JPH1121375A - Production of filler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve sush problems that crushing, which is predominantly used in the treatment of molded materials, requires a large energy and produces loud noise, and that the recycling of the crushed product is incomplete. SOLUTION: A molded material containing a resin, which is at least partially attacked by an aqueous alkali solution, is immersed in an aqueous alkali solution to penetrate the solution into the inside of the material, the combustion residue produced by removing the resin by combustion is ground, and the product of grinding is fully washed with water to obtain the left filler, such as calcium carbonate, aluminum oxide or glass fibers, of the material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a residue of a molding material generated during molding of a package of a motor or an electronic component, and more particularly, to a method of discarding a molding material containing at least a binder material and a filler. The present invention relates to a method for producing a filler that uses at least a part as a filler for another mold material without using the same.

[0002]

2. Description of the Related Art Conventionally, in molding using a molding material, a passage for flowing the molding material to a product mold is generally formed.
This part is produced together with the product as an unnecessary member (gate runner). This member accounts for at least about 10% or more of the molding material used for the product, and is currently mostly treated as industrial waste. Products using the molding material include, for example, a molding motor, a molding transformer, and a package of a semiconductor element. Particularly, in the case of a package of a semiconductor device, a gate runner whose quantity is ten times as large as that used for a product is sometimes manufactured.

[0003] As a method of recycling the mold material that is finally unnecessary as described above, a method of recycling the molding material by pulverizing the filler material is described.
A method of adding up to about 20% to the virgin material has been studied, and a pulverizer such as a hammer mill and a classifier such as a vibrating sieve have been used as a processing apparatus.

[0004]

When this member is mechanically crushed, the sound of crushing is noisy. In addition, since it is reused as a filler containing a resin, if it is mixed in a large amount, the mechanical strength is reduced, so that a large amount cannot be mixed in the filler. Further, when a thermosetting resin is used as a binder material, there is a problem that crushing itself becomes difficult due to high mechanical strength.

Therefore, considering the disadvantages of the conventional method,
It is an object of the present invention to provide a method for producing a filler using a mold material that is no longer needed.

[0006]

SUMMARY OF THE INVENTION In order to solve the problems of this method of treating a residue of a molding material, the present invention provides a method of burning a molding material containing at least a binder material and a filler for a predetermined time, thereby generating the combustion generated. This is a method for producing a filler in which at least a part of the residue is used as a filler for another mold material.

Also, in order to solve this problem,
The present invention, after immersing a mold material containing a binder material and a filler containing a resin at least partially violated in an alkaline aqueous solution for a predetermined time in an alkaline aqueous solution,
Burn for a predetermined time, the generated combustion residue, at least a part of the residue obtained by removing the alkaline substance with a cleaning agent,
This is a method for producing a filler as a filler for another mold material. Further, the present invention is a method for producing a filler, wherein an alkaline substance eluted in the cleaning agent is used as a part of an alkaline aqueous solution.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The molding material used in the present invention is:
What is necessary is just to contain at least a filler and a binder material. The binder material may be either a thermoplastic plastic or a thermosetting plastic. Thermoplastics are, for example, polyethylene, polypropylene, polystyrene, polyester resin and the like, and thermosetting plastics are, for example, unsaturated polyester resin, epoxy resin, phenol resin and the like.

A molding material such as a molding motor or a molding transformer is used as a filler, in addition to a filler, a reinforcing material,
In many cases, a curing agent, a flame retardant, a cross-linking agent, a coloring agent, a thickener, a release agent, and the like are mixed and used.

As the filler, for example, calcium carbonate, calcium silicate, magnesium carbonate, barium sulfate, calcium sulfate, kaolin, aluminum hydroxide,
Examples include talc, mica, diatomaceous earth, and glass balls.

[0011] Aluminum hydroxide is often used as a flame retardant to enhance the flame retardant effect.
When burned at 00 ° C. or higher, it becomes aluminum oxide and cannot be used again as a filler having a flame-retardant effect like aluminum hydroxide. Therefore, it is recommended to use with a filler other than aluminum hydroxide.
However, for example, when calcium carbonate is mixed as another filler, it is preferable to adjust the average particle diameter of aluminum hydroxide and calcium carbonate to be substantially the same in consideration of the fluidity of the molding material.

As the reinforcing material, glass fiber is mainly used. In addition, polyacrylonitrile-based or rayon-based or pitch-based carbon fiber, silicon carbide-based fiber, ceramic fiber, vinylon, polypropylene, polyester, aramid are also used. Organic fibers such as fibers can also be used. When the residue is reused as a reinforcing material by classification of the residue after combustion, it is preferable to use a fiber that can withstand the combustion temperature, and it is preferable to use a ceramic fiber, a silicon carbide-based fiber, or the like.

When a thermosetting plastic is used, the necessary curing agent includes, for example, t-butyl perocate,
Benzoyl peroxide, t-butyl perbenzoate, 2,2, bis (t-butylperoxy) butane, 3,3,5, trimethyl (t-butylperoxy) cyclohexane and the like can be mentioned. Further, examples of the cross-linking material include styrene, methyl methacrylate, vinyl acetate, vinyl toluene, α-methylstyrene, methyl acrylate, 2, hydroxyethyl acrylate, and 2, hydroxyethyl methacrylate.

As the coloring agent, general dyes and pigments can be used, for example, inorganic pigments such as iron oxide, titanium oxide, cadmium yellow, cadmium red, chrome yellow, chromium vermilion, and ultramarine blue, and azo compounds; Organic pigments such as cyanine blue, chlorinated cyanine blue, and cyanine green; dyes such as indigo red and oil red; and carbon black. However, in consideration of combustion, carbon black, etc., which emits only carbon dioxide gas without emitting toxic gases such as hydrogen chloride and lead oxide, and particulate coloring agents such as iron oxide and titanium oxide, which are almost unchanged by heating Is preferred.

Examples of the thickener include magnesium oxide, magnesium hydroxide, calcium hydroxide, polyvalent isocyanate compounds and the like. Examples of the release agent include a fluorine-based surfactant and zinc stearate. Hydroxides are mostly converted to oxides by combustion, and zinc stearate is also converted to zinc oxide, which is included together with the combustion residues of other fillers such as calcium carbonate and aluminum oxide. Even if it is not necessary, for example, it can be reused as a filler by partially replacing the calcium carbonate constituting the molding material.

The molding material used in the present invention is used for, for example, a molding motor, a molding transformer, a resin-sealed electronic component, a semiconductor element, and the like.

In the combustion treatment, it is sufficient that organic substances such as a binder material are oxidized and removed, and it is not necessary to raise the temperature to a temperature at which the filler is melted and solidified. Conversely, in order to reuse the residual inorganic substances, most of which are oxides, as fillers,
It is preferable to burn at a temperature below the temperature at which the filler mixed before burning does not melt and solidify. Therefore, the combustion processing temperature is preferably, for example, 400 ° C to 800 ° C. In particular, when glass fiber is used as a reinforcing material for the mold material, 50
Since a large decrease in mechanical strength occurs at 0 ° C or more, 500 ° C
It is preferred to process with less than. By treating in this manner, glass fibers can be selected from the combustion residue and reused as a part of the reinforcing material.

Hereinafter, embodiments of the present invention will be described. (Embodiment 1) Polybutylene terephthalate (manufactured by Mitsubishi Rayon Co., Ltd., trade name: Toughpet,
(Hereinafter abbreviated as “PBT”) only 100 parts by weight and 200 parts by weight of heavy calcium carbonate having an average particle diameter of φ20 μm (manufactured by Maruo Calcium Co., Ltd.). First, in order to obtain a uniform mixture, PBT and calcium carbonate were mixed in a pressure kneader heated to 280 ° C. and kneaded for about 15 minutes.

This molding material is press-formed at 250 ° C. (2
00 kg / cm ² ) to obtain a plate-like sample (100 × 10
× 10 mm) and the sample was burned. The combustion is performed in an electric furnace, and the combustion temperature and time are 700 ° C. for 2 hours. After combustion, the sample was kept in a sample shape, but it could be easily crushed into particles with a tabletop mill, and almost all of the residue was regenerated as calcium carbonate and reused as calcium carbonate in another mold material There was no problem at all.

(Embodiment 2) The molding material is PBT
(Mitsubishi Rayon Co., Ltd., trade name: Toughpet) 10
A mixture of 0 parts by weight, 180 parts by weight of heavy calcium carbonate (Maruo Calcium Co., Ltd.) having an average particle diameter of 20 μm, and 20 parts by weight of glass fiber having a length of 20 mm was formed. First, in order to obtain a uniform mixture, PBT and calcium carbonate were mixed in a pressure kneader heated to 280 ° C., kneaded for about 15 minutes, and then glass fibers were mixed.

After a sample having the same shape as that of the first embodiment was made and burned, a mixture of calcium carbonate and glass fiber was obtained as a residue. Further, the powder was pulverized by a table mill, and all of the powder including the pulverized glass fiber was reused as a calcium carbonate as a molding material. The mold material using the recycled material of this method had no problem in mechanical strength. In this case, a virgin material was always used for the glass fiber.

(Embodiment 3) The average particle size is based on 65 parts by weight of an unsaturated polyester resin (Nippon Shokubai Co., Ltd., Epolac) and 35 parts by weight of a low shrinkage agent (Nippon Shokubai Co., Ltd., AT100, styrene solution). 180 parts by weight of calcium carbonate having a diameter of 50 μm, 20 parts by weight of glass fiber having a length of 30 mm, and butyl peroxybenzoate as a curing agent (Nippon Oil & Fats Co., Ltd.)
1 part by weight was added and kneaded, cured at 150 ° C.,
A sample made of a cylindrical molding material having a height of 20 mm was prepared. It was burned at 500 ° C. for 2 hours in an electric furnace. As in (Embodiment 2), all of them could be reused as calcium carbonate of the structural material of the mold material after pulverization.

(Embodiment 4) The average particle size is based on 65 parts by weight of an unsaturated polyester resin (Nippon Shokubai Co., Ltd., Epolac) and 35 parts by weight of a low shrinkage agent (Nippon Shokubai Co., Ltd., AT100, styrene solution). 50 parts by weight of calcium carbonate having a diameter of 30 μm, 130 parts by weight of aluminum hydroxide having an average particle diameter of 20 μm, 20 parts by weight of glass fiber having a length of 20 mm, and butyl peroxybenzoate (Nippon Oil & Fats Co., Ltd.) 1 as a curing agent
A part by weight was added and kneaded, and the mixture was cured at 150 ° C. to prepare a sample made of a cylindrical molding material having a diameter of 20 mm and a height of 20 mm. 500 ° C. in an electric furnace as in (Embodiment 3)
For 2 hours. In this case, as a residue, in addition to calcium carbonate and glass fiber, aluminum hydroxide becomes aluminum oxide, but after pulverization, all are reused as calcium carbonate of the structural material of the mold material and retain sufficient mechanical strength. I was able to.

(Embodiment 5) The average particle size is based on 65 parts by weight of an unsaturated polyester resin (Nippon Shokubai Co., Ltd., Epolac) and 35 parts by weight of a low shrinkage agent (Nippon Shokubai Co., Ltd., AT100, styrene solution). 50 parts by weight of calcium carbonate having a diameter of 50 μm, 110 parts by weight of aluminum hydroxide having an average particle diameter of 20 μm, 20 parts by weight of zinc stearate, 20 parts by weight of glass fiber having a length of 20 mm, and butyl peroxybenzoate as a curing agent (Nippon Oil & Fat Co., Ltd. )) 1 part by weight is added and kneaded,
The sample was cured at 150 ° C. to prepare a sample made of a cylindrical molding material having a diameter of 20 mm and a height of 20 mm. Similar to (Embodiment 3), burning was performed at 500 ° C. for 2 hours in an electric furnace. In this case, as a residue, in addition to calcium carbonate and glass fiber, aluminum hydroxide becomes aluminum oxide and zinc stearate becomes zinc oxide, but after grinding, all are reused as calcium carbonate of the structural material of the molding material. However, the mechanical strength was sufficient without any problem.

In another embodiment of the present invention, the resin at least partially violated by the alkaline aqueous solution is preferably a resin containing an ester bond, an ether bond, an amide bond, etc., for example, an unsaturated polyester resin, phenol Resins, epoxy resins, urethane resins and the like can be mentioned. Of these, unsaturated polyester resins are most suitable because they are most susceptible to alkali, and the addition of an aliphatic polyester resin can promote the decomposability thereof.

The aliphatic polyester resin used in the present invention may be any resin which can be easily decomposed by an aqueous alkaline solution, and is obtained by subjecting a polymer obtained by condensation polymerization of a carboxyl group and a hydroxyl group, to a ring-opening polymerization of a cyclic ester compound. In polymers and the like, for example, polycaprolactone, polypropiolactone, polycaprolactone diol, polyhydroxybutyric acid, a copolymer of ε-caprolactone and adipic acid and hexamethylenediol, polycyclohexylene dimethyl adipate, polybutylene adipate, polybutylene succinate , Polylactic acid, polyhydroxyvaleric acid, polyhydroxybutyric acid-hydroxyvaleric acid copolymer and the like. These aliphatic polyester resins,
It is preferable to add it in a state of being dissolved in a monomer or an unsaturated polyester resin. However, in the case of an aliphatic polyester resin which is hardly dissolved, it may be added in a dispersed state.

The alkaline aqueous solution used in the treatment method of the present invention is an aqueous solution containing an alkaline alkali metal compound or an alkaline alkaline earth metal compound. Examples of the alkaline alkali metal compound or alkaline earth metal compound include sodium hydroxide, potassium hydroxide, barium hydroxide, sodium ethoxide, potassium butoxide and the like. The higher the concentration of the solution of the alkaline alkali metal compound or alkaline alkaline earth metal compound, the greater the number of hydroxyl ions, the greater the attack on ester bonds and the like to promote hydrolysis, but the more sodium ions and potassium ions, etc. As a result, the viscosity of the solution increases, and the permeability of the solution into the plastic molded body decreases. Therefore, the concentration is preferably such that a sufficient hydrolysis reaction or the like occurs and the liquid permeability does not decrease. Therefore, the solution concentration of the alkaline alkali metal compound or alkaline alkaline earth metal compound is preferably 10 N or less, and more preferably 2 to 7 N.

The alkaline alkali metal compound or alkaline earth metal compound may be contained not only in a single component but also in a plurality.

In order to improve the permeability of the solution into the plastic molded article, for example, alcohols such as methyl alcohol and ethyl alcohol, acetone, tetrahydrofuran, ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol Diethyl ether, diethylene glycol, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dimethylformamide, dimethylamine and the like may be added.

The treatment temperature is lower than the boiling point of water (100.degree.
It is preferable to heat within the range of the following), but when alcohols are contained, the boiling point is preferably lower than their boiling points.

After immersion in the alkaline aqueous solution, it is of course possible to further immerse in water to swell with water to promote the softening of the mold material. At this time, the higher temperature is better,
It can also be heated to 100 ° C. or higher by putting it in a heating vessel together with water.

In the processing method of the present invention, when an alkaline aqueous solution is permeated into the molding material, the hardness of the molding material is greatly reduced, so that the molding material can be easily peeled off from a molded body such as a molding motor or a molding transformer. In other words, as described above, not only the unnecessary gate runner produced when molding using the molding material is performed, but also the material once formed can be isolated as the molding material, so that it can be easily recycled as the filler. Become.

The aliphatic polyester resin is easily decomposed in an alkaline aqueous solution, so that the permeability of the alkaline aqueous solution into a plastic molded article containing the unsaturated polyester resin to which the aliphatic polyester resin is added is improved. Since the hydrolysis of the unsaturated polyester resin itself is also promoted, the permeability of the alkaline aqueous solution is further improved. In addition, by increasing the treatment temperature with the aqueous solution, the penetration of the alkaline aqueous solution or water can be accelerated, and the treatment can be performed in a shorter time.

Hereinafter, the present invention will be described in more detail with reference to specific examples. (Example 1) In this example, unsaturated polyester resin (Epolac (Nippon Shokubai Co., Ltd.)), epoxy resin (EOCN (Nippon Kayaku Co., Ltd.)), phenol resin (Standlight (Hitachi Chemical Industry) (3) using 100% by weight of each resin with an average particle diameter of φ5.
Add 200 parts by weight of 0 μm calcium carbonate and 20 parts by weight of 20 mm long glass fiber, knead and harden, and add φ
A sample was molded using a cylindrical molding material having a height of 20 mm and a height of 20 mm.

The three types of columnar samples were immersed in a 5N aqueous solution of sodium hydroxide at 80 ° C. for 150 hours, then transferred to 25 ° C. water and immersed for 100 hours. The hardness of the plastic molded body at each point is measured using a rubber hardness tester (KOR
ISEIKI MFG. CO., LTD).
The results are shown in (Table 1).

[0036]

[Table 1]

From these results, it was found that the hardness of each sample after the alkali treatment was 97 degrees or more and hardly changed from that before the treatment, but after the further water treatment, the hardness was greatly reduced to 61 to 69 degrees. At this level of hardness, the compact has softened to the point where it can be scraped off by rubbing with an iron brush. Note that the degree of the hardness decrease was larger in the unsaturated polyester resin than in the epoxy resin and the phenol resin.

Further, with respect to both the samples after the alkali treatment and the water treatment, each of these samples was burned in an electric furnace at 600 ° C. for 2 hours while remaining almost wet. Was almost gasified, leaving calcium carbonate and glass fibers, as well as sodium salts and sodium oxide as alkaline substances. These were easily crushed by a tabletop mill, and after sufficiently washing with a water bath to remove sodium, the precipitated calcium carbonate and glass fiber were taken out and reused as a filler for the molding material.
This glass fiber was mixed and reused as calcium carbonate. However, it is recommended that the water treatment be performed since the residue after combustion has less alkali substances and the water can be easily washed.

Incidentally, sodium is recovered by the water washing, and the water after the water washing is distilled to be recovered as sodium hydroxide, or sodium hydroxide is further added to the water after the water washing containing sodium to form an alkaline aqueous solution. I was able to use it.

Further, alcohols such as methanol and ethanol can be used for washing sodium, and the alcohols can be volatilized after the washing to facilitate recovery of the sodium compound.

The effect of the water treatment in this embodiment is that the alkaline aqueous solution permeates the sample by the alkali immersion treatment, but the sample remains solid even if the treatment is continued. However, when immersed in water in a state where the alkaline aqueous solution has penetrated into the molded body, the water penetrates into the molded body to promote swelling, softening, cracking, and the like of the molded body, and may greatly reduce the hardness. it can. This is characterized in that it is easy to reduce the volume and to easily remove and remove the mold material even after curing with a small force.

Example 2 Using an unsaturated polyester resin (Epollac (Nippon Shokubai Co., Ltd.)) as a resin, styrene was added in a molar ratio of 3 times the amount of the unsaturated dibasic acid in Epolak. This mixture of Epolak and styrene 1
1 part by weight of Perbutyl Z (Nippon Oil & Fats Co., Ltd.) as a curing agent and 12 parts by weight of polystyrene as a low shrinkage agent were added to 00 parts by weight. With respect to 100 parts by weight of the mixed solution, 350 parts by weight of aluminum hydroxide having an average particle diameter of 20 μm and 3 parts of glass chopped strand were used as fillers.
0 parts by weight were added and kneaded, and the mixture was cured at 120 ° C. for 1 hour to obtain a cylindrical sample No. 1 of φ20 × height 20 mm.

In addition, polystyrene as a low-shrinking agent was replaced with an aliphatic polyester resin and polycaprolactone having a low shrinking effect, and the other components were the same as those described above in sample No. 2 (φ20). × height 20 mm).

After immersing these two types of columnar molded bodies in a 5N aqueous solution of sodium hydroxide at 80 ° C. for 170 hours, they were transferred to 25 ° C. water and immersed for 90 hours. The hardness of the sample at each time point was measured with a rubber hardness meter in the same manner as in (Example 2), and the results are shown in (Table 2).

[0045]

[Table 2]

After the alkali treatment, the hardness was 90 ° or more and both were still hard, but after further water treatment, the hardness was greatly reduced to 35 to 56 °. Especially hardness is 40
When the value is less than the value, the mold material is softened to such an extent that it can be scraped off not only by scraping with an iron brush but also with a toothbrush made of polypropylene. At this time, the inner copper coil is not damaged because it is rubbed off with a toothbrush. The magnitude of the decrease in hardness is smaller for the sample with the addition of the aliphatic polyester resin than for the sample with no addition.
No.2 was bigger.

Further, for each of the samples after the alkali treatment and further after the water treatment, each of these samples was burned in an electric furnace at 700 ° C. for 1.5 hours while being almost wet. Almost all of the resin was gasified, leaving aluminum oxide and glass fibers, as well as sodium salts and sodium oxide as alkaline substances. Therefore, the aluminum oxide and the glass fiber which had precipitated were able to be taken out after easily pulverizing with a tabletop mill and thoroughly washing with a water bath to remove the sodium, and then removing the sodium. In the present embodiment, since only aluminum hydroxide is used as a filler, it cannot be reused as a filler for the same molding material, but filling with a molding material containing a filler other than aluminum hydroxide such as calcium carbonate is used. Reused as an agent. At this time, the glass fibers were mixed and reused as calcium carbonate. Similar to the above-described embodiment, the water treatment has less alkali substances in the residue after combustion, and is easier to wash with water.
Recommended.

In the above embodiment, the sample was left standing while the sample was immersed in the alkaline aqueous solution and water by the mold material. However, the present invention is not limited to this method. Alternatively, the volume may be reduced with a brush in the liquid, and the removal and removal may be performed. Further, it is a matter of course that the permeability of the liquid and the disintegration of the molded body may be promoted by applying ultrasonic waves or pressure.

[0049]

As described above, according to the present invention, at least a part of the combustion residue obtained by burning a mold material containing at least a filler and a binder material for a predetermined time is used as a filler for another mold material. Also, even when the binder material contains a resin at least partially violated by the alkaline aqueous solution, after immersing the mold material in the alkaline aqueous solution, the alkali contained in the combustion residue obtained by further burning for a predetermined time is used. After the substance is removed with a cleaning agent, the substance can be used as a filler, and a new method for producing a filler can be provided, and the emission of dust can be significantly reduced.

Claims (3)

[Claims] 1. A method for producing a filler, in which a mold material containing at least a binder material and a filler is burned for a predetermined time, and at least a part of the generated combustion residue is used as a filler for another mold material. 2. A mold material containing a binder and a filler containing a resin that is at least partially violated by at least an alkaline aqueous solution is immersed in the alkaline aqueous solution for a predetermined time, and then burned for a predetermined time, and a generated combustion residue is removed. A method for producing a filler, wherein at least a part of a residue obtained by removing an alkali substance with a cleaning agent is used as a filler for another mold material. 3. The method for producing a filler according to claim 2, wherein an alkaline substance eluted in the cleaning agent is used as a part of the alkaline aqueous solution.