JPS5835533B2 - Expanded polystyrene treatment method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides expanded polystyrene with p-dichlorobenzene and/or tricyclo(5,2,1
,0''・6) Decane (hereinafter abbreviated as JTCD, J).

) is used to shrink the volume of expanded polystyrene as it is.

Conventionally, incineration has been the main method for disposing of expanded polystyrene waste, but recently, from the standpoint of resource conservation, reuse of discarded plastics has become important.

As for the reuse of expanded polystyrene, the only known techniques are heat shrinkage and solvent treatment.

However, the incineration of general discarded combustible plastics, including foamed polystyrene, is problematic because the high heat of combustion often causes damage to the incinerator and the generation of poisonous gas.

Furthermore, heat treatment of combustible plastics also poses a risk in terms of disaster prevention and is not an economically advantageous method.

On the other hand, solvent treatment is also not preferred from a practical standpoint because it is difficult to recover the solvent.

Therefore, the present invention solves these conventional technical problems.

That is, the present invention involves contacting expanded polystyrene with vapors of p-dichlorobenzene, TCD, or a mixture thereof;
The present invention relates to a method for treating expanded polystyrene, which is characterized by shrinking it.

Expanded polystyrene refers to foam moldings and foams of polystyrene or styrene copolymers.

The method of the present invention involves placing foamed polystyrene of any shape in a sealed space, p-dichlorobenzene, TCD
or a mixture thereof, preferably in an amount sufficient to reach the saturated vapor pressure at that temperature.

However, the temperature may be varied between room temperature and 50° C. in order to promote reaching the saturated state.

As a result, the vapor of the sublimate comes into contact with the foamed polystyrene, destroying the cells constituting the polystyrene or styrene copolymer and allowing the polystyrene to shrink in a dry state.

p-dichlorobenzene and TCD may be in any form such as crystal or powder.

A liquid mixture of p-dichlorobenzene and TCD, and p-
Mixtures of dichlorobenzene or TCD and other sublimable compositions and solvents may also be used.

The above-mentioned sealed space may be an airtight container, or may be made of a material that does not allow sublimation substances to pass through, such as polyester film,
Aluminum foil etc. can be used.

Next, examples of the present invention will be shown.

Example 1 P-dichlorobenzene 109 was placed in a sealed container (500CC) containing expanded polystyrene (30cm long cube).
When observing changes in the volume of polystyrene foam at room temperature, the volume decreased to 1/10 on the 5th day after the start of the experiment.
On day 0, it decreased to 1/3o.

Example 2 A test was carried out under the same conditions as in Example 1 using TCD as an alicyclic hydrocarbon having sublimation property. As a result, the volume decreased to 1/3 on the 5th day.

Comparative Example 1 In Example 1, brain damage was used instead of p-dichlorobenzene and the test was carried out under the same conditions as in Example 1. As a result, no shrinkage of expanded polystyrene was observed.

Comparative Example 2 In Example 1, naphthalene was used instead of p-dichlorobenzene under the same conditions as in Example 1. As a result, no shrinkage of the expanded polystyrene was observed.

Comparative Example 3 In Example 1, acetone, which is widely known as a solvent for dissolving styrene foam, was used in p-dichlorobenzene and the same conditions as in Example 1 were used. Dissolved.

As is clear from the above, expanded polystyrene can be easily treated by shrinking the volume of expanded polystyrene using -dichlorobenzene and TcD.

Unlike conventional heat treatment and solvent treatment, which require complicated operations and high processing costs, this method is a simple method and allows expanded polystyrene to be easily reused.

Furthermore, since the sublimable substance can be used in powder or crystalline form, recovery and reuse are extremely easy.

These sublimated substances are generally widely used as deodorants and insect repellents, and have the advantage of being industrially available at low cost.

In addition, the increased density of shrunken polystyrene makes it easier to crush and recycle.

Claims (1)

[Claims] 1. A method for treating foamed polystyrene, which comprises bringing the foamed polystyrene into contact with vapor of p-dichlorobenzene, tricyclo(5,2,1,02.6)decane, or a mixture thereof to shrink the foamed polystyrene.