JPH06157812A - Method of reclaiming molding of flame-retardant resin composition - Google Patents

Abstract

PURPOSE:To provide a method by which a reusable resin and reusable flame retardants are separately reclaimed from a molding of a flame-retardant resin composition. CONSTITUTION:A molding of a flame-retardant resin composition is immersed in an aqueous acid solution having a pH of 5 or lower to dissolve and/or precipitate the various flame retardants contained in the molding. The flame retardants are separated from the resulting solution as derivatives thereof and/or metal ions, while the resulting resin is burnt or shattered. Thus, the resin and the various flame retardants can be recovered separately from the molding and reused.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an electric wire, a cable covering material using a flame-retardant resin composition recovered for reasons such as disposal or renewal, and a molded product such as various pipes and building materials. TECHNICAL FIELD The present invention relates to a method for reclaiming a flame-retardant resin composition molded body, which allows the flame retardant and the flame retardant to be separated and reused.

[0002]

2. Description of the Related Art Flame-retardant additives such as flame retardants and flame retarding aids are used for coatings of electric wires and cables, molded products of resin compositions such as various pipes and building materials, from the viewpoint of preventing fire spread. A flame-retardant resin composition prepared by blending is widely used. In recent years, from the viewpoint of fire prevention due to the sophistication and high density of urban functions, there is a demand for higher flame retardancy in materials such as electric wires, cable covering materials, building materials, members of electrical equipment, and housings. A flame-retardant resin composition that retains flame retardancy and a non-halogen type flame-retardant resin composition that does not generate a harmful halogen-based gas during combustion have been used. These flame-retardant resin compositions exhibit a high degree of flame-retardancy by adding a flame-retardant imparting agent such as a flame-retardant / flame-retardant aid to the resin. For example, in a molded product of a polyvinyl chloride (PVC) resin composition, by adding antimony trioxide to the PVC resin, higher flame retardancy than that of the PVC resin alone is exhibited. Further, in the halogen-free flame-retardant resin composition, a large amount of metal hydroxide such as magnesium hydroxide or aluminum hydroxide is blended with the resin to exhibit high flame retardancy and low smoke generation.

[0003]

Problems to be Solved by the Invention Electric wires, cables, wiring,
When the equipment and buildings that use water and hot water supply pipes, buildings, etc. are discarded or rebuilt, the resin composition of electric wire and cable coatings, wiring, water and hot water supply pipes, various building materials, etc. The molded article will be discarded and processed. It has been common practice to incinerate ordinary resin composition molded articles by incineration. However, the flame-retardant resin composition molded body has a problem that it is difficult to incinerate due to the high flame retardancy imparted thereto, and the treatment becomes difficult. In recent years, it has been required to reuse resources, and in particular, the reuse of plastic materials has become a global problem. Therefore, the method of treating and reusing the discarded resin molding has become an important issue. Therefore, conventionally, for example,
In the case of a flame-retardant PVC resin composition molded body, a method is used in which the molded body is crushed into a granular form and then reprocessed into another molded body for reuse. However, since the molded product obtained by this method has limited applications, it is not a sufficient recycling method. Further, there is no established method for treating and reusing a non-halogen type flame-retardant resin composition molded article, particularly a cross-linked flame-retardant resin composition molded article, which has been a serious problem.

[0004]

The present invention has conducted extensive studies to solve these problems, and as a result, the flame-retardant resin composition molded body was dipped and held in an acid solution having a pH of more than 5. Various flame retardancy-imparting agents that are added to and contained in the resin composition molded body are dissolved and / or separated and precipitated in the acid solution, and the flame-retardancy-imparting component is obtained from the obtained acid solution. Is fractionated as a derivative and / or a metal ion of the constituents of the flame retardant-imparting agent, while the residue obtained by removing the flame retardant-imparting agent from the flame-retardant resin composition molded article is incinerated or crushed into particles It is a method for reclaiming a flame-retardant resin composition molded article, which is characterized in that it can be reused. The flame-retardant resin composition molded article to which the present invention is applied is not particularly limited in the composition of the resin composition, but is a non-halogen type flame-retardant resin composition molded article containing a metal hydroxide as a flame retardant. Is effective in. Further, in the present invention, it is more effective to simultaneously treat only the flame-retardant resin composition molded article having the same composition.

The acid solution used in the present invention has a pH of 5
The reason for defining as a stronger acid solution is that an acid solution having a pH lower than 5 cannot achieve the object of the present invention, and a preferred acid solution is an acid solution having a pH higher than 2. The acid having a pH higher than 5 is preferably an acid capable of dissolving a part or all of the flame retardancy-imparting agent contained in the resin of the flame-retardant resin composition molded article, and examples thereof include hydrochloric acid, sulfuric acid, nitric acid and the like. Inorganic strong acid, organic strong acid such as formic acid, or 2
A mixed solution of two or more species can be used. The acid solution having a pH of more than 5 used in the present invention has a small difference in processing ability due to a difference in the strength of oxidizing power. When a metal element is contained therein or the resin composition molded article to be treated is accompanied by a metal piece or metal powder such as an electric wire or a coating material for a cable, these metals are It is preferable to use an acid having a weak oxidizing power, since a dangerous substance or a harmful substance such as hydrogen gas may be generated by a redox reaction with a strong acid.

The solution and precipitate obtained in the above-mentioned method in an acid solution having a pH of more than 5 imparts flame retardancy such as a flame retardant and a flame retardant auxiliary agent added to the flame retardant resin composition. When the derivative and / or the metal ion of the agent is a main component, and the solution and precipitate of these are a mixture,
It is important for reuse to separate the mixture and separate it as a single substance. The method of separating the mixture from the acid solution containing the dissolved substance and / or the precipitate obtained by the method of the present invention and separating the simple substance is a known method of separating metal ions, a method of separating organic substances, or the like. Can be applied as is. Further, molding of a resin composition to be treated after the flame retardant-imparting agent such as the flame retardant, the flame retardant aid, etc., which has been compounded by the dipping treatment, is separated as a dissolved matter and a precipitate into an acid solution having a pH of more than 5. The body no longer has its high flame retardancy, so it is mechanically crushed and granulated for reuse.
Can be incinerated easily.

When the molded product of the flame-retardant resin composition is dipped in an acid solution, the acidity of the acid solution decreases (the pH value increases) with the passage of time. The optimum dipping time for dipping and holding can be set by measuring the acidity (pH) of the acid solution and using this as an index.

[0008]

In the present invention, when the molded product of the flame-retardant resin composition is dipped and held in an acid solution having a pH of more than 5, most of the various flame-retardant additives added and blended into the resin molded product are retained. Since it is a basic or amphoteric substance, a part or the whole of the addition amount thereof is transferred from the resin molded product into the acid solution in the form of dissolution and / or precipitation. Therefore, the constituent components of the resin and various flame retarding agents can be easily separated and separated.

[0009]

【Example】

Example 1 A cable-made flame-retardant polyethylene resin composition jacket (hereinafter referred to as "resin composition molded article A") was sampled, immersed in a sulfuric acid solution having a pH of 1 at room temperature for one day, and then immersed in the resin. The composition-made coating (hereinafter referred to as resin composition molded body B) was taken out, and the dip-treated sulfuric acid solution was filtered to collect a precipitate (precipitate A). Next, when hydrochloric acid having a pH of 2 was added to the sulfuric acid solution after the filtration treatment, a new precipitate was formed. By filtering this solution, a filtrate (solution A) and a precipitate (precipitate B) were obtained. Elemental analysis was performed on the precipitates A, B and the solution A thus obtained. As a result, it was found that the precipitate A was mainly composed of carbon and phosphorus, and the precipitate B was mainly composed of aluminum and chlorine. Also,
A large amount of magnesium was detected in the solution A. On the other hand, p
The resin composition molded body A before the dipping treatment in the sulfuric acid solution of 1 and the resin composition molded body B after the dipping treatment were each cut into a size of 100 mm × 10 mm × 2 mm to make a sample, and A so-called vertical combustion test was performed in which the long side was set upright and the Bunsen burner flame was applied to the lower end for 30 seconds. As a result, the flame of the non-immersion-treated flame-retardant polyethylene resin molded body A disappeared in 5 seconds or less, but the flame-retardant polyethylene resin molded body B subjected to the immersion treatment was completely burned.
Therefore, the flame-retardant polyethylene resin composition molded body B obtained by applying the method of the present invention is no longer a polyethylene resin composition molded body which has lost its high flame retardancy and can be easily reused. You can see that

Example 2 A flame-retardant PVC resin composition jacket (hereinafter referred to as a resin composition molded body C) was taken from an electric cable, immersed in a sulfuric acid solution having a pH of 1 at room temperature for one day and then immersed. Flame retardant P after treatment
The VC resin composition coat (hereinafter referred to as resin composition molded body D) was taken out, and the dipping-treated sulfuric acid solution was filtered to obtain a filtrate (solution B) and a precipitate (precipitate C). Elemental analysis was performed on the precipitate C and the solution B thus obtained. As a result, it was found that the precipitate C was mainly composed of carbon, and the solution B was mainly composed of antimony and calcium. On the other hand, the flame-retardant PVC resin composition molded body C before the immersion treatment in a sulfuric acid solution having a pH of 1 and the flame-retardant PVC resin composition molded body D after the immersion treatment are respectively
A so-called vertical burning test was performed by cutting out into a sample of a size of 00 mm × 10 mm × 2 mm, setting the long side of each sample vertically, and applying a Bunsen burner flame to the lower end for 30 seconds. As a result, the flame of the non-immersion-treated flame-retardant PVC composition molded body C disappeared in 5 seconds or less, but the flame-retardant PVC resin composition molded body D of the immersion-treated treatment was completely burned. From this, the flame-retardant PVC resin composition molded body D obtained by applying the method of the present invention is no longer its high flame-retardant property, and can be recycled easily. You can see that you have become a body.

[0011]

INDUSTRIAL APPLICABILITY In the method of the present invention, when the flame-retardant resin composition molded body is dipped in an acid solution having a pH of more than 5, the flame retardant, flame retardant auxiliary agent and the like added and compounded from the composition molded body are added as described above. Since it dissolves in the acid solution and / or migrates as a precipitate, the acid solution after the dipping treatment is then subjected to a known filtration treatment to separate the added flame retardant as a derivative or metal ion and re-collect it. Available. Further, since the flame-retardant resin composition molded body after the immersion treatment in an acid solution having a pH higher than 5 has a significantly lower content of the flame retardancy-imparting agent than before the immersion treatment, it is crushed and granulated as it is. It can be reused as high-quality resin granules, or can be easily incinerated and reused as fuel.

Claims (5)

[Claims] 1. A flame-retardant resin composition molded article is dipped and held in an acid solution having a pH of more than 5, and various flame retardancy-imparting agents contained in the resin composition molded article are added to the acid. A method for reclaiming a flame-retardant resin composition molded article, which comprises dissolving and / or separating and precipitating it in a solution. 2. A derivative of a flame retardant-imparting component, which is dissolved and / or decomposed and precipitated in an acid solution from a flame-retardant resin composition molded article, to be contained in the acid solution. And / or a metal ion is collected, The method for regenerating a flame-retardant resin composition molded article according to claim 1, which is characterized in that: 3. The method for reclaiming a flame-retardant resin composition molded article according to claim 1, wherein an inorganic strong acid solution is used as the acid solution having a pH higher than 5. 4. A method for reclaiming a flame-retardant resin composition molded article according to claim 1, wherein an organic strong acid solution is used as the acid solution having a pH higher than 5. 5. The method for regenerating a flame-retardant resin composition molded article according to claim 3, wherein an acid solution having a weak oxidizing power is used as the acid solution having a pH higher than 5.