JPH0881631A - Polyarylene sulfide resin composition - Google Patents

Abstract

PURPOSE: To obtain a polyarylene sulfide resin composition excellent in fluidity and adhesion; etc., useful as a sealer for IC, etc., comprising a polyarylene sulfide resin, silica, terpolymer elastomer and polyslloxane-based rubber with the blend proportion satisfying specified conditions. CONSTITUTION: This composition comprises (A) a polyarylene sulfide resin (pref. 5-30 Pa.s in the melt viscosity at 300 deg.C and a shear rate of 200s<-1> and 4150 ppm in Na content), (B) silica (pref. fused silica arid/or crystalline silica <=50μm in average particle diameter), (C) a terpolymer elastomer made from ethylene, α, β-unsaturated carboxylic alkyl ester and maleic anhydride, and (D) a polysiloxane-based rubber having cross-linked structure. The blend ratios for the components A to D satisfy the relationships I, II and III. Besides, it is preferable that this composition contain (E) glass fibers at proportion satisfying the relationship IV.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyarylene sulfide resin (hereinafter sometimes referred to as PAS) composition. More specifically, it relates to a PAS composition which is effectively used for IC encapsulation and various electronic component encapsulation.

[0002]

2. Description of the Related Art In general, physical properties required of a resin composition as a sealing material for ICs are that the bonding wire of an element is molded without being cut or deformed, so that it has a low melt viscosity and a linear expansion coefficient. The value is close to that of metal. The linear expansion coefficient has been adjusted by adding a large amount of filler until now, but it was unavoidable that the mechanical strength was deteriorated. From this viewpoint, thermosetting resins such as epoxy resin and silicone resin have been conventionally used. However, thermoplastic resins are attracting attention because of their poor productivity and their difficulty in recycling because spool runners cannot be reused. Among them, polyarylene sulfide (PAS), especially polyphenylene sulfide (PPS) Due to its excellent heat resistance and flame retardancy, it has been drawing attention as a sealing material. PAS like this
A composition using a silane coupling agent for improving physical properties (Japanese Patent Publication No. 5-18351). An olefin copolymer composed of α-olefin and α, β-unsaturated glycidyl ester was added. (JP-A-63-17549 and JP-A-3-68101) Aminated polyphenylene sulfide (PPS) to which an ethylene-based copolymer elastomer is added (JP-A-4-1871)
Japanese Patent Laid-Open No. 5-202245 discloses a composition comprising PPS, an ethylene-based terpolymer copolymer elastomer, and a silane compound.

[0003]

However, in the case of, there is no improvement effect on toughness and fluidity,
In the case of 1, the hydrogenated SBS is added in a large amount, and the heat resistance and chemical resistance are inferior. In the case of 1, the molecular weight of PPS is large and the fluidity is poor, so that it is unsuitable as a sealing material. In the case of and, in order to improve the mechanical strength of PPS, reduction in viscosity of the composition, which is an important element as a sealing composition, is not taken into consideration, and the disclosed silanes. Coupling agents have problems such as not being preferable because the viscosity of the composition increases, and in all cases, the hygroscopicity is high, the reliability of the element is reduced, and the adhesion to the lead frame and the wire is poor. Since it is inferior in performance and the reliability of the element is insufficient, it cannot be said to be sufficiently satisfactory. The present invention
The present invention has been made in view of the above problems, and an object thereof is to provide a polyarylene sulfide resin composition that is suitable as a sealing material, has low hygroscopicity, and has excellent mechanical strength and adhesion.

[0004]

To achieve the above object, according to the present invention, a polyarylene sulfide resin (A), silica (B), ethylene and an α, β-unsaturated carboxylic acid alkyl ester and maleic anhydride are used. A terpolymer elastomer (C) and a polysiloxane rubber (D) having a crosslinked structure, and the compounding ratio (% by weight) thereof is represented by the following formulas (I) to (III The polyarylene sulfide resin composition is provided. 30 ≦ A / (A + B + C + D) ≦ 60 (I) 40 ≦ B / (A + B + C + D) ≦ 70 (II) 3 ≦ / (C + D) / (A + B + C + D) ≦ 30 (III)

In a preferred embodiment, the resin temperature of the polyarylene sulfide resin (A) is 300.
The melt viscosity at a shear rate of 200 S ^{-1 at} 5 ° C.
Provided is a polyarylene sulfide resin composition characterized by being Pa · S.

A polyarylene sulfide resin composition is also provided in which the sodium content of the polyarylene sulfide resin (A) is 150 ppm or less.

Further, there is provided a polyarylene sulfide resin composition, wherein the silica (B) is fused silica and / or crystalline silica having an average particle size of 50 μm or less.

The composition ratio of the monomer component in the terpolymer elastomer (C) is 50% ethylene.
˜90% by weight, α, β-unsaturated carboxylic acid alkyl ester 5 to 49% by weight, and maleic anhydride 0.5 to 1
Provided is a polyarylene sulfide resin composition, which is an ethylene-based copolymer comprising 0% by weight.

The polysiloxane rubber (D) having the above-mentioned crosslinked structure is the polyorganosiloxane rubber 10
0% or polyorganosiloxane rubber component 1 to 9
9% by weight and polyalkyl (meth) acrylate rubber 99
Each of the polyorganosiloxane-based graft copolymers obtained by graft-copolymerizing one or more vinyl-based monomers with a composite rubber having a structure in which one to one weight% of them are intertwined with each other so that they cannot be separated, or those A polyarylene sulfide resin composition is provided which is a mixture of

Further, the above composition further contains glass fiber (E), and its proportion (% by weight).
Provides a polyarylene sulfide resin composition characterized by satisfying the following formula (IV): 0 <E / (A + B + C + D + E) ≦ 30 (IV)

Hereinafter, the polyarylene sulfide resin composition of the present invention will be specifically described for each composition component. 1. Polyarylene sulfide resin (A) Examples of the polyarylene sulfide resin (A) used in the present invention include compounds represented by the general formula-(Ar-S-) n- known per se. Here, -Ar- is a divalent aromatic residue containing at least one 6-membered carbon ring, for example, as shown in the following [Chemical formula 1], and F, Cl, Br are added to each aromatic ring. An atom such as a halogen atom or the like, or a substituent such as an alkyl group such as a methyl group, a nitro group, a carboxylic acid / metal salt, an amino group or a phenyl group may be introduced.

[0012]

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Among these, those which are not cross-linked or partially cross-linked are preferable because the viscosity change by heat is small.

The melt viscosity of the PAS resin (A) is 5 at a resin temperature of 300 ° C. and a shear rate of 200 S ^-1.
-30 Pa · S is preferable, and 6-25, particularly 7-20 Pa · S is particularly preferable. 5 Pa
If it is lower than S, the mechanical strength will be poor, and if it is higher than 30 Pa · S, the viscosity will be high and the bonding wire may be deformed during molding.

The sodium content in the PAS resin (A) is preferably 150 ppm or less, and 100 ppm
The following is more preferable. If it is more than 150 ppm, the metal part in the element such as IC may be corroded and the reliability of the element may be lowered.

The mixing ratio of the PAS resin (A) is P
It is 30 to 60% by weight, preferably 35 to 55, with respect to the total amount (A + B + C) of the AS resin (A), silica (B), and ethylene-based terpolymer elastomer (C).
It is particularly preferable that the amount is 40% by weight, and further 40 to 50% by weight. If it is less than 30% by weight, the fluidity becomes poor, and 6
If it is more than 0% by weight, the coefficient of linear expansion of the composition becomes large, and the reliability of the device may deteriorate.

2. Silica (B) The silica (B) in the present invention is used for maintaining rigidity and matching the linear expansion coefficient. The silica (B) may be either fused silica or crystalline silica, or a mixture of both. The silica (B) may be surface-treated with epoxysilane, aminosilane, or another silane coupling agent to the extent that the effect of the mercaptosilane coupling agent described later is not impaired.

The average particle size of the silica (B) is 50.
It is preferably not more than μm, and particularly preferably not more than 35 μm. The average particle size of silica (B) is 5
If it exceeds 0 μm, the reliability of the device may be deteriorated.

The sodium content of the silica (B) is
It is preferably 5 ppm or less, and it may be eluted in an element such as an IC to reduce the reliability of the element.

The mixing ratio of the silica (B) is 40 to 70% by weight based on the total amount of the PAS resin (A), the silica (B) and the ethylene terpolymer elastomer (C). Which is preferably 45 to 65% by weight, and particularly preferably 50 to 60% by weight. The content is 4
If it is less than 0% by weight, the coefficient of linear expansion of the composition becomes large, and the reliability of the device may deteriorate. On the other hand, if it exceeds 70% by weight, fluidity may deteriorate. 3. Ethylene Terpolymer Copolymer Elastomer (C) The elastomer (C) in the present invention is used for improving the adhesion between the resin and the element and imparting toughness. This elastomer (C) is an ethylene terpolymer elastomer composed of ethylene, an α, β-unsaturated carboxylic acid alkyl ester and maleic anhydride.

The α, β-unsaturated carboxylic acid alkyl ester is preferably an alkyl ester of an unsaturated carboxylic acid having 3 to 8 carbon atoms such as acrylic acid and methacrylic acid, and among them, ethyl acrylate and acrylic acid. n
-Butyl and methyl methacrylate are particularly preferably 3 ppm or less. When it exceeds 5ppm, Na ⁺ is
Are especially preferred.

The proportion of the monomer component in the ethylene elastomer (C) is 50 to 90% by weight of ethylene, preferably 60 to 85% by weight, and the α, β-unsaturated carboxylic acid alkyl ester is 5 to 49% by weight, preferably 7 to 45% by weight, maleic anhydride 0.5 to 10% by weight, preferably 1 to 8% by weight
Is. When the ratio of the monomer component is within this range, the resin composition has excellent mechanical strength such as toughness and fluidity.

4. Polysiloxane rubber (D) having a crosslinked structure The polysiloxane rubber (D) having a crosslinked structure in the present invention is used to obtain a resin composition having low hygroscopicity and excellent mechanical strength. Examples of the polysiloxane-based rubber having the crosslinked structure include the following or each of the following, or a mixture thereof. Polyorganosiloxane (R ₂ SiO) _n : R = hydrogen atom, methyl group, phenyl group, n = 5 to 2000, component 1
100% and cross-linked by reacting with 3 to 4 lower alkoxy groups, for example, trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane and the like, or by a general peroxide cross-linking method. Organosiloxane (R ₂ SiO) _n : R = hydrogen atom, methyl group, phenyl group, n = 5 to 2000, 1 to 9
Polymers of 9 wt% and 99 to 1 wt% of a linear or branched acrylate of an alkyl group having 1 to 8 carbon atoms and a polymer of an alkyl methacrylate having an alkyl group of 6 to 12 carbon atoms are intertwined with each other so that they cannot be separated. Polyorganosiloxane-based graft copolymer obtained by graft-copolymerizing one or more vinyl-based monomers (α-olefin compounds) with the composite rubber

In this case, the particle size of the rubber particles is preferably 30 μm or less. If it exceeds 30 μm, the moldability may be lowered, the effect may be lowered, and the reliability of the element after molding may be lowered.

The proportion (% by weight) of the polysiloxane rubber (D) having this crosslinked structure satisfies the following formula (III). 3 ≦ (C + D) / (A + B + C + D) ≦ 30 (II
I) That is, the total amount of the terpolymer elastomer (C) as an elastomer and the polysiloxane rubber (D) having the crosslinked structure is 3% of the total amount of the polyarylene sulfide resin (A + B + C + D) of the present invention. -30% by weight. Among them, 5 to 25% by weight is preferable, and 10 to
20% by weight is more preferred. If the amount is less than 3% by weight, the compounding effect, that is, excellent mechanical strength and adhesiveness, and low hygroscopicity may not be obtained.
On the other hand, if it exceeds 30% by weight, the rigidity, heat resistance and flame retardancy may be impaired.

The respective blending ratios of the elastomer components (C) and (D) are preferably 5 to 95% by weight of the total elastomer (rubber) component ((C) + (D)).

5. Glass Fiber (E) In the present invention, glass fiber (E) may be used, if necessary, to further improve the mechanical strength of the resin composition. The glass fiber (E) is not particularly limited, and is usually used chopped or milled GF, and may be surface-treated so long as the effects of the present invention are not impaired. The mixing ratio (% by weight) is expressed by the following formula (I
V) shall be satisfied. 0 <E / (A + B + C + D + E) ≦ 30 (IV) When it exceeds 30% by weight, the fluidity of the resin composition decreases.

6. Other Components In addition to the above-mentioned components, other components may be added / blended to the polyarylene sulfide resin composition of the present invention, if necessary, within a range that does not impair the object of the present invention.

Examples of the component of the element include various additives such as inorganic fillers, antioxidants, heat stabilizers, lubricants, silane coupling agents, colorants, plasticizers, polyamides, epoxy resins, silicone resins, silicones. Examples include oils, silicone oils having various functional groups introduced therein, thermoplastic resins and / or thermosetting resins such as polyolefins, hydrogenated SBS, hydrogenated NBR, rubbers such as silicone rubber and fluororubber, and pigments. it can.

Examples of the inorganic filler include oxides such as calcium oxide, magnesium oxide, titanium oxide and alumina oxide, hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide, magnesium carbonate, calcium carbonate and dolomite. Such as carbonate, barium sulfate, calcium sulfate, sulfate such as magnesium sulfate,
Sulfites such as calcium sulfite, silicates such as calcium silicate, ceramics such as silicon carbide, silicon nitride, boron nitride, calcium titanate whiskers, alumina whiskers, magnesia whiskers, graphite whiskers, silicon carbide whiskers, various shapes Examples thereof include whiskers such as zinc oxide whiskers, inorganic fibers such as glass fibers, aramid fibers and carbon fibers, talc, clay, mica, glass beads, carbon black, diatomaceous earth, asbestos and zeolite.

The contents of the other components described above can be appropriately selected within a range that does not impair the object of the present invention.

7. Preparation of Polyarylene Sulfide Resin Composition The polyarylene sulfide resin composition of the present invention has the PAS resin (A), the silica (B), the ethylene-based terpolymer elastomer (C), and the crosslinked structure. It can be prepared by blending the polysiloxane-based rubber particles (D) and other components selected as necessary and melt-kneading them. The melt-kneading can be carried out by an ordinary known method, but in any case, the respective components are uniformly mixed and dispersed in the resin to obtain a predetermined resin composition. Usually, a twin-screw extruder, a single-screw extruder or the like can be preferably used for the melt-kneading.

The conditions of the melt-kneading are not particularly limited, but extremely high temperature and extremely long residence time are avoided in order to limit decomposition or foaming of other components added as necessary. Is preferred. The specific temperature is usually 280 to 350 ° C, preferably 285 to 330 ° C.

The thus-prepared polyarylene sulfide resin composition is usually granulated into a shape and size suitable for secondary processing materials such as pellets, particularly for mold molding materials and injection molding materials. Or it is cut and acquired.

[0035]

In the polyarylene sulfide resin composition of the present invention, the polysiloxane rubber particles (D) having a crosslinked structure used in the polyarylene sulfide resin composition are blended in a specific ratio to improve the hygroscopicity of the composition. Along with the decrease, the combination with the terpolymer elastomer (C) improves the adhesion between the lead frame, the wire and the resin while maintaining the mechanical strength, and improves the reliability of the device.

[0036]

EXAMPLES Hereinafter, the polyarylene sulfide resin composition of the present invention will be described more specifically by way of examples.

<Preparation of PAS Resin> A polymerization tank equipped with a stirrer was charged with 833 mol of hydrous sodium sulfide (Na ₂ S5H ₂ O), 830 mol of lithium chloride (LiCl) and 500 liters of N-methyl-2-pyrrolidone (NMP). It was dehydrated for 1 hour while keeping it at 145 ° C. under reduced pressure. Then, the reaction system was cooled to 45 ° C and then dichlorobenzene (DC
B) 905 mol was added and the mixture was polymerized at 260 ° C. for 3 hours. The contents were washed 5 times with hot water, 1 time with NMP at 170 ° C., 3 times with water and dried at 185 ° C. to obtain a linear PAS. The obtained PAS had a melt viscosity of 10 Pa · S and a sodium content of 90 ppm.

[Examples 1 to 8 and Comparative Examples 1 to 6] <Preparation of Samples> Using a twin-screw extruder, the PAS resin and other components were dry blended at the blending ratios shown in the following table, and then the resin The pellets were manufactured by melt mixing at a temperature of 290 ° C. The other components blended in the PAS resin are as follows. Silica: manufactured by Denki Kagaku Kogyo Co., Ltd. (fused silica FB74) Average particle size: 31.5 μm Ternary copolymer elastomer: Sumitomo Chemical Co., Ltd. Bondine-AX 8390 (68 wt% ethylene, 30 wt% ethyl acrylate, 2 maleic anhydride) % By weight) Polysiloxane rubber having a crosslinked structure; Silicone rubber powder: Toray Dow Corning Silicone (Trefil E501) average particle size 10 μm, polyorganosiloxane co-weight of polyorganosiloxane rubber-polyalkyl (meth) acrylate rubber Coalescence: Mitsubishi Rayon Co., Ltd. (Metaprene S-2001) average particle size 0.2μ
m, polyorganosiloxane rubber-polyalkyl (meth) acrylate rubber polyorganosiloxane copolymer epoxy surface-treated product, Mitsubishi Rayon Co., Ltd. (metaprene SX101) average particle size 0.2 μm

<Evaluation of Physical Properties> Melt-mixed pellets were molded at a cylinder temperature of 290 ° C. and a mold temperature of 135 ° C. to prepare test pieces, and bending properties (according to ASTM D790) were measured. The results are shown in Tables 1 and 2. The melt viscosity was measured using a capillary viscometer at a resin temperature of 300 ° C. at a neat temperature and a shear rate of 200 S ⁻¹ , and for a compound product, a resin temperature of 310 ° C. and a shear rate of 1200 S ⁻¹ . . Regarding hygroscopicity, the test piece prepared above was immersed in water at 23 ° C. for 24 hours, and then the increase in weight was measured. Regarding the adhesiveness, the composition was first sandwiched at 320 ° C. between aluminum plates and press-molded,
Next, before resin solidification, the resin was solidified under pressure at 135 ° C. for 10 minutes, and then the adhesion between the aluminum plate and the resin was evaluated by an ultrasonic flaw detector (UH PLUSE 100 manufactured by Olympus Corporation). The results are shown in Table 1 and Table 2, respectively.

[0040]

[Table 1]

[0041]

[Table 2]

From the above Examples and Comparative Examples, the following was found. Comparative Example 1 uses only the terpolymer elastomer (C) and has good adhesion, but high water absorption and low bending strength. Further, Comparative Examples 2 to 4 using only the polysiloxane rubber (D) have high bending strength and low water absorption, but have poor adhesion. On the other hand, Examples 1 to 5 containing both the terpolymer elastomer (C) and the polysiloxane rubber (D) have low water absorption, good adhesion, and high bending strength. Comparative Example 5 in which the glass fiber (E) was added and the terpolymer elastomer (C) and the polysiloxane rubber (D) were not added at all in the system had high strength and low water absorption, but had poor adhesion. bad. Comparative Example 6 in which only the ternary copolymer elastomer (C) is added has high strength and good adhesion, but has high water absorption. On the other hand, Examples 6 to 8 in which the terpolymer elastomer (C) and the polysiloxane rubber (D) were added,
It has low water absorption, good adhesion, and high bending strength. As described above, it is understood that only the system in which both the terpolymer elastomer (C) and the polysiloxane rubber (D) are mixed has good adhesion, high strength and low water absorption. In addition, it is understood from the comparison between Example 2 and Examples 7 and 8 that the strength can be further increased by adding the glass fiber (E) to this system while maintaining the above characteristics.

[0043]

As described above, according to the present invention,
It is possible to provide a polyarylene sulfide resin composition that is suitable as a sealing material for ICs and the like, has a low moisture absorption, and has excellent mechanical strength and adhesion while maintaining high fluidity.

Claims (7)

[Claims] 1. A polyarylene sulfide resin (A),
It contains silica (B), a terpolymer elastomer (C) composed of ethylene, an α, β-unsaturated carboxylic acid alkyl ester and maleic anhydride, and a polysiloxane rubber (D) having a crosslinked structure. And a blending ratio (wt%) thereof satisfies the following formulas (I) to (III). 30 ≦ A / (A + B + C + D) ≦ 60 (I) 40 ≦ B / (A + B + C + D) ≦ 70 (II) 3 ≦ / (C + D) / (A + B + C + D) ≦ 30 (III) 2. The polyarylene sulfide according to claim 1, wherein the polyarylene sulfide resin (A) has a melt viscosity of 5 to 30 Pa · S at a resin temperature of 300 ° C. and a shear rate of 200 S ⁻¹ . Resin composition. 3. The polyarylene sulfide resin composition according to claim 1, wherein the sodium content of the polyarylene sulfide resin (A) is 150 ppm or less. 4. The silica (B) has an average particle size of 5
The polyarylene sulfide resin composition according to any one of claims 1 to 3, which is fused silica and / or crystalline silica having a size of 0 µm or less. 5. The composition ratio of the monomer components in the terpolymer elastomer (C) is 50 to 90% by weight of ethylene and 5 to α, β-unsaturated carboxylic acid alkyl ester.
49% by weight, and maleic anhydride 0.5-10% by weight
The polyarylene sulfide resin composition according to any one of claims 1 to 4, wherein the polyarylene sulfide resin composition is an ethylene copolymer. 6. The polysiloxane rubber (D) having the crosslinked structure is a polyorganosiloxane rubber 100.
%, Or polyorganosiloxane rubber component 1 to 99
% By weight and polyalkyl (meth) acrylate rubber 99 to
Polyorganosiloxane-based graft copolymers obtained by graft-copolymerizing one or more vinyl-based monomers to a composite rubber having a structure in which 1% by weight cannot be separated from each other, either alone or in combination. It is a mixture, The polyarylene sulfide resin composition of any one of Claims 1-5. 7. A composition comprising the composition according to any one of claims 1 to 6 and further containing glass fiber (E), and the ratio (% by weight) thereof satisfies the following formula (IV). And a polyarylene sulfide resin composition. 0 <E / (A + B + C + D + E) ≦ 30 (IV)