Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2000-03-24
2002-12-31
Cain, Edward J. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S805000, C524S839000, C524S840000
Reexamination Certificate
active
06500894
ABSTRACT:
The present invention relates to compositions to be applied on textiles to make them hydro- and oil-repellent in combination with a very good softness and with the maintenance of the textile appearance.
In order to make hydro- and oil-repellent the surfaces of various materials, the use of various types of polymers, also fluorinated, is known in the prior art. For example fluorinated polymers with various kinds of functionality can be mentioned. Specifically for textiles, fluorinated polymers having an acrylic base wherein the fluorinated part is formed of fluorocarbon chains, can be mentioned. Other fluorinated polymers used to give hydro- and oil-repellence are those having a (per)fluoropolyether structure, in particular polyurethanes. These polymers are used in the form of their aqueous dispersions -to treat textiles. Hydro- and oil-repellence depend on the kind of polymer and the functionality.
In all the patents of the prior art no reference is made to the softness of the treated textiles. This is an essential feature since the treated textiles in addition to very good hydro- and oil-repellence values must show a softness which is substantially similar to that of the untreated textiles. By textile appearance it is meant that the treatment does not substantially change the colour and the gloss with respect to the textiles as such.
U.S. Pat. No. 2,995,542, U.S. Pat. No. 3,356,628 and U.S. Pat. No. 4,529,658 relate to the synthesis of fluoroacrylic polymers and their use for the fiber and textile treatment. After treatment with these polymers, very good hydro- and oil-repellence values, higher than those obtainable with other fluorinated polymers which have other kinds of functionality and structure, are obtained. However, the fluoroacryl polymers show the following drawbacks: the fiber or textile surface appearance is modified, perspirability is reduced and textiles become stiffer. This last aspect of the treated textiles is determined by the softness examination, as called in the technical language. In case of the application of said films, the textile softness becomes worse.
The need was therefore felt to have available compositions for the surface textile treatment combining the very good hydro- and oil-repellence characteristics with the appearance and softness of the untreated textiles. In other words there was the need to find compositions which, besides conferring very good hydro- oil-repellence, did not worsen the textile softness and appearance.
It has now been surprisingly and unexpectedly found that it is possible to solve said technical problem by treating textiles with compositions in the form of aqueous dispersions as hereinunder defined.
It is an object of the present invention compositions formed of aqueous dispersions comprising a mixture of the following fluorinated polymers:
A) (meth)acrylic (co)polymers containing fluorine, and
B) cationic ionomers of fluorinated polyurethanes based on (per)fluoropolyethers,
the weight ratio A):B), on the dry product, being in the range 70:30 and 30:70, preferably 60:40 and 40:60, with the proviso that component A) must not be lower than about 0.5% by weight as dry product in the dispersion.
Preferably component B) is present in the dispersion at a concentration of about 0.4% by weight, more preferably 0.5%.
The invention compositions are used in aqueous dispersions at a concentration in the range 0.7-3% w/w, preferably 0.8-1.5% w/w, still more preferably 0.9-1.3% w/w, determined as dry residue.
Component B), cationic ionomer fluorinated polyurethanes, usable in the present invention, are based on (per)-fluoropolyethers and are obtainable with known methods of the prior art. See for example EP 273,449, EP 337,312, EP 533,159, EP 689,908.
The (per) fluoropolyether-based ionomer polyurethanes have a fluorine content preferably higher than 15% by weight, more preferably higher than 25% by weight, still more preferably higher than 35% by weight, and contain in their structure hydrophilic ionic groups of cationic nature, wherein the cationic groups can be present as side groups and/or in the chain, the side groups being separated from the polymer chain by a bivalent alkylen radical ((R)
a
)
zI
, wherein zI is an integer equal to one or zero, a is an intger from 1 to 20, preferably from 3 to 10, R being of the CR
1
R
2
, Y(CR
1
R
2
)
b
type wherein:
Y is a linking bivalent radical, different from CR
1
R
2
, preferably —COO—, —CONH—, —OCONH—, —O—; b is an integer from 0 to 20; R
1
and R
2
, equal to or different from each other, are: H, aliphatic radicals having from 1 to 10 carbon atoms, cycloaliphatic radicals having from 5 to 20 carbon atoms, aromatic having from 6 to 20 carbon atoms, the cyclic radicals can optionally contain heteroatoms.
The ionomer polyurethanes are obtained by polymerization in two steps according to known various processes which have in common the following steps:
a first step, wherein a fluorinated diisocyanate prepolymer is prepared by reacting with hydrogenated diisocyanates in organic solvents of polar type, for example ketones and acetates, bifunctional (per) fluoropolyethers having alcoholic or acid functionality, optionally mixed with hydrogenated macrodiols. a second step, which depending on the processes consists of:
I) partial chain extension by chain extenders such as dials or diamines (C
2
-C
12
) and ionomers, described in the above mentioned prior art which is herein incorporated by reference, then subsequent dispersion in water and salification with polymerization completion by formation of ureic bonds; or
II) insertion of ionomers and then salification, dispersion and polymerization by chain extension in water in the presence of diamines; or
III) insertion of ionomers and completion of the chain extension in solvent to obtain the polymer having the desired molecular weight, and contemporaneous dispersion and salification in water of the so obtained polymer; alternatively the polymer can be first salified and then dispersed in water.
The hydrogenated macrodiols are for example saturated or unsaturated C
2
-C
4
polyoxyalkylenes, for example PTMEG (polytetramethylenglycol), PEG (polyethylenglycol), PPG (polypropylenglycol), PBDH (polybutadienglycol), polyesters obtained by polycondensation of aliphatic anhydrides of dicarboxylic acids having from 4 to 9 carbon atoms with aliphatic C
2
-C
8
diols, alone or in admixture, ex. PCL (polycaprolactonediol).
The fluorinated polyurethanes according to the present invention contain in the chain units derived from ionomers such as for example the following:
a. diols containing a substituted aminic group, having formula:
wherein R
N
is a linear or branched C
1
-C
6
alkyl, zII is 1 or 2, when zII=1 the nitrogen free valence is saturated with one H atom, R
CI
is H or C
1
-C
4
alkyl, NI ranges from 1 to 4;
b. tertiary alkyldialkanolamines of formula
wherein R
N
and NI have the above mentiond meanings; examples of said amines are methyldiethanolamine, butyldiethanolamine, methyldiisopropanolamine, or
c. the ionomers corresponding for example to the formula:
wherein T is an alkylene radical with a number of carbon atoms from 1 to 20 and has the meaning of R
1
, X=N(R
1
)
2
, R has the above mentioned meaning of R
1
; or
d. diol compounds containing substituted aminic groups corresponding to the following formulae:
wherein R has the above mentioned meaning of R
1
wherein R has the above mentioned meaning of R
1
e is aninteger from 1 to 10.
The PFPEs contained in ionomer fluorinated polyurethanes are used in the synthesis of these polymers in the first step of the above described synthesis method; said PFPEs have average number molecular weight in the range 500-4.000, preferably 1.000-2.000, and contain repeating units selected from the following:
(CF(CF
3
)—CF
2
O), (CF
2
CF
2
O), (CF
2
(CF
3
)O), (CF
2
—CF(CF
3
)O) (CF
2
CF
2
CF
2
O), (CF
2
CF
2
CH
2
O), said units being statistically distributed in the polymer chain.
In particular they belong to one or more of the following classes:
1)—O(CF(CF
Carignano Gabriella
Lenti Daria
Trombetta Tania
Arent Fox Kintner Plotkin & Kahn
Ausimont S.p.A.
Cain Edward J.
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