JPH08134438A - Artificial snow and its production - Google Patents

Abstract

PURPOSE: To obtain an artificial snow which is suitable for providing an artificial skiing ground or a similar environment and dispenses with an apparatus for maintaining and restoring a refrigeration apparatus, etc., by incorporating a waxy substance into an oil-absorbing polymer. CONSTITUTION: This artificial snow is obtd. by incorporating a waxy substance into an oil-absorbing polymer. A suitable example of the oil-absorbing polymer is agglomerates of polyphase polymer particles having voids and obtd. by subjecting a monomer which gives a polymer having a glass transition temperature of 40 deg.C or higher to polymn. in an aq. medium in the presence of polymer particles. The polymer particles used for producing the polyphase polymer are pref. produced from a monomer which forms a polymer having a glass transition temperature of 0 deg.C or lower and pref. have been cross-linked. The oil-absorbing polymer may be a core-shell polymer, pref. comprising a core with a glass transition point of 0 deg.C or lower and a shell with that of 40 deg.C or higher. Pref. the waxy substance is an org. compd. having an m.p. of 30 deg.C) or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to artificial snow suitable for use in, for example, an artificial ski resort, artificial snow suitable for playing a simulated environment at an event site or a display, and a method for manufacturing the artificial snow.

[0002]

2. Description of the Related Art At the present, in artificial ski resorts and the like, water is frozen by an artificial snowfall machine into snow, which is then sprayed and supplied onto a running surface. However, in this method, the sliding floor is cooled in order to prevent the melting of snow, and while the room is being cooled, it is necessary to constantly replenish the amount of snow that has melted or consumed,
The maintenance cost was enormous, and the facilities were large.

Various artificial snows have been developed in order to remedy this type of drawback. For example, JP-A-4-102472
Japanese Patent Laid-Open Publication No. 9-242242 discloses a water-absorbent resin frozen by adsorbing water.

However, according to this method, the seed artificial snow must be cooled in order to maintain and regenerate it, and there is a drawback that a large-scale refrigerating equipment is required.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks. The seed artificial snow can be provided at low cost, and equipment for maintaining and regenerating refrigeration equipment is unnecessary. An artificial snow and a method for manufacturing the same are provided. The appearance of artificial snow here is like that of natural snow, and when it is spread on a slope such as an artificial ski resort, it shows sufficient gliding properties.

[0006]

The present invention provides an artificial snow characterized by containing a wax-like substance in a highly oil-absorbing polymer. As the highly oil-absorbing polymer, it is possible to use a commercially available polymer as long as it is in the form of particles. However, a polymer that forms a polymer having a glass transition temperature of 40 ° C. or higher in the presence of the polymer particles can be used. Agglomerates of multiphase polymer particles having voids formed by aqueous polymerization of a monomer are preferably used.

The polymer particles used for producing the multi-phase polymer particles having voids suitable as the highly oil-absorbing polymer of the present invention can be prepared by a known polymerization method such as solution polymerization, emulsion polymerization and suspension polymerization. It can be produced, and preferably emulsion polymerization is used.

When the polymer particles are produced by emulsion polymerization, the monomers forming the polymer particles are emulsion-polymerized by a conventional method using additives such as a polymerization initiator and an emulsifier.

As the emulsifier, anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate, and nonionic surfactants such as polyoxyethylene nonylphenyl ether and sorbitan monolaurate are used. Peroxides such as potassium sulfate, hydrogen peroxide, cumene peroxide, 2,2'-
Azo compounds such as azobis (2-amidinopropane) hydrochloride can be used.

In such emulsion polymerization, seed emulsion polymerization in which the number of particles is constant is carried out. Therefore, it is preferable that the monomer and the emulsifier are sequentially added to proceed with the polymerization so that the amount of the emulsifier is not too large.

The monomer forming the polymer particles is a known vinyl compound, and in the present invention, the glass transition temperature is 0 ° C. or lower, preferably −20 ° C. or lower, particularly preferably −30 ° C. or lower. It is preferable to use a monomer that forms coalesced particles.

When the glass transition temperature exceeds 0 ° C., the oil absorption amount becomes low when an aggregate of multiphase polymer particles is used as an oil absorption material.

The glass transition temperature referred to in the present invention is 1
It is the peak temperature of loss modulus E ″ in dynamic viscoelasticity in the 0 Hz tensile mode.

Examples of the monomer that gives polymer particles having a glass transition temperature of 0 ° C. or lower include conjugated dienes such as butadiene, isoprene and chloroprene, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate and 2-ethylhexyl methacrylate. Examples thereof include (meth) acrylic acid esters such as nonyl acrylate, nonyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, and stearyl methacrylate. Of these, butadiene, butyl acrylate, 2-ethylhexyl acrylate and nonyl acrylate are preferably used, and butadiene and butyl acrylate are particularly preferably used. In this case, as long as a polymer having a glass transition temperature of 0 ° C. or lower can be formed, a monomer copolymerizable with the above-mentioned monomer may be used in addition to the above-mentioned monomer. Examples of such a monomer include aromatic vinyl such as styrene, α-methylstyrene, vinyltoluene, vinyl cyanide such as acrylonitrile and methacrylonitrile, vinylidene cyanide, methacrylic acid such as methyl methacrylate and butyl methacrylate. Esters may be mentioned, and styrene is preferably used.

The polymer particles are preferably a crosslinked polymer so as not to be eluted with oil. for that reason,
Along with the above-mentioned monomers, a polyfunctional monomer copolymerizable therewith, that is, a crosslinkable monomer is copolymerized. Examples of such crosslinkable monomers include aromatic divinyl monomers such as divinylbenzene, ethylene glycol diacrylate, ethylene glycol dimethacrylate, butylene glycol diacrylate, hexanediol diacrylate, hexanediol dimethacrylate, oligos. Alkane polyol polyacrylates such as ethylene glycol diacrylate, oligoethylene glycol dimethacrylate, trimethylol propane diacrylate, trimethylol propane dimethacrylate, trimethylol propane triacrylate, trimethylol propane trimethacrylate and alkane polyol polymethacrylate. it can. Divinylbenzene, butylene glycol diacrylate and hexanediol diacrylate are preferably used. The amount of the crosslinkable monomer is 0.01 to 5% by weight of the polymer particles, preferably 0.05 to 2% by weight, and more preferably 0.1.
Is in the range of 1% by weight.

Further, in the subsequent aqueous polymerization, for the purpose of chemically bonding the polymer having a glass transition temperature of 40 ° C. or more to the polymer particles, the above-mentioned monomer and the crosslinkable monomer are grafted together. Monomers can be used. As such a grafting monomer, for example, unsaturated carboxylic acid allyl esters such as allyl acrylate, allyl methacrylate, diallyl maleate, diallyl fumarate and diallyl itaconate are used, and allyl methacrylate is preferably used. The amount of the grafting monomer is 5% by weight or less of the polymer particles, preferably 2% by weight.
It is particularly preferably 1% by weight or less.

The polymer particles may be core-shell polymers. When the core-shell polymer is used, the amount of the monomer necessary for producing a tack-free aggregate in the subsequent aqueous polymerization can be reduced, and an aggregate having more voids can be obtained.

The core-shell polymer can be obtained by seed emulsion polymerization. When producing the core-shell polymer, the same emulsifier and polymerization initiator as those described above can be used, but since seed emulsion polymerization with a constant number of particles is carried out, the amount of emulsifier should not be too large. body,
It is preferable that the emulsifier is added sequentially to advance the polymerization.

The core-shell polymer has a glass transition temperature of 0.
What forms a core having a glass transition temperature of 40 ° C. or higher with a core having a temperature of 0 ° C. or lower is preferable. As the monomer forming the core having a glass transition temperature of 0 ° C. or lower, the above-mentioned monomer forming a polymer having a glass transition temperature of 0 ° C. or lower is used,
A crosslinkable monomer may be used for the purpose of preventing elution with oil, and a grafting monomer may be used for the purpose of chemically bonding with the shell. As the crosslinkable monomer, the same ones as described above can be similarly used, and divinylbenzene, butylene glycol diacrylate, and hexanediol diacrylate are preferably used. The amount of this crosslinkable monomer is in the range of 0.01 to 5% by weight of the core, preferably 0.05 to 2% by weight, more preferably 0.1 to 1% by weight. As the grafting monomer, the same ones as above can be used in the same manner, and allyl methacrylate is preferably used. The amount of this grafting monomer is
It is 5% by weight or less of the core, preferably 2% by weight or less, and particularly preferably 1% by weight or less.

Examples of the monomer forming the shell having a glass transition temperature of 40 ° C. or higher include aromatic vinyl such as styrene, α-methylstyrene and vinyltoluene, vinyl cyanide such as acrylonitrile and methacrylonitrile, and cyan. Examples thereof include methacrylic acid esters such as vinylidene chloride, methyl methacrylate, and ethyl methacrylate. Styrene and methyl methacrylate are preferably used. Further, as long as a shell having a glass transition temperature of 40 ° C. or higher can be formed, a monomer copolymerizable with the above monomer may be used in combination with the above monomer. Examples of such a monomer include conjugated dienes such as butadiene, isoprene and chloroprene, ethyl acrylate, butyl acrylate, cyclohexyl acrylate and 2-
Examples thereof include (meth) acrylic acid esters such as ethylhexyl acrylate and butyl methacrylate.

The shell is preferably grafted to the core or the shell itself is a cross-linked polymer in order to prevent elution with oil. Therefore, when the grafting monomer is not used in the polymerization of the core, it is preferable to copolymerize the above-mentioned monomer with the crosslinking monomer. Further, even when a grafting monomer is used in the polymerization of the core, a crosslinking monomer may be used. As the crosslinkable monomer, the same ones as described above can be similarly used, and divinylbenzene, butylene glycol diacrylate, and hexanediol diacrylate are preferably used. The amount of this crosslinkable monomer is in the range of 0.01 to 5% by weight of the shell, preferably 0.05 to 2% by weight, and more preferably 0.1 to 1% by weight. Further, in the subsequent aqueous polymerization, the grafting monomer exemplified in the previous polymerization can also be used for the purpose of chemically bonding the polymer having a glass transition temperature of 40 ° C. or higher to the polymer particles,
Allyl methacrylate is preferably used. The amount of the grafting monomer is in the range of 5% by weight or less of the shell, preferably 2% by weight or less, more preferably 1% by weight or less. The glass transition temperature of the shell is 40 ° C. or higher, preferably 50 ° C. or higher, more preferably 60 ° C. or higher. When the glass transition temperature of the shell is less than 40 ° C., as described above, the amount of the monomer required for producing the non-tacky aggregate in the subsequent aqueous polymerization can be reduced, and the voids can be further reduced. The characteristic of using a core-shell polymer that a rich aggregate can be obtained is impaired.

The ratio of the core to the whole core-shell polymer is 40 to 95% by weight, preferably 50 to 90% by weight.

The polymer particles produced in this way are
Weight average particle diameter is 0.05 to 1 μm, especially 0.1 to
It is preferably 0.6 μm. If the weight average particle size is less than 0.05 μm, it may not be possible to stably produce aggregates in the aqueous polymerization, and if the weight average particle size exceeds 1 μm, the voids of the aggregates produced by the aqueous polymerization may become insufficient. It may be insufficient.

The agglomerates of multiphase polymer particles having voids of the present invention have a glass transition after the water-soluble polymer and / or the inorganic aggregating agent is added in the presence of the above-mentioned polymer particles before the aqueous polymerization. It is produced by subjecting a monomer forming a polymer at a temperature of 40 ° C or higher to aqueous polymerization, or in the presence of polymer particles, a monomer forming a polymer having a glass transition temperature of 40 ° C or higher is added. It is produced by adding a water-soluble polymer and / or an inorganic flocculant to an aqueous dispersion of a multiphase polymer produced by aqueous polymerization after the completion of aqueous polymerization.

The aqueous polymerization referred to in the present invention is a vinyl polymerization in which a polymer produced using water as a medium is unnecessary for water, and includes both concepts of suspension polymerization and emulsion polymerization. In this aqueous polymerization, a radical polymerization initiator and these monomers are added all at once or continuously during the polymerization in the presence of polymer particles, and polymerization is carried out at a decomposition temperature of the radical polymerization initiator or higher. Radical polymerization initiators include organic peroxides such as benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, azo compounds such as azobisisobutyronitrile and azobisdimethylvaleronitrile, sodium persulfate, potassium persulfate. Compounds that generate free radicals such as persulfates are used. Further, if necessary, an inhibitor of water phase polymerization such as sodium nitrite and water for adjusting the solid content concentration are added.

The glass transition temperature of the polymer produced by aqueous polymerization is 40 ° C. or higher, preferably 50 ° C. or higher, more preferably 60 ° C. or higher. When the glass transition temperature is lower than 40 ° C., the aggregate of multiphase polymer particles becomes tacky,
Easy to block.

In this aqueous polymerization, all the monomers exemplified in the production of polymer particles are homopolymerized or copolymerized at an arbitrary ratio when the glass transition temperature of the produced polymer is 40 ° C. or higher. be able to. The monomers exemplified in the production of the shell when the polymer particles are core-shell polymers are preferable, and styrene, acrylonitrile, methyl methacrylate, butyl methacrylate and butyl acrylate are particularly preferably used. The amount of monomers forming a polymer having a glass transition temperature of 40 ° C. or higher is 50 to 50% by weight.
It is 50 to 5 parts by weight with respect to 95 parts by weight, preferably 40 to 10 parts by weight with respect to 60 to 90 parts by weight of polymer particles,
When the polymer particles are core-shell polymers, the amount is preferably 30 to 10 parts by weight with respect to 70 to 90 parts by weight of the polymer particles. If the amount of the monomer exceeds these ranges, it may not be possible to obtain aggregates having voids. If the amount of the monomers is less than these ranges, the obtained aggregates become sticky and cannot be used as an oil absorbing material. There are cases.

The glass transition temperature formed by aqueous polymerization is 4
The polymer at 0 ° C. or higher is preferably crosslinked so as not to be eluted by oil. Therefore, the crosslinkable monomers and grafting monomers exemplified in the production of polymer particles can be used. Among them, divinylbenzene, butylene glycol diacrylate, hexanediol diacrylate, and allyl methacrylate are preferably used. The amount of the crosslinkable monomer and / or the graftable monomer used is 0.01 to 5% by weight, preferably 0.05 to 2% by weight of the polymer having a glass transition temperature of 40 ° C. or higher formed by aqueous polymerization. % By weight, particularly preferably 0.1 to
It is in the range of 1% by weight.

In order to agglomerate the multiphase polymer particles produced in this aqueous polymerization and stabilize the dispersion of the agglomerates,
A water-soluble polymer and / or an inorganic flocculant is used. Such water-soluble polymer, gelatin, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose,
Examples thereof include polyethylene glycol, polyethylene glycol polypropylene glycol block copolymer, polyacrylamide, polyacrylic acid, polyacrylic acid salt, sodium alginate and polyvinyl alcohol, and polyvinyl alcohol, hydroxyethyl cellulose and hydroxypropyl cellulose are preferably used. Examples of the inorganic coagulant include sodium chloride, calcium chloride, aluminum chloride, ferrous sulfate, ferric sulfate, ferric chloride, aluminum sulfate, activated silica and the like. These water-soluble polymers and / or inorganic flocculants may be added before carrying out the aqueous polymerization, or after the completion of the polymerization as an aqueous solution to the aqueous dispersion of the multiphase polymer particles. . When a water-soluble polymer and / or an inorganic flocculant is added before aqueous polymerization, a multiphase polymer coated with a polymer having a glass transition temperature of 40 ° C. or higher in the state where one or more polymer particles are aggregated. Particles can be generated to obtain a slurry of aggregates in which the multiphase polymer particles are further aggregated. When adding a water-soluble polymer and / or an inorganic flocculant after completion of the polymerization,
It is possible to obtain a slurry of aggregates in which a plurality of multiphase polymer particles are aggregated. Such agglomerates are agglomerates having a size of 0.1 to 10 mm and having innumerable voids of about 1 to 100 μm.

The agglomerate has a large number of voids as described above, and therefore has a bulk density of 0.4 g / cm ³ or less, preferably 0.3 g / cm ³ or less, more preferably 0.25 g / cm ^3. cm
It is ³ or less. When the bulk density exceeds 0.4 g / cm ³ , the aggregates have few voids and the oil absorbing ability is lowered.

The highly oil-absorbent polymer is obtained as a powder by dehydrating the slurry of this aggregate with a centrifuge, washing and drying.

The wax-like substance contained in the highly oil-absorbent polymer can be used in an artificial ski resort to impart good lubricity and has low toxicity even when it comes into contact with a human body, and It is preferable to use one that has low contamination and that has low odor. Such a waxy substance has a melting point of 30.
An organic compound having a temperature of 0 ° C. or higher is preferably used. Further, in consideration of the temperature at which the highly oil-absorbing polymer is not decomposed in the artificial snow manufacturing process, the melting point range of the organic compound is 30 to 150.
C., preferably 50 to 100.degree. Furthermore, an organic compound that is a white solid at room temperature and becomes colorless and transparent after melting is suitable.

Specifically, long-chain aliphatic alkanes having 18 to 30 carbon atoms such as n-nonadecane and n-eicosane, 1-tetradecanol, 1-hexadecanol, 1-octadecanol, 1,6 -C14-C26 aliphatic monoalcohols such as hexanediol or aliphatic diols, lauric acid, myristic acid, palmitic acid, stearic acid or other C9-25 aliphatic monocarboxylic acids and salts thereof, p-
Aromatic compounds such as methoxybenzene, o-cresol, p-cresol, salicyl alcohol, waxes such as paraffin wax, polyethylene glycol and the like can be mentioned, and 1-hexadecanol, stearic acid, paraffin wax and polyethylene glycol can be mentioned. It is preferably used. You may use the said organic compound individually or in combination of 2 or more types.

The optimum content of the waxy substance in the highly oil-absorbent polymer is 10 to 90%, preferably 20 to 80% of the maximum oil absorption of the highly oil-absorbent polymer, and when the upper limit is exceeded, swelling occurs. As a result, a gel-like substance or a large lump is formed, and if the amount is less than the lower limit, the effect of the wax-like substance may be reduced. Further, when the wax-like substance is contained in the highly oil-absorbent polymer, the bulk specific gravity tends to change, and natural snow,
Alternatively, it is preferable to control the content within the above range while considering the bulk specific gravity of snow produced by artificially freezing water.

As a method of incorporating the wax-like substance into the highly oil-absorbing polymer, various methods described below are possible. (1) The highly oil-absorbing polymer and the wax-like substance are mixed so as to be uniform, and the mixture is heated with stirring to a temperature higher than the melting point of the wax-like substance. The wax-like substance in the liquid state is adsorbed and impregnated inside the secondary agglomerated gap, and further adsorbed to the inner layer through the gap. After stirring for several hours, slowly cool to room temperature. (2) The wax-like substance is previously heated and melted to a temperature equal to or higher than the melting point, and the highly oil-absorbent polymer is added thereto while stirring. After stirring for several hours, the mixture is slowly cooled to room temperature as in (1) above. (3) The highly oil-absorbent polymer slurry is heated to a temperature not lower than the melting point of the wax-like substance under stirring, and in this state, the wax-like substance previously melted is supplied and mixed. Thereafter, the particles are taken out by centrifugation and dried. (4) The wax-like substance is previously dissolved in a low-melting point solvent having an affinity for the wax-like substance, a highly oil-absorbing polymer is added, and the mixture is stirred for several hours, then the solvent is removed and dried.

By any of the above methods, a large amount of artificial snow can be manufactured at low cost. Furthermore, pulverization and classification of particles can be performed by any method. When these operations are performed in consideration of the bulk specific gravity and the average particle size of natural snow, each particle obtained at room temperature has the same appearance and texture as natural snow.

The artificial snow obtained can be formed in a semi-transparent white color, which is the color of the raw material, but can be colored in any desired color by previously mixing a colorant into the wax-like substance.

FIG. 1 shows artificial snow 1 obtained as described above.
No. 0 is spread and laid along the slope of the sliding floor 12 on the artificial ski, and it shows a state of being appropriately compacted. In this state, the appearance and texture are similar to those of a snowy field, and due to the smoothness of the wax-like substance, You will be able to descend.

The upper surface of this artificial snow is skied 14
If the artificial snow 10 is compacted along the spur of the ski 14 according to the weight, the organic compound slips on the contact surface with the ski 14, and at the same time the ski 14 is applied. Part of the organic compound is melted into a transparent state by the pressure P and frictional heat,
Further, since the frictional force is reduced, it is possible to glide on the artificial snow 10 with a feeling of gliding that is exactly the same as a natural snow surface.

The spur 10a thus compacted can be easily restored to its original elastic state by crushing it with an appropriate crushing machine or by leveling it.

Although artificial snow is used for artificial ski resorts in the above embodiments, since it has appearance and physical properties similar to natural snow, it can be used at event venues and displays other than artificial ski resorts. It can also be used as artificial snow to play a simulated environment in.

[0042]

EFFECTS OF THE INVENTION According to the above-mentioned constitution, artificial snow having a granular appearance like ordinary snow at room temperature can be obtained according to the color and shape of the highly oil-absorbent polymer, the particle size, and the bulk specific gravity. In addition, due to the lubricity of the wax-like substance impregnated by adsorption, a continuous lubrication effect can be obtained at room temperature. The spewed surface of the obtained artificial snow has a snow-like elastic texture, is aggregated by rolling and is appropriately compacted, and is restored to its original state by crushing the compacted portion. Also, even if artificial snow adheres to the body, the clothes will not get dirty. Further, compared with the artificial snow using the conventional super absorbent resin, it is not necessary to cool it for maintenance and regeneration, and both equipment cost and maintenance cost can be reduced.

[0043]

The present invention will be described below with reference to specific examples.
The present invention is not limited to these examples. In the following, all "parts" indicate parts by weight.
The abbreviations used below are as shown below.

Abbreviations: Butadiene: Bd Ethyl acrylate: EA Acrylonitrile: AN Butyl acrylate: BA 2-Ethylhexyl acrylate: 2EHA Methyl methacrylate: MMA Styrene: St Butylene glycol diacrylate: BGA Allyl methacrylate: AlMA Divinylbenzene *): DVB deionized water : DIW dioctyl sulfosuccinate sodium salt: SSS alkyl biphenyl ether sulfonate sodium salt: SSL polyvinyl alcohol (saponification degree 88 mol%): PVA sodium persulfate: SPS azobisisobutyronitrile: AIBN sodium bicarbonate: SHC *) divinyl Consists of 58% by weight of benzene and 42% by weight of aromatic vinyl monomer.

Example 1 Synthesis of Multiphase Polymer Particle Aggregate A (Synthesis of Latex of Polymer Particles a) A 5 liter autoclave was charged with 2.8 g of 10% SSL aqueous solution, 72 g of 1% SHC aqueous solution, and DIW 1053.7 g. The internal temperature was raised to 70 ° C. with charging and stirring under a nitrogen stream. EA 7
2 g was added, the mixture was dispersed for 10 minutes, and then the atmosphere was replaced with nitrogen.
A seed latex was prepared by adding 144 g of a 2% SPS aqueous solution and polymerizing for 20 minutes. Subsequently, the internal temperature was maintained at 70 ° C., and a monomer mixture liquid 1368 having the following composition was used.
g, 10% SSL aqueous solution 144 g, 1% SHC aqueous solution 5
A monomer emulsion consisting of 4 g of DIW and 486 g of DIW was continuously added over 90 minutes. Monomer mixture composition Bd 576.0g 2EHA 788.4g BGA 1.8g AlMA 1.8g After adding the monomer emulsion, aging is continued at 70 ° C for 360 minutes, and after cooling, it is filtered through a 300 mesh wire net. By doing so, a latex of polymer particles a was obtained.

(Synthesis of Multiphase Polymer Particle Aggregate A) DIW 2 was placed in a 2 liter capacity polymerization vessel equipped with a reflux condenser.
64 g of 1% PVA aqueous solution (990 g) was charged, and 633 g of the latex of the polymer particles a polymerized in advance was added at room temperature while stirring under a nitrogen stream, and stirring was continued for 180 minutes. 56.4 g of MMA, 6.6 g of EA, and BG in which 0.13 g of AIBN was dissolved in advance in this mixed solution.
A 0.33 g of the monomer mixture was added. Inner temperature 70
The temperature was raised to 0 ° C., and the aqueous polymerization was continued for 180 minutes. Further, it is aged at 80 ° C for 60 minutes to obtain a solid content of 17.6%.
A slurry liquid of was obtained. The slurry liquid was cooled, dehydrated and washed using a centrifuge, and then air-dried at 40 ° C. for one day to obtain multi-phase polymer particle aggregate A.

Example 2 Synthesis of Multiphase Polymer Particle Aggregate B (Synthesis of Latex of Core-Shell Polymer Particle b) 97.3 g of 1% SSS aqueous solution in 5 liter autoclave, 1
% SHC aqueous solution 97.3 g and DIW 1329 g were charged, and the internal temperature was raised to 75 ° C. with stirring. MMA 3
A mixed liquid of 7.0 g and St 11.6 g was added, the mixture was dispersed for 10 minutes, and then the atmosphere was replaced with nitrogen. 2% SPS aqueous solution 2
9.2 g was added, and polymerization was performed for 60 minutes to prepare a seed latex. Next, while maintaining the internal temperature at 70 ° C., 1571 g of a monomer mixed solution having the following composition, a monomer emulsion made of 101.0 SSL aqueous solution 81.0 g, and 1% SHC aqueous solution 243.0 g was continuously added over 300 minutes. Then, seed polymerization for core formation was performed. Monomer mixture composition Bd 314.3g 2EHA 801.4g St 447.8g BGA 7.8g After adding the monomer emulsion, aging was continued for 360 minutes at 70 ° C, and after cooling, filtered with a 300 mesh wire mesh. By doing so, a core latex was obtained.

The core latex synthesized by the above method was transferred to a polymerization vessel of 5 liter capacity equipped with a reflux condenser, the internal temperature was raised to 75 ° C. with stirring under a nitrogen stream, and then a 2% SPS aqueous solution 9 was added. 0.0 g was added and dispersed for 10 minutes. Thereafter, 80 g of a monomer mixture liquid having the following composition, 55.8 g of a 10% SSL aqueous solution, and DIW 5
A monomer emulsion consisting of 4 g was continuously added over 120 minutes to perform seed polymerization. Composition of Monomer Mixed Liquid St 38.7 g MMA 30.5 g AN 9.9 g BGA 0.9 g After adding the monomer emulsion, the latex of core-shell polymer particles b is obtained by continuously aging at 80 ° C. for 60 minutes. Got

(Synthesis of Multiphase Polymer Particle Aggregate B) In Example 1, instead of the latex of the polymer particles a, 136.1 g of the latex of the core-shell polymer b and DIW.
1208 g was used, and the composition of the monomer mixture liquid was St 20.
8g, MMA 70.4g, AN 5.4g, DVB
Synthesis was performed by the same method except that the amount was changed to 0.24 g to obtain a multiphase polymer particle aggregate B.

Example 3 Synthesis of Multi-phase Polymer Particle Aggregate C (Synthesis of Latex of Polymer Particle c) 10% SSS aqueous solution 3 in a 5 liter capacity polymerization container equipped with a reflux condenser.
2 g, 1% SHC aqueous solution 80 g and DIW 1110
The internal temperature was raised to 70 ° C. with stirring under a nitrogen stream. 80 g of EA was added and dispersed over 10 minutes, 160 g of a 2% SPS aqueous solution was added, and polymerization was performed for 10 minutes to prepare a seed latex. Subsequently, the internal temperature was maintained at 70 ° C., and a monomer mixture liquid 152 having the following composition
0 g, 1% SSS aqueous solution 568 g, 1% SHC aqueous solution 8
A monomer emulsion consisting of 0 g was continuously added over 180 minutes. Monomer mixed liquid composition BA 1508.8 g BGA 3.2 g AlMA 8.0 g After addition of the monomer emulsion, aging was continued at 70 ° C. for 90 minutes to obtain latex c of polymer particles.

(Synthesis of Latex of Multiphase Polymer Particle d)
Continuously, keep the internal temperature at 70 ℃, 2% SPS aqueous solution 40g
Was added and dispersed for 10 minutes, and then 400 g of a monomer mixture liquid having the following composition, 120 g of 1% SSS aqueous solution, 1%
A monomer emulsion consisting of 40 g of SHC aqueous solution was continuously added over 60 minutes. Monomer mixture composition MMA 358.0g EA 40.0g BGA 2.0g After addition of the monomer emulsion, aging is carried out for 60 minutes at 80 ° C, and after cooling, multiphase is obtained by filtering with a 300 mesh wire mesh. A latex of polymer particles d was obtained.

(Production of Aggregate of Multiphase Polymer Particles d) 1.0% PV was placed in a 2 liter container equipped with a reflux condenser.
811 g of aqueous solution A was charged, and the internal temperature was raised to 80 ° C. while stirring at 300 rpm. Add 1000 g of latex of multilayer polymer particles d over 10 minutes,
Stir at 180 ° C for 180 minutes to obtain multi-phase polymer particle aggregate F
A slurry liquid of was obtained. The slurry liquid was cooled, dehydrated and washed using a centrifuge, and then air-dried at 40 ° C. for one day to obtain a multiphase polymer particle aggregate C.

Example 4 (Manufacturing example of artificial snow) Example 1 in a container having a capacity of 2 liters
Highly oil-absorbing polymers A and B synthesized in &
g and a predetermined amount of wax-like substance were charged, and the temperature was raised to the melting point or higher of the wax-like substance while stirring. After stirring for another 2 hours, the mixture was slowly cooled to room temperature while stirring.

Table 1 shows the amount of the wax-like substance (adsorption compound) added in this example and the properties of the obtained artificial snow.

[0055]

[Table 1]

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an operation at an artificial ski resort where artificial snow is laid.

[Explanation of symbols] 10 artificial snow 10a spur 12 gliding floor 14 skis

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Miki Aoyama 4-640 Shimo-Seido, Kiyose-shi, Tokyo Inside Obayashi Technical Research Institute Co., Ltd. (72) Inventor Nagao Hori 4-640 Shimo-Seido, Kiyose-shi, Tokyo Obayashi Technical Research Co., Ltd. In-house (72) Inventor Koichiro Takahashi 4-640 Shimoseido, Kiyose-shi, Tokyo Inside Obayashi Technical Research Institute Co., Ltd.

Claims (10)

[Claims] 1. An artificial snow comprising a highly oil-absorbing polymer and a wax-like substance. 2. A highly oil-absorbing polymer is a coagulation of multiphase polymer particles having voids formed by aqueous polymerization of a monomer forming a polymer having a glass transition temperature of 40 ° C. or higher in the presence of the polymer particles. The artificial snow according to claim 1, which is a collection. 3. The artificial snow according to claim 2, wherein the polymer particles are core-shell polymers. 4. The artificial snow according to claim 1, wherein the waxy substance is an organic compound having a melting point of 30 ° C. or higher. 5. The artificial snow according to claim 4, wherein the organic compound having a melting point of 30 ° C. or higher is an aliphatic monoalcohol. 6. The artificial snow according to claim 4, wherein the organic compound having a melting point of 30 ° C. or higher is an aliphatic monocarboxylic acid or a salt thereof. 7. The artificial snow according to claim 4, wherein the organic compound having a melting point of 30 ° C. or higher is polyethylene glycol. 8. A method for producing artificial snow, which comprises impregnating a highly oil-absorbing polymer with a wax-like substance by adsorption. 9. The method for producing artificial snow according to claim 8, wherein the wax-like substance is adsorbed and impregnated while being heated to a temperature equal to or higher than the melting point. 10. After dissolving the wax-like substance in a solvent,
The method for manufacturing artificial snow according to claim 8, wherein the artificial snow is adsorbed and impregnated.