JPH0710938B2 - Waste treatment method for glass fiber reinforced thermosetting resin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a treatment method of thermally decomposing a glass fiber reinforced thermosetting resin and discarding it, and recovering useful components such as phthalic acid from a decomposition product. is there.

Conventional technology Glass fiber reinforced thermosetting resin (hereinafter abbreviated as FRP)
Is a laminated molded product of resin reinforced by adding glass fiber etc. to plastic, and is characterized by being lightweight overall, excellent in corrosion resistance, formability, and tough. In addition to other industrial products, it is also widely used for bathtubs in general households. This FRP has the property that the resin decomposes when heated and changes into oil, carbon and gas, leaving the glass fiber as it is.

On the other hand, the FRP has the above-mentioned corrosion resistance and toughness, which makes it difficult to dispose of it. The usual disposal method is simply incineration or landfill.

With respect to the above, Japanese Patent Publication No. 53-16031 discloses that a vertical fluidized bed carbonization device is filled with sand having an appropriate particle size as a heating medium to form a fluidized bed, and the temperature of the preheating zone in the upper part of the device is controlled. 15
0-600 ℃, lower flow zone (decomposition zone) in the device
Is set to 300 to 600 ° C. and a hot air waste gas containing an inert gas such as nitrogen or air is fed from the gas combustion furnace into the carbonization device.

While the FRP waste suspended on the hook in such a carbonization device circulates vertically, it is preheated while passing through the upper preheating zone, and is carbonized in the lower decomposition zone to decompose the resin component and finally By allowing only glass fibers to remain, the glass containing oil can be decomposed and removed, and the dry distillation products that have been separated and recovered can be reused as resources such as oils, flammable gases, and glass fibers.

SUMMARY OF THE INVENTION However, among such conventional FRP discarding means,
When FRP is simply incinerated, there is a risk that pollution such as soot and carbon dioxide may occur, and when treated as landfill, it is difficult to secure a landfill site. .

On the other hand, if the vertical fluidized bed carbonization device described in JP-B-53-16031 is used, oily matter from FRP,
Combustible gas, glass fiber, etc. can be recovered, and a desirable treatment method is provided from the viewpoint of effective utilization of unused resources. However, a crystalline substance precipitates in the low temperature part in the fluidized bed carbonization device, There is a problem that the furnace tube may be blocked. This precipitate is a phthalic acid-based compound, but it is technically difficult to recover this, and it has not been attempted in the past.

Therefore, the present invention solves the problems that the conventional FRP waste treatment methods have, and eliminates the phenomenon of clogging of the furnace tube due to the precipitation of crystalline substances, and the use of phthalic acid-based compounds. It is intended to provide a method of treating FRP waste that can be collected.

Means for Solving the Problems The present invention, in order to achieve the above object, inside a heat-resistant tube set to have a predetermined temperature distribution in advance, at least maleic anhydride as an unsaturated dibasic acid, saturated Unsaturated polyester produced by reacting phthalic anhydride as a dibasic acid with a polyhydric alcohol, and a waste mainly composed of a glass fiber reinforced thermosetting resin containing a resin obtained by polymerizing styrene are placed, Water is introduced from an input pipe connected to one end of the heat-resistant pipe, the glass fiber reinforced thermosetting resin is pyrolyzed in a steam atmosphere, and is connected to an output pipe taken out from the other end of the heat-resistant pipe. Disclosed is a method for waste treatment of glass fiber reinforced thermosetting resin, characterized in that decomposition products are deposited in a tank.

Further, phthalic acid as a saturated dibasic acid is separated from the above decomposition products by filtration, and an oily substance containing styrene or the like is separated from the aqueous layer and recovered to be collected. Provide a processing method.

According to such a waste treatment method for glass fiber reinforced thermosetting resin, the waste mainly composed of FRP is placed in the heat-resistant pipe set in advance to have a predetermined temperature distribution, and the heat-resistant pipe is A predetermined amount of water is introduced from an input pipe connected to one end of the FRP to thermally decompose the FRP for a predetermined time in a steam atmosphere. Then, the decomposition products are deposited in the tank connected to the output pipe taken out from the other end of the heat resistant pipe.

The decomposition product is precipitated by appropriately setting the temperature distribution in the heat-resistant pipe and performing heat treatment for a certain period of time while maintaining a predetermined water supply amount, and phthalic acid is separated from the precipitated decomposition product by filtration. An oily substance that is separated and contains maleic anhydride and styrene can be separated from the aqueous layer and recovered.

The steam supplied into the heat-resistant pipe acts as an inert atmosphere during the thermal decomposition of FRP, and therefore there is no difference from the case where the thermal decomposition of FRP is carried out in a nitrogen atmosphere. The effect that there is no clogging phenomenon in the low temperature part of is obtained.

Examples Hereinafter, one example of a waste treatment method for glass fiber reinforced thermosetting resin according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic view of an example of an apparatus used for carrying out the present invention, in which 1 is a heat-resistant tube made of quartz or the like, and 2 is a tubular furnace into which the heat-resistant tube 1 is inserted. . FRPs 4, 4, ... As wastes are placed on a base 3 arranged inside the heat-resistant pipe 1.

Reference numeral 5 is a thermocouple taken out from the base 3, and 6 is a thermometer.
An input pipe 7 for introducing water is connected to one end of the heat resistant pipe 1.

Reference numeral 8 is an output tube taken out from the other end of the heat resistant tube 1, and the output tube 8 is introduced into the tank 9. A gas vent pipe 10 is provided above the tank 9, and the tank 9 is immersed in a water tank 12 filled with water 11. 13 is a decomposition product of FRP deposited in the tank 9.

According to this configuration, after the tubular furnace 2 is set to have a predetermined temperature distribution in advance, the waste mainly composed of FRP is placed on the base 3 provided in the heat resistant tube 1, Heat-resistant tube 1
A predetermined amount of water is introduced from an input pipe 7 connected to one end of the heat-resistant pipe 1, and the FRP is pyrolyzed in a steam atmosphere for a predetermined time to remove the output pipe 8 from the other end of the heat-resistant pipe 1. Decomposition products 13 are deposited in the tank 9 connected to.

In this example, FRP4,4 ... as wastes were maleic anhydride as an unsaturated dibasic acid and unsaturated polyester produced by reacting phthalic anhydride as a saturated dibasic acid with a polyhydric alcohol. A resin obtained by polymerizing styrene with styrene was used. Specific examples will be shown below.

[Example 1] FRP4,4 ... As a sample, 10 layers of glass fibers were laminated, the resin content was adjusted to 55%, and a sample of 20 g in total cut into 1 cm squares was provided in the heat-resistant tube 1. The sample was placed on the obtained base 3 and pyrolyzed at 320 to 600 ° C. in a steam atmosphere while supplying water from the input pipe 7 at a rate of 29 ml / Hr using a metering pump. The temperature of the tubular furnace 2 was adjusted using a slidac.

By such thermal decomposition, the product obtained in the tank 9 was filtered to separate phthalic acid crystals, and the liquid was separated into an oil layer and a water layer. The composition of the solid produced by pyrolysis is KBr
It measured with the infrared spectrophotometer (A7199 by a Nicolet) by the tablet method. The decomposed oil was measured by a gas chromatograph (GC-14A manufactured by Shimadzu Corporation) and a gas chromatograph mass spectrometer (GCM-QP1000A manufactured by Shimadzu Corporation).

As a result of the above thermal decomposition, the temperature inside the heat resistant tube 1 was 320 ° C,
Table 1 shows the amounts (%) of products and residues at 350 ° C, 400 ° C, 500 ° C and 600 ° C.

As can be seen from Table 1, phthalic acid is completely recovered when the temperature in the heat resistant tube 1 is 350 ° C or higher, but a temperature of 500 ° C or higher is required to completely recover the oily substance.

FIG. 2 shows the correlation between the length from the inlet of the heat-resistant tube 1 and the temperature, that is, the temperature distribution, with and without water being supplied into the heat-resistant tube 1 set at a temperature of 500 ° C.

Figure 3 shows the temperature distribution when the temperature inside the heat resistant tube 1 is set to 600 ° C, the temperature distribution when the temperature is set to 500 ° C, and the temperature distribution when the temperature is set to 400 ° C. ing. According to FIG. 3, the inlet portion of the heat-resistant pipe 1 is about 3 cm.
Water vaporization occurred in the vicinity, and the temperature was about 100 ° C.
Since the sample occupies about 12 cm in the center of the heat resistant tube 1,
The temperature difference between the samples was 20 ° C, 25 ° C, and 30 ° C at the temperatures of 600 ° C, 500 ° C, and 400 ° C, respectively.

Next, for comparison with the first embodiment, the input tube 7 is used as in the conventional example.
FRP at 10 ml while supplying nitrogen gas at a rate of 230 ml / min.
Table 2 below shows the correlation between the amount (%) of the product when pyrolyzed for minutes and the temperature. In the thermal decomposition in a nitrogen atmosphere, phthalic acid adhered to the wall of the quartz tube, and the phthalic acid was scraped off and weighed.

For phthalic acid, it becomes 2.4% at 320 ° C and about 10% above 350 ° C as in the case of steam.

Oil does not form at 320 ° C, 0.5% at 350 ° C, 19.
85.1%, 25.1% at 500 ℃ and 26.1% at 600 ℃ can be recovered.

From the above results, it is clear from the comparison between Tables 1 and 2 that similar results can be obtained for the decomposition performance of FRP even when steam is used instead of the conventional nitrogen atmosphere. That is, even if there is a difference between nitrogen and water vapor in the atmosphere in the heat-resistant pipe 1, there is no difference in operation. Especially when water vapor is used, this water vapor acts as an inert atmosphere. In addition, when nitrogen is used, there is a risk that phthalic acid crystals will adhere to the wall surface of the tube and block the furnace tube. Can be prevented.

Next, Table 3 shows the styrene content in the oily matter when steam was used and when nitrogen was used.

As can be seen from Table 3, the oil obtained by using the present invention has a styrene content of 3 to 3 as compared with the oil according to the conventional example.
It was revealed to be 4% higher.

[Example 2] The styrene contents in the product and the residue and the oily substance when the resin used in the FRP 4, 4 ... Was pyrolyzed at 500 ° C in the same manner as in Example 1 are shown in Table 4. Shown in.

From the above explanation, the oil produced by thermal decomposition of FRP in a steam atmosphere has styrene as the main component, and in addition to it, styrene-derived substances such as benzene and toluene, phthalic anhydride,
Contains phthalic acid-derived products such as dimethyl phthalate. The solid produced by thermal decomposition is phthalic acid when the atmosphere is water vapor, and phthalic anhydride when the atmosphere is nitrogen.

Furthermore, if the decomposition time of FRP is 10 minutes, phthalic acid will be 350 ℃
About 10% is recovered at the temperature of. Furthermore, a temperature of 500 ° C or higher is required to recover the oil, and the recovery amount is about 25%.

Moreover, by supplying steam into the heat-resistant pipe, the steam acts as an inert atmosphere during the thermal decomposition of FRP, and therefore there is no difference from the case where the thermal decomposition of FRP is performed in a nitrogen atmosphere, and the cleaning effect of the steam prevents phthalation. It is possible to obtain the effect that there is no clogging phenomenon in the low temperature portion of the furnace tube due to the acid crystals.

EFFECTS OF THE INVENTION As described in detail above, according to the waste treatment method for glass fiber reinforced thermosetting resin according to the present invention, at least the phthalate is provided inside the heat resistant tube which is preset to have a predetermined temperature distribution. An unsaturated polyester produced by the reaction of an acid with a polyhydric alcohol or an unsaturated dibasic acid, and a waste mainly composed of a glass fiber reinforced thermosetting resin containing a resin obtained by polymerizing styrene are placed on the heat resistant tube. A tank connected to an output pipe taken from the other end of the heat-resistant pipe by introducing water from an input pipe connected to one end of the heat-resistant pipe to thermally decompose the glass fiber reinforced thermosetting resin in a steam atmosphere. Since the method for treating the waste of the glass fiber reinforced thermosetting resin in which the decomposition product is deposited is used, the following operational effects are brought about.

That is, a waste mainly composed of FRP is placed in a heat-resistant tube set in advance to have a predetermined temperature distribution, and a predetermined amount of water is introduced from an input tube connected to one end of the heat-resistant tube. By heat-treating the FRP in a steam atmosphere for a certain period of time, the FRP is thermally decomposed, and the decomposition product can be deposited in the tank connected to the output pipe taken out from the other end of the heat resistant pipe. Moreover, phthalic acid can be separated from the precipitated decomposition product by filtration, and an oily substance containing styrene or the like can be separated from the aqueous layer and recovered.

The steam supplied into the heat-resistant pipe acts as an inert atmosphere during the thermal decomposition of FRP, and therefore there is no difference from the case where the thermal decomposition of FRP is carried out in a nitrogen atmosphere. The effect that there is no clogging phenomenon in the low temperature part of

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an apparatus used for carrying out the present invention, FIG. 2 is a graph showing an example of temperature distribution of a heat resistant tube, and FIG. 3 is a graph showing different temperature set values in the heat resistant tube. It is a graph which shows the temperature distribution in the case of making it. 1 ... Heat resistant tube, 2 ... Tubular furnace, 3 ... Base, 4 ... FRP, 5 ... Thermocouple, 6 ... Thermometer, 7 ... Input tube, 8 ... Output tube, 9 ... Tank, 12 ... … Aquarium 13 …… Decomposition products

Front page continuation (72) Inventor Kazuhide Hamada 3992 Fushida, Kochi City, Kochi Prefecture Kochi Prefecture Industrial Technology Center (72) Inventor Kiyokata Imai 3992, Fushida Kochi City Kochi Prefecture Kochi Prefecture Industrial Technology Center (72) Inventor Hiroko Uematsu 3992-3 Fushida Kochi City, Kochi Prefecture Kochi Prefecture Industrial Technology Center (72) Inventor Hirohisa Kawakita 3992 Fushida Kochi City Kochi Prefecture Kochi Prefecture Industrial Technology Center (72) Inventor Tamura Mitsumasa 3992 3 Nunoshida, Kochi City, Kochi Prefecture Kochi Prefecture Industrial Technology Center Examiner Ryuichi Ide (56) References JP-A-51-129473 (JP, A) JP-A-63-35309 (JP, A) JP-A-SHO 50-53475 (JP, A) Japanese Patent Publication Sho 53-16031 (JP, B2)

Claims (2)

[Claims] 1. A maleic anhydride as an unsaturated dibasic acid and a phthalic anhydride as a saturated dibasic acid are mixed with a polyhydric alcohol in a heat-resistant tube preset to have a predetermined temperature distribution. Unsaturated polyester produced by the reaction and waste containing mainly glass fiber reinforced thermosetting resin containing a resin obtained by polymerizing styrene are placed, and moisture is discharged from an input pipe connected to one end of the heat resistant pipe. Was introduced, and the glass fiber reinforced thermosetting resin was pyrolyzed in a steam atmosphere, and the decomposition product was deposited in the tank connected to the output pipe taken out from the other end of the heat resistant pipe. A method for treating waste of glass fiber reinforced thermosetting resin, which is characterized. 2. The phthalic acid as a saturated dibasic acid is separated from the decomposition product by filtration, and an oily substance containing styrene or the like is separated from the aqueous layer and recovered. Of waste treatment of glass fiber reinforced thermosetting resin.