JPH08113619A - Thermosetting polyester resin, molded motor, resin-sealed semiconductor element and decomposition thermosetting polyester resin - Google Patents

Abstract

PURPOSE: To obtain a thermosetting polyester resin which can be easily decomposed when disposed of and to provide a method for decomposing the resin. CONSTITUTION: This resin is the one comprising an unsaturated polyester and styrene in an amount to give a molar ratio to the unsaturations of the polyester of 1.3-2.5 or comprises these two components and at least one member selected from between a polycaprolactonediol and a polycaprolactonetriol. To decompose this resin, it is immersed in a solution containing at least a base and a hydrophilic solvent. When a molded motor formed by using this resin as the molding resin or a semiconductor element sealed with this resin is disposed of, the inner valuables can be recovered by easily decomposing the resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting polyester resin, a molded motor using the resin, a resin-sealed semiconductor element, and a method for decomposing a thermosetting polyester resin.

[0002]

2. Description of the Prior Art Thermosetting polyester resins have a three-dimensional complex structure, unlike thermoplastic resins, which have a one-dimensional structure. Since their birth in the 1930s, they are related to construction and automobiles. , Has been used in a wide range of fields such as the electrical industry. It is often used as a composite material rather than being used as a resin alone, and fiber reinforced plastics and calcium carbonate, kaolin, aluminum hydroxide, talc, mica with reinforcing materials such as glass fiber, carbon fiber and organic fiber added. There is a particle dispersion type composite material in which a filler such as Applications of thermosetting polyester resins are broadly classified into laminated products and cast products. As laminated products, corrugated sheets, flat plates, flooring materials, wall materials, bathtubs, toilet tanks, water tanks, wash basins, etc. for construction-related products, yachts, boats, canoes, fishing boats, hydrofoil ships, etc. for ships, and automobiles for cars. Passenger cars, containers, sleepers, tanks, etc. for bodies, air spoilers, camping trailers, etc., radar domes, propellers, ailerons, gliders, etc. for aircraft, pipes, tanks, reaction tanks, etc. for mining and chemical industries. In the electrical industry, it is used for various insulating plates, printed circuit boards, switchboards, cases, motors, transformer seals, VTRs, audio products, etc., and others, such as chairs, desks, trunks, helmets, surfboards, and snowboards. As for cast products, artificial marble, tiles, doors, pipes, mortar concrete, etc. for civil engineering and construction, capacitors, coils, electrical equipment parts encapsulation, capacitors, joint terminal encapsulation, etc. for electrical and communication equipment, etc. Used for buttons, figurines, tableware, etc.

As a method for producing a thermosetting polyester resin, an unsaturated polyester composed of an unsaturated polybasic acid, a saturated polybasic acid, and glycols is dissolved, and a monomer or a polymerization inhibitor which also serves as a crosslinking agent, is promoted. Generally, a curing reaction is caused by adding an agent or the like. From the aspects of performance and cost, maleic anhydride and fumaric acid are often used as the unsaturated polybasic acid, phthalic anhydride, isophthalic acid, terephthalic acid, etc. are used as the saturated polybasic acid, and propylene is used as the glycols. Glycol, ethylene glycol, diethylene glycol and the like are used. It is common to use styrene as the monomer. Thermosetting polyester resin is a rubber-like elastic material,
A wide variety of products having a heat distortion temperature of 250 ° C or higher have been developed, and their physical properties can be widely changed. Detailed studies have been conducted on the composition and mechanical strength, electrical properties, chemical resistance, and water resistance of thermosetting polyester resins. In particular, in the research on chemical resistance and water resistance depending on the type and composition ratio of polybasic acid, glycols and monomers of thermosetting polyester, water resistance test with boiling water, solvent resistance test with organic solvent, sodium hydroxide Detailed examinations have been made on the alkali resistance test with an aqueous solution. However, there has been little research on the effects of solutions that combine these solutions,
At present, there is almost no research from the viewpoint of degradability.

[0004]

As described above, the thermosetting polyester resin is generally an insoluble and infusible resin because it has a complicated crosslinked three-dimensional structure due to the curing reaction. Therefore, it is difficult to disassemble and recycle it,
It is a resin that is difficult to reuse. However, recently, the problem of waste has been highlighted, and the reuse of various products (buildings, automobiles, electric appliances, etc.) has been required. In particular, unlike the case of metal, the recycling and recycling of resin is not technically established, and it is particularly difficult to recover and reuse the thermosetting polyester resin. Further, the thermosetting polyester resin is often used as a structural material, and in many cases, for example, is used as a molding material for a motor or a semiconductor encapsulating material, and contains metal or the like therein. Therefore, it is difficult to recycle and reuse useful internal parts and materials. Further, in order to reduce the volume of the thermosetting polyester resin, for example, a method of pulverizing the thermosetting polyester resin as it is can be considered, but pulverization requires a large amount of energy because of its strength.

In view of the above, an object of the present invention is to provide a thermosetting polyester resin which can be easily treated at the time of disposal. Another object of the present invention is to provide a molded motor and a resin-sealed semiconductor element using such a thermosetting polyester resin. Another object of the present invention is to provide a method for decomposing a thermosetting polyester resin.

[0006]

The thermosetting polyester resin of the present invention has a molar ratio of 1.3 to 2. to the unsaturated polyester and the unsaturated groups in the unsaturated polyester.
Consists of 5 times styrene. Here, it is preferable to contain at least one of polycaprolactone diol and polycaprolactone triol. In the molded motor of the present invention, the molding material containing the thermosetting polyester resin is molded in direct contact with at least a part of the iron core or the winding to form the outer shell of the motor.

In the resin-encapsulated semiconductor element of the present invention, the encapsulating material containing the thermosetting polyester resin is brought into direct contact with at least a part of the semiconductor element, the lead wire and the bonding wire to form the semiconductor element. Is sealed. The method for decomposing a thermosetting polyester resin of the present invention is a thermosetting polyester containing an unsaturated polyester and styrene in a molar ratio of 1.3 to 2.5 times the unsaturated group in the unsaturated polyester. The resin is immersed in a decomposition solution containing at least a base and a hydrophilic solvent.

[0008]

The thermosetting polyester resin of the present invention has a sufficient three-dimensional skeleton because the amount of styrene added is 1.3 to 2.5 times the molar ratio of unsaturated groups in the unsaturated polyester. It is possible and has the same physical property value as a general thermosetting polyester resin. Moreover, this thermosetting polyester resin has high permeability to a decomposition solution containing at least a base and a hydrophilic solvent, and easily solvolytically decomposes the ester portion of the thermosetting polyester resin skeleton, resulting in waste after use. In this case, the ester solution can be rapidly decomposed with the above decomposition solution to disintegrate the three-dimensional structure and facilitate disposal. The thermosetting polyester resin containing at least one of polycaprolactone diol and polycaprolactone triol is
The polycaprolactone diol and the polycaprolactone triol further improve the permeability of the decomposition solution, and the ester portion of these is also solvolytically decomposed, so that the decomposition solution further permeates. Therefore, the solvolysis of the ester portion in the thermosetting polyester resin skeleton also rapidly progresses, the three-dimensional structure of the resin collapses, and the disposal can be easily performed in a shorter time.

Further, in the molded motor using the molding material containing the thermosetting polyester resin, after the use, the resin portion is disintegrated by the decomposition solution so that the valuable materials inside (iron core, winding, etc.) can be easily obtained. It is possible to provide a molded motor that can be taken out and is easily reused. Further, the resin-encapsulated semiconductor element using the encapsulating material containing the thermosetting polyester resin, the same as in the case of the molded motor, it is of course that the internal semiconductor element and lead wire, the bonding wire can be easily taken out and reused, If the semiconductor device is a harmful substance, such as GaAs, which is not desirable to discard as it is, the harmful substance inside can be taken out by solvolysis of the encapsulant with a decomposition solution. It is possible to provide a resin-sealed semiconductor element that can be easily removed.

[0010]

EXAMPLES As the unsaturated polyester used in the present invention, any unsaturated polyester composed of an unsaturated polybasic acid, a saturated polybasic acid and glycols as a main raw material can be used. Examples of the unsaturated polybasic acid include maleic anhydride, fumaric acid, itaconic acid and the like. Examples of the saturated polybasic acid include phthalic anhydride, isophthalic acid,
Terephthalic acid, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride, adipic acid,
Sebacic acid etc. are mentioned. Examples of glycols include propylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, dibromoneopentyl glycol,
1,3-butanediol, 1,4-butanediol, hydrogenated bisphenol A and the like can be mentioned.

The monomer serving as the crosslinking agent used in the present invention is styrene, and it is preferable to add it in a molar ratio of 1.3 to 2.5 times that of the unsaturated polybasic acid. Molar ratio 1.
If it is less than 3, the amount of unreacted unsaturated polybasic acid increases and the strength of the resin decreases. Also, when the molar ratio exceeds 2.5,
Permeability of the decomposition solution decreases and sufficient decomposition cannot be obtained. Further, it is more preferable to add 1.9 to 2.3 times in terms of mechanical properties and decomposition treatment. The general structure of the polycaprolactone diol used in the present invention is shown in the following formula (1), and the general structure of the polycaprolactone triol is shown in the formula (2).

[0012]

Embedded image

Note that l, m in the equations (1) and (2),
n represents an integer of 1 or more. Further, M ₁ represents a group represented by the formula (3), for example. Here, p and q are integers and R ₁ , R ₂ and R ₃ are aliphatic alkylene groups. Examples of R ₁ , R ₂ and R ₃ include aliphatic alkylene groups such as methylene group, ethylene group, propylene group, butylene group, pentyl group and hexyl group. p = q =
In the case of 0, M ₁ = R ₁ is obtained, which is a simple aliphatic alkylene having no ether bond or ester bond. Also,
If p or q is 2 or more, there will be 2 or more R
₂ and R ₃ may be the same aliphatic alkylene or different aliphatic alkylene. Further, M ₁ may of course be a group having an ether bond and an ester bond in random order. M ₂ represents a group represented by the formula (4), for example. Here, p and q are integers and R ₁ , R ₂ and R ₃ are aliphatic alkylene groups. Examples of R ₁ , R ₂ and R ₃ include aliphatic alkylene groups such as methylene group, ethylene group, propylene group, butylene group, pentyl group and hexyl group. However, the end of R ₁ has three bonding hands. When p and q are 2 or more, two or more R ₂ and R _{3 which} are present may be the same aliphatic alkylene or different aliphatic alkylenes. Also, the order of the ether bond and the ester bond in M ₂ may be different from the formula (4). Furthermore, in equation (4), R
₁ termini have three bonds hand, although linked polycaprolactone via O, 1 in R ₂ and R ₃
One may have three bonding hands and be bonded to polycaprolactone via O.

[0014]

Embedded image

Those containing a neopentyl group as R ₁ , R ₂ and R ₃ have high solubility in styrene and increase the compatibility of the unsaturated polyester resin with polycaprolactone diol or polycaprolactone triol. Since a large amount of polycaprolactone diol or polycaprolactone triol can be mixed in the thermosetting polyester resin and the dispersibility is good, high degradability can be obtained, which is preferable.

When the thermosetting polyester resin of the present invention is used as a composite material, additives such as those mentioned above, such as glass fiber, are added to the thermosetting polyester resin.
Reinforcing materials such as carbon fibers and organic fibers and fillers such as calcium carbonate, kaolin, aluminum hydroxide, talc and mica can be mixed. When the thermosetting polyester resin of the present invention is used as a molding material for a molded motor, a filler, a reinforcing material, a curing agent, a coloring agent, a thickener,
In many cases, a release agent or the like is mixed and used, and since the filler is contained in the largest amount, the characteristics of the molding material are greatly affected. As the filler, for example, calcium carbonate, calcium silicate, magnesium carbonate, barium sulfate, calcium sulfate, kaolin, aluminum hydroxide,
Examples thereof include talc, mica, diatomaceous earth, glass balls, silica gel and the like. As the reinforcing material, glass fiber is mainly used, but other than that, polyacrylonitrile-based or rayon-based or pitch-based carbon fiber, vinylon,
Organic fibers such as polypropylene, polyester and aramid fibers can also be used. Examples of the curing agent include t-butyl peroctoate, benzoyl peroxide, t-butyl perbenzoate, and 2,2-bis (t-butyl peroxy).
Examples include butane and 3,3,5-trimethyl (t-butylperoxy) cyclohexane. As a colorant,
For example, carbon black and the like can be mentioned. Examples of the thickener include magnesium oxide, magnesium hydroxide, calcium hydroxide, polyvalent isocyanate compounds and the like. Examples of the release agent include zinc stearate and the like. Further, also when using the thermosetting polyester resin of the present invention as a sealing material for a resin-sealed semiconductor element, as in the case of using as a molding material, a filler, a reinforcing material, a curing agent, a coloring agent, a thickener, A release agent is often mixed and used. The examples of these contaminants are the same as the case of the above-mentioned molding material.

The decomposition solution used in the present invention contains at least a base and a hydrophilic solvent. Examples of the base include sodium hydroxide, potassium hydroxide, barium hydroxide, sodium ethoxide, potassium butoxide and the like. Further, examples of the hydrophilic solvent include methanol, ethanol, propanol, acetone, tetrahydrofuran, dimethylformamide, ethylene glycol, diethylene glycol diethyl ether, dimethylamine and the like. Note that not only these single components but also a plurality of them may be contained.

The present invention will be described in more detail below with reference to specific examples. [Example 1] Mixing of unsaturated polyester (Epolac manufactured by Nippon Shokubai Co., Ltd.) and a cross-linking agent styrene in a molar ratio of 1.3 to 4.0 times with respect to the unsaturated dibasic acid in the unsaturated polyester. To 100 parts by weight of the liquid, 1 part by weight of a curing agent (Perbutyl Z of NOF CORPORATION) was added, and the temperature was 120 ° C.
After curing for 1 hour, several kinds of thermosetting polyester resins having different styrene contents were obtained. The obtained resin was cut into a size of 10 × 20 × 1 mm, and sodium hydroxide 1.
After immersing in a decomposition solution obtained by mixing 1 g, 21.0 g of ethanol and 6.0 g of water and stirring for 200 hours at room temperature,
The resin was taken out, the weight after drying was measured, and the change in weight and the change in appearance were observed. Table 1 shows the tensile strength of each sample before decomposition, the weight change after decomposition, the change in appearance, and the like.

[0019]

[Table 1]

As is clear from the results shown in Table 1, there is almost no difference in the tensile strength before decomposition depending on the styrene content ratio, and any styrene content ratio can be similarly used.
When immersed in a decomposition solution and decomposed, the styrene content ratio is 2.5.
In the following, it can be seen that minute cracks are generated on the resin surface and the weight is greatly reduced, and the solvent addition or hydrolysis of the resin is progressing. By controlling the styrene content ratio in this way, it is possible to change only the decomposability with respect to the decomposition solution containing the base and the hydrophilic solvent without changing the mechanical strength of the resin. As a comparative example, a sample having a styrene content ratio of 1.3 was immersed in a decomposition solution in which 1.1 g of sodium hydroxide and 27.0 g of water were mixed for 200 hours.
In that case, the weight change was 0%, and the weight change was 0% even when immersed in ethanol only. From this, it can be seen that even a sample having a small styrene content ratio does not change in alkali resistance and solvent resistance and can be used similarly to the conventional thermosetting polyester resin.

[Example 2] 100 parts by weight of a mixture of unsaturated polyester (Epolac manufactured by Nippon Shokubai Co., Ltd.) and styrene in a molar ratio of 1.9 times the unsaturated dibasic acid in the unsaturated polyester. In contrast, 1 part by weight of a curing agent (Perbutyl Z manufactured by NOF CORPORATION) was added, and 50 to 300 parts by weight of calcium carbonate was further added as a filler, followed by curing at 120 ° C. for 1 hour to give a calcium carbonate content. Several kinds of filler-mixed resins of different types were obtained. The obtained resin was cut into a size of 10 × 20 × 1 mm, and sodium hydroxide 1.1 g, ethanol 21.0 g and water 6.0 g were cut.
After immersing in the decomposition solution in which was mixed and stirring at room temperature for 200 hours, the resin was taken out and the weight after drying was measured, and the change in weight and the change in appearance were observed. Table 2 shows the changes in weight and appearance of each sample after decomposition.

[0022]

[Table 2]

From the results shown in Table 2, even when calcium carbonate is mixed, weight loss is observed when immersed in the decomposition solution, and the amount of decrease is smaller as the amount of calcium carbonate mixed is larger. However, the weight change with respect to the amount of thermosetting polyester resin of each sample does not depend on the amount of calcium carbonate mixed.
At 0%, there was almost no difference. This value is about the same as in the case of a resin containing no calcium carbonate (Example 1), and it can be seen that calcium carbonate has almost no effect on degradability. From this, even when a filler or fiber is mixed as the composite material, the same decomposability of the resin portion as in the case of only the resin can be obtained, so that the resin material can be easily disintegrated and treated. Further, even when it is used as a molding material or a sealing material, it is possible to easily take out valuable materials inside or remove harmful materials. An example of using it as a molding material or a sealing material will be described in Examples below Example 5.

Example 3 Unsaturated polyester (Epolak manufactured by Nippon Shokubai Co., Ltd.) was mixed with 1.3 to 4.0 times the amount of styrene by molar ratio with respect to the unsaturated dibasic acid in the unsaturated polyester. 12 w of polycaprolactone diol in which M ₁ in the formula (1) is represented by the formula (5).
t% was added. To 100 parts by weight of this mixed solution, 1 part by weight of a curing agent (Perbutyl Z of NOF CORPORATION) was added, and the mixture was cured at 120 ° C. for 1 hour, and several types of heat curing with different styrene contents were performed. A transparent polyester resin was obtained. The obtained resin was transparent at a styrene content ratio of 2.5 or less, but was slightly cloudy at a styrene content ratio of 2.8, and was considerably cloudy at a styrene content ratio of 4.0. When the styrene content ratio was 2.5 or less, the tensile strength was similar to that of the resin in which polycaprolactone diol was not mixed, but when the styrene content ratio was 2.8 or 4.0, the strength was slightly reduced.

[0025]

Embedded image

The resin thus obtained has a size of 10 × 20 × 1 mm.
Cut into 1.1 g of sodium hydroxide and 2 parts of ethanol
After immersing in a decomposition solution in which 1.0 g and 6.0 g of water were mixed and stirring for 200 hours at room temperature, the resin was taken out, the weight after drying was measured, and the change in weight and the change in appearance were observed. Table 3 shows the changes in weight and appearance of each sample after decomposition. From the results in Table 3, when the styrene content ratio was 2.5 or less, the weight was drastically reduced, and the phenomenon that the resin collapsed into pieces in the decomposition solution was observed. When the styrene content ratio is larger than that, the weight reduction is observed only in the amount of polycaprolactone diol mixed (12%), and it is understood that the decomposition of the unsaturated polyester resin portion hardly occurs.
Further, when the styrene content ratio is 1.3 or 1.9, a greater weight reduction than the combined weight reduction of the resin shown in Example 1 and the amount of polycaprolactone diol added is observed.
It can be seen that the addition of polycaprolactone diol also promotes the decomposition of the unsaturated polyester resin.

[0027]

[Table 3]

Example 4 To an unsaturated polyester (Epolac manufactured by Nippon Shokubai Co., Ltd.), 1.9 times the molar amount of styrene was added to the unsaturated dibasic acid in the unsaturated polyester. 12 wt% of the same polycaprolactone diol as in Example 3 was added. To 100 parts by weight of this mixed solution mixed solution, 1 part by weight of a curing agent (Perbutyl Z of NOF CORPORATION) was added, and further 50 to 300 parts by weight of calcium carbonate was added as a filler, followed by 120 ° C. for 1 hour. Upon curing, several types of filler mixed resins with different calcium carbonate contents were obtained. The size of the obtained resin is 10 × 2
It was cut into 0 × 1 mm, immersed in a decomposition solution in which 1.1 g of sodium hydroxide, 21.0 g of ethanol and 6.0 g of water were mixed and stirred for 200 hours at room temperature, then, the resin was taken out and the weight after drying was measured. It was measured and observed for weight change and appearance change. Table 4 shows the changes in weight and appearance of each sample after decomposition. From the results in Table 4, as in Example 2, the amount of weight loss decreases as the amount of calcium carbonate mixed increases, but the weight change with respect to the thermosetting polyester resin amount of each sample does not depend on the amount of calcium carbonate mixed, and in any case. 40
%, There was almost no difference. This value is about the same as in the case of a resin containing no calcium carbonate (Example 3), and it can be seen that calcium carbonate has almost no effect on degradability.

[0029]

[Table 4]

[Example 5] A molded motor was prepared by using a resin obtained by mixing 100 parts by weight of calcium carbonate and 15 parts by weight of glass fiber with the resin of Example 1 as a molding material. The schematic sectional view is shown in FIG. A shaft 4 of a rotor 3 is rotatably supported by a bearing 2 provided on a bracket 1. A stator winding 6 made of an enamel-coated copper wire is wound around a silicon steel plate of a stator iron core 5 arranged so as to surround the rotor 3 with a space. The stator core 5, the stator winding 6, and the bracket 1 were in contact with each other and the molding material was molded to form an outer shell 7 of the motor. Reference numeral 8 is a mounting hole. This mold motor was immersed in a decomposition solution at room temperature for 500 hours to examine its decomposability. The thickness of the mold was about 1 mm at the thin portion and about 5 mm at the thick portion, and the same decomposition solution as in Example 1 was used as the decomposition solution. Table 5 shows the state changes of each sample after decomposition.

[0031]

[Table 5]

When the styrene content ratio was 1.3 to 2.3, the mold in the thin portion was rather shabby and could be easily peeled off by hand. Further, even the thick portion was peeled and cracked on the surface, and the inside was softened like a rubber, so that it could be peeled by hand. In the case where the styrene content ratio was 2.5, there were several parts where the decomposition liquid had not penetrated into the thick part of the mold, and these parts could not be peeled off by hand. However, by lengthening the decomposition time or increasing the penetration of the decomposition liquid by applying ultrasonic waves, the remaining portion can be removed by hand. When the styrene content ratio was 2.8 and 4.0, there was no change. As described above, the mold motor of the present invention using the mold material in which the styrene content ratio is controlled to 1.3 to 2.5 can be easily decomposed at room temperature with a decomposition solution containing a base and a hydrophilic solvent. Valuable materials in the motor can be easily taken out.

[Embodiment 6] A resin obtained by mixing 8 parts by weight of glass fiber with the resin of Embodiment 2 is used as a molding material, and Embodiment 5 is used.
A molded motor similar to the above was created. This mold motor was immersed in a decomposition solution at room temperature for 500 hours to examine its decomposability. The same decomposition solution as in Example 2 was used as the decomposition solution. Table 6 shows the state changes of each sample after decomposition. In the case of the resin containing 50 parts by weight of calcium carbonate and 100 parts by weight of calcium carbonate, the mold in the thin portion could be easily peeled off by hand, and the thick portion could be peeled off by hand because it was softened like rubber. Calcium carbonate 200 and 30
In the case of the resin mixed with 0 parts by weight, the mold in the thick portion was slightly harder than in the case of the resin mixed with 50 parts by weight of calcium carbonate and 100 parts by weight, but it could be peeled off by hand. Thus, sufficient decomposability can be obtained even if the calcium carbonate content is changed, and valuable materials such as the iron core and windings of the molded motor can be easily taken out.

[0034]

[Table 6]

[Embodiment 7] A mold motor similar to that of Embodiment 5 was prepared by using a resin obtained by mixing 100 parts by weight of calcium carbonate and 15 parts by weight of glass fiber with the resin of Example 3 as a molding material. This mold motor was immersed in a decomposition solution at room temperature for 300 hours, and its decomposability was examined. As the decomposition solution, the same decomposition solution as in Example 3 was used. Table 7 shows the state changes of the samples after decomposition. When the styrene content ratio is 1.3 to 2.5, most of the thin part of the mold peels off spontaneously in the decomposition solution, the thick part also peels off at several points on the surface, large cracks occur, and the inside is Since it had softened into a rubber, it could be peeled off by hand. In the case of the styrene content ratios of 2.8 and 4.0, some cracks were generated on the surface, and some molds on the surface could be peeled off by hand, but most molds could not be peeled off. Despite the shorter decomposition time of 300 hours as compared with Example 5, all the samples obtained a higher decomposability than Example 5. It is considered that this is due to the improvement of the permeability of the decomposition solution due to the incorporation of polycaprolactone diol.

[0036]

[Table 7]

[Embodiment 8] A resin obtained by mixing 8 parts by weight of glass fiber with the resin of Embodiment 4 is used as a molding material, and Embodiment 5 is used.
A mold motor similar to the above was prepared and immersed in a decomposition solution at room temperature for 300 hours to examine its decomposability. The same decomposition solution as in Example 4 was used as the decomposition solution. Table 8 shows the state changes of the samples after decomposition. In all the samples, the mold was rubber-like and was totally shabby, and could be easily peeled off by hand. Especially in the case of adding 50 and 100 parts by weight of calcium carbonate,
Even if it was not peeled off by hand, there was a part that peeled off naturally in the decomposition solution, and it had high decomposability. Compared to Example 6,
Despite the short decomposition time of 300 hours, polycaprolactone diol was mixed in, so that all samples were tested in Example 6.
Greater degradability was obtained.

[0038]

[Table 8]

Example 9 In place of the calcium carbonate of Example 2, 250 parts by weight of silica and 8 glass fibers were used.
A resin-encapsulated IC was prepared using the resin added by weight.
The schematic diagram is shown in FIG. The semiconductor element 10, the wire 11, and the lead wire 12 were sealed with the sealing resin 13. The resin-encapsulated IC was immersed in a decomposition solution at room temperature for 200 hours to examine its decomposability. The thickness of the mold is about 1
The same decomposition solution as in Example 2 was used as the decomposition solution. After dipping for 200 hours, cracks were generated on the surface of the sealing resin and peeling of minute pieces was observed. Further, the sealing resin became rubbery and could be easily peeled off by hand. Therefore, the gold wire inside could be easily recovered, and the harmful GaAs element could be removed.

[Embodiment 10] As the encapsulating material for the resin-encapsulated IC of Embodiment 9, a resin in which 250 parts by weight of silica and 8 parts by weight of glass fiber are added in place of the calcium carbonate of Example 4 is used. A resin sealed IC was created. The resin encapsulation I
C was immersed in the decomposition solution at room temperature for 200 hours to examine the decomposability. The same decomposition solution as in Example 4 was used as the decomposition solution. After dipping for 200 hours, cracks and peeling were observed in several places of the sealing resin, and the sealing resin naturally peeled in the decomposition solution without being peeled by hand. Therefore, the wires and elements inside could be taken out more easily than in Example 9.

Example 11 An experiment was conducted under the same conditions except that the polycaprolactone diol of Example 3 was changed to the polycaprolactone triol represented by the formula (6) in which M ₂ of the formula (2) was changed. The state and decomposability of the obtained resin were almost the same as those when polycaprolactone diol was mixed in, and when the styrene content ratio was 2.5 or less, the weight was drastically reduced and the decomposability was high (maximum weight change rate-38.6% ( The ratio of styrene was 1.3)).

[0042]

[Chemical 4]

[Example 12] The amount of polycaprolactone diol mixed in the resin of Example 3 was set to 6% by weight, and the same polycaprolactone triol as in Example 11 was added to 6% by weight.
% Mixed resin was prepared. Although those resins were transparent when the styrene content ratio was 2.5 or less, the styrene content ratio was 2.
In the case of No. 8, the resin was a little cloudy, and at a styrene content ratio of 4.0, it was a cloudy resin. As a result of decomposing these resins under the same conditions as in Example 3, the state and degradability of the obtained resin were 12% by weight of Example 3 and 12% by weight of polycaprolactonetriol mixed with 12% by weight of polycaprolactone diol.
Almost the same result as in the case of the mixed Example 11 was obtained, and when the styrene content ratio was 2.5 or less, the weight was drastically reduced and high degradability (maximum weight change rate-40.2% (when styrene content ratio was 1.3)). showed that.

In the above examples, a mixed solution containing sodium hydroxide, ethanol and water was used as the decomposition solution, but it is not limited to this mixed solution, and at least a base and a hydrophilic solvent are contained. Any mixed solution can be used. Further, in the above examples, as the unsaturated polyester, one made of fumaric acid, phthalic acid, and propylene glycol was used. However, the unsaturated polyester is not limited to the unsaturated polyester and is generally used as described above. Any unsaturated polyester composed of saturated polybasic acid, saturated polybasic acid and glycols may be used. Further, the molded motor and the resin-sealed semiconductor element are not limited to the configurations described in the above embodiments. For example, a resin coated on the surface of a molding resin or a sealing resin for the purpose of increasing the moisture resistance, a resin having different decomposability and molded or sealed in double or more, a resin having no solvolysis May be a molded motor or resin-sealed semiconductor element having a structure in which the thermosetting polyester resin of the present invention is dispersed and molded or sealed.

[0045]

As described above, according to the present invention, by controlling the styrene content of the thermosetting polyester resin to a low level, the decomposition solution containing at least the base and the hydrophilic solvent easily penetrates into the resin, so that Provided is a thermosetting polyester resin which easily decomposes and disintegrates. Further, at least one of polycaprolactone diol and polycaprolactone triol is added to the thermosetting polyester resin.
By mixing the types, it is possible to further improve the decomposability of the resin, and it is possible to easily perform the processing after discarding the resin, the mold motor, and the resin-sealed semiconductor element. Furthermore, since the decomposition treatment method of the present invention allows the resin to be decomposed easily at room temperature, it is also effective in saving energy, and since a decomposition solution containing at least a base and a hydrophilic solvent is used, the molded motor and the resin-sealed semiconductor Valuables in the element,
For example, they can be taken out without significantly affecting the metal.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a schematic configuration of a molded motor according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing a schematic configuration of a resin-sealed IC according to an embodiment of the present invention.

[Explanation of symbols]

 1 Bracket 2 Bearing 3 Rotor 4 Rotor shaft 5 Stator iron core 6 Stator winding 7 Mold resin 8 Mounting hole 10 Semiconductor element 11 Wire 12 Lead wire 13 Sealing resin

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08L 67/06 MSJ H01L 23/29 23/31 H02K 5/08 A 15/12 E // (C08L 67/06 67:04)

Claims (5)

[Claims] 1. The unsaturated polyester and the unsaturated groups in the unsaturated polyester are in a molar ratio of 1.3 to 2.
Thermosetting polyester resin consisting of 5 times styrene. 2. The thermosetting polyester resin according to claim 1, containing at least one of polycaprolactone diol and polycaprolactone triol. 3. A mold forming the outer shell of a motor by molding the molding material containing the thermosetting polyester resin according to claim 1 or 2 in direct contact with at least a part of an iron core or a winding. motor. 4. The encapsulating material containing the thermosetting polyester resin according to claim 1 or 2 is in direct contact with at least a part of a semiconductor element, a lead wire and a bonding wire to encapsulate the semiconductor element. Resin-sealed semiconductor device. 5. The unsaturated polyester and the unsaturated groups in the unsaturated polyester are in a molar ratio of 1.3 to 2.
Thermosetting polyester resin containing 5 times the amount of styrene,
A method for decomposing a thermosetting polyester resin, which comprises immersing in a decomposition solution containing at least a base and a hydrophilic solvent.