Solid anti-friction devices – materials therefor – lubricant or se – Solid anti-friction device – article or material therefor – Halogen compound
Reexamination Certificate
2000-02-10
2001-09-04
Gupta, Yogendra N. (Department: 1751)
Solid anti-friction devices, materials therefor, lubricant or se
Solid anti-friction device, article or material therefor
Halogen compound
C508S590000, C570S136000
Reexamination Certificate
active
06284715
ABSTRACT:
The present invention relates to the use of fluorinated solvents, such as perfluorinated alkyls or perfluorinated alkyl ethers, for the application of fluorinated waxes on skis, snowboards, toboggans, or other items where smooth gliding properties on snow or water is desired.
BACKGROUND OF THE INVENTION
Substrates called “ski waxes” which improve gliding properties of the ski by lowering the friction coefficients between the ski sole and the snow surface are well known in the field of skiing.
As a rule the sole of any ski consists of a very high molecular weight polyethylene and there are several reasons why the ski waxes are applied to the ski sole, namely:
1. To reduce or eliminate surface roughness of the sole and irregularities of the sole in such a manner that the sole is rendered nearly perfectly smooth and even and, therefore, resistance due to mechanical friction of the gliding surface is reduced.
2. To lower the surface tension so that adhesion of the gliding surface to the snow surface is reduced due to the lower interfacial energy of a chemical nature between the two surfaces.
3. To act as an actual lubricant, liquid or solid depending on the types of wax used, between the ski sole and the snow surface.
The first ski waxes used in the field of snow skiing, and the ones used most commonly today, consist of various paraffins. The waxes differ from one another in several ways which include differences in:
Molecular weight distribution curves of their components
Number of branching or cross-link density
Possible oil contents
Degree of crystallization and melting point, which usually depend on the three characteristics listed above.
Since 1985, in addition to paraffin ski waxes described above, fluorinated ski waxes, or so-called “fluorinated waxes,” became available. In fluorinated waxes hydrogen atoms of the paraffin are completely substituted with fluorine atoms.
These fluorinated waxes exhibit extremely low surface tension which, in turn, results in a lower coefficient of friction of the ski on the snow.
These waxes, however, have some disadvantages such as high vapor pressure in conjunction with a high melting point and immiscibility with or insolubility in hydrogenated paraffins.
For increasing the range of applicability of these waxes, over the past few years waxes with mixed chains that serve as compatibilizers between the fluorinated and hydrogenated waxes have been developed. These compatibilizing waxes comprise chains that are partially hydrogenated and partially fluorinated. Addition of hydrogenated paraffins to fluorinated waxes improves the characteristics of the fluorinated waxes by lowering their volatility as well as the melting point.
One of the most important characteristics determining the quality of a ski wax is its ability to be applied to a ski sole without impairing the physico-mechanical properties of the sole.
Thus, a hydrogenated paraffin can be effectively applied to a ski sole as long as its melting point is below 105° C. to 110° C.
If, however, the melting temperature of the paraffin is above 118° C. to 120° C., the ski sole the paraffin is applied onto and which absorbs such paraffin may separate from the ski or the surface of the sole may be damaged so as to impair the original characteristics of the sole.
Recently sprayable paraffins or paraffin solutions have been marketed which present several advantages over the conventional paraffins as follows:
a) sprayable paraffin can be distributed more uniformly or evenly over the sole while the amounts of the paraffin being consumed is reduced;
b) paraffins of high molecular weight can be utilized in sprayable paraffin solutions which could not be previously applied in a powder form solely due to its high molecular weight.
These sprayable solutions currently available on the market, however, present the following disadvantages:
a) they contain, in many cases, toxic substances such as chlorinated or aromatic solvents, and, in many cases, are flammable;
b) after application to a ski sole, and after the majority of the solvent has evaporated part of the solvent still remains trapped within the paraffin modifying the characteristics of the latter.
Up to now, no fluorinated wax in sprayable form has been available or disclosed in the literature, because the fluorinated waxes, i.e containing completely fluorinated or perfluoronated chains, are not soluble in any hydrogenated organic solvent.
The present invention provides fluorinated waxes that can be applied as sprays or aerosols and eliminate the above-mentioned disadvantages of the known sprayable solutions containing paraffins or paraffin waxes.
SUMMARY OF THE INVENTION
One or more fluorinated solvents is employed for the application of one or more fluorinated waxes to ski soles or other surfaces for improving the gliding properties of the ski or surface by lowering the coefficient of friction between the surface and the snow surface or water surface. High melting point waxes may be applied by spraying without ruining or impairing the physico-mechanical characteristics of the ski sole or other surface. The one or more fluorinated solvents may be a linear, branched, cross-linked, or cyclic perfluorinated compound having a boiling point from about 30° C. to about 150° C., preferably from about 50° C. to about 100° C. The sprayable composition is a solution or a suspension at room temperature and about atmospheric pressure. The fluorinated wax may be one or more compounds having at least twelve carbon atoms in a chain. The carbon chains may be saturated or unsaturated, perfluorinated, or partially fluorinated. The sprayable compositions may be stored in spray cans or aerosol cans and can be sprayed as a wax in the form of an aerosol or spray onto ski soles, snowboard soles, toboggan soles, and the like.
DESCRIPTION OF THE INVENTION
The present invention provides a sprayable liquid composition or sprayable suspension comprising fluorinated ski waxes and fluorinated solvents. The sprayable compositions may be stored in a spray can or aerosol can for spraying onto the gliding surface of skis, snowboards, toboggans, and other items where smooth gliding properties on snow or water is desired.
Fluorinated waxes suitable for the present invention are perfluorinated compounds containing carbon chains with at least 12 carbon atoms, for example 12 to 20 carbon atoms. The carbon chains can be saturated or unsaturated. The perfluorinated compounds may be completely fluorinated C
12
and up carbon chains, R
f
, or may be mixed perfluorinated-hydrogenated chains comprising completely fluorinated block(s) and hydrogenated block(s) such as R
f
—R
H
or R
f
—R
H
—R
f
, wherein R
f
is a completely fluorinated carbon chain or group and R
H
is a completely hydrogenated carbon chain or group. The chains can be linear or branched. Examples of unsaturated fluorinated waxes which may be utilized are C
8
F
17
—CH
2
—CH═CH—C
8
F
17
or C
6
F
13
—CH
2
—CH
2
—CH═CF—C
5
F
11
and mixtures thereof. Examples of compounds which may be employed further include compounds with hydrogenated cores having two or four fluorinated substituents such as
Examples of compounds having a hydrogenated core and two or more perfluorinated chains which may be used in the present invention and disclosed in my copending U.S. patent application, Ser. No. 09/261,131, filed Mar. 3, 1999, for Lubricant for Improved Gliding Properties of Skis and Its Application in Skiing, now U.S. Pat. No. 6,121,212. As disclosed therein, the compound may have four perfluorinated chains attached to a hydrogenated core in such a manner as to form a tetra-substituted derivative according to the formula
wherein each R
x
group can be the same or different and comprises a perfluorinated alkyl group. R
x
may be a group selected from R
f
, R
f
—CH
2
—, or R
f
—CH
2
—CH
2
—, wherein R
f
is a perfluorinated alkyl group such as a C
4
F
9
, C
6
F
13
, C
8
F
17
, C
10
F
21
, C
12
F
25
, or C
14
F
29
group. In embodiments of the invention all four groups designated R
x
may be the same, or two of the R
x
groups may
Centeiro Trading LDA
Gupta Yogendra N.
Hollander Law Firm, P.L.C.
Webb Gregory E.
LandOfFree
Use of fluorinated solvents for application of fluorinated... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Use of fluorinated solvents for application of fluorinated..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Use of fluorinated solvents for application of fluorinated... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2547211