JPH09234735A - Method for reducing volume of resin molded object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently realize the substantial vol. reduction of a resin molded object composed of foamed polystyrol by a simple process and to prevent the contamination of the resin molded object after vol. reduction. SOLUTION: In reducing the vol. of a resin molded object 4 composed of foamed polystyrol, boiled vapor 5 of a liquid 2 not dissolving the resin molded object 4 is used as a heating medium and the resin molded object 4 is exposed to the boiling vapor 5 to reduce the vol. of the molded object 4. As the liquid 2 not dissolving a resin, for example, a highly fluorinated compd. or low mol.wt. polyorganaosiloxane is used. The resin molded object 4 is exposed to the boiling vapor 5 to be thermally shrunk to be taken out as thermally shrunk matter 7.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for reducing the volume of a resin molding such as expanded polystyrene.

[0002]

BACKGROUND OF THE INVENTION As is well known, foamed polystyrene is widely used in packaging materials for home electric appliances, fish boxes (toro boxes), food trays at the retail stage, etc., and is used in Japan. The annual amount reaches 170,000 tons. Since this material is not easily decomposed in the natural world, the treatment method after use has become a social issue. Therefore, recently, studies are being conducted in the direction of collecting and recycling (recycling) used expanded polystyrene, mainly by relevant organizations such as local governments and related industries.

However, when attempting to collect and recycle foamed polystyrene, it is a used material, but it is a used material, but there is a problem in that it is expensive to transport. For example, packaging materials for home appliances and fish boxes (toro boxes) are 50 times larger, and for food trays
Since it is foamed 20 to 30 times, even if you try to transport expanded polystyrene with a large-capacity 4 ton truck, you can only carry 200 kg, which is 1/20 of 4 tons.

Therefore, when recovering and recycling foamed materials such as expanded polystyrene, it is essential to reduce the volume, and various volume reduction methods have been proposed. As a concrete volume reduction method of expanded polystyrene, for example, (1) a method of heating the expanded polystyrene with a heater or the like to melt-extrude, (2) a method of crushing the expanded polystyrene to finely crush it, (3) foaming Method of dissolving polystyrene in a solvent such as limonene (JP-A-5-263065)
(See Japanese Patent Laid-Open No. 6-32938), (4) Method of immersing foamed polystyrene in a heating oil and melting it by heating (Japanese Patent Laid-Open No. 6-32938)
-91647 and JP-A-6-136178).

[0005]

However, any of the conventional volume reduction methods for foamed polystyrene and the like described above has the following drawbacks. That is, in the method of melt extrusion of (1), although there is an advantage that impurities such as solvents are not mixed, in order to apply to a mechanical melt extrusion mechanism, foamed polystyrene is made to have a certain size or less before melting. It has a drawback that it has to be crushed and the volume reduction process becomes complicated. Alternatively, when power to the heater is cut off due to power failure or the like and the temperature of the system drops, the molten styrene resin cannot be solidified and taken out of the system, and the structure of the device becomes complicated to cope with this. I have a defect.

Further, since the crushing method of (2) is not an essential volume reduction technique, it is possible to reduce the volume of a molded article having a complicated shape, but in the case of lumpy expanded polystyrene etc. It has the drawback that it cannot be reduced in volume. Furthermore, the method of dissolving with the solvent of (3) causes the solvent to remain in the dissolved styrene resin solution, causing a problem when reusing the styrene resin, or taking out the solvent remaining in the styrene resin solution, resulting in running costs. There is a problem such as raising.

Although the method (4) of using the heating oil has advantages such as excellent heat transfer efficiency to the polystyrene foam and the like, and heat shrinkage, the heating oil is generally used. Is a non-volatile and highly viscous oil, so it is difficult to separate the heat-shrinkable or melted styrene resin and the heating oil.For example, heat-shrinkable polystyrene foam is contaminated with oil or dirt brought in. The use of the obtained styrene resin is mainly limited to fuel, and when it is reused for product use, it has a drawback that it must be washed as a post-treatment.

As described above, all the conventional methods for reducing the volume of expanded polystyrene and the like have some drawbacks, and it has been a problem to solve such drawbacks.

The present invention has been made in order to solve such a problem, and realizes essential volume reduction of a resin molded product such as expanded polystyrene in a simple process efficiently and after volume reduction. It is an object of the present invention to provide a method for reducing the volume of a resin molded body that prevents contamination.

[0010]

The method for reducing the volume of a resin molded body of the present invention uses a boiling vapor of a liquid which is insoluble in the resin molded body as a heat medium when reducing the volume of the resin molded body. It is characterized in that the resin molding is exposed to the boiling steam to reduce the volume.

In the method for reducing the volume of the resin molded body of the present invention, the boiling water of the liquid that does not dissolve the resin molded body is used as the heat medium as described above. When the resin molded body is exposed to such boiling steam, the resin molded body is uniformly distributed from the entire surface by the temperature of the boiling steam and the heat (condensation heat) generated when the boiling steam condenses on the surface of the resin molded body. Be heated. Further, since the heat medium is boiling steam having excellent heat transfer efficiency, the resin molded body is efficiently heated. Therefore, it is possible to efficiently shrink the resin molded body in a short time to reduce the volume.

Further, since the boiling steam as a heat source is a liquid vapor which does not dissolve the resin molded body, the heat medium does not remain as an impurity in the heat-shrinkable material of the resin molded body. Further, the resin molded body after the heat shrinkage is easily dried, and the heat shrinkable product can be taken out in a clean state. Therefore, the resin molded body after volume reduction can be used for various purposes without performing a washing step as a post-treatment.

[0013]

Embodiments of the present invention will be described below.

In the method for reducing the volume of the resin molded body of the present invention, boiling vapor of a liquid that does not dissolve the resin molded body (hereinafter referred to as a resin insoluble liquid) is used as a heat medium for reducing the volume of the resin molded body. To use. The boiling steam referred to here means the steam generated when the resin-insoluble liquid is heated to near its boiling point.

In the volume reducing method of the present invention, first, the resin insoluble liquid described above is placed in a container having a heating means such as a heater, and the resin insoluble liquid is heated to a temperature in the vicinity of the boiling point of the boiling vapor. Is generated and this is used as a heat transfer medium. The heating means is not particularly limited.

Then, the resin molded body is exposed to the boiling vapor of such a resin-insoluble liquid to carry out a volume reduction treatment by thermal contraction of the resin molded body. In the volume reduction treatment of the present invention, it is preferable to reduce (heat shrink) the initial volume of the resin molded body to at least 1/5 or less. The heat-shrinkable resin molded product has an advantage that it can be used as it is without being crushed when it is used as a raw material for product use.

Here, as the resin molding to be treated by the volume reduction method of the present invention, first, foamed polystyrene is mentioned. In the present invention, the expanded polystyrene can be easily heat-shrunk. However, the object to be treated in the present invention is not limited to expanded polystyrene, and it is possible to treat foams of various thermoplastic resins. Further, not only the foamed resin molded body, but also various resin molded bodies that can be shrunk and reduced in volume can be treated by applying heat such as a vinyl resin molded body such as a vinyl bag or a PET bottle.

When the resin molding is exposed to boiling vapor of the resin-insoluble liquid, the entire surface of the resin molding comes into contact with a large amount of boiling vapor at the same time. As a specific method of exposing the resin molded body to boiling steam, the resin molded body is allowed to fall naturally in an atmosphere in which boiling steam exists, or the resin molded body is housed in a mesh basket or the like, It is possible to employ a method such as charging in an atmosphere in which The boiling vapor of a resin-insoluble liquid is the temperature that it has and the heat generated when the boiling vapor condenses on the surface of the resin molding (condensation heat).
And uniformly heat the entire surface of the resin molded body.
Further, since the heat medium is boiling steam having excellent heat transfer efficiency, the resin molded body is efficiently heated.

The heat treatment temperature of the resin molded body by the above-mentioned boiling steam, that is, the boiling point of the resin insoluble liquid used is
The softening point and melting temperature of the resin molded product to be treated, and further appropriately set based on the shape of the resin molded product, etc., but practically 50 K higher than the softening point of the resin molded product,
And it is preferable that the temperature is lower than the temperature at which the resin molded body is melted. The resin-insoluble liquid has a softening point of the resin molding.
It is more preferable to have a boiling point higher than 70K.

If the boiling point of the resin-insoluble liquid, that is, the heat treatment temperature is too low, the resin molding cannot be sufficiently shrunk. On the other hand, if the temperature exceeds the melting temperature of the resin molded body, it may be difficult to collect the resin molded body after the heat shrinkage. If the heat treatment temperature is too high, the resin may decompose. When reusing the volume-reduced resin molded product for use, it is desirable to suppress the decomposition of the resin. Therefore, it is preferable to set the temperature at which the resin is not differentiated. The boiling point of a specific resin-insoluble liquid is 423K.
It is preferably at least 433K, more preferably at least 433K.

The boiling point of the resin-insoluble liquid is preferably set according to the density after the heat-shrinking treatment, if the density is set. For example, FIG. 3 shows the relationship between the heat treatment temperature and the density after heat-shrinking the expanded polystyrene at various temperatures. From such a diagram, the heat treatment temperature, that is, the boiling point of the resin insoluble liquid may be set according to the density after the heat shrinkage. In the case of expanded polystyrene, it is practically desirable to reduce the density to 0.4 g / cm ³ or more, and therefore it is understood from FIG. 3 that the heat treatment temperature is preferably 423 K or more. More preferably, it is at least 433K.

Further, as the resin-insoluble liquid to be used, it is preferable to use a liquid having a heat of condensation of 15 cal / g or more at the boiling point thereof in consideration of the heat shrinkage efficiency of the resin molding. When the heat of condensation at the boiling point is 15 cal / g or more, the resin molded product can be efficiently heat-shrunk.
The heat of condensation at the boiling point of the resin-insoluble liquid is more preferably 16 cal / g or more.

In addition to these, the above resin insoluble liquid is
It is preferable that the vapor pressure at 298 K is 0.01 mmHg or higher, or the boiling point at normal pressure is 540 K or higher,
By using the boiling vapor of the resin-insoluble liquid having such a vapor pressure or boiling point as the heat medium, the heat-shrinkable material of the resin molded product after the volume reduction treatment (heat treatment) is cleaned at the time of taking it out after the treatment. Can be dried.

By heating the resin-molded body with the boiling steam as described above, each part of the resin-molded body shrinks at once, and the resin-molded body can be efficiently heat-shrunk, that is, the volume can be reduced in a short time. On the other hand, when the resin molded body is heated with a planar heating element, for example, foamed polystyrene has a good heat insulating property, and unless it is crushed by applying force at the same time as heat, heat treatment can be performed efficiently. Can not.

Further, since the boiling vapor as the heat source is the vapor of the resin insoluble liquid, the heat medium (the resin insoluble liquid) does not remain as an impurity in the heat-shrinkable material of the resin molding. . Further, since the heating temperature of the resin molded body can be made substantially constant, thermal decomposition of the resin molded body or the like will not be caused by appropriately setting the boiling point of the resin insoluble liquid. Furthermore, since steam is used as the heat medium, contamination brought in by the resin molded product, contamination by monomers, oligomers, and various additives released from the resin molded product does not occur. When the resin molded body is immersed in a liquid serving as a heat medium and subjected to heat treatment, stains and monomers brought into the liquid may be reattached.

Further, since the heat medium is boiling steam, the resin molded body after heat shrinkage is easily dried, and the heat shrinkable product can be taken out in a clean state. This becomes more effective by using a resin insoluble liquid having a vapor pressure at 298K of 0.03 mmHg or more. Therefore, the resin molded body after volume reduction can be used for various purposes without performing a washing step as a post-treatment.

Specific examples of the resin-insoluble liquid used in the present invention include fluorinated compounds which satisfy the above-mentioned conditions, particularly highly fluorinated compounds and low molecular weight polyorganosiloxanes. Here, the fluorinated compound is a compound in which at least a part of hydrogen of the hydrocarbon compound is replaced with at least fluorine, and the highly fluorinated compound is a large part or substantially all of the hydrogen of the hydrocarbon compound. Is a compound in which is substituted with fluorine.

Specific examples of the fluorinated compound include chlorofluorocarbon (CFC), perfluorocarbon (PFC), hydrofluorocarbon (ΗFC),
Hydrochlorofluorocarbon (ΗCFC) and the like can be mentioned, but CFC and HCFC, etc. are
Its use has been determined to be regulated. On the other hand, PF
Highly fluorinated compounds such as C and ΗFC are highly safe, and in particular, PFC having a high boiling point is commercially available and is easily manpowerable. Further, it is known that its properties are normally liquid at normal temperature, are nonflammable, do not dissolve resins, and have high condensation heat and vapor pressure.

As described above, among the fluorinated compounds, highly fluorinated compounds, particularly perfluorocarbons, are preferable as the resin-insoluble liquid in the present invention. According to the non-flammable liquid made of a highly fluorinated compound, since it is non-flammable, it does not cause a fire when the resin-insoluble liquid is heated to near its boiling point, and the heat treatment can be safely carried out. Benefits are obtained.

The term "perfluorocarbon" refers to a compound in which almost all the substituents that can be bonded to carbon atoms in the molecular structure are fluorine atoms, but in the industrially used perfluorocarbons, all the substituents are It is not limited to a fluorine atom, but also includes one in which hydrogen, chlorine, bromine or the like is bonded as a part of impurities. These are inevitable impurities in manufacturing and are contained in perfluorocarbon in an amount of about 0.5 to 5%, and a perfluorocarbon containing such impurities has no practical problem. Further, it may be a compound in which a part of hydrogen is intentionally left. Further, the perfluorocarbon used in the present invention is not limited to one having a carbon main chain only, and may partially contain oxygen such as an ether bond, nitrogen, silicon or the like.

The low molecular weight polyorganosiloxane used as the resin insoluble liquid is

Embedded image (Wherein, R represents the same or different unsubstituted or substituted monovalent hydrocarbon group, and p represents an integer of 1 to 3), or a linear diorganosiloxane represented by the formula:

Embedded image (Wherein R represents the same or different unsubstituted or substituted monovalent hydrocarbon group, and q represents an integer of 4 to 6).

The R group in the above formulas (1) and (2) is an unsubstituted or substituted monovalent hydrocarbon group, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group or a butyl group,
Examples of the monovalent unsubstituted hydrocarbon group such as phenyl group and monovalent substituted hydrocarbon group such as trifluoromethyl group are preferred, and methyl group is most preferred from the viewpoint of system stability and volatility. . Specific examples of the above low molecular weight polyorganosiloxane include octamethyltrisiloxane (boiling point = 426K,
Heat of condensation = 40 cal / g), decamethyltetrasiloxane (boiling point
= 467K, heat of condensation = 40cal / g), octamethylcyclotetrasiloxane (boiling point = 447K, heat of condensation = 37cal / g), decamethylcyclopentasiloxane (boiling point = 483K, heat of condensation = 33ca)
l / g), dodecamethylcyclohexasiloxane (boiling point = 51
8K, heat of condensation = 30 cal / g).

The low molecular weight polyorganosiloxane as described above is usually liquid at room temperature, is inexpensive, does not dissolve various resins such as styrene resin, and has high boiling point and high condensation as described above. Have heat.
Therefore, various resin moldings such as expanded polystyrene can be easily heat-shrunk. Furthermore, since low molecular weight polyorganosiloxane is used in a vapor state like perfluorocarbon, it has excellent volatility, and easily volatilizes from the resin molded body after heat treatment, and heat shrinkage of the resin molded body as a residue is generated. No pollution. Furthermore, it is thermally stable and can withstand long-term heating.

Next, as a concrete embodiment of the method for reducing the volume of a resin molded article of the present invention, an example of the configuration of a volume reduction processing apparatus to which the present invention is applied will be described with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing a structural example of a volume reduction processing apparatus to which the present invention is applied. In the figure, 1 is a container for the resin insoluble liquid 2 made of stainless steel or the like,
A resin insoluble liquid 2 is contained in the lower part of the liquid container 1. The resin insoluble liquid 2 is as described above, and a highly fluorinated compound or low molecular weight polyorganosiloxane is preferably used.

The liquid container 1 containing the resin-insoluble liquid 2 is placed on a heater 3 capable of heating the resin-insoluble liquid 2 to near its boiling point. By heating the resin-insoluble liquid 2 to near the boiling point with the heater 3, the boiling steam 5 used as a heat medium when the resin molded body 4 is heat-treated is generated.

The resin molded body 4 is accommodated in the mesh-shaped basket 6 and is put into the liquid container 1 in which the boiling vapor 5 of the resin insoluble liquid 2 is generated. At this time, the resin molded body 4 is not immersed in the resin insoluble liquid 2, but the mesh-shaped basket 6 is arranged in the liquid storage container 1 so as to be exposed only to the boiling vapor 5.

When the resin molding 4 is exposed to the boiling vapor 5 of the resin insoluble liquid 2, the temperature of the boiling vapor 5 and the condensation heat generated when the boiling vapor 5 condenses on the surface of the resin molding 4 cause
The resin molding 4 is uniformly heated by a large amount of heat from the entire surface thereof, and heat-shrinks efficiently in a short time. Reference numeral 7 in the figure denotes a heat-shrinkable product of the resin molded body 4. After confirming that the resin molded body 4 has undergone heat shrinkage, the mesh-shaped basket 6 is pulled up, whereby the heat shrinkable material 7 of the resin molded body 4 is recovered and reused for various purposes.

Heat-shrinkable material 7 pulled up from liquid container 1
The resin-insoluble liquid 2 does not easily volatilize and the resin-insoluble liquid 2 does not remain in the heat-shrinkable material 7, and thus is taken out as a clean dried material. Further, since the monomers, oligomers, various additives, stains and the like liberated when the resin molded body 4 is thermally contracted do not fall into the resin insoluble liquid 2 and are not mixed in the boiling steam 5, these There is no possibility of recontamination due to.

According to the apparatus for reducing volume of a resin molded body as described above, a resin molded body such as expanded polystyrene can be heat-shrunk efficiently, and the heat-shrinkable material after heat treatment can be easily and contaminated. It can be collected without inviting. With these, the resin molded product can be taken out as a clean product (heat shrinkage product) having a high volume reduction rate after the heat treatment.

Next, another configuration example of the volume reduction processing apparatus to which the present invention is applied will be described with reference to FIG. The volume reduction processing apparatus for a resin molded body shown in FIG. 2 is an apparatus for heat-shrinking a resin molded body.

In FIG. 2, reference numeral 11 denotes a volume reducing device main body, and a resin non-dissolving liquid 12 is contained in the lower portion of the volume reducing device main body 11. The resin-insoluble liquid 12 is as described above. A heater 13 is arranged in the resin insoluble liquid 12 as a heating means, and the heater 13 heats the resin insoluble liquid 12 to near the boiling point to generate boiling vapor 14 used as a heat medium. That is, below the body 11 of the volume reducing device is the boiling steam chamber 1.
5. A cooling water chiller coil 16 is installed above the boiling steam chamber 15 so that the boiling steam 14
Is prevented from being volatilized and lost.

At the upper part of the body 11 of the volume reducing device, there is provided an inlet 18 for a resin molding 17 to be subjected to a heat shrinkage treatment.
The resin molded body 17 charged into the charging port 18 is crushed as needed by a cutter 19 installed below the charging port 18, and then the boiling steam chamber filled with the boiling steam 14 through the hopper 20. Drop into 15.

In order to transfer the heat-shrinked resin molding (heat-shrinkable material) 22 from the lower part of the hopper 20 to the discharge port 21 provided on the side surface of the body 11 of the volume reducing apparatus, into the boiling steam chamber 15. As a means of this, a net conveyor 23 is installed. The resin molding 17 dropped from the hopper 20 into the boiling steam chamber 15 is exposed to the boiling steam 14 while reaching the net conveyor 23, and the temperature of the boiling steam 14 and the boiling steam 14 are condensed on the surface of the resin molding 17. Due to the heat of condensation generated at this time, the resin molded body 17 is uniformly heated by a large amount of heat from the entire surface of the resin molded body 17 and thermally contracts. At this time, since the temperature of the boiling steam 14 is controlled by the boiling point of the resin-insoluble liquid 12, the resin molded body 17 does not melt even though it shrinks due to heat. /
The heat-shrinkable material 22 is reduced in volume to about 10 to 1/20.

The heat-shrinkable material 22 dropped on the net conveyor 23 is further exposed to the boiling steam 14 and transferred to the discharge port 21 while the heat-shrinkage is progressing. Since the final stage of the net conveyor 23 is located above the cooling water chiller coil 16, that is, above the boiling steam chamber 15 and serves as a cooling zone, the heat shrinkable material 22 is sufficiently cooled and solidified. After this, the heat-shrinkable material 22 is discharged from the discharge port 21 into the recovery container 2
4

According to the heat-shrinking type volume reduction apparatus for a resin molded product described above, a resin molded product such as expanded polystyrene can be efficiently heat-shrinked, and the resin molded product (heat Since the heat medium is easily volatilized from the surface of the contracted material), the resin-insoluble liquid does not remain. Therefore,
It is possible to easily take out a clean heat-shrinkable product that does not need to be washed as a subsequent process.

[0047]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described.

Example 1 In this Example 1, the volume reduction treatment of expanded polystyrene was performed using the volume reduction treatment apparatus shown in FIG. First, perfluorocarbon (trade name: Fluorinert FC-70, manufactured by Sumitomo 3M Limited) was put into the liquid container 1. This perfluorocarbon has a boiling point of 488 K, a specific gravity of 1.94, a vapor condensation heat of 16 cal / g at the boiling point, and a vapor pressure of 0.1 mmHg at 298 K. The perfluorocarbon was heated by the heater 3 to a boiling point of 488K.

In the liquid container 1 in which the boiling vapor of perfluorocarbon is produced in this manner, the expanded polystyrene contained in the mesh-shaped basket 6 is charged, and the expanded polystyrene is heated by the boiling vapor of perfluorocarbon. Contracted. The expanded polystyrene was heat-shrinked immediately after it was exposed to the boiling vapor of perfluorocarbon, and the volume of this heat-shrinkable product was reduced to about 1/15 of that of the original foam. Further, there was no contamination with perfluorocarbon.

Example 2 In this Example 2, expanded polystyrene was heat-treated by using the volume reducing apparatus shown in FIG. First, the same perfluorocarbon (trade name: Fluorinert FC-40, manufactured by Sumitomo 3M Limited) as in Example 1 was put in the lower portion of the volume reducing apparatus main body 11. The heater 13 was equipped with one having a capacity of 3.0 kw, and the perfluorocarbon was heated to its boiling point of 488K. Further, tap water was connected to the cooling water chiller coil 16 and water at room temperature was flowed.

When the expanded polystyrene was put into such a volume reducing apparatus, the expanded polystyrene could be heat-shrinked at a rate of about 2.4 kg per hour. The volume of the obtained heat-shrinkable material was reduced to about 1/15 of the volume of the original foam, and no perfluorocarbon remained, so that it could be taken out in a clean state.

Example 3 In this Example 3, the volume reduction treatment of expanded polystyrene was performed using the volume reduction treatment apparatus shown in FIG. First, decamethylcyclopentasiloxane (trade name: TSF465, manufactured by Toshiba Silicone Co., Ltd.) was put into the liquid container 1. This decamethylcyclopentasiloxane has a boiling point of 483K,
Specific gravity is 0.96, condensation heat of vapor at boiling point is 33 cal / g, 29
The vapor pressure at 8K is 0.06 mmHg. The heater 3 heated the above decamethylcyclopentasiloxane to a boiling point of 483K.

In the liquid container 1 in which the boiling vapor of decamethylcyclopentasiloxane was produced in this manner,
The expanded polystyrene contained in the mesh-shaped basket 6 was introduced, and this expanded polystyrene was thermally shrunk by boiling steam of decamethylcyclopentasiloxane. The expanded polystyrene was heat-shrinked immediately after it was exposed to the boiling vapor of decamethylcyclopentasiloxane, and the volume of this heat-shrinkable product was reduced to about 1/15 of that of the original foam. In addition, there was no contamination with decamethylcyclopentasiloxane.

Example 4 In Example 4, the heat-shrinkable volume reducing apparatus shown in FIG. 2 was used to heat the expanded polystyrene. First, octamethylcyclotetrasiloxane (trade name: TSF404, Toshiba Silicone Co., Ltd.)
Manufactured). This octamethylcyclotetrasiloxane has a boiling point of 449K, a specific gravity of 0.956, a vapor heat of condensation of 37cal / g at the boiling point, and a vapor pressure of 1.5mmHg at 298K. The heater 13 is equipped with one having a capacity of 3.0 kw, and the octamethylcyclotetrasiloxane has the boiling point.
Heated to 449K. Further, tap water was connected to the cooling water chiller coil 16 and water at room temperature was flowed.

When the expanded polystyrene was put into such a volume reducing apparatus, the expanded polystyrene could be heat-shrinked at a rate of about 3 kg per hour. The obtained heat-shrinkable material has a volume reduced to about 1/15 of that of the original foam, and octamethylcyclotetrasiloxane does not remain, so it can be taken out in a clean state. It was

[0056]

As described above, according to the method for reducing the volume of a resin molded article of the present invention, the volume of a resin molded article such as expanded polystyrene can be efficiently reduced to about 1/5 to 1/20. In addition, contamination by a heat medium or the like does not occur after the volume is reduced. Therefore, when collecting and recycling a resin molded product such as expanded polystyrene, the transportation cost can be significantly reduced, and the regenerated resin can be used for various purposes.

[Brief description of drawings]

FIG. 1 is a diagram showing a volume reduction processing apparatus of an embodiment to which a volume reduction method for a resin molded body of the present invention is applied.

FIG. 2 is a diagram showing a volume reduction processing apparatus of another embodiment to which the volume reduction method for a resin molded body of the present invention is applied.

FIG. 3 is a diagram showing the relationship between the density and the heat treatment temperature when heat-shrinking expanded polystyrene, which is one type of resin molded product, at various temperatures.

[Explanation of symbols]

 1 ... Liquid storage container 2, 12 ... Resin insoluble liquid 3, 13 ... Heater 4, 17 ... Resin molding 5, 14 ... Boiling steam 7, 22 ... Heat shrinkable material 11 ... Volume reduction Main unit 15 ... Boiling steam chamber

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08L 25/06 KFW B09B 3/00 303E B29K 25:00 105: 04 105: 26 (72) Inventor Minoru Inada 1-1-1, Shibaura, Minato-ku, Tokyo Inside Toshiba Head Office (72) Inventor Ihiko Kimoto 5-33-10 Kugahara, Ota-ku, Tokyo Ueki Corporation (72) Inventor Nobuhiro Saito 6-23-1, Roppongi, Minato-ku, Tokyo Inside Toshiba Silicon Co., Ltd.

Claims (7)

[Claims] 1. When reducing the volume of a resin molded body, boiling vapor of a liquid that is insoluble in the resin molded body is used as a heat medium, and the resin molded body is exposed to the boiling vapor to reduce the volume. A method for reducing the volume of a resin molded body, which is characterized by carrying out. 2. The method for reducing the volume of a resin molded body according to claim 1, wherein the insoluble liquid is a softening point of the resin molded body.
A method for reducing the volume of a resin molded body, which comprises using a liquid having a boiling point higher than 50 K and lower than a temperature at which the resin molded body melts. 3. The method for reducing the volume of a resin molded article according to claim 1, wherein the non-soluble liquid has a heat of condensation of 15 at its boiling point.
More than cal / g and vapor pressure at 298K is 0.01mmHg
A method for reducing the volume of a resin molded body, which uses the above liquid. 4. The method for reducing the volume of a resin molding according to claim 1, wherein a liquid having a heat of condensation of 15 cal / g or more and a boiling point of 540 K or more at normal pressure is used as the insoluble liquid. A method for reducing the volume of a resin molding, which is characterized by: 5. The method for reducing the volume of a resin molding according to claim 1, wherein at least one liquid selected from a highly fluorinated compound and a low molecular weight polyorganosiloxane is used as the insoluble liquid. Volume reduction method for resin molded product. 6. The method for reducing the volume of a resin molded body according to claim 1, wherein the resin molded body is expanded polystyrene. 7. The method for reducing volume of a resin molded body according to claim 1, wherein the resin molded body is exposed to the boiling steam to cause heat shrinkage to reduce the volume.