alcohol is first 
prereacted (by reflux at 80.degree. C. for two to four hours), with the 
diisocyanate to react one of the --NCO groups (mainly the position 4 --NCO 
function, in the case of tolylene-2,4-diisocyanate), then the reaction 
mixture is cooled to 35.degree.-40.degree. C., and the powdered amino acid 
is added and reflux and stirring continued for about two hours to yield 
the acid adduct. Aqueous base addition and solvent removal is carried out 
as described in Examples 1 and 2 to yield the salts, if they are desired. 
Alternatively, all the organic reagents can be reacted together, as in 
Example 1. 
Thus the compounds represented by formulas 13-15 were prepared using 
10-aminoundecanoic acid as the amino acid reagent. 
EXAMPLE 16 
In a 250-ml flask (equipped as described in Example 1) were placed 132 g 
(0.2 mole) N-methyl(perfluorooctane)sulfonamidoethyl acrylate, 20 g (0.1 
mole) 10-aminoundecanoic acid, and 50 g isopropyl alcohol. The resulting 
mixture was stirred and refluxed for 6 hours, allowed to cool overnight, 
and the flask adapted for distillation and heated to 80.degree.-90.degree. 
C. to remove most of the solvent. The fluorochemical acid product, which 
solidified on cooling, is represented by the following formula: 
EQU [C.sub.8 F.sub.17 SO.sub.2 N(CH.sub.3)C.sub.2 H.sub.4 OCOC.sub.2 H.sub.4 
].sub.2 N(CH.sub.2).sub.10 COOH 16A. 
Salts of the above-described product, such as the ammonium salt, are 
prepared by dissolving the desired quantity of the fluorochemical acid in 
a minimum amount of acetone and adding a slight molar excess of aqueous 
ammonium hydroxide. Such a salt is represented by the formula 16, Table 1 
supra. 
EXAMPLE 17 
In a 250-ml flask (equipped as described in Example 1) were placed 55.4 g 
(0.1 mole) N-ethyl(perfluorooctane)sulfonamidoethyl alcohol, 10 g (0.1 
mole) succinic anhydride, 17 g dimethylformamide solvent, and 0.3 g zinc 
chloride catalyst. The resulting mixture was stirred and heated at 
120.degree.-125.degree. C. for 1.5 hours, then at about 150.degree. C. for 
an additional 2 hours. The resulting reaction mixture was cooled and 
aqueous KOH solution containing 0.1 mole of base was added. The solution 
contained a salt product represented by the formula 17, Table 1 supra. 
The aqueous mixture containing the salt was dissolved in a mixture of 70 
parts by weight water and 30 parts by weight isopropyl alcohol to yield a 
10 weight percent solution of the salt, which was extracted with CF.sub.2 
ClCFCl.sub.2 to remove any unreacted fluorochemical alcohol starting 
material. 
EXAMPLE 18-40 
In these examples, samples of chrome tanned leather were treated with 
various fluorochemical compositions in accordance with this invention and 
the properties of the treated leather tested. For comparison, similar 
treatments were made on other samples using fluorochemicals outside the 
scope of this invention or on a sample without use of any fluorochemical. 
The size of each tanned leather sample was about 20 g. with a thickness of 
2 to 3 mm. The samples were both received and stored wet until their 
treatment and evaluation. 
The apparatus used for treating the tanned leather samples comprised a 
roller mill with a variable speed for rotating the treating drums, each 
drum being 30 cm in diameter, 11.5 cm in length, and made of 
polymethylmethacrylate (1 cm thickness), the drum having a drain hole and 
a loading hole, which holes were closed with rubber stoppers during use. 
Heating of the drum contents was performed by means of infrared lamps 
placed about 10 cm away from the wall of the drum. Temperature during 
treatment was maintained about 45.degree. C. except for the final rinsing 
step. During treatment, the drums were rotated at about 20 to 25 rpm. 
For each treatment, the leather sample was placed in the drum along with 
several rubber stoppers to provide agitation and flexing of the leather 
sample during treatment. 
In addition to the fluorochemical composition used in treating the leather 
samples, various other leather treating chemicals were used: in most runs, 
a fatliquor, dye, and neutralizing agent were used. 
In treating the various leather samples, the following steps were used, and 
though the sequence given below is preferred (its the sequence normally 
used in the post-tanning of cattlehide, with step "f" omitted), the 
sequence of steps sometimes was altered in the examples and some of the 
steps sometimes were omitted: 
TABLE 2 
______________________________________ 
No. Step 
______________________________________ 
a. washing 
b. neutralizing 
c. retanning 
d. dyeing 
e. fatliquoring 
f. fluorochemical treatment 
g. rinsing 
h. drying 
______________________________________ 
Steps "a" through "f" were generally carried out in the rotating drum in 
the sequence listed in Table 2. In Examples 18, 30, 32, the sequence of 
steps e and f were reversed; and in Examples 19, 20, 21, 16, 31, 34, step 
e was omitted. In Examples 20, 21, 30, 32, the retanning step was used, 
and in Examples 20, 21 the dyeing step was omitted. In some cases, a 
treating agent was poured from the drum after its use, i.e., discarded, 
and in other cases it was allowed to remain in the drum, i.e., retained. 
In the washing step, the leather was washed using an amount of water about 
5 times (i.e., "500%") the weight of the leather sample. Washing was 
carried out for about 30 minutes at 25.degree. C. and the used wash water 
having a pH of about 2.5 to 3.0 was discarded. 
In the neutralizing step, an aqueous solution of one or more neutralizing 
agents was added to the drum in an amount of about 3 times the weight of 
the leather sample, the drum then rotating for about 45 minutes at about 
40.degree. C. to bring the pH of the bath to 4.5 to 5.0. The used 
neutralizing bath was discarded and the neutralized leather sample then 
rinsed for about 10 minutes with an amount of water of about 5 times the 
weight of the leather sample. The neutralizing agents used were those in 
the following table, where they are numbered for later reference. 
TABLE 3 
______________________________________ 
No. Name 
______________________________________ 
1 ammonium sulfate 
2 sodium bicarbonate 
3 sodium formate 
4 ammonium hydroxide 
______________________________________ 
Where a retanning step was used in the procedure, the retanning agent was 
"Baykanol Pak", and it was added during the neutralizing step. 
In the dyeing step, the following amounts were added successively to the 
drum with the treatment times as indicated: 
1. water (equal to the weight of the leather sample) containing 9.1 weight 
percent NH.sub.4 OH (5 min.) 
2. a brown acid dye "Dermabrown" RB, in an amount 0.02 times the weight of 
the leather sample (10 min.) 
3. water, in an amount 3 times the weight of the leather sample (15 min.) 
4. formic acid (about 1 ml of 9 weight percent aqueous solution) was added 
to acidify the bath to a pH of about 4.5 (15 min.) 
The aqueous dye bath was discarded after the dyeing step. 
In some examples where a fatliquoring step was used, a mixture of fatliquor 
(0.08 to 0.1 times the weight of the leather sample) and water (3 times 
the weight of the leather sample) was added to the drum and the leather 
sample treated for about 45 minutes therewith, the aqueous fatliquor bath 
being retained. The fatliquor used was a mixture of equal amounts of 
"Coripol" DXF chlorinated fatty acid and "Coripol" BZN lanolin based, 
non-penetrating oil. 
In the fluorochemical treatment or finishing step, an aqueous dispersion of 
about 20 weight percent of fluorochemical was added to the bath, the 
amount of fluorochemical agent being about 0.02 times the weight of the 
leather sample, and the treatment with fluorochemical carried out for 
about 20 minutes, afterwhich the bath was acidified with formic acid to a 
pH of about 4. The fluorochemical-fatliquor bath was discarded unless the 
fluorochemical treatment step preceeded the fatliquor treatment step, in 
which case the bath was retained; also, water in the amount of 3 times the 
weight of the leather samples was added with the fluorochemical agent and 
a minimum amount of water added with the fatliquor if the fluorochemical 
treatment step preceeded the fatliquor treatment step. 
Upon adding the aqueous dispersion of the fluorochemical to the aqueous 
medium in the drum, the aqueous bath became turbid. Over the 20-minute 
treatment period, the bath became almost clear. Upon acidifying the bath 
to pH 4 with the formic acid, the bath became clear, indicating 
essentially complete exhaustion of the fluorochemical onto the leather. 
In the rinsing step, water in the amount of 10 times the weight of the 
leather sample was added, the fluorochemical treated leather washed 
therewith, and the water then discarded. 
In the drying step, the fluorochemical treated, wet leather samples were 
stretched on a frame, dried in air at room temperature over-night, dried 
for about 1 hour at 60.degree. C. in a forced-air oven, and the samples 
removed from the frames when they cooled to room temperature. 
The dried, fluorochemical treated leather samples were tested generally on 
both the grain (hair) side and the suede (flesh) side for oil and water 
repellency. 
In testing the fluorochemical treated leather sample for oil repellency 
(OR), AATCC Standard Test 118-1978 was used, which test is based on the 
resistance of treated fibrous substrates to penetration by oils of varying 
surface tensions. Treated leather samples resistant only to "Nujol" 
mineral oil (the least penetrating of the test oils) are given a rating of 
"1", whereas treated leather samples resistant to heptane (the most 
penetrating of the test oils) are given a value of "8". Other intermediate 
values are determined by use of other pure oils or mixtures of oils. The 
rated oil repellency corresponds to the most penetrating oil (or mixture 
of oils) which does not penetrate or wet the leather after 30 seconds 
contact. Higher numbers indicate better oil repellency. In general, an oil 
repellency of "2" or greater is desirable. 
The aqueous stain repellency (WR) of the treated leather samples was 
measured using a water/isopropyl alcohol test, and the repellency is 
expressed in terms of a rating ratio. Treated leather samples which are 
penetrated by or resistant only to a 100 percent water/0 percent isopropyl 
alcohol mixture, the least penetrating of the test mixtures, are given a 
rating of "100/0", whereas treated samples resistant to a 0 percent 
water/100 percent isopropyl alcohol mixture, the most penetrating of the 
test mixtures, are given a rating of "0/100". Other intermediate values 
are determined by use of other water/isopropyl alcohol mixtures, in which 
the percentage amounts of water and isopropyl aocohol are each multiples 
of 10. The water repellency rating corresponds to the most penetrating 
mixture which does not penetrate or wet the leather after 30 seconds 
contact. In general a water repellency rating of "90/10" or better (e.g., 
80/20 or 70/30, etc.) is desirable. 
The water repellency (SR) of fluorochemical treated leather samples was 
measured by Standard Test Number 22, published in the 1977 Technical 
Manual and Yearbook of the American Association of Textile Chemists and 
Colorists (AATCC), and is expressed in terms of the water "spray rating" 
of the tested sample. The spray rating is measured using a 0 to 100 scale, 
where "100" is the highest possible rating. In general, a spray rating of 
"70" or greater is desirable, particularly for outerwear apparel, for 
example, leather coats or jackets. 
In testing fluorochemical treated leather samples for water penetration 
(P), the extent of penetration of the fluorochemical treating agent into 
the leather was determined by measuring resistance of a cut surface of the 
treated leather sample to wicking or absorption of a water droplet placed 
on the cut surface. The leather sample is cut with a razor blade through 
about 75 percent of its thickness and the leather sample bent so that the 
cut surface forms a flat horizontal surface on which the water droplet is 
placed. The treated leather is visually rated with the unaided eye about 5 
seconds after the water droplet is placed and is evaluated as follows: 
"3" is a rating for complete water resistance or non-wicking, indicated by 
the water droplet remaining substantially in the form of a bead on the cut 
surface of the leather; 
"2" is a rating for partial wicking, indicated by partial dissipation of 
the water droplet into a portion of the undyed region of the leather; and 
"1" is a rating for complete wicking of the water droplet by the cut 
leather surface, indicated by substantially complete dissipation of the 
water droplet into the leather up to the dyed region of the leather. 
(A value of 3 is desired for leather to be used in shoe-uppers.) 
Table 4 summarizes the examples. 
TABLE 4 
__________________________________________________________________________ 
Treatment of Chrome-Tanned Leather 
Conditions 
Neutra- 
Fat Properties of treated samples 
Ex. 
FC % lizer 
liquor 
Grain side 
Suede side 
No. 
used.sup.a 
SOF.sup.b 
used.sup.d 
used? 
OR WR SR 
OR WR SR 
P 
__________________________________________________________________________ 
18 1 1.9 2,3 yes 3 80/20 
80 
3 60/40 
90 
1 
19 1 2.0 1 no 0 80/20 6 30/70 1 
20 2 2.0 1 no 1 80/20 
50 
3 80/20 
80 
2 
21 2 2.0 1 no 1 80/20 
70 
4 80/20 
80 
2 
22 3 2.2 1,2 yes 1 90/10 2 70/30 
70 
2 
23 4 2.2 1,2 yes 3 80/20 3 80/20 
80 
2 
24 5 2.3 1,2 yes 3 90/10 
70 
5 80/20 
70 
2 
25 .sup.c 
1.6 1,2 yes 1 80/20 3 70/30 
80 
1 
26 7 2.6 1 no 0 60/40 
50 
5 20/80 
80 
1 
27 8 2.0 1,2 yes 3 80/20 3 90/10 
70 
1 
28 16 1.6 1,2 yes 3 70/30 4 70/30 
70 
1 
29 17 2.5 1,2 yes 3 80/20 4 60/40 
80 
3 
30 9 0.8 1 yes 3 80/20 
80 
3 70/30 
80 
1 
31 9 2.5 1 no 3 80/20 
70 
5 30/70 
90 
2 
32 10 0.8 1 yes 3 60/40 
80 
4 50/50 
90 
1 
33 10 1.1 1,2 yes 3 70/30 
70 
3 70/30 
80 
1 
34 11 1.2 1 no 1 80/20 2 30/70 2 
35 12 3.0 1,2 yes 3 70/30 4 70/30 
80 
2 
36 13 2.3 1,2 yes 0 90/10 
50 
0 80/20 
70 
1 
37 14 2.0 1,2 yes 3 80/20 5 80/20 
70 
2 
38 15 1.8 1,2 yes 3 70/30 3 80/20 
70 
1 
39 23 2.0 1,2 yes 3 90/10 5 70/30 
30 
3 
40 24 2.2 1,2 yes 3 80/20 3 80/20 
70 
C-1 1.9 1,2 yes 0 100/0 0 100/0 
70 
2 
C-2 2.0 1,2 yes 0 80/20 0 80/20 
70 
1 
C-3 1.9 1 yes 0 90/10 
70 
0 90/10 
70 
1 
C-4 2.1 1 yes 1 90/10 
70 
3 80/20 
80 
3 
C-5 2.0 1,2 yes 0 90/10 3 80/20 
70 
1 
C-6 
None 
0 2,3 yes 0 100/0 
0 
0 NWR.sup.e 
0 
__________________________________________________________________________ 
.sup.a The indicated number of FC (fluorochemical) used corresponds to th 
formula number of Table 1. For the comparison examples, C1 through C5, th 
fluorochemicals used were: 
C1 C.sub.7 F.sub.15 CONH(CH.sub.2).sub.10 COONH.sub.4 
C2 C.sub.8 F.sub.17 C.sub.2 H.sub.4 SCH(COONH.sub.4)CH.sub.2 COONH.sub.4 
C3 C.sub.8 F.sub.17 SO.sub.2 N(C.sub.2 H.sub.5)CH.sub.2 COOH.chrome 
complex 
##STR27## 
C5 C.sub.9 F.sub.19 CONHCH.sub.2 COONH.sub.4. 
.sup.b "% SOF" is the level of FC in the treating bath and it is based 
upon the weight of the tanned leather sample (dry basis) used. 
.sup.c The FC used in Example 25 was the product prepared as described in 
Examples 3-12 and was a mixture of the FC of formulas 1, 25, and 
##STR28## 
.sup.d The indicated number of neutralizing agent used corresponds to the 
number in Table 3. 
.sup.e "NWR" means there was no resistance to water, as shown by complete 
penetration of the water droplet into the leather in less than 15 seconds 
after placement of the water droplet. 
As the data in Table 4 show, the properties of the leather samples treated 
in accordance with this invention, that is, Examples 18-40, are generally 
good, especially when compared with the comparative examples, Examples C-1 
to C-6. These good properties were obtained notwithstanding changes (in 
Examples 18-21, 26, 30-32, 34) in the normal sequence of wet processing 
steps and the omission of some commonly used post-tanning agents. However, 
better oil repellency on the grain side was obtained when the fatliquoring 
step was not omitted (cf. Example 18 vis-a-vis Example 19); thus, the 
practice of this invention is preferably used in conjunction with 
fatliquoring, a conventional post-tanning step in the leather industry. 
And better oil repellency on the grain and suede sides, and better water 
repellency on the grain side, are obtained with the low softening point 
fluorochemicals (cf. Example 36 vis-a-vis Example 38, the softening points 
(measured in a capillary tube) for the fluorochemicals used in Examples 
36, 38 being &gt;200.degree. C. and about 30.degree. C., respectively). 
EXAMPLE 41-52 
Following the general procedure of Examples 18-40, various tanned leathers 
were treated with two different fluorochemicals of this invention. 
However, if a particular leather sample to be treated with the 
fluorochemical had already been subjected to a standard leather processing 
step, that step was omitted. Also, none of the samples were treated with a 
retanning agent. 
The types of leather samples used are shown in Table 5 
TABLE 5 
______________________________________ 
No. Type 
______________________________________ 
A chrome-crust cowhide 
B dyed, fatliquored cowhide 
C chrome-crust cowhide suede 
split 
D vegetable-tanned cowhide 
E dyed, fatliquored pigskin 
F tanned sheepskin, wool-on 
(tanned woolly sheepskin) 
______________________________________ 
The size of each tanned leather sample was about 20 g. with a thickness of 
2 to 3 mm. The samples were both received and stored wet until their 
treatment and evaluation. 
Table 6 summarizes the examples. 
TABLE 6 
__________________________________________________________________________ 
Treatment of Various Types of Leather 
Conditions 
Type Properties of treated leather 
Ex. FC leather 
% Grain side Suede side 
No. used 
used.sup.a 
SOF 
OR WR SR OR WR SR P 
__________________________________________________________________________ 
41 1 A 2.1 
3 70/30 
80 4 70/30 
80 1 
42 1 B 2.2 
3 80/20 
50 4 60/40 
80 2 
43 1 C 1.6 
3 70/30 
80 3 70/30 
80 2 
44 1 D 1.0 
3 80/20 4 60/40 
45 1 E 1.5 
0 100/0 
70 0 80/20 
80 1 
46 1 F 1.6 
3 70/30 3 70/30 
80 1 
47 10 A 2.0 
3 80/20 
70 5 30/70 
90 1 
48 10 B 2.3 
3 80/20 
70 5 40/60 
80 2 
49 10 C 1.6 
5 40/60 
100 
4 50/50 
100 
1 
50 10 D 1.0 
1 90/10 5 60/40 
51 10 E 1.6 
0 100/0 
80 3 70/30 
90 2 
52 10 F 1.5 
5 60/40 5 30/70 
80 2 
__________________________________________________________________________ 
.sup.a The indicated letter of leather used corresponds to that described 
in Table 5. 
As shown by Table 6, the water and oil repellency properties were generally 
good except for the grain side of the pigskin (leather E, Examples 45 and 
51) in this series of examples. 
EXAMPLES 53-57 
A number of samples of chrome-tanned leather (Type A in Table 5) were 
treated with blends of fluorochemicals (FC) denoted by formula numbers 1 
and 10 of Table 1, and, for comparison, such leather was treated with just 
one of these fluorochemicals. The neutralizer used was a mixture of 
ammonium sulfate and sodium bicarbonate, the dye used was "Dermabrown" RB 
(a brown acid dye), the fatliquors used were "Coripol" DXF and "Coripol" 
BZN, and the treatment steps and sequence were those of Table 2 except 
that the retanning step c was omitted. Properties of the resulting treated 
leather samples were determined as in the previous examples, along with 
the water absorption (WA) of the treated samples. The water absorption was 
determined on a "Bally" penetrometer, Model 5022, (a dynamic testing 
machine for shoe leather uppers). The WA values represent the increase in 
weight of the treated samples after 3 hrs. of repeated flexing of the 
samples during immersion of the grain side in water. The lower the value 
is, the greater the water repellency of the treated sample. Results are 
summarized in Table 7. 
TABLE 7 
__________________________________________________________________________ 
Relative 
amount (parts) 
Properties of treated samples 
Ex. 
of FC used 
Grain side Suede side 
No. 
FC-1 
FC-10 
OR WR SR WA OR WR SR 
P 
__________________________________________________________________________ 
53 100 0 3 80/20 
50 61.0% 
3 80/20 
70 
2 
54 75 25 3 80/20 
70 48.4 4 70/30 
80 
2 
55 50 50 3 70/30 
70 51.4 5 60/40 
80 
2 
56 25 75 3 70/30 
80 17.2 5 60/40 
90 
3 
57 0 100 3 70/30 
80 16.6 5 40/60 
90 
2 
__________________________________________________________________________ 
The data of Table 7 show generally good overall properties were obtained, 
and that for some particularly desired properties, a mixture of the 
fluorochemicals may be used rather than a single fluorochemical. 
EXAMPLES 58 and 59 
Following the general procedure of Examples 18-40, samples of sheepskin 
(wool-on), Type F of Table 3, were treated with two fluorochemicals of 
this invention, viz., those of formulas 1 and 10 of Table 1, the amounts 
of each deposited on the sheepskin being 1 wt% of the treated sample. 
These examples and results are shown in Table 8. 
TABLE 8 
______________________________________ 
Treatment of Sheepskin (Wool-on) 
Properties of treated samples 
Suede side 
Before After Wool 
Ex. FC abrasion.sup.a 
abrasion.sup.a 
side 
No. used OR WR OR WR SR OR WR 
______________________________________ 
58 1 3 90/10 3 50/50 80 1 70/30 
59 10 4 50/50 5 40/60 80 4 70/30 
______________________________________ 
.sup.a Values given were obtained by rubbing the treated side with a 
"Scotchbrite" scouring pad for about 1 minute before measuring the 
indicated property. 
The data of Table 8 show that desirable oil and water repellency can be 
obtained on sheepskin (with wool on) even at low fluorochemical levels. 
Various modifications and alterations of this invention will be apparent to 
those skilled in the art without departing from the scope and spirit of 
this invention.