JP2001342291A - Method for producing dechlorinated resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a dechlorinated resin by which the chlorine is relatively simply removed from the chlorine-containing resin by utilizing an alcohol solution containing sodium hydroxide or potassium hydroxide dissolved therein. SOLUTION: This method for producing the dechlorinated resin comprises making mechanical energy act on a mixture of a granular material of the chlorine-containing resin with the alcohol solution containing the sodium hydroxide or potassium hydroxide dissolved therein and thereby removing the chlorine in the chlorine-containing resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a dechlorinated resin having a lower chlorine content than the original chlorine-containing resin.

[0002]

2. Description of the Related Art Conventionally, methods for treating and disposing of a chlorine-containing resin include (1) landfill disposal, (2) incineration treatment,
(3) A method such as reuse processing is employed. this house,
(1) In landfill disposal, there are concerns about the depletion of disposal sites and the possibility of harmful substances eluting into groundwater after landfill disposal. Therefore, (2) volume reduction by incineration treatment,
In many cases, the reduced volume is landfilled as specially managed industrial waste. However, in incineration, harmful gases such as chlorine gas, hydrochloric acid gas, and dioxin are generated in large quantities depending on the incineration equipment and combustion conditions, and in many cases, the equipment is corroded and damaged, and humans and animals are damaged. Problem.

[0003] On the other hand, (3) in the recycling process, a simple pretreatment such as reuse, washing and pulverization is performed as it is, and recycled as a recycled material for various molded articles and other uses. Many processing methods have been proposed and implemented, such as thermal recycling for reuse, and chemical recycling for converting oil and other substances for reuse. Although reuse is the most rational method, not all things can be reused, and the amount is rather small.

In the material recycling treatment, the chlorine-containing resin can be washed and pulverized and used as a recycled resin, but cannot be used for applications other than the chlorine-containing resin. As with the incineration treatment, the thermal recycling treatment involves problems in terms of facilities and disposal of incineration ash. Also, in chemical recycling, depending on the purpose and application of reuse, there are still many types of processing such as removal of various impurities including chlorine compounds, complicated processing equipment, and a large amount of energy required for processing. I have a problem.

However, many of these problems are caused by chlorine contained in the chlorine-containing resin, and development of an effective, stable and inexpensive method for removing chlorine has been awaited. . As one example, in JP-A-11-61147, a chlorine-containing resin is heated at 300 ° C.
A method is disclosed in which a pyrolysis treatment is performed at about 450 ° C. to form an oil, and chlorine and hydrogen chloride gas generated are removed to convert the residue into a fuel. However, in this method, a large amount of energy is required to remove the chlorine-based compound from the chlorine-containing resin after the thermal decomposition, and there is still a problem that the equipment is inevitably complicated.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention makes it possible to relatively easily remove chlorine from a chlorine-containing resin by using an alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved. An object of the present invention is to provide a method for producing a dechlorinated resin.

[0007]

SUMMARY OF THE INVENTION The present invention provides a method for producing a chlorine-containing resin by applying mechanical energy to a mixture of a granular material of a chlorine-containing resin and an alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved. This is a method for producing a dechlorinated resin for removing chlorine in the resin.

Hereinafter, the present invention will be described in more detail. The chlorine-containing resin in the present invention refers to a resin having a chlorine element in the resin and the resin skeleton, and specifically includes vinyl chloride resin, polyvinylidene chloride, chlorinated polyethylene and the like. Among the above-mentioned chlorine-containing resins, vinyl chloride resins are preferred in that they are generally used in a large amount and are usable. Further, it is preferable to use the waste from the viewpoint of recyclability. The waste of chlorine-containing resin is not limited to used resin or resin products,
It may be a waste that includes unnecessary substances such as burrs and runners generated during molding.

In the present invention, the above chlorine-containing resin granules are used, but the particle size is not particularly limited as long as it can be processed by a processing apparatus described later. It is preferably 100 mm or less, more preferably 0.001 to 10 mm. When the particle size is less than 0.001 mm, the weight of the particles is reduced, and the operability is reduced due to dust flying when the powder is charged into the processing apparatus. On the other hand, if the particle size exceeds 100 mm, the surface area per unit weight decreases, and the efficiency of the dechlorination reaction decreases.

[0010] The sodium hydroxide and potassium hydroxide used in the present invention are not particularly limited, and sodium hydroxide and potassium hydroxide may be used in combination.

The alcohol used in the present invention includes:
Although not particularly limited, ethanol is preferred in terms of versatility, safety, and cost. Further, alcohol and water may be used in combination.

Sodium or potassium hydroxide;
The ratio of the alcohol is not particularly limited as long as it is completely soluble in the alcohol used, but is preferably 0.1 to 3 mol / L (hereinafter, L) in consideration of the efficiency of dechlorination. Is 0.2 to
2.5 mol / L, more preferably 0.5 to 2 mol
/ L. When the concentration is less than 0.1 mol / L,
If the dechlorination efficiency decreases, on the other hand, if it exceeds 3 mol / L, the viscosity of the alcohol solution increases, and mechanical energy cannot be sufficiently transmitted to the chlorine-containing resin, and as a result, the dechlorination efficiency decreases.

The mixing ratio of the chlorine-containing resin to the alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved is expressed by the following formula: [weight of chlorine-containing resin / sodium hydroxide or potassium hydroxide dissolved] Alcohol solution]
Is preferably 1 to 40, more preferably 3
-30, more preferably 4-25. When the weight ratio is less than 1, the solvating effect of alcohol with respect to chloride ions is reduced, and the dechlorination efficiency is reduced. As a result, the efficiency of dechlorination decreases.

The type of mechanical energy for removing chlorine that acts on a mixture of the above-mentioned chlorine-containing resin and an alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved (hereinafter referred to as mixture 1) is Although not limited, for example, a compressive force, a shearing force, an impact force, a frictional force and the like can be mentioned.

The processing device for applying the mechanical energy is not particularly limited. For example, the processing can be performed using a crushing device generally used for the purpose of crushing. Examples of the above pulverizer include a ball mill, a vibration mill, a planetary mill, and a medium stirring type mill, such as impact, friction, compression,
Roller mill; mortar; jet crusher mainly for grinding.
Among these apparatuses, a ball-medium type mill is preferable because mechanical energy can be effectively applied to the mixture mechanically.

The load of the mechanical energy is not particularly limited, and may be appropriately determined depending on the amount of the chlorine-containing resin as a raw material and the amount of the mixture 1. If the amount is too small, the chlorine in the chlorine-containing resin may not be sufficiently removed.If the amount is too large, for example, in the case of a ball-medium mill, an excessive load on a crushing device, severe abrasion of a ball or a container as a medium, treatment, Inconveniences such as disadvantages in production, such as high costs due to prolonged time, occur. Specifically, for example, when a planetary mill having two stainless steel pots is used, the amount of energy applied varies greatly depending on the amount of input raw materials. It is often processed with mechanical energy for 3000 minutes.

As described above, when mechanical energy is applied to the mixture 1, the chlorine in the chlorine-containing resin chemically moves to an alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved, and the mixture 1 Is assumed to change to a mixture of a dechlorinated resin, an alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved, and a solution in which chloride is dissolved in the alcohol solution (hereinafter, referred to as mixture 2). . In the mixture 2, unreacted chlorine-containing resin may remain.

If the mixture 2 obtained above is filtered, a dechlorinated resin which is a solid content is obtained. By washing the obtained solid content with water, a purified dechlorinated resin is obtained. When the adhesion of the alkali is severe, an acid treatment using dilute nitric acid or the like may be performed as a pretreatment before washing with water. The method of water washing and, if necessary, acid treatment is not particularly limited, and a general powder washing method can be applied. The dechlorinated resin after washing can be reused as a powder as it is, or melted and pelletized, and used as a recycled resin raw material.

The term "dechlorinated resin" as used in the present invention means a resin having a chlorine content lower than that of the original chlorine-containing resin, which is a relative one and is completely free of chlorine. It does not mean that the resin is in the closed state.

(Operation) As described above, in the present invention, the mixture 1 is applied by applying mechanical energy.
The chlorine contained in the chlorine-containing resin chemically moves to the alcohol solution side in which sodium hydroxide or potassium hydroxide is dissolved to form a dechlorinated resin, and the mixture 1 becomes the mixture 2
And a dechlorinated resin is produced. Therefore, the method for producing a dechlorinated resin is simple in energy loading method, does not generate harmful gases such as chlorine gas and hydrochloric acid gas, and can greatly suppress the corrosion of the apparatus. Further, a purified dechlorinated resin can be easily obtained from the mixture 2 by a usual filtration and water washing method (acid treatment as necessary).

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

(Examples 1 to 7) As a chlorine-containing resin, used vinyl chloride resin pipe (manufactured by Sekisui Chemical Co., Ltd .;
The vinyl chloride resin content of 95% by weight and the remaining 5% by weight are washed with a lubricant such as metal soap, a filler such as calcium carbonate, a stabilizer such as organic tin and organic lead, and other coloring agents, and the like. Pulverized to an average particle diameter of 1 mm to obtain a granular material.

As an alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved, a predetermined amount of sodium hydroxide / potassium hydroxide (both manufactured by Wako Pure Chemical Industries) is added to ethanol (manufactured by Wako Pure Chemical Industries). It was prepared by dissolving. The chlorine-containing resin obtained as described above and the alcohol solution were mixed to form a mixture 1, and this mixture 1
The mixture was subjected to mechanical energy for 3 hours to obtain a mixture 2. Thereafter, the mixture 2 was filtered and washed with water to obtain a purified dechlorinated resin.

As a method of applying mechanical energy to the mixture 1, two stainless steel pots (capacity: 50 cm ³ ) are installed on a desk horizontally rotating clockwise, and each pot is the same as the desk. A planetary mill capable of rotating counterclockwise at a rotational speed was used. The revolving radius of the pot is 70mm and the rotation speed is 600r
pm.

In the above embodiment, seven stainless steel balls having a diameter of 15 mm and a total amount of 5 g of the mixture 1 were poured into the pot, and the planetary mill was operated at room temperature. In order to prevent an excessive rise in the temperature in the pot, the operation was suspended for 30 minutes after the 15-minute operation, and this was taken as one cycle. After the completion of 12 cycles, the mixture was taken out of the pot to obtain a mixture 2.

In the above embodiment, the mixing ratio of the chlorine-containing resin and the alcohol solution in the mixture 1 was set to 5 by weight [alcohol solution in which sodium hydroxide or potassium hydroxide was dissolved / chlorine-containing resin]. .

(Comparative Example) The chlorine-containing resin used in the examples, which was not subjected to any treatment, was used as a comparative example. Table 1 shows the alkali species used in the examples and comparative examples, the concentration of the alcohol solution in which the alkali was dissolved, and the results of their dechlorination rates.

Examples 8 to 12 Next, the concentration of the alcohol solution was fixed at 0.5 mo / L as in Examples 1 and 2, and the mixing ratio of the chlorine-containing resin and the alcohol solution [hydroxylation Dechlorination was carried out in the same manner as in Examples 1 to 7, except that the alcohol solution containing sodium or potassium hydroxide / chlorine-containing resin; weight ratio was changed. Table 2 shows details of the examples.

[0029]

[Table 1]

[0030]

[Table 2]

In Tables 1 and 2, the chlorine removal rate was determined by precisely weighing 2 mg of the purified dechlorinated resin obtained in the example and the chlorine-containing resin of the comparative example, and then placing the resin and pure water in a flask. After burning in a flask under an oxygen atmosphere, the total amount of chloride ions contained in pure water was measured by ion chromatography and calculated by the following equation. Chlorine removal rate (%) = 100− (total amount of chlorine ions from dechlorinated resin obtained in Examples / total amount of chlorine ions from resin of comparative example) × 100

[0032]

As described above, according to the method for producing a dechlorinated resin of the present invention, by applying mechanical energy without applying heat, relatively low energy and complicated processing equipment are not required. From a mixture of a chlorine-containing resin and an alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved (mixture 1), an alcohol solution in which the dechlorination resin and sodium hydroxide or potassium hydroxide are dissolved and chloride are dissolved. A mixture with the above (mixture 2) is obtained.

By filtering the mixture 2 thus obtained, a dechlorinated resin which is a solid content is obtained, and a purified dechlorinated resin is obtained by washing the solid content with water. The purified dechlorinated resin has a lower chlorine content than the original chlorine-containing resin and has no or little harmful gas or the like caused by chlorine even when used as an incineration treatment or as a fuel. .

Further, by actively using a vinyl chloride resin or a waste vinyl chloride resin as the chlorine-containing resin,
Because chlorine is contained, processing is difficult, and waste vinyl chloride resin can be dechlorinated.This technology can be used as an aid to environmental measures. This is expected as an environmentally friendly recycling method. In particular, since chlorine-containing resins such as vinyl chloride resins have good performance and are inexpensive, the production and consumption thereof are large, and even if they are wastes, they can be recycled by the method for producing dechlorinated resins of the present invention. It is expected that the usefulness of the treatment method will be great.

Claims (4)

[Claims] 1. A method for removing chlorine in a chlorine-containing resin by applying mechanical energy to a mixture of a granular material of the chlorine-containing resin and an alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved. A method for producing a dechlorinated resin, comprising: 2. The method for producing a dechlorinated resin according to claim 1, wherein the chlorine-containing resin is a vinyl chloride resin. 3. The concentration of sodium hydroxide or potassium hydroxide in the alcohol solution is 0.1 to 3 mol / L.
The method for producing a dechlorinated resin according to claim 1 or 2, which is (liter). 4. The method for producing a dechlorinated resin according to claim 1, wherein the ratio of the alcohol solution in which sodium hydroxide or potassium hydroxide is dissolved to the chlorine-containing resin is 1 to 40.