JP2551307B2 - Heat-resistant resin recovery method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method and an apparatus for recovering bromine and / or antimony from a heat-resistant resin containing bromine and / or antimony.

[0002]

2. Description of the Related Art For example, when a semiconductor device is manufactured by encapsulating a semiconductor pellet with a resin, a heat-resistant resin is used for encapsulation in order to withstand heat generated when energized. The heat-resistant resin is mainly an epoxy resin, which is particularly brominated (Br) having a fire-preventing effect, and further contains an antimony compound (Sb ₂ O ₃ ) and silica (SiO ₂ ). Some are mixed as a heat-resistant agent and a filler, respectively.
Here, after the resin molding, it may protrude from the molding die,
Unwanted resin that has become defective is disposed of as industrial waste by landfilling.

[0003]

The problem to be solved by the present invention has become difficult because the number of landfill sites has decreased in recent years with the increase of industrial waste.
In addition, bromine and antimony, which are mixed in the heat-resistant resin for sealing semiconductor devices, are highly toxic, and when incinerated,
Since it pollutes the atmosphere, it is difficult to process.

[0004]

The present invention provides, as a method,
Bromine and / or antimony-containing heat-resistant resin is thermally decomposed to generate bromine and / or antimony-containing gas, which is chemically reacted with an alkaline aqueous solution.
Alternatively, it is characterized by recovering antimony as a compound,

As a device, a bromine- and / or antimony-containing heat-resistant resin is thermally decomposed in a state where air is shut off,
A decomposition furnace for generating bromine and / or antimony-containing gas and the decomposition furnace are connected. The inner middle of the upper part of the connection port is sealed with a filler as a coarse filter, and the bottom of the connection part is made of an alkaline aqueous solution. The cleaning solution is stored, and the cleaning solution is circulated above the packing material and dropped in a shower shape, and the gas supplied from the decomposition furnace is brought into gas-liquid contact with the cleaning solution at the packing material to generate the bromine. And / or a gas scrubber for recovering antimony as a compound, and an incinerator for generating a bromine and / or antimony-containing gas by burning and thermally decomposing a bromine- and / or antimony-containing heat-resistant resin. , Is connected to the incinerator, and the inner middle of the upper part of the connection port is sealed with a filler to form a coarse filter, and the bottom of the connection part is filled with an alkaline aqueous solution. That the cleaning liquid was stored, and, by dropping in a shower shape by circulating the washing liquid in the filling upward,
A gas scrubber for recovering the bromine and / or antimony as a compound from a chemical reaction liquid generated by gas-liquid contact of the gas supplied from the decomposition furnace with the scrubbing liquid in the packing is provided.

[0006]

According to the above technical means, bromine and / or bromine and / or antimony-containing heat-resistant resin produced by thermal decomposition are produced.
Alternatively, the antimony-containing gas is chemically reacted with a cleaning solution composed of an aqueous alkali solution, and bromine and / or antimony is recovered from the reaction solution as a compound, which is purified and then reused.

[0007]

An embodiment of the present invention will be described below with reference to FIG. In the figure, (1) is a decomposition furnace and (2) is a gas cleaning tower. The decomposition furnace (1) contains the heat-resistant resin (3) containing unnecessary bromine and / or antimony generated during the manufacturing of the semiconductor device, and thermally decomposes it in a state in which the air is shut off to obtain bromine and / or Antimony-containing gas (G) (for example, a mixed gas of HBr, SbBr ₃ , and H ₂ O, CO ₂ )
Generate. The heat resistant resin (3) contains silica (SiO ₂ ) as a filler in addition to the bromine and antimony compounds, and after decomposition, the silica remains as burning residue. In the gas cleaning tower (2), the middle of the side wall surface is connected to the exhaust port of the cracking furnace (1) by a connecting pipe (4), and the inner middle above the connecting port is a non-reactive packing (5 ) (For example, terraret), and the cleaning liquid (6) made of an alkaline aqueous solution (NaOH aqueous solution) is stored in the bottom portion below the connection port.
Further, the cleaning liquid (6) is circulated above the filling material (5) by the pump (7) and dropped like a shower.

The operation (method) of the present invention based on the above configuration will be described below. First, the bromine and / or antimony-containing heat-resistant resin (3) is thermally decomposed in a decomposition furnace (1) in a state where air is shut off, and the generated bromine and / or antimony-containing gas (G) is passed through a connecting pipe (4). Supply to the gas scrubber (2). At this time, the silica remaining as burnt residue is landfilled and discarded. Next, the NaOH cleaning liquid (6) drops from above the filler (5) in a shower shape and passes through the minute gaps of the filler (5), and the supplied gas (G) is charged into the filler (5). Rise to the side. Then, the NaOH cleaning liquid (6) passing on the surface of the packing (5)
Is in gas-liquid contact with the gas (G), the gas (G) is absorbed by the liquid and the gas (G) is dissolved therein, and the compound of bromine (Br) or antimony (Sb) is produced by the chemical reaction shown by the following formula. (NaBr, Sb ₂ O ₃ ) begins to be generated, and the reaction solution further falls into the NaOH cleaning solution (6) at the bottom to continue and complete the reaction. That is,

HBr + NaOH → NaBr + H ₂ O ₂ SbBr ₃ +6 NaOH → Sb ₂ O ₃ + 6NaBr + 3
H ₂ O Therefore, while the NaOH cleaning solution (6) is circulated through the pump (7) and its solubility is measured in advance, and when the compound dissolves to near saturation, NaOH is dissolved before the compound precipitates.
The reaction liquid that dropped into the cleaning liquid (6) was recovered, and bromine (B
r) and / or antimony (Sb) with NaBr, Sb ₂
It is fixed as a compound such as O ₃ and carried out of the tower, and at the same time N
A new solution of aOH is supplied from the supply port (2a). Alternatively,
When the pH concentration is measured during the reaction and approaching the neutralization, a new solution of NaOH may be continually replenished little by little from the supply port (2a), and the reaction solution may be carried out after sufficiently dissolving. Next, the recovered compounds such as NaBr and Sb ₂ O ₃ may be purified in a separate step to separate Na, Br and Sb and reused.

Further, instead of the decomposition furnace (2), an existing incinerator (not shown) is connected to the gas cleaning tower (2), and the heat-resistant resin containing bromine and / or antimony is in the air in the incinerator. You may burn and collect bromine and / or antimony in a gas washing tower (2). In this case, since the incinerator is normally installed, the device can be used universally.

[0011]

EFFECTS OF THE INVENTION According to the present invention, since bromine and / or antimony is recovered as a useful substance from unnecessary bromine- and / or antimony-containing heat-resistant resin, the waste becomes valuable and the waste disposal site becomes The unnecessary and highly toxic bromine and antimony are not carelessly released into the atmosphere, and the air pollution can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a heat resistant resin recovery device according to the present invention.

[Explanation of symbols]

 1 Decomposition furnace 2 Gas cleaning tower 3 Heat resistant resin 5 Filling material 6 Cleaning liquid G gas

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C01D 3/10 ZAB C01D 3/10 ZAB C01G 30/00 ZAB C01G 30/00 ZAB C08J 11/12 ZAB C08J 11/12 ZAB

Claims (3)

(57) [Claims] 1. A bromine- and / or antimony-containing gas produced by thermally decomposing a bromine- and / or antimony-containing heat-resistant resin is chemically reacted with a cleaning liquid composed of an alkaline aqueous solution,
A method for recovering a heat-resistant resin valuable material, comprising recovering the bromine and / or antimony as a compound from the reaction solution. 2. A decomposition furnace for thermally decomposing a bromine and / or antimony-containing heat-resistant resin in a state where air is shut off to generate a bromine and / or antimony-containing gas, and a decomposition furnace connected to the decomposition furnace above the connection port. While sealing the inner middle of the like in a coarse filter shape with a filling, storing a cleaning solution consisting of an alkaline aqueous solution in the bottom part below the connection port, and circulating the cleaning solution above the filling and dropping it in a shower shape,
Heat resistance characterized by comprising a gas cleaning tower for recovering the bromine and / or antimony as a compound from a chemical reaction liquid generated by gas-liquid contact of a gas supplied from a decomposition furnace with a cleaning liquid in a packing Recovery equipment for resin valuables. 3. An incinerator for combusting a bromine and / or antimony-containing heat-resistant resin to decompose it by heat to generate a bromine- and / or antimony-containing gas, and an internal intermediate connected to the incinerator above the connecting port. Is sealed in a coarse filter shape with a filling material, and a cleaning solution composed of an alkaline aqueous solution is stored in the bottom portion below the connection port, and the cleaning solution is circulated above the filling material to drop in a shower shape and supplied from an incinerator. And a gas cleaning tower for recovering the above-mentioned bromine and / or antimony as a compound from a chemical reaction liquid generated by gas-liquid contact with the cleaning liquid in the filling material. apparatus.