JP2782375B2 - Manufacturing method of artificial snow for indoor ski slope - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing artificial snow for use on an indoor ski slope.

More specifically, the present invention relates to a method for producing artificial snow used for a slope of an indoor ski resort, which is made of free-flowing artificial snow or falling wild goose-shaped artificial snow by absorbing water, swelling and freezing the highly water-absorbent resin spherical body.

[Prior Art] (Natural snow) In recent years, the amount of snow has been decreasing year by year, and this has hindered the opening of ski resorts. In addition, the natural snow on the ground is too soft and the skis are slippery, making it unsuitable for use as a slope, so the snow plow must compress the snow many times. In addition, snow compaction is not suitable for competitions, but instead uses a method of “foot feet” that people step on with shoes only, or a method of spraying water on laid snow. The slope made in this manner is greatly affected by the temperature of the outside air, and the snow quality changes over time. Sublimation inside snow
This is because condensation occurs and the snow crystals change,
Proceed from "Summer snow" to "Snow snow". Rough snow is very slippery snow for skiers, so the work of breaking the snow, that is, grooming, must be performed frequently, but it is still not sufficiently effective.

(Artificial snow) In recent years, ski resorts in Japan have been actively introducing artificial snowfall equipment to speed up or extend the gliding season. Artificial snowfall devices are roughly classified into two types: gun type and fan type. The method of making snow with these apparatuses is a method of making fine ice by using adiabatic expansion of compressed air with high-pressure water in an atmosphere of 0 ° C. or lower or using cold air. The artificial snow thus produced contains more than 10% of water, has a density of 0.3-0.4 g / cm ³ and a strength of 1 kg / cm ²
The following is not suitable for skiing without snow compaction. In addition, such snow changes its snow quality more rapidly than natural snow, and after several days, it may progress to rough snow having an outer diameter of about 1 to 5 mm. As mentioned above, rough snow is a troublesome snow property for skiing, and the same measures are taken as described above.

In addition, artificial snowmakers have been introduced to freeze water into ice blocks, apply physical impact and crush the ice particles and snowflakes, but this is also annoying snowy material, like shaved ice or snow. There is a disadvantage that can only be obtained, and the same measures as described above are taken.

In the case of artificial snow made by mixing a water-swellable material (water-absorbent resin) with water (absorbing water), aerating and then freezing, as disclosed in Japanese Patent Application Publication No. 63-500526, Density and strength tend to vary depending on aeration conditions and freezing conditions, with a density of 0.4 to 0.9 g / cm ³ and a strength of 10 to several hundreds kg / cm ² . Such snow is more like crushed fine ice or ice burn than snow. The same condition as that of the ice burn must be crushed by applying a physical impact as described above to form ice grains or snowflakes, and only a rough snow-like product can be obtained. Therefore, when making artificial snow using only the water-swellable material, add a surfactant or adjust the particle diameter and water absorption ratio so that frozen particles do not bond more than necessary to make it suitable for skiing. And grooming must be performed frequently. Such snow is very hard to use for ski resorts.

In addition, since outdoor skiing areas are affected by the weather, indoor skiing areas that can be used throughout the year are becoming increasingly popular. An artificial slope at an indoor ski resort is also made by arranging the artificial snow, artificial ice grains, snowflakes, or the like, or artificial snow made from a water-swellable material (water-absorbent resin) and water on an artificial slope. However, indoor ski resorts made by these methods have the same problems as described above.

In addition, the water-swellable material (water-absorbent resin) and water are mixed with an artificial slope at an indoor ski resort (weight ratio: about 1/80 to 1/10).
0) There is also an artificial slope where ice is shaved off by gliding only the surface of the ice, and then ice is formed once, like a skating rink. In addition to the above-mentioned problems, indoor ski resorts created by this method also have
Under the artificial snow, there is an ice layer such as an ice barn, so that there is a problem that the stock does not stand.

Also, developed by the present inventors, using the high water-absorbent resin granules to absorb or without absorbing water,
The above problem can be solved by using natural snow, artificial snow made by artificial snowfall equipment, or artificial snow made by mixing and freezing with ice and snow made by an artificial snowmaking machine. The artificial snow is suitable for outdoor use, and when used at indoor ski slopes, it is an artificial snow that can be used as it is without mixing with natural snow or artificial snow or ice snow made by other methods. What can be easily maintained so as to be suitable for skiing is desired.

[Problems to be Solved by the Invention] Conventional natural snow and artificial snow have the following problems, and they are not particularly suitable for indoor ski slopes.

I have to snow.

Snow of any density or intensity depending on the level and preference of the skier is not available.

Snow quality changes over time, making it difficult to maintain the condition of the slopes.

Slope construction and maintenance costs are high.

It must be incorporated into various types of snow, such as natural snow and artificial snow.

Artificial snow made by freezing from a water-swellable material (water-absorbent resin) and water becomes an ice block, which must be ground once.

[Means for Solving the Problems] The present inventors have found a method for producing artificial snow for use on a slope of an indoor ski resort which has solved the conventional problems.

The invention of claim 1 of the present invention maintains a spherical shape even when absorbing water, is non-adhesive to each other, and has a water absorption capacity for ion exchanged water of about
A method for producing artificial snow used for a ski slope in an indoor ski resort comprising a step of absorbing water by a highly water-absorbent resin spherical body having a particle size of about 20 to 500 μm before water absorption of about 30 to 500 times and swelling and freezing it. is there.

According to a second aspect of the present invention, in the method for producing artificial snow used for a slope at an indoor ski resort according to the first aspect, the freezing step includes swelling the swollen superabsorbent resin spherical body with dry ice, liquid nitrogen, It is characterized by being made into artificial snow which has been frozen by stirring and mixing with at least one coolant selected from liquid air.

According to a third aspect of the present invention, in the method for producing artificial snow used for a slope at an indoor ski resort according to the first aspect, in the freezing step, the swollen super-water-absorbent resin spherical body is cooled by a coolant. It is characterized by being placed on a foundation and frozen to make artificial snow in the shape of a falling goose.

In the present invention, the ion-exchanged water refers to water obtained by ion-exchanging water such as tap water with an ion-exchange resin or the like.

Examples of the superabsorbent resin used in the present invention include starch-based, cellulose-based or synthetic resin-based polymers such as acrylamide, acrylic acid, acrylate, methacrylate, styrene, vinyl ether, and the like, copolymers, terpolymers, and the like. Among them, in particular, a spherical polyacrylic acid salt obtained by reverse-phase suspension polymerization in an organic solvent, a copolymer of vinyl alcohol and acrylate or a copolymer of isobutylene and maleic anhydride is preferred. Are preferred.

The form of the superabsorbent resin used in the present invention is spherical, about 20 to 500 μm before the particle system absorbs water, and about
Those having a thickness of about 0.05 mm to 2 mm are preferable. If the particle size is less than about 20 μm before water absorption, the artificial snow is too fine and the artificial snow becomes too hard, and if it is more than 500 μm, the artificial snow becomes rough and undesired.

Spherical superabsorbent resin is preferred because it is easy to handle, the artificial snow obtained by freezing also becomes spherical, skis are good because it is spherical artificial snow, it is difficult to melt due to the influence of outside air, etc. It is economical and easy to mix with natural snow and the like.

Even if the superabsorbent resin used in the present invention retains fluidity in a spherical shape even after absorbing water and is non-adhesive to each other, the degree of crosslinking may be increased with a polyvalent epoxy or a polyvalent amine, If the cross-linking is excessive, the water-absorbing ability decreases, so the amount of the cross-linking agent is adjusted so as to obtain an appropriate water-absorbing capacity.

It is considered that the reason why the superabsorbent resin used in the present invention is spherical and retains fluidity even after absorbing water is that little water adheres between the absorbed particles and the particles slide with each other to form voids.

Some superabsorbent resins become pasty when they absorb water, but when they become pasty they become one large ice block when frozen and cannot be used as artificial snow for skiing unless they are finely crushed. This artificial snow is undesirable because it is difficult to maintain it suitable for skiing as described above.

The artificial snow of the present invention obtained by freezing the water-absorbent resin spherical body is finely and uniformly dispersed according to the freezing method, particle size, water absorption ratio, water absorbing ability, etc.
Thus, for example, a “falling geese” of confectionery in which the particles are lightly adhered to each other is produced.

The water-absorbent raw resin used in the present invention has a water absorption capacity of 30 to 500 times, preferably 50 to 200 times, with respect to ion-exchanged water.
When the water absorption capacity is smaller than 30 times, the obtained artificial snow has a low water absorption capacity, so that it becomes difficult to absorb the liquid water generated by melting of the artificial snow and maintain the snow quality of the target condition. On the other hand, when the ratio is more than 500 times, the gel strength when absorbing water is weak, and when pressure is applied, the gel is easily broken, which is not preferable.

The water absorption of the superabsorbent resin is equal to or less than the maximum water retention of the superabsorbent resin, and is about 5 to 100 times in terms of water absorption. When it is desired to obtain soft artificial snow, it is preferably about 5 to 50 times, and when it is desired to obtain hard artificial snow, it is preferably about 30 to 100 times.

The artificial snow made by freezing it is still capable of absorbing water because it absorbs water below the maximum water retention of the superabsorbent resin. Thus, it is possible to keep the snow quality of the target condition unchanged.

For example, to obtain hard and heavy snow quality, the particle size is small (20 to 150 μm) and the ratio of water absorption capacity / water absorption capacity is large (3
0-80%).

On the other hand, if you want to get soft and light snow,
~ 500μm), the ratio of water absorption capacity / water absorption capacity is small (10 ~ 5
0%).

Any method may be used to cause the superabsorbent resin to absorb water. For example, the particles may be put into stirred water and left for a few minutes depending on the water absorption capacity. The water absorption rate is affected by the water temperature. The water absorption rate tends to be slower at lower temperatures and higher at higher temperatures. For example, when the water temperature is 10 ° C. or lower, it is desirable to appropriately heat and absorb water.

Even if the water-absorbing superabsorbent resin is left at room temperature as it is, it does not release water and can be kept stable for a long time, so even if there is a certain period of time before freezing and creating artificial snow (for example, No more adverse effects.

Since the high water-absorbing resin itself is water-absorbing, it is desirable to store it in a closed container, for example, so as not to absorb moisture when it is stored.

The method of freezing the water-absorbing resin spherical body is to create "free-flowing artificial snow" or "falling-goose-shaped artificial snow"
Is different from building

In the case of producing "snow-dried artificial snow", the above-mentioned artificial snowfall machine or artificial snowmaker may be used, but it is preferable to stir and mix under direct contact with a cooling agent such as dry ice, liquid nitrogen, and liquid air. Use a method that freezes rapidly while heating. More preferably, a method using dry ice powder is used. The amounts of these coolants and the mixing time are not particularly limited. It is preferable that the temperature of the frozen artificial snow be about 0 to -30 ° C, but it depends on various conditions. In the case of dry ice, the mixing state changes depending on the size and the stirring speed, so that it is desirable that freezing proceeds uniformly and rapidly.

In the case of making “falling snow-like artificial snow”, a superabsorbent resin spherical body that has absorbed water is placed on a pipe, sheet, floor, board or other base cooled by a coolant and frozen. The temperature of the substrate is preferably about −40 ° C. or less, and the lower the temperature, the harder the material.

The artificial snow of the present invention can be used on a slope as it is. An artificial ski resort can be easily constructed by directly using it alone, and maintenance becomes easy. However, it may be used by appropriately blending it with natural snow, artificial snow or ice snow produced by a method other than the present invention. The mixing ratio may be arbitrary.

When making the slopes, for example, laying down `` falling geese artificial snow '' underneath and placing `` snow-free artificial snow '' on it and configuring it with an appropriate thickness, you can make a ski without the above problems A suitable slope can be made, and there is no problem that the stock does not stand.

The superabsorbent resin spherical body used in the present invention can be separated and recovered by an appropriate method, dried, and reused.

Since the superabsorbent resin spherical body used in the present invention itself has photodegradability and biodegradability, there is no problem in disposing after use, but particularly when early photodegradation or biodegradation is desired, A known accelerator for photodisintegration and biodegradation, a catalyst, an additive, or the like may be blended, added, impregnated, or coated with the water-absorbent resin. Since the superabsorbent resin itself is safe for the human body, it is preferable to select these additives in consideration of safety.

The artificial snow of the present invention and / or the superabsorbent resin used in the present invention may be colored by a known method using a pigment, a dye or the like. Colored artificial snow is beautiful and can add new commercial value. For example, it can be used to distinguish a ski slope for beginners, a ski slope for beginners, and the like by color, which makes skiing more enjoyable.

A new commercial value can be added by perfuming the artificial snow of the present invention and / or the superabsorbent resin used in the present invention with known perfumes, fragrances, fragrances and the like.

Antioxidant, ultraviolet absorber, fluorescent agent, nucleating agent, extender, a substance having a low coefficient of friction in the superabsorbent resin used in the present invention,
Other additives and the like may be added, blended, coated, impregnated, etc. within a range that does not impair the gist of the present invention.

[Examples] Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

The water absorption capacity, fluidity, density and strength of the artificial snow after freezing in the following Examples and Comparative Examples are determined by the following operations.

(Water absorption capacity for ion-exchanged water) Disperse 0.5 g of dry polymer in 1 ion-exchanged water,
After standing for a period of time, the weight (W) of the water-swollen body obtained by filtration through a 60-mesh wire gauze was measured, and this value was obtained by dividing this value by the initial dry polymer (W ₀ ).

(Fluidity after water absorption) After adding 50 cc of ion-exchanged water to 1.0 g of the dried polymer to completely absorb the water, observe the water swelling body while moving,
×, △.

 The angle of repose was measured.

(Density of artificial snow after freezing) The snow whose volume is known is taken out, weighed, and obtained by dividing the weight by the volume. The unit is g / cm ³ . When the snow is soft, a thin stainless steel box with a known volume can be inserted into the snow cover to remove the volume of the snow. In the case of hard snow, cut the snow into a square with a saw and measure the size with a ruler to calculate the volume.

(Strength of artificial snow after freezing) Using a Kinoshita-type hardness meter, drop the weight on artificial snow and measure the drop strength. The unit is kg / cm ² . Replace the adapter so that the disk sinks into the artificial snow within 7 to 30 mm, and obtain the strength from the conversion table.

(Synthesis example of superabsorbent resin spherical body) 150 g of ion-exchanged water was charged into a 500 ml separable flask equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer and a nitrogen gas inlet tube, and partially saponified polyvinyl as a dispersant. 0.2 g of alcohol (GH-23 manufactured by Nippon Synthetic Chemical Co., Ltd.) was added, and the mixture was heated and melted, and then replaced with nitrogen.

Meanwhile, in a conical flask, lauryl acrylate and tridecyl mixed ester (manufactured by Osaka Organic Chemical Co., Ltd.)
LTA) 22.5 g, hydroxyethyl methacrylate 10.0 g, and methyl methacrylate 17.5 g were dissolved by adding 1.0 g of azobisdimethyl valeronitrile, and added dropwise to the above separable flask over 1 hour under nitrogen gas bubbling. The mixture was kept at 65 ° C. for 5 hours to terminate the reaction. After cooling, the solid was filtered, washed with water, and dried under reduced pressure to obtain a bead-shaped dispersant.

Stirrer, reflux condenser, dropping funnel, 360.7 g of n-hexane and 4.32 g of the above dispersant were charged into a 1000 ml separable flask equipped with a nitrogen gas inlet tube, and heated to 50 ° C. to disperse. It was replaced with nitrogen.

On the other hand, acrylic acid 72.0
sodium hydroxide dissolved in 103.6 g of ion-exchanged water 32.
Partially neutralize with 2 g, and further add potassium persulfate 0.24 g at room temperature
Was dissolved. The monomer aqueous solution was added dropwise to the above separable flask at a stirring speed of 300 rpm under nitrogen gas bubbling over 1 hour, refluxed for 2 hours, and then 0.1 g of 30% hydrogen peroxide solution.
Was added and reflux was continued for 1 hour to complete the polymerization.
Then, ethylene glycol diglycidyl ether 0.73
g, azeotropic dehydration, filtration and drying under reduced pressure to obtain a white superabsorbent resin sphere.

(Example 1) The above-mentioned highly water-absorbent resin spherical body has an average particle diameter of 100 µm and exhibits excellent fluidity.

When water is absorbed for 19 seconds while stirring in water at room temperature,
It swells by absorbing water 50 times (weight), and its average particle size is about 0.
4 mm, which also showed excellent fluidity. The superabsorbent spheres swollen by 50 times (by weight) were left at room temperature for 60 days or more, but could be stably retained without releasing water.

The water absorption capacity of ion-exchanged water obtained by ion-exchanging tap water with an ion-exchange resin was approximately 100 times.

Table 1 shows examples in which the method of producing the superabsorbent resin sphere, the particle size, and the water absorbing ability were changed.

(Example 2): Manufacture example 1 of artificial snow Put dry ice under an aluminum plate having a thickness of 1 mm, cool it to -40 ° C or lower, and then absorb 50 times water on the plate to swell the highly water-absorbent resin sphere. (Temperature approx. 19 ℃)
× 10 cm) and frozen at room temperature of -8.3 ° C for about 1-2 hours. Table 2 shows the results.

The resulting artificial snow was stored at -1 ° C and the change over time was examined. However, even after one month, the state immediately after production was still maintained.

(Example 3): Manufacture example 2 of artificial snow 100 parts by weight of a highly water-absorbent resin swelled by absorbing 50 times and swollen with 60 parts by weight or more of granular dry ice at room temperature of -8.3 ° C. for a home hand mixer. (Hitachi Hand Mixer HF-
The mixture was frozen for about 5 minutes using the method of (330) to produce artificial snow. Table 3 shows the results.

The resulting artificial snow was stored at -1 ° C and the change over time was examined. However, even after one month, the state immediately after production was still maintained.

(Example 4) (Colored artificial snow) A highly water-absorbent resin spherical body (BL-100) was made to absorb water 50 times to form a water-swelled body, and the colored body was impregnated with a pink dye and colored. In the same manner as in Example 3, a frozen artificial snow was produced. Beautiful snow colored pink.

(Example 5) (Colored and perfumed artificial snow) Super-water-absorbent resin spherical body (BL-100) is made to absorb water 50 times to form a water-swelled body, and a pink dye and a fragrance having a rose scent. Was impregnated and colored and scented, and frozen in the same manner as in Example 3 to produce an artificial snow.
Beautiful snow with pink color and rose scent.

[Effects of the Invention] The present invention provides an excellent method for producing artificial snow used for a slope of an indoor ski resort, which solves the problems of conventional natural snow and artificial snow.

The water-absorbed superabsorbent resin spherical body can be frozen with dry ice or the like and used as artificial snow as it is.This artificial snow does not need to be compacted, and the snow quality does not change with time, so the condition of the slope is maintained. It is easy to handle, and is inexpensive and easy to handle.

The highly water-absorbent resin spherical body of the present invention can be recovered and reused.

Furthermore, the present invention provides artificial snow using a highly water-absorbent resin having photodegradability and / or biodegradability and having no pollution problem after use, and artificial snow which is colored and / or perfumed.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takayuki Nate 4-1-1 Tsukiji, Chuo-ku, Tokyo Tonen Petrochemical Co., Ltd. (72) Inventor Masahisa Otsuka 2191-1 Kamiizumi, Oizumi-cho, Ouraku-gun, Gunma Prefecture ( 72) Inventor Toshitaka Nagai 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Inside Sanyo Electric Co., Ltd. (56) References Special Table Sho 63-500526 (JP, A) Special Table Sho 62-503118 (JP, A) JP-B 7-91476 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) F25C 3/04 C09K 3/24

Claims (3)

(57) [Claims] 1. A highly water-absorbent resin sphere having a spherical shape even after absorbing water, being non-adhesive to each other, having a water absorption capacity of about 30 to 500 times with ion exchanged water, and a particle size before water absorption of about 20 to 500 μm. A method for producing artificial snow for use on an indoor ski slope, comprising the steps of absorbing water, swelling and freezing the water. 2. The freezing step according to claim 2, wherein the freezing step is performed by stirring and mixing the swollen superabsorbent resin spherical body with at least one coolant selected from dry ice, liquid nitrogen, and liquid air to freeze. The method for producing artificial snow used for a slope of an indoor ski resort according to claim 1. 3. The indoor ski according to claim 1, wherein in the freezing step, the swollen superabsorbent resin spherical body is placed on a base cooled by a cooling agent and frozen to form a fallen goose-shaped artificial snow. A method for producing artificial snow used for ski slopes.