JPH0739546B2 - Polyphenylene sulfide resin composition for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a molding polyphenylene sulfide (hereinafter abbreviated as PPS) resin composition in which corrosion of a mold during molding and corrosion of a metal of an insert molded product are reduced. It is about things.

<Problems to be solved by conventional techniques and inventions> PPS resin has excellent heat resistance and chemical resistance, and also has good dimensional stability, mechanical strength, electrical characteristics, and moldability. In recent years, it has been used in various fields as high-performance engineering plastics.

However, PPS resin generates a considerable amount of metal corrosive gas at high temperatures, so it corrodes molds and molding machines during molding, and corrodes if the molded product is aged above 100 ° C and below its melting point. There is a problem that a corrosive gas is generated and the insert metal parts are corroded. For example, troubles such as poor contact of the connector contact portion and poor solder adhesion of the insert metal portion have occurred.
In particular, when it is used as a sealing material for electronic parts, which has recently been drawing attention, a low molecular weight polymer is used as the PPS resin, so corrosive gases such as sulfurous acid gas and hydrogen sulfide are easily generated, and the reliability of electronic parts is improved. As a result, the sex is deteriorated.

Conventionally, in order to prevent adverse effects due to the generation of corrosive gas, a hydroxide or carbonate of an alkali metal (USP4,017,450) and an ammonia precursor having a carbon number of 0 to 8 (USP
4,115,344) and zinc oxide (JP-A-59-181408) have been tried to be added, but since sufficient effects cannot be obtained, their use as molding materials and molded products is currently limited. .

In view of the above situation, the present inventors have conducted extensive studies to prevent the adverse effect of corrosive gas generation of molded products, and as a result, PPS
The inventors have found that the addition of γ-alumina to a resin is effective, and have reached the present invention.

That is, the present invention provides a PPS resin composition for molding, which is characterized by adding 0.05 to 200 parts by weight of γ-alumina to 100 parts by weight of PPS resin, and a molded article using the same. .

The PPS resin of the present invention has the general formula It is possible to use an uncrosslinked polymer, a polymer crosslinked with oxygen, sulfur, or a trifunctional monomer, or a mixture thereof, which has a repeating unit of 70 mol% or more. Although the melt flow rate of the PPS resin can be selected at any level, it is the melt flow rate measured by ASTM D-1238-74 (315.6 ° C, 5 kg load) for injection molding and extrusion molding applications. A range of about 1,000 to 1 is common. 10,000 when used as a sealing material for electronic parts
A melt flow rate of ~ 500 (preferably 10,000-1,000) is suitable.

The γ-alumina in the present invention means an intermediate alumina or anhydrous alumina, for example, ρ · χ · η.
-Alumina having a crystal structure such as δ / θ / κ type can be used. One of the characteristics of γ-alumina is that it has a very large specific surface area as compared with α-alumina and hydrated alumina, and yet another characteristic is that the crystals are divided into extremely small pieces, and the structure is unstructured. It means that the organization is in a disordered state. It is speculated that due to the characteristics of γ-alumina, the gas adsorption capacity is greatly increased, and a remarkable effect is exhibited in the reduction of corrosive gas which is the object of the present invention.

When various types of hydrated alumina are baked at high temperature, they pass through γ-alumina and finally α-alumina (generally, alumina is α-alumina.
Referred to as alumina. ), This γ-alumina usually contains a small amount of water. The moisture content of γ-alumina in the present invention is not particularly limited, but substantially 40%.
It can be used as long as no weight loss is observed by heating at 0 ° C. Any particle size of γ-alumina can be used, but usually 0.2 to 500 μm, preferably 1 to 300
The range of μm is suitable. If the particle size is too large, the effect of reducing corrosive gas is insufficient, or if the surface roughness is too small, on the other hand, if the particle size is too small, scattering of the raw material powder or biting during extrusion kneading becomes worse or composition Inconveniences such as increased viscosity tend to occur. The specific surface area of γ-alumina in the present invention is usually 3 m ² / g or more, preferably 10 m ² / g or more, from the viewpoint of the effect of reducing corrosive gas.

The r-alumina of the composition of the present invention is added in an amount of 0.05 to 200 parts by weight, preferably 0.2 to 80 parts by weight, based on 100 parts by weight of the PPS resin. If the added amount is too small, the effect of reducing the corrosive gas becomes poor, and conversely, if the added amount is too large, the melt flow during molding tends to deteriorate.

Various fillers can be added to the composition of the present invention in order to improve mechanical properties.

As the filler that can be used in the present invention, glass fiber, asbestos fiber, silica fiber, silica-alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber,
Fibrous fillers such as silicon nitride fibers, boron fibers, silicon carbide whiskers, potassium titanate whiskers, calcium silicate fibers, wollastonite stone fibers, polyamide fibers and phenol fibers, silica, talc, gray,
Fillers such as mica, glass, calcium silicate, montmorillonite, bentonite, etc., or fillers of calcium carbonate, calcium sulfate, barium sulfate, etc., commercially available natural products, purified products, crushed products of synthetic products, spherical and hollow Things can be used.

The fibrous filler may be of any diameter and length, and the preferred addition amount is 1 per 100 parts by weight of PPS resin.
~ 250 parts by weight.

Among the above-mentioned fillers, silica is particularly suitable for the composition for sealing electronic parts in terms of purity, and is 1 to 100 parts by weight of PPS resin.
250 parts by weight are used, and various sizes (0.1 μ to 100 μ) of fibrous, unstable, spherical and hollow, and amorphous, crystalline or a mixture thereof are used.

Further, these fillers may be treated with a sizing agent or a coupling agent without any problem.

Further, within a range that does not impair the object of the present invention, an antioxidant,
Additives such as a heat stabilizer, a lubricant, a crystal engraving agent, a colorant, an ultraviolet absorber, a fluidity improver and a coupling agent can be added. For example, one or more silane coupling agents such as mercaptosilane, vinylsilane, aminosilane, epoxysilane, and halosilane may be added to improve various physical properties such as moisture resistance, strength, and fluidity during melting.

Furthermore, in the composition of the present invention, various thermosetting resins,
A small amount of thermoplastic resin such as epoxy resin, silicone resin, polyester resin, phenol resin, polybutadiene, diallyl phthalate resin, nylon, polycarbonate, polysulfone, polyphenylene oxide, hydrogenated styrene butadiene rubber can be added.

As a method for preparing the PPS resin composition of the present invention, a mixture of PPS resin, γ-alumina and, if necessary, a filler and an additive is mixed with a Henschel mixer, a V-blender or the like and then directly used. Alternatively, a method of kneading and granulating with an extruder or the like, a method of melting and kneading with a Banbury mixer, a single-screw or multi-screw extruder, a kneader, or the like, or a method of molding can be employed.

Further, the molded product of the present invention can be obtained by a known molding method such as injection, extrusion, transfer or compression molding using the above composition. Examples of the molded product of the present invention include a bracket (electric meter), a coil bobbin, a color collector foam (TV component), a shaft (TV tuner), a magnetic sensor head (tape recorder), a roller bracket (computer facsimile), a solid state relay, Frame, socket, heat insulator (hair dryer grill), capacitor housing, heater drum (disk attached to both ends of heating roller of computer facsimile), rotating gear and fan shaft (microwave oven) headphone case, insulation pillar, knob (electronic) Range), screen (hair dryer grill), condenser, micro switch, resistor, resistor network, motor drum, brush holderー, Fuse holder, Contact breaker, Chip carrier, Transistor, Diode, Triode, Thyristor, Varistor, Converter, Crystal oscillator,
Rectifier, power supply IC parts, LSI, hybrid IC, electric / electronic parts such as TTL, knob (rice cooker valve), gear (copier, gear pump), heater cover (copier), mechanical sealing and gland, tower packing, pump Mechanical devices such as housing (oil pump), insulator (automatic chain saw), heat insulator, housing (magnet lock), pump impeller, valve, flow meter, level gauge pulley, hook, flange, spray nozzle, pipe bracket, meter, fan, etc. Parts, Tie rod end stabilizer, Exhaust gas circulation modulator, Battery housing, Orifice (gasoline pump), Seat reed valve (carburetor), Ignition system housing, Motor brush holder, Or Tanator terminal block, connector, vaporizer, tistributor part, radiator part, tie rod end stabilizer, reflector, brake part, clutch part, temperature sensor, transmission part, oil pump, igniter case, alternator socket and other automotive parts, tachometer Housing, insulator (level gauge),
Joint (gas meter), camera, gear, clock,
Precision parts such as measuring instruments and computer parts are included.

In addition to the above, extruded products such as tubes, films and fibers are exemplified.

Examples of the encapsulated electric / electronic component of the present invention include capacitors, resistors, resistor networks, integrated circuits, transistors, diodes, triodes, thyristors, coils, varistors, connectors, capacitors,
Transducers, crystal oscillators (crystal oscilla)
tors), fuses, rectifiers, power supplies, and microswitches.

The definitions of each of the electronic components described above also mean a broad sense and a broad sense. For example, the term integrated circuit includes, but is not limited to, a large scale integrated circuit, TTL [transistor-transistor logic circuit (logi
c)], hybrid integrated circuit
s), linear amplifiers, operational amplifiers, instrumentation amplifiers, isolation amplifiers, multipliers and dividers.
s), log / anti log amplifier
s), RMS-DC converters, voltage reference converters, conditioners, instrumentation, digital-to-analog converters
nvertors), analog-to-digital co
nvertors), Voltage / frequency converter
s), synchro-digital converter (Cynchro-digital conve
rtors), sample / truck-hold amplifier (sample / truck-ho
ld amplifiers), CMOS switches and multiplexers
d multiplexers), data acquisition subsystem
s), power supplies, memory integrated circuits, microprocessors, etc.

<Effects of the Invention> The PPS resin composition obtained in the present invention has the effect of preventing adverse effects due to the generation of corrosive gas, so that the molding cost during injection molding, extrusion molding, compression molding, and the maintenance cost of the molding machine. Can be reduced. Further, various molded products molded with the PPS resin composition of the present invention, the generation of corrosive gas is suppressed, so that the failure rate such as corrosion of insert metal parts and poor solder adhesion is greatly improved. be able to.

<Example> Hereinafter, the present invention will be described with reference to Examples and Comparative Examples.

Examples 1 to 9 Comparative Examples 1 to 8 PPS resin, γ-alumina, silica, glass fibers, additives, fillers, etc. were mixed in a Henschel mixer in the proportions shown in Table 1, and twin screw extrusion at a cylinder temperature of 320 ° C. It was melt-kneaded using a machine and pelletized. The pellets were crushed and, as shown in FIG.
Put 0.5g, hang 5x5mm copper foil 4 with copper wire 2, and
It was heated in a solder bath at 30 ° C. for 3 minutes, and the degree of discoloration of the copper foil was observed. The results are shown in Table 1.

As shown in Table 1, it can be seen that the composition of the present invention significantly improves the generation of metal corrosive gas.

Examples 10-14, Comparative Examples 9-12 PPS resins, γ-alumina, glass fibers, additives, fillers, etc. were mixed in the proportions shown in Table 2 and melted using a twin screw extruder having a cylinder temperature of 325 ° C. Kneaded and pelletized. The pellets were crushed, and the degree of discoloration of the copper foil was observed by the same method as in the above example. The results are shown in Table 2.

As shown in Table 2, it was found that the composition of the present invention significantly improved the generation of metal corrosive gas.

Examples 15 to 23, Comparative Examples 13 to 19 The pellets obtained in Examples 1 to 9 and Comparative Examples 1 to 7 were used as a cylinder temperature of 340 ° C using an injection molding machine and a mold of 170 ° C. A copper piece (0.25 mm thick) having the shape shown in FIG. The results are shown in Table-3.

From Table-3, it was found that the molded product of the present invention was significantly improved in metal corrosion.

Examples 24 to 28, Comparative Examples 20 to 23 The pellets obtained in Examples 10 to 14 and Comparative Examples 9 to 12 were heated to a cylinder temperature of 320 ° C using an injection molding machine and a mold of 150 ° C. A pin connector having a thickness of 4 mm shown in the figure was obtained. With the pin still inserted in the connector, heating was performed at 250 ° C. for 100 hrs, and the discoloration of the pin was examined. The results are shown in Table-4.

From Table 4, it was found that the molded product of the present invention does not corrode metal parts in contact with it.

Example 29, Comparative Example 24 The pellets obtained in Example 8 were heated at a cylinder temperature of 340 ° C.
The transistor was sealed with the injection molding machine described above and a pressure cooker test (121 ° C., 2 atm) was performed, and the defect rate after 50 hours was examined, and it was 0/100. On the other hand, when the pellets obtained in Comparative Example 6 were similarly tested
The defective rate was 75/100.

[Brief description of drawings]

Fig. 1 shows the cross section of the test tube for adjusting the corrosiveness of PPS resin powder on the copper foil in the corrosiveness test of PPS pellets, and Fig. 2 inserts the copper piece in the corrosiveness test of the molded product. Fig. 3 shows a PPS resin molded product, and Fig. 3 shows a PPS resin pin connector in a corrosion test of the molded product. 1 ... Coil sled, 2 ... Copper wire, 3 ... Glass test tube, 4
…… Copper foil, 5 …… Sample, 6 …… Copper strip of gas vent, 7 ……
Resin injection port, 8 ... Insert copper piece, 9 ... PPS resin molded product.

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Claims (4)

[Claims] 1. A polyphenylene sulfide resin composition for molding, wherein 0.05 to 200 parts by weight of γ-alumina is added to 100 parts by weight of the polyphenylene sulfide resin. 2. The composition according to claim 1, further comprising a fibrous filler in the polyphenylene sulfide resin and γ-alumina. 3. The composition according to claim 1, further comprising silica in the polyphenylene sulfide resin and γ-alumina. 4. A melt flow rate of polyphenylene sulfide resin (ASTM D-1238-74, 315.6 ° C., 5 kg load)
Is in the range of 1,000 to 1, and the composition according to claim 1.