Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – For cleaning a specific substrate or removing a specific...
Reexamination Certificate
1998-02-18
2001-07-17
Kopec, Mark (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
For cleaning a specific substrate or removing a specific...
C510S475000, C510S506000, C252S364000
Reexamination Certificate
active
06262006
ABSTRACT:
The present invention relates to solvents utilizable as cleaning rinsing agents capable of removing traces of solvents, oils, greases, waxes, etc. from the substrates in general.
In particular as oils silicone oils, mineral oils and turpentines can be mentioned; as substrates, surfaces of metal components, plastic and glass material can be mentioned; as solvents, the organic ones, among which hydrocarbons, aliphatic esters, etc., can be mentioned.
More specifically the present invention relates to solvents capable of removing such substances without solubilizing them. The problem is particularly felt in industry where it is necessary to remove organic solvents or oils from the components coming into contact with the above mentioned materials during the cleaning or processing cycles. It is clear that after such removal process (de-solving and/or de-oiling) such components must result completely free of stains or residues.
A product meeting such requirements must not degrade, attack or modify the surface of the treated components.
Moreover, such product must result non-inflammable, non toxic, have no impact on the ozone (null ODP), must be thermally stable and capable of removing a wide range of solvents and oils even though its shows a poor or even null miscibility with the organic solvents and the oils to be removed.
The technical problem to be solved by the present invention relates to the need to have available solvents being not toxic and having the characteristics indicated above. Such a problem is particularly felt since the laws of the various countries have banned or are going to ban the use of most solvents utilized up to now owing to problems of impact on the ozone.
As an example of solvents which will not be utilized any longer due to their impact on the ozone, chlorinated solvents, chlorofluorocarbons (CFC) and in the future also hydrochlorofluorocarbons (HCFC) can be mentioned. The chlorofluorocarbons (CFC), in particular CFC-113, have been utilized for many years in various washing and drying processes. The above mentioned CFCs meet almost completely the characteristics mentioned above except for the high ODP which has even led to the banning.
The processes utilizing organic solvents or mineral and/or silicone oils are numerous.
Those having low molecular weight have the advantage of a quick drying, but have the drawback to be easily flammable since they have a low flash point. To overcome this drawback oils having a higher molecular weight are used. In this case the drawbacks are represented by the long time of drying and by the presence of stains and residues on the pieces after drying. Various techniques have been suggested to speed up and improve this processing step, such as hot air drying, drying under vacuum, air knife and in oven. This leads to various drawbacks such as for instance surface oxidations which modify the surface to be cleaned, sometimes hindering successive treatments such as painting or welding; prolongation of the processing times and utilization of more processing steps and consequently higher costs.
It has been unexpectedly and surprisingly found a composition capable of removing organic solvents and oils also with high molecular weight avoiding to use complex and expensive processes as pointed out above.
The present invention allows to remove organic solvents and silicone oils characterized by a relatively high boiling point, generally higher than 100° C.
An object of the present invention is a composition utilized to remove traces of organic solvents and/or oils from the surfaces of components comprising:
i) perfluoropolyethers having perfluoroalkylic end groups, optionally said groups containing hydrogen;
ii) fluorinated additive having a structure selected from the following:
T—OR
f
(CFY)—L (I)
L—CF
2
OR
f
CF
2
—L (II)
with L=X—CH
2
CH
2
(OCH
2
CH
2
)
n
B
wherein X=CH
2
O, CH
2
NR″, CONR″, CH
2
OCH
2
CH
2
NR″, CH
2
OCOCH
2
O;
B=OH, SH, NHR″, OCH
3
, OCOCH
3
;
with R″=H, alkyl C
1-3
;
Y=CF
3
or F;
T is selected among —CF
3
, —C
2
F
5
, —C
3
F
7
, ClCF
2
CF(CF
3
)—, CF
3
CFClCF
2
—, ClCF
2
CF
2
—, ClCF
2
—;
R
f
is selected among the radicals of the type: A)
(per)fluoropolyethereal comprising repeating units randomly distributed along the polymer chain selected among:
(CF
2
CF
2
O), (CFYO) wherein Y is equal to F or CF
3
, (C
3
F
6
O) (CF
2
(CF
2
)
z
O) wherein z is an integer equal to 2 or 3, (CF
2
CF (OR
f′
)O), (CF(OR
f′
)O) wherein R
f′
is equal to —CF
3
, —C
2
F
5
, —C
3
F
7
; CR
4
R
5
CF
2
CF
2
O wherein R
4
and R
5
are equal to or different from each other and are selected among H, Cl or perfluoroalkyl, for instance with 1-4 C atoms;
and
B) perfluoroalkanes and hydrofluoroalkanes having molecular weight comprised between 300 and 1200.
The additive is preferably of formula (I).
The component i) is represented by highly fluorinated organic compounds having a pefluoropolyether structure (PFPE) free from chlorine and bromine, and having the above mentioned end groups. The PFPE repeating units are those indicated in R
f
in A).
The PFPE are chemically inert products and have a good compatibility with most of the fluorinated and non fluorinated materials commonly used in industry. They are not toxic, do not damage the ozone and are not flammable.
Since the organic solvents, the turpentines and the silicone oils are not mixible with PFPEs, the removal of traces of the above mentioned products cannot occur by simple dissolution, but by displacement.
In the component ii) the number average molecular weight of the (per)fluoroether part (T—OR
f
or CF
2
R
f
CF
2
) is comprised between 500 and 1200 and the ratio by weight (K) between (per)fluorinated part and hydrogenated part is comprised between 1.5 and 3.5.
In particular the following R
f
fluoropolyethers can be mentioned as preferred:
—(CF
2
CF(CF
3
)O)
a
(CFYO)
b
— (a)
wherein Y is F or CF
3
; a and b are such numbers that the molecular weight is comprised in the range indicated below; a/b is comprised between 10 and 100; or the repeating units indicated in (a) can be combined as follows:
—(CF
2
CF(CF
3
)O)
a
(CFYO)
b
—CF
2
(R′
f
)
x
CF
2
—O—(CF
2
CF(CF
3
)O)
a
(CFYO)
b
—
wherein
R′
f
is a fluoroalkylenic group, for instance from 1 to 4 C;
—(CF
2
CF
2
O)
c
(CF
2
O)
d
(CF
2
(CF
2
)
z
O)
h
— (b)
wherein c, d and h are integers such that the molecular weight is comprised in the range indicated below; c/d is comprised between 0.1 and 10; h/(c+d) is comprised between 0 and 0.05, z has the value indicated above, h can be also equal to 0;
—(CF
2
CF(CF
3
)O)
e
(CF
2
CF
2
O)
f
(CFYO)
g
— (c)
wherein Y is F or CF
3
; e, f, g are integers such that the molecular weight is comprised in the range indicated below; e/(f+g) is comprised between 0.1 and 10, f/g is comprised between 2 and 10;
—(CF
2
O)
j
(CF
2
CF(OR
f″
)O)
k
(CF(OR
f″
)O)
l
— (d)
wherein: R
f″
is —CF
3
, —C
2
F
5
, —C
3
F
7
; j,k,l are numbers such that the molecular weight is comprised in the range indicated below; k+l and j+k+l are at least equal to 2, k/(j+l) is comprised between 0.01 and 1000, l/j is comprised between 0.01 and 100;
—(CF
2
(CF
2
)
z
O)
s
— (e)
wherein s is an integer such as to give the molecular weight indicated below; z has the meaning already defined;
—(CR
4
R
5
CF
2
CF
2
O)
j′
— (f)
wherein R
4
and R
5
are equal to or different from each other and are selected among H, Cl or perfluoroalkyl, for instance with 1-4 C atoms, j′ being an integer such that the molecular weight is that indicated below; said unit inside the fluoropolyoxyalkylenic chain being combined between each other as follows:
—(CR
4
R
5
CF
2
CF
2
O)
p′
—R′
f
—O—(CR
4
R
5
CF
2
CF
2
O)
q′
—
wherein R′
f
is a fluoroalkylenic group, for instance from 1 to 4 C, p′ and q′ are integers such that the molecular weight is that indicated above;
—(CF(CF
3
)CF
2
O)
j″
—&em
Fontana Simonetta
Silvani Rossella
Arent Fox Kintner & Plotkin & Kahn, PLLC.
Ausimont S.p.A.
Kopec Mark
Mruk Brian P.
LandOfFree
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