JPH0786151B2 - Polystyrene foam and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polystyrene-based foam suitable for in-situ foaming or suitable for a method of using the foam for ground improvement and a method for producing the same.

[0002]

2. Description of the Related Art Polystyrene-based foams are small in deformation against external stress and are excellent in shape retention and dimensional stability, making use of their characteristics such as packaging and packing of home electric appliances and precision equipment, cooler boxes, and heat insulating building materials. It has been widely used for.

In recent years, blocks made of polystyrene foam are vertically and horizontally stacked on soft ground, sloping ground or landslide areas to construct a bank of embankment, on which bridges, paved roads, airfields, railways, etc. are provided. Civil engineering method called EPS method has also become popular.

As a conventional method for producing such a useful polystyrene foam, polystyrene beads containing a foaming agent are filled in a mold (mold, template, trapezoid, sink, etc.), and steam is used. It is usually carried out by a bead molding method in which heat energy is supplied for molding, a polystyrene raw material is melted by heating using an extruder, a foaming agent is mixed, and then extruded in a sheet form.

All of these conventional foaming methods are based on the so-called external heating method in which foaming is performed by heating from the outside.

However, since such an external heating method requires a large-scale heating facility, it is manufactured in a factory equipped with the heating facility, and after being made into a foam form, it is later used by a user or a construction site at a remote place. It is usually transported to and used. For this reason, there are drawbacks such that transportation costs and storage costs are increased due to the bulkiness of the foam, resulting in an extremely high cost.

To solve this problem, Japanese Patent Laid-Open No. 63-134
Japanese Patent No. 708 proposes a quicklime-based ground improvement agent and a ground improvement method which are obtained by mixing quicklime and polystyrene as a raw material for molding. This method uses polystyrene as a ground improvement agent by utilizing the exothermic reaction of quick lime and water, but since the expansion ratio of polystyrene foam is extremely low, a large amount of resin is required and the construction cost becomes high. That the foaming speed is slow and construction efficiency is poor,
There are problems that a solid three-dimensional molded product with weak bonding between foamed particles is difficult to obtain, and that soil is excessively alkalinized due to quick lime, causing soil pollution and groundwater pollution.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and it is desired to use a foam without using an external heating device, a foam construction site. (EN) It is possible to provide a polystyrene-based foam which can be foamed and foam-molded by (1), has a high expansion ratio and can be rapidly foamed, and has no problem of soil pollution or groundwater pollution, and a method for producing the same.

[0009]

[Means for Solving the Problems] The present inventors finally arrived at the present invention as a result of intensive studies for many years. The outline is as follows.

That is, the polystyrene foam of the present invention is a polystyrene foam in which inorganic acid and / or organic acid is mixed with calcium oxide, magnesium oxide, calcium chloride, calcium hydroxide, magnesium hydroxide, magnesium chloride. A polystyrene foam comprising a salt with a metal compound containing at least one of the above.

Further, the method for producing a polystyrene foam according to the present invention is characterized in that the heat of reaction produced by mixing and mixing the following (1) to (3) is mainly used for foaming the polystyrene foam. It is a manufacturing method.

(1) expandable polystyrene resin, (2) metal compound containing at least one of calcium oxide, magnesium oxide, calcium chloride, calcium hydroxide, magnesium hydroxide and magnesium chloride, (3) inorganic acid And / or an organic acid, or alternatively, the method for producing a polystyrene foam of the present invention utilizes reaction heat generated mainly by mixing and mixing the same (1) to (3) as described above in a mold of an arbitrary shape. The method for producing a polystyrene-based foam is characterized by molding a foam having an arbitrary shape by foaming.

Alternatively, in the method for producing a polystyrene foam of the present invention, foaming is carried out in a flexible container mainly by using the reaction heat generated by mixing and mixing the same (1) to (3) as described above. A method for producing a polystyrene-based foam, which comprises molding a foam having an arbitrary shape.

[0014]

The present invention will be described in detail below.

According to the present invention, a polystyrene foam is foam-molded by utilizing the heat of reaction between the above-mentioned compounds (1) to (3). Alternatively, the presence of a specific “salt” produced by the reaction of an organic acid (hereinafter, referred to as an acid component) with a specific metal compound, and in the production method thereof, the acid component and the specific metal The essential requirement is that the reaction heat with the compound causes foaming.

With such a configuration, the present invention enables not only the foaming without using the heating device but also the foaming at the construction site where the heating device is not provided. Compared with the method of foaming polystyrene using the heat of reaction with (Japanese Patent Application Laid-Open No. 63-134708), the calorific value is high and the heat generation is rapid, so that extremely high expansion ratio, rapid foaming, and foam particles The inter-bonding can be strengthened, and a three-dimensional molded article of any shape can be obtained. In addition, when it is used in the soil, it has a characteristic that it is not accompanied by excessive alkalinization or acidification of the soil.

The foam according to the present invention is produced mainly by mixing and mixing a foamable polystyrene resin, an acid component and a metal compound, and the foam mainly contains the acid component and a specific metal compound. There is a particular "salt" formed by the reaction with.

Examples of the polystyrene resin component of the present invention include polystyrene, styrene-ethylene copolymer,
A thermoplastic resin composed of one or more of acrylonitrile / styrene copolymer and ABS resin, which contains a low boiling point blowing agent such as propane, butane, pentane, hexaneheptane, cyclohexane and a mixture thereof. Used.

As the acid component, for example, at least one of organic acids such as p-toluenesulfonic acid, phenolsulfonic acid and xylenesulphonic acid, and inorganic acids such as phosphoric acid are used. The acid component may be an aqueous solution containing water.

The metal compound is preferably one which rapidly reacts with an acid component to generate high heat of reaction, and specifically, at least calcium oxide, magnesium oxide, calcium chloride, calcium hydroxide, magnesium hydroxide and magnesium chloride. One or more types are selected and used. Among the above-mentioned metal compounds, calcium oxide and magnesium oxide are particularly preferable, and a preferable effect can be exhibited by using them alone or in combination with other metal compounds.

The addition amount of the acid component and the metal compound is not particularly limited, but both components are generally in the range of 1 to 50 parts with respect to 100 parts by weight of the resin in order to perform sufficient foaming. . In practice, the amount of addition can vary greatly depending on the combination of the acid component and the metal compound, and it is preferable that the addition amount be appropriately adjusted so that the entire composition is not extremely biased to the acidic side or the alkaline side.

In addition, the metal compound is added in order to rapidly generate heat of the composition and increase the heat generation amount per unit of the metal compound.
It is preferable to increase the surface area and to uniformly disperse the resin particles, and for that purpose, it is desirable to make the metal compound into fine particles. Any known method can be used for forming fine particles, and for example, a dry mill can be preferably used. The average particle size required to obtain good dispersion is approximately 0.1 μm or more, 1000 μm
The range is m or less.

The mixing order of the compound is preferably such that the foamable resin component and the metal compound are mixed and the acid component is mixed with the mixture. Also, by mixing the foamable resin component and the acid component,
It is also possible to mix a metal compound with the mixture. The former method is preferred.

By mixing the above-mentioned three components in this manner, mainly by the reaction of the acid component and the metal compound, self-heating occurs rapidly and at a high temperature, and foaming starts by vaporization of the foaming agent in the foamable resin component. After foaming, a "salt" is produced in the foam by the reaction of the acid component and the metal compound.

By allowing such a "salt" to be present in the foam, the acid component and the metal compound react with each other to rapidly and self-heat to a high temperature, and further, the acid side or the alkaline side is not biased extremely. In-situ foaming is possible. For example, when calcium oxide and phenol sulfonic acid are used, calcium phenol sulfonate is produced. When magnesium oxide and toluene sulfonic acid are used, magnesium toluene sulfonate is produced. The presence of such "salt" is analyzed by a qualitative or quantitative analysis method such as ICP emission spectroscopy, powder X-ray diffraction method, ion chromatography, etc. to determine the presence of "salt" in the foam and its formation. The quantity is confirmed. That is, the present invention is proved by the presence of such a "salt", and the production amount thereof is not particularly limited, but as a rough guide, it is 0.5 to 30 with respect to the amount of the foam resin. Parts by weight.

By performing such foaming under pressure in a mold of an arbitrary shape, the bonding between the foam particles is strengthened, and a solid three-dimensional molded article of an arbitrary shape can be obtained. For example, it is possible to mold on-site a cushioning material for a home electric appliance or a fish box that is usually manufactured in a factory.

A flexible container (flexible,
It is also possible to form a foam that is wrapped in a flexible container (for example, a cloth bag, a film bag, or the like) by performing foaming in a container having various shapes. This foam formation method can be created by appropriately changing the density, size, shape, etc. according to the situation of the civil engineering site, etc.This foam is used for soft ground, steep slopes or landslide areas. It can be preferably used as a material for civil engineering work such as.

A flame retardant, depending on the purpose of use and application,
There is no problem in adding a neutralizing agent, a filler, a plasticizer, a pigment, a dye or the like.

Further, as described above, heating from the outside is not necessarily required to carry out the present invention, but various kinds of heating such as electric heater, microwave heating, hot air heating, etc. are performed depending on the specifications, applications, purposes and the like. There is no problem in using the heating method together.

[0030]

EFFECTS OF THE INVENTION According to the present invention, in-situ foaming is possible not only in a place without a heating device, but also the calorific value is high and the heat generation is quick, and the foaming ratio is extremely high. It is possible to rapidly foam and strengthen the bond between the foam particles, and it is possible to obtain a three-dimensional molded product of any shape.

Further, when used in soil, it is easy to use without excessive alkalization or acidification of soil.

[0032]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the scope of the validity and rights of the present invention is not limited by or limited thereto.

Example 1 As the expandable resin component, commercially available expandable beads of polystyrene were used, and as the metal compound, 10 parts by weight of magnesium oxide, 2 parts by weight of calcium hydroxide and 100 parts by weight of expandable beads, and chloride were used. 1 part by weight of magnesium and 1 part by weight of calcium chloride were added and mixed. Inner size is 500mm (vertical) x 250mm after both are mixed well
(Horizontal) × 1000 mm (height) put into a metal mold with a lid. While stirring the expandable bead / magnesium oxide blend with a stirrer, 20 parts by weight of a 65% aqueous solution of phenolsulfonic acid was further added as an acid component. Foaming started about 30 seconds after the addition of the acid component. The lid of the metal mold was closed to allow sufficient foaming. After about 10 minutes, water was poured from outside the metal mold to cool it, and then the foam was taken out. A block foam having the above dimensions was obtained. The foaming ratio of block foam is about 30
It was double.

The block-shaped foam was applied to a road model of EPS method and a compression test was conducted. as a result,
It was found to have the same degree of compression resistance as a foam block molded in a conventional factory. Moreover, the foamed pieces were finely crushed and placed in water, and the pH was measured and found to be 8.5. In addition, qualitative analysis confirmed that magnesium phenolsulfonate was produced.

Example 2 Commercially available polystyrene expandable beads were used as the expandable resin component, and 12 parts by weight of calcium oxide, 2 parts by weight of calcium hydroxide, and magnesium chloride were used as the metal compound per 100 parts by weight of the expandable beads. 1 part by weight and 1 part by weight of calcium chloride were added and mixed. After both were sufficiently mixed, they were fed into a metal mold having a fish box shape. After closing the metal mold, 30 parts by weight of a 40% aqueous phenolsulfonic acid solution was added as an acid component through a large number of pores provided in the metal mold. About 30 seconds after the addition of the acid component, heat generation started and foaming started a little later. After about 10 minutes, water was poured from the outside of the metal mold to cool, and a fish box having a desired shape was obtained. The expansion ratio of the foam was about 40 times. Although the foam had some uneven expansion ratio, it had no problem in practical use.

Example 3 Using commercially available polystyrene expandable beads as the expandable resin component, as the metal compound, 12 parts by weight of calcium oxide and 2 parts by weight of magnesium chloride were added to 100 parts by weight of the expandable beads and mixed. did. After both were thoroughly mixed, the mixture was fed into a cloth bag made of polypropylene slit yarn fabric. As an acid component, 30 parts by weight of a 40% aqueous solution of phenolsulfonic acid was added and mixed with stirring. After mixing, the opening of the cloth bag was tied with a string and foamed to fill the volume to obtain a foamed product with a cloth bag.
The expansion ratio of the foam with a cloth bag was about 30 times.

When the obtained foam with a cloth bag was used as an embankment (sandbag) on soft ground, it was possible to carry out civil engineering work without any practical problems. Further, the foamed piece was finely crushed and put in water, and the pH was measured and found to be 6.5. In addition, qualitative analysis confirmed that magnesium phenolsulfonate was produced.

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Claims (4)

[Claims] 1. A metal compound containing, in a polystyrene foam, an inorganic acid and / or an organic acid and at least one or more of calcium oxide, magnesium oxide, calcium chloride, calcium hydroxide, magnesium hydroxide and magnesium chloride. A polystyrene foam comprising a salt of 2. A method for producing a polystyrene foam, which comprises foaming mainly by utilizing reaction heat generated by mixing and mixing the following (1) to (3). (1) Expandable polystyrene resin, (2) calcium oxide,
A metal compound containing at least one or more of magnesium oxide, calcium chloride, calcium hydroxide, magnesium hydroxide and magnesium chloride, (3) an inorganic acid and / or an organic acid, 3. A polystyrene system characterized in that a foam of arbitrary shape is formed by using reaction heat generated by mixing and mixing the following (1) to (3) in a mold of arbitrary shape. Method for producing foam. (1) Expandable polystyrene resin, (2) calcium oxide,
A metal compound containing at least one or more of magnesium oxide, calcium chloride, calcium hydroxide, magnesium hydroxide and magnesium chloride, (3) an inorganic acid and / or an organic acid, 4. A polystyrene system characterized in that a flexible container is foamed in an arbitrary shape by mainly utilizing the reaction heat generated by mixing and mixing the following (1) to (3). Method for producing foam. (1) Expandable polystyrene resin, (2) calcium oxide,
A metal compound containing at least one or more of magnesium oxide, calcium chloride, calcium hydroxide, magnesium hydroxide and magnesium chloride, (3) an inorganic acid and / or an organic acid,