Sliding wax

Sliding wax such as ski wax is made from gallium or molybdenum disulfide. The wax having a low melting point can be applied to sliding apparatuses readily at sites where they are used, and the wax is advantageously applicable to any snow conditions.

BACKGROUND OF THE INVENTION 
This invention relates to wax which is applied on various sliding surfaces, 
such as the running surfaces of skis, for improving their sliding 
characteristics. The physical properties of wax, of this kind, especially 
ski wax is adjusted by selecting paraffin in accordance with the 
atmospheric temperature and snow temperature. Since the selection of the 
paraffin determines largely the winner or loser of a ski tournament, 
skiers and ski manufacturers make a frantic search for the proper wax 
composition, by measuring atmospheric and snow temperatures, just before 
the race start. 
For popular skiers, there is available in the market wax which does not 
require specific adjustment of paraffin and can widely be used in various 
snow conditions. However, multipurpose wax of this kind adversely affects 
the sliding property of the skis, especially when it is used at the low 
atmospheric temperature at which the snow becomes powder, and the wax has 
a further drawback that the layer of it on the running surfaces of the 
skis comes off rather easily. 
BRIEF SUMMARY OF THE INVENTION 
In view of the above-mentioned background, this invention provides a 
sliding wax which is easy to deal with and gives excellent sliding 
characteristics, regardless of snow conditions. More particularly, this 
invention provides a sliding wax which is made from an element selected 
from the group consisting of gallium and molybdenum disulfide. 
First, this invention is briefly explained further when gallium is 
employed. Metallic gallium, with a melting point of 29.6.+-.1.degree. C., 
a density of 5.91 g/cc, and a thermal conductivity of 0.29-0.38 (at 
30.degree. C.), is soft at low temperatures, glossy, and easy to handle in 
various shapes. In has been found in this invention that gallium, having 
the above-mentioned physical properties, can advantageously be employed as 
a ski wax. The wax can be applied to the running surfaces of skis readily 
and evenly, without hurting the surfaces. The wax can be applied on them 
by warming it in warm water when it is cold and can be applied on them in 
a thin layer with a minimum amount since it is malleable. It is 
advantageous also the metallic gallium, when applied on sliding surfaces, 
becomes harder when it abuts snow surfaces of a low temperature, whereby 
it has longer life than paraffin wax. Experiments show that wax made in 
accordance with this invention has good sliding performance under various 
snow conditions, viz. such as fresh snow, granulated snow, damp snow, and 
ice-up snow, which the conventional multipurpose wax can hardly attain. 
While metallic gallium itself can provide good sliding performance, its 
melting point becomes reduced so that it becomes easier to deal with, its 
frictional resistance against snow surfaces becomes reduced so that skis 
can run faster, and its production cost becomes cheaper when it is alloyed 
with a specific amount of one or more of the metallic elements such as In, 
Zn, Sn, Al and others. The specific amount is 20-60 weight % for In, 
10-20% for Zn, 10-30% for Sn, and 3-5% for Al. The balance is Ga, the 
composition of which with one or more of the aforementioned metallic 
elements in the above-mentioned specific amount can easily be mixed and 
melted at a temperature lower than 100.degree. C., as shown by the phase 
diagrams of Ga with the metallic elements. Metallic elements other than 
the aforementioned metallic elements can be employed, provided that they 
can be alloyed with Ga, and melt at a temperature lower than 100.degree. 
C. 
As mentioned above, Ga alloys come to have a melting point lower than Ga 
itself, that is about 30.degree. C. For example, a binary alloy of Ga 
(76%)-In (24%) has a melting point of 15.7.degree. C., and a ternary alloy 
of Ga (82%)-Sn (12%)-Zn (6%) has a melting point as low as 17.degree. C., 
whereby they become more easier to deal with. And, it is found to this end 
that the Ga content must be more than 60% when it constitutes a binary 
alloy, and more than 30% when it constitutes a ternary alloy. It is found 
also that the addition of Zn to Ga is effective, especially when 
atmospheric and snow temperatures are comparatively high. 
One of the most advantageous points of the ski wax of this invention, which 
is made from Ga, is that it can be warmed by hands and softened so that it 
can be applied readily on the running surfaces of skis and then can be 
spread by a piece of gauze or sponge evenly over the surfaces. This work 
takes extremely less time than that required with the conventional ski 
wax. The conventional wax is applied by means of a burner or iron, shaved 
portionally so as to make it smooth, and is then applied again. This is 
quite laborious. 
As mentioned above, it is an advantageous point of this wax that it can be 
safely used in tournaments, because it is hardly affected by snow 
conditions, as illustrated in the following Example 1. 
Second, this invention is briefly explained further when molybdenum 
disulfide is employed. 
Molybdenum disulfide, MoS.sub.2, has an atomic structure in which a single 
Mo atom is sandwiched at its two lateral sides by two atoms of S, and 
belongs to a hexagonal system, and its molecules are cleavable from each 
other. Its grains have a flat form which is indeterminate but oval, and 
the thickness of which is about 1/20 of the length of the longitudinal 
axis thereof. Its color is silver-gray or black-gray, and it has a Mohs' 
scale hardness of 1-1.2, a specific gravity of 4.8-5.0, and a thermal 
conductivity of 0.328 cal. cm.sup.-1 deg.sup.-1. Though it is considered 
to be a semi-conductor, its outer membrane becomes conductive when it is 
strongly compressed. In addition, molybdenum disulfide has the 
characteristic that its resistance decreases when the temperature 
increases. 
Molybdenum disulfide alone having the above properties, or its mixture with 
paraffin can provide, in this invention, wax which exhibits good sliding 
and coating characteristics. The characteristics are far superior to those 
of paraffin wax, and even superior to those of conventional multipurpose 
ski wax made from paraffin mixed with aluminium. While commercial powders 
of molybdenum disulfide have an average grain diameter of 0.5-5.mu., it is 
preferable in this invention to use the powders having diameters less than 
about 1.0.mu., because such powders have better affinity with paraffin and 
produce better sliding and coating characteristics. 
Thus, it should be noted that while molybdenum disulfide alone can provide 
excellent ski wax, its mixture with paraffin can also provide wax which 
has good sliding characteristics which are comparable to those of wax 
which is prepared specifically for competition purposes. In fact, wax made 
from molybdenum disulfide and paraffin, in accordance with this invention, 
works best with damp and fasten snow.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
This invention is further described below by way of examples. 
EXAMPLE 1 
Comparative sliding tests were conducted between two kinds of conventional 
wax and the wax made in accordance with this invention. 
They are as follows. 
(a) Multipurpose ski wax, trade name TOKO and made in Switzerland, 
consisted of paraffin wax mixed with aluminum. 
This multipurpose wax was applied on the running surfaces of a pair of 
skis. The wax was spreaded evenly over the surfaces by an iron, and the 
waxed surface was thinly shaved off. And, the wax was applied and spread 
once again, and finished. 
(b) Competition wax of: 
(b)-(1): The red and yellow competition waxes trade name of HOLMENKOL made 
in Germany, were mixed at a ratio of 1:1 by melting them by a burner. This 
mixed wax was twice applied on the running surfaces of skis as described 
in the above (a), and finished. 
(b)-(2): The red and white competition waxes trade name TOKO and made in 
Switzerland were mixed at a ratio of 2:1 by melting them by a burner. The 
mixture was applied twice as described in the above (a), and finished. 
(c) The wax of the invention: 
Three waxes made in accordance with this invention, viz. one made from Ga 
alone, another of Ga 60%-In 40%, and further another of Ga 80%-Zn 20%, 
were each applied to the running surfaces of a pair of skis, and they were 
finished by being spread evenly over the surfaces with a piece of gauze. 
Two skiers who were instructors of the All Japan Ski League and 
representative players at the Japan National Games wore the skies and 
tested them ten times. The test course had an average slant of 15.degree. 
and a distance of 250 meters. 
Average times required for the skies are as given in the following Table 1. 
TABLE 1 
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(Time: second) 
Skis with 
(c) This invention wax 
Snow (b) competition wax 
Ga--In 
Ga--Zn 
conditions 
(a) multi-purpose wax 
(b)-(1) 
(b)-(2) 
Ga alone 
60:40 
80:20 
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atmospheric 
24.73 21.24 
21.39 21.14 
20.97 
-- 
temperature -5.degree. C. 
snow 
temperature -6.degree. C. 
(snow condition) 
fresh snow 
atmospheric 
22.50 20.61 
-- 21.24 
-- 20.12 
temperature 0.degree. C. 
snow 
temperature -1.degree. C. 
(snow condition) 
powder snow 
atmospheric 
23.16 -- -- -- -- 21.51 
temperature 
snow temperature 
(snow condition) 
damp snow 
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EXAMPLE 2 
The following three waxes, (a'), (b'), and (c'), were subjected to 
comparative tests. 
(a') Conventional multipurpose wax comprising paraffin wax with aluminum 
mixture: 
This wax was applied on the running surfaces of skis, and was spread with a 
cork block. Surfaces of wax were thinly shaved off. The above step was 
repeated. 
(b') Competition wax: 
Wax "white" and "yellow", trade names of a company, were mixed at a ratio 
of 1:1 by melting them. This mixed competition wax was applied on skis as 
in the above (a'). 
(c') The wax of the invention: 
(c')-(1) wax was made from molybdenum disulfide alone, while (c')-(2) wax 
was prepared from the above (b') competition wax added with 30% of 
molybdenum disulfide. They were applied on skis as in the above (a') and 
(b'). 
Tests were made under the conditions that snow temperature was 0.degree. 
C., weather was cloudy, and snow was damp and granulated. Results were as 
shown in the following Table 2. 
TABLE 2 
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(Time: second) 
(c') this invention wax 
(c')-(2) 
(c')-(1) 
competition wax (b') 
(a') multipurpose wax 
(b') competition wax 
MoS.sub.2 alone 
added by MoS.sub.2 
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1st run 
11.71 10.70 10.69 10.68 
2nd run 
11.53 10.92 10.79 10.70 
average 
11.62 10.81 10.74 10.69 
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As readily seen in the Tables 1 and 2, wax made in accordance with this 
invention has better sliding capacities, compared to conventional ones. In 
addition, the wax of this invention can stand up well to various snow 
conditions, including fresh, damp, granulated, and iced snow. As the wax 
can be spread easily at low temperatures, one can promptly apply it to 
skis at the skiing grounds.