JPH02209966A - Polyarylene sulfide resin composition and molded article thereof - Google Patents

Abstract

PURPOSE:To obtain the title composition suitable for insert molded articles of electronic parts, having excellent adhesivity to metals, excellent occurrence of burr in molding, strength at weld part, etc., by compounding a polyarylene sulfide resin with a specific amount of a crosslinked polyarylene sulfide resin showing a gelatinous state in melting. CONSTITUTION:(A) 100 pts.wt. polyarylene sulfide resin comprising a repeating unit shown by the formula -(Ar-S)- (Ar is arylene) and having 10-5X10<4> poise melt viscosity is compounded with (B) 0.2-90 pts.wt. crosslinked polyarylene sulfide resin having 5X10<5>-1X10<9> melt viscosity and showing a gelatinous state in melting, (C) 5-400 pts.wt. fibrous filler and/or nonfibrous inorganic filler (e.g. mixture of glass fiber and inorganic powdery or granular filler having <=5 aspect ratio) and (D) 0.05-15 pts.wt. silicone-based polymer (e.g. unmodified silicone oil or silicone rubber).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides an improved polyarylene sulfide resin composition for molding, and improved inserts such as electronic parts molded by injection molding using the same. Regarding molded products.

[Conventional technology and its issues]

In recent years, various equipment parts have improved reliability, added value,
Insert injection molding (including outsert molding), in which two or more materials are composited and molded at the same time, is being used heavily for miniaturization, high-density packaging, high productivity, and reduced parts mounting costs.

In particular, in the field of electrical and electronic components, there is a demand for injection molding materials that have good electrical properties and are heat resistant to withstand soldering temperatures during mounting.

Polyarylene sulfide resins (PAS), typified by polyphenylene sulfide resins (PPS), are resins that are well suited to such purposes, and their application to the above-mentioned chip components is being actively attempted.

Such chip components are often composites of resin and metal, which are made by insert molding metal pieces such as lead frames. However, polyphenylene sulfide resin has poor adhesion at the interface between the resin and metal, and there is a problem in that solder flux, cleaning solvents, or moisture in the air can enter the interface and deteriorate the electrical characteristics and function of the parts. In addition, burrs are generated during molding, which in the case of switch parts, for example, covers the contact parts and causes poor contact.Furthermore, there is the problem of having to add one step to the production process to remove burrs. In addition, such insert molded products have a weld portion during molding, and the use of pps compositions that inherently have weak weld strength is currently limited.

For this reason, various attempts have been made to improve interfacial adhesion, reduce parity, and even improve weld strength, but no resin composition has been found to fully satisfy all of these requirements. Not obtained.

That is, as a means for improving the adhesion strength of conventional pps compositions, for example, (JP-A-57-17153, JP-A-57-2
No. 1844, JP-A-57-40557, JP-A-57-
No. 158256, JP-A-59-31503, JP-A-6
There are proposals such as JP-A No. 0-120753, JP-A-59-20911, JP-A-62-197451, JP-A-57-135859). However, although these methods have the effect of improving adhesion, they are not only ineffective in reducing the occurrence of fringing and improving weld strength, but they also encourage fringing or increase the production process. However, the object of the present invention has not yet been satisfied.

In addition, various methods for reducing Paris have been tried and have been found to be effective, but there is currently no method that achieves both adhesion and weld strength. At present, the application of polyarylene sulfide resins to insert molded products is limited.

[Means to solve the problem]

The present inventors have developed various methods to improve the adhesion of the resin-to-metal interface without deteriorating the heat resistance of polyarylene sulfide resin compositions, particularly polyphenylene sulfide resin compositions, and to reduce paris. The composition was prepared, a molded article with a metal insert was injection molded, and the usability of the part was evaluated. As a result, a composition made by blending a crosslinked polyarylene sulfide resin that exhibits a gel-like state when melted has improved adhesion between the insert metal and the resin, reduced burrs, and has been molded into electronic parts. It has been found that it has excellent properties, and that these properties can be further improved by blending a small amount of silicone polymer with it, leading to the completion of the present invention. That is, the present invention has (A) a repeating unit of 10 Ar-3+- (where Ar is an arylene group) as a main component, and a melt viscosity (temperature of 310°
100 parts by weight of a polyarylene sulfide resin with a C1 shear rate of 5/sec) of 10 to 5X104 poise, and (B) a gel-like state when melted with a melt viscosity of 5X10' to lXl0' poise (temperature 310"C1 shear rate of 5/sec). 0.2 to 90 parts by weight of a crosslinked polyarylene sulfide resin (C) 5 to 400 parts by weight of a fibrous filler, a non-fibrous inorganic filler, or a mixture of both (D) 0.05 to 15 parts by weight of a silicone polymer The present invention relates to a polyarylene sulfide resin composition prepared by blending the polyarylene sulfide resin composition, and to an insert molded product such as an electronic component in which a lead frame is inserted using the composition.

The base resin as component (A) in the composition of the present invention is a substantially linear polyarylene sulfide resin,
It is composed of -(-Ar-S-)- (where Ar is an arylene group) as a main repeating unit.

As an arylene group, for example, R is an alkyl group, preferably a C3-C6 alkyl group or a phenyl group, and n is an integer of 1-4.

p, p'-diphenylene sulfone group p, p'-diphenylene ether group 1) tl)''-diphenylene carbonyl group, etc. can be used.

In this case, among the arylene sulfide groups composed of the above-mentioned arylene groups, a polymer using the same repeating unit, that is, a homopolymer, can be used,
Copolymers containing different repeat units may be preferred from the viewpoint of processability of the composition.

As the homopolymer, one in which a p-phenylene group is used as an arylene group and a p-phenylene sulfide group is used as a repeating unit is particularly preferably used.

As a copolymer, the above-mentioned arylene group or the like.

Among the arylene sulfide groups, combinations of two or more different types can be used, but among them, a combination containing a p-phenylene sulfide group and a m-phenylene sulfide group is particularly preferably used. In this, p-
Those containing phenylene sulfide groups in an amount of 50 mol % or more, preferably 60 mol % or more, more preferably 70 mol % or more are suitable from the viewpoint of physical properties such as heat resistance, moldability, and mechanical properties.

In addition, m-phenylene sulfide group is 1 to 50 mol%,
Particularly preferred is one containing 5 to 25 mol%.

In this case, components whose repeating units are contained in blocks (for example, Japanese Patent Laid-Open No. 61-1989-1) rather than random repeating units
The material described in Japanese Patent Publication No. 14228) has almost the same processability, but has excellent heat resistance and mechanical properties, and can be preferably used.

The polyarylene sulfide resin as component (A) used in the present invention is preferably a polymer having a substantially linear structure obtained by polycondensation of monomers mainly consisting of difunctional monomers.

Among them, the melt viscosity measured at a temperature of 310''C2 and a shear rate of 5/sec is 10 to 5×10′ voids, preferably 50 to 5×10′ voids, particularly preferably 100 to 5×10′ voids.
A material in the range of 5×10′ voids is suitable. 10
If it is less than the void, the fluidity is too good and melt processing is difficult, and even if a molded product is obtained, the mechanical strength etc. are low, which is not preferable. Moreover, those having more than 5×10′ voids have poor fluidity and are difficult to melt process.

Component (B) in the composition of the present invention is a polyarylene sulfide resin whose structural repeating unit is +Ar-S-)- as a main constituent like component (A), but it is characteristically different. is the melt viscosity (temperature 310°C1
The crosslinked polyarylene sulfide resin exhibits a gel-like state when melted, and has a shear rate of 5/sec) of 5 x 10' to 1 x 10'' voids, more preferably 1 x 10' to 1 x lO9 voids.

If the melt viscosity is less than 5 x 10' voids, the effect of improving the Paris properties and weld strength will be small, and if a large amount is blended, the effect of improving the Paris property will be obtained, but the fluidity of the composition will deteriorate excessively and the processability will deteriorate. Undesirable.

In addition, if the melt viscosity exceeds 10 qpoise, the component (B) will be dispersed in the melt of component (A), which is the base resin, as a fine gel during melt processing, and the effect of improving the spring and weld properties will be reduced. This is not preferable as it will be insufficient.

In addition, uncrosslinked polyarylene sulfide resin that is non-gel-like when melted has a high viscosity (
It is undesirable because it becomes compatible with component A), resulting in insufficient improvement effects on the spring and weld properties, and in addition, it deteriorates the fluidity of the composition.

Methods for producing component (B) include a method in which a crosslinked structure is formed using a crosslinking agent such as polyhalobenzene having three or more functional groups when dihalobenzene and an alkali metal sulfide are polymerized; Preferably used is a method in which the polyarylene sulfide polymer is heated and cured to increase the degree of crosslinking.

As for the former method, for example, dihaloaromatic compound 10
Mix 0.05 to 20 moles of a polyhaloaromatic compound having three or more halogen substituents per 0 mole, add water and/or an alkali metal carboxylic acid salt, etc. as appropriate, until the melt viscosity is 5X10. A method can be used in which the reaction is carried out under polymerization conditions that produce a crosslinked polyarylene sulfide resin that exhibits a gel-like state when melted with '~lXl0' voids. In addition, as for the latter manufacturing method, for example, polyarylene sulfide resin is prepared in the presence or absence of oxygen at a high temperature, for example, 200° C. or higher, lower than the melting point of polyarylene sulfide, and the melt viscosity is 5XIOS to IX10.
A method is used in which the degree of crosslinking is increased by curing treatment for a time that produces a polymer that exhibits a gel-like state when melted.

In particular, the polymerized crosslinked polyarylene sulfide resin obtained by the former method is more preferable than the thermally crosslinked polyarylene sulfide resin obtained by the latter method, since it is superior in color tone and thermal stability.

The blending amount of component (B) in the molding composition of the present invention is:
(A) 0.2 to 90 parts by weight per 100 parts by weight of component,
Preferably 0.5 to 80 parts by weight, particularly preferably 0.5
A range of 60 parts by weight is suitable. If it is less than 0.2 parts by weight, the effect of improving Paris and weld properties is insufficient, and 90%
If the amount exceeds 1 part by weight, the fluidity of the composition will deteriorate and the mechanical properties of the resulting molded product will deteriorate, which is undesirable.

Next, as the filler of component (C) used in the present invention, fibrous or non-fibrous (powder-like, plate-like) fillers are used depending on the purpose.

Fibrous fillers include glass fiber, asbestos fiber,
Carbon fiber, silica fiber, silica/alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, stainless steel, aluminum,
Examples include inorganic fibrous materials such as fibrous materials of metals such as titanium, copper, and brass. Particularly typical fibrous fillers are glass fibers or carbon fibers. In addition, polyamide,
High melting point organic fibrous substances such as fluororesins and acrylic resins can also be used.

On the other hand, the powdery fillers include carbon blank, silica, quartz powder, glass peas, glass powder, calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, silicates such as wollastonite, iron oxide, Metal oxides such as titanium oxide, zinc oxide, and alumina, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, silicon carbide, silicon nitride, boron nitride, and various metals. Examples include powder.

Further, examples of the plate-like filler include mica, glass flakes, and various metal foils.

These inorganic fillers can be used alone or in combination of two or more. The combined use of a fibrous filler, particularly glass fiber or carbon fiber, and a granular and/or plate-like filler is a particularly preferable combination from the viewpoint of combining mechanical strength, dimensional accuracy, electrical properties, and the like.

A particularly preferred combination for insert molded products is a combination of glass fibers with an average fiber length of 30 to 500 microns and an inorganic powdery granular material with an aspect ratio of 5 or less.

When using these fillers, it is desirable to use a sizing agent or a surface treatment agent if necessary. Examples of this include functional compounds such as epoxy compounds, incyanate compounds, silane compounds, and titanate compounds. These compounds may be used after surface treatment or convergence treatment, or may be added at the same time when preparing the material.

The amount of inorganic filler used is 5 to 400 parts by weight per 100 parts by weight of polyarylene sulfide resin (A),
Preferably it is 10 to 250 parts by weight.

If it is too small, the mechanical strength will be poor, and if it is too large, the molding operation will be difficult and problems will also arise in the mechanical strength of the molded product.

The composition of the present invention further contains a silicone polymer as component (D).

As such silicone polymers, silicone oil, ie, linear organopolysiloxane, and/or silicone rubber, ie, partially crosslinked organopolysiloxane, are preferably used. As the silicone oil, silicone oils such as dimethylpolysiloxane and methylphenylpolysiloxane are preferably used.

The effect of adding component (D) appears in the adhesion between the metal and the resin, and the effect is particularly noticeable when it coexists with component (B). It is also possible to use modified silicone oils such as amino-modified, epoxy-modified, carboxyl-modified, and alcohol-modified silicone oils as shown in the prior art.

The degree of polymerization of the silicone oil that can be used is preferably as high as possible in order to prevent the generation of volatile matter during molding and use, and is preferably 5,000 centistokes or more, particularly preferably 10,000 centistokes or more.
5oooooo centistokes can be used.

Those with an ultra-high degree of polymerization generally do not exhibit an oily state and are called silicone gums, but are preferred for the purpose of the present invention.

On the other hand, the silicone rubber used in the present invention refers to a partially crosslinked organopolysiloxane, which can be obtained by heating and crosslinking a linear highly polymerized polysiloxane with an organic peroxide or the like. , those made by adding a crosslinking agent to polysiloxane partially having active groups and crosslinking by the action of heat, ultraviolet rays, etc. can be used.

In particular, silicone rubbers made by crosslinking polysiloxanes, mainly composed of dimethylpolysiloxane, methylphenylpolysiloxane, methylvinylpolysiloxane, methylphenylvinylpolysiloxane, etc., are preferably used.

Methods for producing such silicone rubber include radical reaction type, condensation reaction type, addition reaction type, etc., depending on the method of crosslinking reaction, but for the purpose of the present invention, addition reaction type using a platinum catalyst is particularly suitable. is preferably used from the viewpoint of less impurities.

In addition, it is preferable to use silicone rubber processed into a powder form from the viewpoint of operability and adhesion. Examples of this include pulverized silicone rubber salt, and fine particles suspended in a liquid during rubber production. The latter, which is processed into a fine shape without going through a pulverization process, has a good particle size distribution and has a good effect on adhesion, and is therefore preferably used.

The amount of these silicone polymers used is 0.05 parts by weight per 100 parts by weight of the polyarylene sulfide resin (A).
~15 parts by weight, preferably 0.1 to 5 parts by weight. If it is less than 0.05 parts by weight, the effect of improving adhesion will be insufficient, and if it exceeds 15 parts by weight, gas will be generated during composition kneading or molding, and the mechanical properties of the resulting molded product will deteriorate. This is not desirable as it causes other inconveniences.

Further, as the base resin of the present invention, in addition to the polyarylene sulfide resin, it is also possible to use a small amount of other thermoplastic resin as an auxiliary amount, within a range that does not interfere with the purpose.

The other thermoplastic resin used here may be any thermoplastic resin that is stable at high temperatures.

For example, aromatic polyesters made of aromatic dicarboxylic acids and diols or oxycarboxylic acids such as polyethylene terephthalate and polybutylene terephthalate; polyamides; polycarbonates; Examples include etherimide, polyetherketone, and fluororesin. Moreover, two or more types of these thermoplastic resins can also be used in combination.

Furthermore, the composition of the present invention contains known substances that are generally added to thermoplastic resins and thermosetting resins, such as stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, dyes and pigments. Coloring agents such as lubricants, crystallization promoters, crystal nucleating agents, etc. can also be added as appropriate depending on the required performance.

The polyarylene sulfide resin composition of the present invention can be prepared using equipment and methods generally used for preparing synthetic resin compositions.

That is, the necessary components can be mixed, kneaded and extruded using a single-screw or twin-screw extruder to form pellets for molding, and some of the necessary components can be mixed as a masterbatch and melt-extruded. All of these things are possible.

In particular, when component (D) is an adhesive liquid, for example, (C)
A preferred method for smoothly preparing the composition is to adsorb it onto some of the components before adding it.

Compared to ordinary pps compositions, the composition of the present invention has extremely little generation of flakes during molding, less decrease in strength at weld parts, and good adhesion to metals, so it can be used for general molded products. This method is suitable, and is particularly suitable for molding composite parts with metal inserts.

The best example of this is electronic components with insert molded lead frames. This shows an electronic component formed by a molding method that integrates a metal lead frame and molded resin during injection molding.

Such electronic components include, for example, chip-type digital switches such as key type, dip type, rotary type, and slide type, chip-type volumetric switches such as rotary type, slide type, and trimmer type, chip-type capacitors, chip-type fixed resistors, Examples include chip-type inductors, chip-type filters, chip-type coils, chip-type capacitors, chip-type fuses, chip-type rectifiers, and parts constituting these.

Further, the electronic components of the present invention include IC, l-run sister,
Semiconductor encapsulation in which a semiconductor element such as a diode is directly encapsulated with the molding resin of the present invention by injection molding may be used, but this is not necessarily suitable for encapsulating such a particularly easily damaged object. However, the composition of the present invention can be preferably used for a so-called pre-molded type package in which a lead frame or an insert-molded resin case is molded with the resin composition of the present invention and then an element is placed therein. Moreover, it is of course effective not only as an electrical/electronic component but also as an insert molded product as a mechanical component.

〔Example〕

Production Example 1 (Preparation of polyphenylene sulfide resin (A)) 1200 kg of N-methylpyrrolidone and 420 kg of hydrated sodium sulfide (purity 46.4%) were placed in a Ti-lined crepe and heated to approximately 200'C. , water 1
Next, 366 kg of p-dichlorobenzene was charged and polymerization was carried out at 218°C for 5 hours, and then 90 kg of water was added and the temperature was raised to 260°C. It was held at 260°C for .5 hours. Continue to 242℃
Polymerization was carried out for 4 hours to obtain a slurry containing the produced polymer. This slurry was sieved through a 0.1-mesh screen to separate only the granular polymer, which was then washed with acetone and water to obtain a crude polymer.

This linear polymer was immersed in a 2% aqueous ammonium chloride solution, treated at 40°C for 30 minutes, washed with water, and dried under reduced pressure at 80°C for 12 hours to obtain a purified linear polymer. The melt viscosity of the resulting uncrosslinked polymer was 1 x 104 voids as measured at 310'C and a shear rate of 5/sec.

Production example 2 (crosslinked polyphenylene sulfide resin (8)
2.0 kg of N-methylpyrrolidone and 420 g of hydrous sodium sulfide (purity 46.4%) were placed in an autoclave and heated to about 200°C to distill off 90 g of water. 355 g of dichlorobenzene and 1
．． 2.4. After charging 1 g of 5-tetrachlorobenzene and carrying out polymerization at 215 °C for 8 hours, 30 g of water was added and the temperature was raised to 250 °C over about 30 minutes, and then at 250 °C. It was held for 20 minutes. 2 for another 15 minutes
The mixture was cooled to 10°C, heated again to 245°C over 30 minutes, and held for 12 hours. A cross-linked polyphenylene sulfide resin that exhibits a gel-like state when melted was obtained. Melt viscosity is 3
Measurement at 10°C and a shear rate of 5/sec gave lXl0' poise.

Production Example 3 (Preparation of low-viscosity cross-linked polyphenylene sulfide resin (Bo)) In Production Example 2, the temperature was directly lowered to 245° C. to obtain a low-viscosity cross-linked polyphenylene sulfide resin. The melt viscosity was 10 voids as measured at 310°C and a shear rate of 5/sec.

Examples 1 to 11 and Comparative Examples 1 to 8 As shown in Table 1, for the polyphenylene sulfide resin (A) prepared in Production Example 1, which is the (A) component, (B)
The cross-linked polyphenylene sulfide resin (B) prepared in Production Example 2 as a component or the cross-linked polyphenylene sulfide resin (Bo) prepared in Production Example 3 as a component, and the silicone-based polymer as a component (D) were added in the amounts shown in Table 1 using a Henschel mixer. We met for 2 minutes. Furthermore, a filler was added as component (C) in the amount shown in Table 1, and mixed for 30 seconds using a blender. This was put into an extruder with a cylinder temperature of 310°C to make pellets of polyphenylene sulfide resin composition.
A STM test piece was molded at a mold temperature of 150°C, and the tensile strength and tensile elongation were measured. Next, using a mold with gates at both ends of the test piece, a weld part was formed in the center. A test piece for measuring weld strength was prepared, the tensile strength was measured, and the ratio to that of a test piece without weld (100) was shown.

Furthermore, using an injection molding machine, the cylinder temperature is 320"C.
, At a mold temperature of 150°C, a copper lead frame was inserted using a mold for a microswitch, 6.2
A microswitch case of s+s x 6.2a+m x 2+sh was molded. Similarly, 4.5mmX4
．． A microvolume case for Osa X2.4n+mh was also molded.

The paris at the parting line portion of the obtained molded article was measured using a stereomicroscope, and the paris length was determined.

Furthermore, the molded product was immersed in a solder bath controlled at 260°C±2°C for 60 seconds, and after taking it out, the appearance, deformation, and surface roughness were observed to determine the solder heat resistance.

Next, the molded product was heated at room temperature for 60 minutes using fluorescent ink (manufactured by Eiken Chemical).
After the ink was fixed by immersing the lead frame in C.benetrant) and drying for 80'CX150 minutes, the lead frame was peeled off and ink penetration was observed. Adhesion to the insert metal was evaluated on a scale of 1 to 5, with 5 indicating penetration to the center and 1 indicating no penetration.

e) Dimethylpolysiloxane 10,000 centistokes f) Dimethylpolysiloxane 3,000,000 centistokes [Effects of the Invention] As is clear from the above description, the composition of the present invention has excellent adhesion to metals. It is also excellent in terms of the occurrence of flashing during molding and the strength of the weld part, making it extremely suitable as a material for insert molded products of metals and the like. Therefore, the composition of the present invention is not only suitable for a wide variety of mechanical composite parts, but also has the following effects, for example, for electronic parts in which lead frames are insert-molded.

(1) It has high heat resistance and can withstand molten solder temperature, so it can be soldered by reflow method, and as a result, component mounting costs can be reduced.

(2) No deburring process is required. Furthermore, there is no deterioration in reliability of electrical characteristics caused by Paris.

(3) Excellent interfacial adhesion between the lead frame and resin prevents solder flux from penetrating, resulting in high reliability of parts after mounting. In addition, even if the parts are mounted through a cleaning process using organic solvents, detergents will not enter through the interface.
It can be used as a washable part. Furthermore, it can be used as a dust-proof component, expanding the range of applications of the component.

(4) Since there is little decrease in strength at the weld part, defect-free molded products can be obtained even in parts with complex shapes.

(5) It is safe because the resin does not contain any dangerous ingredients.

(6) Since no expensive components are used in the composition, it can be manufactured at low cost.

Claims (1)

[Claims] 1 (A) Repeating unit, ▲ includes mathematical formulas, chemical formulas, tables, etc. ▼, provided that Ar is an arylene group) as the main constituent, and has a melt viscosity (temperature of 310°C, shear rate of 5/sec) is 10~5×10
^4 poise polyarylene sulfide resin 100
Part by weight (B) Melt viscosity (temperature 310°C, shear rate 5/sec) is 5
Cross-linked polyarylene sulfide resin exhibiting a gel-like state when melted with ×10^5 to 1 ×10^9 poise 0.2 to 90 parts by weight (C) Fibrous filler, non-fibrous inorganic filler, or mixture of both 5 to A polyarylene sulfide resin composition containing 400 parts by weight (D) of 0.05 to 15 parts by weight of a silicone polymer. 2. The polyarylene sulfide resin composition according to claim 1, wherein component (C) comprises a combination of glass fiber and an inorganic powdery filler having an asbestos ratio of 5 or less. 3. The polyarylene sulfide resin composition according to claim 1 or 2, wherein the silicone polymer (D) is an unmodified silicone oil. 4. The polyarylene sulfide resin composition according to claim 1 or 2, wherein the silicone polymer (D) is silicone rubber. 5. An insert molded article molded using the composition according to any one of claims 1 to 4. 6. An electrical/electronic device part or mechanical part in which a metal is inserted using the composition according to any one of claims 1 to 4. 7. The electronic device component according to claim 6, wherein the metal is a lead frame.