JP3494227B2 - Polyarylene sulfide resin composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyarylene sulfide resin composition, and more particularly to a polyarylene sulfide resin composition for encapsulating electronic parts, which is characterized by having a small anisotropy of linear expansion coefficient and excellent mechanical strength. The present invention relates to a thermoplastic resin composition that can be preferably used, and is particularly suitable for IC encapsulation.

[0002]

2. Description of the Related Art In recent years, polyarylene sulfide resins (hereinafter sometimes referred to as PAS) have been found to have excellent chemical resistance and mechanical properties.
Since it has heat resistance and flame retardancy, etc.
It is used as an excellent engineering plastic in a wide range of fields such as automobile parts.

Thermosetting resins have hitherto been used as resins for electronic parts, especially IC encapsulation, but due to problems such as difficulty in recycling and inability to reuse spool runners, thermoplastic resins have recently been used. Resins are receiving attention.
Among them, PAS has been extensively studied because of its excellent heat resistance and flame retardancy.

When such a thermoplastic resin is used for IC encapsulation, in order to mold the lead wire and bonding wire without cutting and deforming, the molecular weight of the resin is lowered and the coefficient of linear expansion approaches that of metal. It is important to let Therefore, it was considered to add a large amount of filler, but it was possible to make the linear expansion coefficient close to that of metal by adding a large amount of filler. However, the mechanical strength of the molded product was lowered, and new problems such as cracks occurred.

Therefore, in order to solve the above problem, for example, Japanese Patent Publication No. 5-18351 proposes a method of improving mechanical strength by adding a silane coupling agent to PAS. However, although it has some effect of improving the toughness, it cannot be said to be sufficient. In addition, JP-A-57-158256 discloses a PAS.
, Glass beads or quartz glass, glass fiber,
A method of adding an organic silane has been proposed. However, there is a problem that when the blending amount of the glass fiber is increased, there is a risk of cutting the wire in the element, and the reliability of the manufactured element is poor. Japanese Patent Laid-Open No. 62-158754 proposes a method of adding silica, a fibrous inorganic filler, and epoxysilane to polyphenylene sulfide (hereinafter sometimes abbreviated as PPS). Since the linear filler is used, the coefficient of linear expansion becomes anisotropic, which also causes a problem in the reliability of the device.

That is, a resin composition having a small anisotropy of linear expansion coefficient and an excellent mechanical strength has been desired for the purpose of being used for sealing electronic parts such as ICs. In order to solve such a problem, the inventors of the present invention have made extensive studies, and as a result, a resin composition obtained by mixing PAS with silica, a silane coupling agent, and zinc oxide whiskers having a unique three-dimensional structure , Found that the linear expansion coefficient has little anisotropy and at the same time has excellent mechanical strength,
The present invention has been completed. That is, the present invention provides a resin composition suitable for encapsulation of electronic parts such as ICs, which has a small anisotropy of linear expansion coefficient, is excellent in strength, and is excellent in heat resistance and flame retardancy. The purpose is to do.

[0007]

The invention according to claim 1 for solving the above-mentioned problems comprises a polyarylene sulfide containing an amino group, silica, an epoxysilane coupling agent, and a three-dimensional structure. A zinc oxide whisker having a polyarylene sulfide resin composition, wherein the polyarylene sulfide has an amino group-containing arylene sulfide unit of 0.1. The polyarylene sulfide resin composition according to claim 1, wherein the polyarylene sulfide resin composition is a resin composition for IC encapsulation. The polyarylene sulfide resin composition according to claim 1.

The polyarylene sulfide resin composition of the present invention will be described in detail below.

-Amino Group-Containing Polyarylene Sulfide- The amino group-containing polyarylene sulfide resin of the present invention (hereinafter sometimes referred to as aminated PAS) is represented by the following formula (Formula 1). However, it is a polymer resin containing at least an arylene sulfide unit containing an amino group.

[0010]

[Chemical 1]

However, in the formula, Ar represents a structure having an aromatic ring. Further, the position where the amino group in the above formula is bonded to the aromatic ring is arbitrary. In the above formula, R ¹ and R ² represent a hydrogen atom and a hydrocarbon group, respectively, and R ¹ and R ² may be the same as or different from each other. When R ¹ and R ² are hydrocarbon groups,
Examples of the hydrocarbon group include lower saturated hydrocarbon groups such as methyl group, ethyl group, and propyl group, aromatic hydrocarbon groups such as phenyl group, and the like. Preferred as R ¹ and R ² is a hydrogen atom. In the above formula, n represents a positive number, and is specifically an arbitrary positive number from 1 to 8 determined according to the structure of the aromatic nucleus to which the amino group is bonded.

Examples of the structure having an aromatic ring in the above formula include the structure represented by the following formula (Formula 2).

[0013]

[Chemical 2]

The polyarylene sulfide in the present invention may contain an arylene sulfide unit having a structure represented by the formula (Formula 2) in addition to the arylene sulfide unit represented by the formula (Formula 1).

In the polyarylene sulfide of the present invention, the content of the arylene sulfide unit containing an amino group is usually 0.1 mol% or more, preferably 0.1 to 0.1 mol%.
It is 30 mol%, more preferably 0.3 to 10 mol%, and particularly preferably 0.3 to 5 mol%.

When the content is less than 0.1 mol%, few amino groups are introduced, so that the effect of improving physical properties such as strength is small, and when the content exceeds 30 mol%, aminated P is contained.
It is not preferable because the crystallinity of AS is decreased and the physical properties such as heat resistance are deteriorated.

The aromatic ring containing an amino group or the aromatic ring not containing an amino group in the arylene sulfide unit further contains an atom such as a halogen atom such as F, Cl, Br or the like, or an alkyl group such as a methyl group. Substituents such as nitro group, carboxylic acid / metal salt, and phenyl group may be introduced.

In the aminated PAS, for example, a halogenated aromatic compound containing an amino group, a dihaloaromatic compound, and a sulfur source are subjected to polycondensation reaction by employing various methods in an organic polar solvent. Can be obtained.

Examples of the halogenated aromatic compound containing an amino group include chloro-substituted anilines such as monochloroaniline, N-alkylmonochloroaniline, dichloroaniline and N-alkyldichloroaniline. . The halogenated aromatic compound containing an amino group is not limited to such anilines and may be any substance containing an amino group in the aromatic ring. The halogenated aromatic compounds containing an amino group may be used alone or in combination of two or more.

Examples of the dihalo aromatic compound include dihalobenzenes such as m-dihalobenzene and p-dihalobenzene; 2,3-dihalotoluene, 2,5-dihalotoluene, 2,6-dihalotoluene, 3,4-dihalotoluene, 2, 5-dihaloxylene, 1-ethyl-2,5-
Dihalobenzene, 1,2,4,5-tetramethyl-3,
6-dihalobenzene, 1-normalhexyl-2,5-
Alkyl-substituted dihalobenzenes such as dihalobenzene, 1-cyclohexyl-2,5-dihalobenzene or cycloalkyl-substituted dihalobenzenes; 1-phenyl-2,
Aryl-substituted dihalobenzenes such as 5-dihalobenzene, 1-benzyl-2,5-dihalobenzene, 1-p-toluyl-2,5-dihalobenzene; dihalobiphenyls such as 4,4′-dihalobiphenyl, 1,4 Examples thereof include dihalonaphthalene, dihalonaphthalene, 1,6-dihalonaphthalene, and 2,6-dihalonaphthalene. The two halogen elements in these dihalo-aromatic compounds are respectively fluorine, chlorine, bromine or iodine, which may be the same or different from each other.

As the sulfur source, alkali metal sulfides such as lithium sulfide and sodium sulfide, calcium sulfide,
Examples thereof include alkaline earth metal sulfides such as barium sulfide. Further, the alkali metal sulfide or alkaline earth metal sulfide is an alkali metal hydrosulfide such as lithium hydrosulfide or sodium hydrosulfide, or an alkaline earth metal hydrosulfide such as calcium hydrosulfide or barium hydrosulfide. It may be obtained by reacting each with a base such as an alkali metal hydroxide.

Examples of the organic polar solvent include organic solvents such as amide compounds, lactam compounds, urea compounds, cyclic organic phosphorus compounds and sulfone compounds. Preferred examples of these are N-alkyl lactams, especially N-alkyl pyrrolidone and sulfolane.

In the present invention, during the polycondensation reaction, a branching agent such as an active hydrogen-containing haloaromatic compound, a polyhaloaromatic compound having 3 or more halogen atoms in one molecule, a haloaromatic nitro compound, etc. , A monohalo aromatic compound, an alkali metal salt such as a carboxylic acid or a sulfonic acid, a molecular weight modifier such as an alkali metal halide such as lithium chloride, and the like may be appropriately added to the reaction system. By using the branching agent, the molecular weight modifier, etc., the degree of branching of the aminated PAS produced by the polycondensation reaction can be increased, the molecular weight can be further increased, or the residual salt content can be decreased. Various characteristics are improved.

As a preferred example of the aminated PAS, for example, a polyphenylene sulfide resin containing a phenylene sulfide unit having an amino group represented by the following (Chemical Formula 3) (hereinafter may be referred to as aminated PPS).
Can be mentioned.

[0025]

[Chemical 3]

The preferred molecular weight of the aminated PAS in the present invention can be represented by the logarithmic viscosity as an index representing the molecular weight. That is, the value of the logarithmic viscosity of the α-chloronaphthalene solution 0.4 g / dl and 206 ° C. is usually 0.07 to 0.2, preferably 0.1 to 0.
20 and particularly preferably 0.15 to 0.20. If the value is less than 0.07, the viscosity may be too low and the mechanical strength of the molded product may be poor. On the other hand, if it exceeds 0.2, the viscosity becomes high and the fluidity deteriorates, and problems such as deformation of the bonding wire of the element occur.

The sodium content of the aminated PAS is preferably 150 ppm or less. If it exceeds 150 ppm, metal parts in the element are likely to be corroded.

The amount of the aminated PAS used in the present invention is usually 30 to 60% by weight, preferably 30 to 50% by weight, based on the total amount of the aminated PAS, silica and zinc oxide whiskers. Especially 30 ~
45% by weight is preferred. If the content is less than 30% by weight, the viscosity may be too high and the moldability may be poor. On the other hand, if it exceeds 60% by weight, the linear expansion coefficient becomes large.

-Silica-As the silica, fused and / or crystalline silica can be used. The silica may or may not be surface-treated with a silane coupling agent such as epoxysilane or aminosilane. The average particle size is preferably 50 μm or less. Average particle size is 50 μm
If it exceeds, the fluidity of the resin composition will decrease. The sodium content of the silica is preferably 5 ppm or less, and particularly preferably 3 ppm or less. 5 ppm
If it exceeds the range, Na ⁺ is eluted into the device and reduces the reliability of the device, which is not preferable.

The amount of the silica compounded is 5 to 70% by weight, preferably 20 to 70% by weight, particularly 50 to 70% by weight, based on the total amount of the aminated PAS, the silica and the zinc oxide whiskers. Is preferred. If the content is less than 5% by weight, the coefficient of linear expansion of the composition may increase. On the other hand, if it exceeds 70% by weight, the fluidity may be insufficient and the yield of the element after molding may be lowered.

—Epoxysilane Coupling Agent— The epoxysilane coupling agent is an alkoxysilane or halosilane having at least one epoxy group in the molecule, and is, for example, β- (3,4-cyclohexyl) ethyltrimethoxy. Examples thereof include silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyldimethoxysilane, γ-glycidoxypropyltriethoxysilane, vinyl-tris (2-methoxyethoxy) silane, and methyltrimethoxysilane. it can. Among these, γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyldimethoxysilane are preferable because of their excellent efficacy.

The compounding amount of the epoxy silane coupling agent in the present invention is 0.01 with respect to the total amount of the aminated PAS, the silica and the zinc oxide whiskers.
To 2 parts by weight, preferably 0.1 to 1.5% by weight,
Particularly, 0.5 to 1.0% by weight is preferable. The content is
If the amount is less than 0.01 parts by weight, the effect of compounding is not exhibited,
On the other hand, if it exceeds 2 parts by weight, the fluidity becomes poor.

-Zinc Oxide Whiskers-One of the important things in this invention is that the zinc oxide whiskers have a three-dimensional structure. The zinc oxide whiskers used in the present invention roughly have a tetrapot-like shape with linear portions extending from the center of a regular tetrahedron to each vertex. As described above, the zinc oxide whiskers according to the present invention have a three-dimensional peculiar structure, so that the coefficient of linear expansion of the composition has no anisotropy and the strength also has no anisotropy.

The zinc oxide whiskers according to the present invention are
As a material thereof, it is sufficient that the surface of the whiskers is formed of at least zinc oxide, or the whiskers themselves may be formed of zinc oxide. The zinc oxide whiskers used in the present invention can be obtained by heating and oxidizing metallic zinc in an oxygen atmosphere. The bulk specific gravity of the zinc oxide whiskers is preferably 0.02 to 0.1.

The amount of the zinc oxide whiskers blended is usually 5 to 65% by weight, preferably 10 to 55% by weight, particularly preferably 20% by weight based on the total amount of the aminated PAS, the silica and the zinc oxide whiskers. -30% by weight is preferred.

If the content is less than 5% by weight, the effect of reducing the anisotropy of linear expansion coefficient may be small.
On the other hand, if it exceeds 65% by weight, problems such as poor molding due to deterioration of fluidity and reduction of device yield occur.

The shape is preferably one having a three-dimensional structure, and among them, those having a structure in which needle crystals grow from the center of the regular tetrahedron to each vertex (shape like tetrapot) are particularly preferable. When zinc oxide whiskers having such a preferable shape are used, the anisotropy of the coefficient of linear expansion is particularly reduced, and a resin composition having excellent strength can be obtained.

-Other Components-In the polyarylene sulfide resin composition according to the present invention, in addition to the above-mentioned components, other components may be added and blended, if necessary, within a range not impairing the object of the present invention. Good.

As the other components, for example, various additives such as inorganic fillers, antioxidants, heat stabilizers, lubricants, colorants, etc., thermoplastic resins such as polyamide, epoxy resin, silicone resin, polyolefin and / or Examples thereof include thermosetting resins, hydrogenated SBS, hydrogenated NBR, rubbers such as silicone rubber and fluororubber, and pigments.

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 carbonates, barium sulfate, calcium sulfate, magnesium sulfate, and other sulfates,
Sulfites such as calcium sulfite, silicates such as calcium silicate, silicon carbide, silicon nitride, ceramics such as boron nitride, calcium titanate whiskers, alumina whiskers, magnesia whiskers, graphite whiskers, silicon carbide whiskers and other whiskers, glass Inorganic fibers such as fibers, aramid fibers and carbon fibers, as well as talc, clay, mica, glass beads, carbon black, diatomaceous earth, asbestos and zeolite can be mentioned.

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.

—Preparation of Polyarylene Sulfide Resin Composition— In the polyarylene sulfide resin composition according to the present invention, at least the aminated PAS, the silica, the epoxysilane coupling, and the zinc oxide whiskers are contained in the predetermined ratio. It can be prepared by blending so that the above-mentioned other components may be blended as necessary, and this may be melt-kneaded.

The melt-kneading can be carried out by an ordinary known method, but in any case, by uniformly mixing and dispersing the above-mentioned components in the resin,
It is a predetermined resin composition.

For the melt-kneading, a usual twin-screw extruder, a single-screw extruder or the like can be preferably used. The conditions of the melt-kneading are not particularly limited, but it is preferable to avoid extremely high temperature and extremely long residence time in order to limit decomposition or foaming of other components added as necessary. As a specific temperature, it is usually 280 to 350 ° C.
And is 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.

[0046]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. In the following examples and comparative examples,
As the silica, fused silica FB35, FB74 and FS784 of Denki Kagaku Kogyo Co., Ltd., which had not been surface treated, were used.
Their average particle size and sodium content are as follows.

FB35; average particle size 11.8 μm, Na
Content 1.0 ppm FB74; average particle size 31.5 μm, Na content 0.7
ppm FS784; average particle size 12.5 μm, Na content 1.1
ppm SH6040 manufactured by Toray Dow Coating Co., Ltd. as an epoxy silane coupling agent, Panatetra manufactured by Matsushita Amtec Co., Ltd. as a zinc oxide whisker (bulk specific gravity: 0.1 g /
cm ³ , surface untreated), potassium titanate whiskers (needle whiskers) manufactured by Otsuka Chemical Co., Ltd. Tismo D
101 was used respectively.

(Examples 1 to 3 and Comparative Examples 1 to 4) -Production of PPS1 (linear PPS) -Hydrous sodium sulfide (Na ₂ S.5H ₂ O) was placed in a polymerization reaction tank equipped with a stirrer. 840 mol, 830 mol of LiCl, and N-methylpyrrolidone (hereinafter referred to as NMP).
510 L was added thereto, and dehydration treatment was carried out for 1 hour while maintaining the temperature at 145 ° C. under reduced pressure. Next, after cooling the reaction system to 45 ° C., 898 mol of p-dichlorobenzene was added to the polymerization reaction tank, and the polymerization reaction was carried out at 260 ° C. for 3 hours. The polymerization reaction product thus obtained was washed 5 times with hot water, then once with NMP, and finally 3 times with water. Then, by drying at 185 ° C., a linear PPS resin having an inherent viscosity η inh of 0.16 and a sodium content of 95 ppm was obtained.

-Production of PPS2 (aminated PPS) -In the dehydration treatment, the compounding amount of LiCl was set to 833 mol, and the polymerization reaction was carried out by adding 912 mol of p-dichlorobenzene and 41.5 mol of dichloroaniline at 240 ° C. An aminated PPS was obtained in the same manner as in the case of PPS1 except that the polymerization reaction was carried out for 5 hours. The aminated PPS thus obtained had an inherent viscosity ηinh of 0.15 and a sodium content of 90 p.
It was pm.

The linear PPS or aminated PPS obtained as described above was dry-blended with the silica shown in Table 1, the epoxysilane coupling agent and the whiskers in the composition shown in Table 1. This dry blended product was melt-kneaded and granulated at a resin temperature of 290 ° C. using a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., TEM35B; diameter 20 mm) to obtain pellets of a PPS resin composition. It was Next, a test piece was prepared by molding the obtained pellet at a cylinder temperature of 290 ° C. and a mold temperature of 135 ° C.

[0051]

[Table 1]

Using the test pieces of the obtained PPS resin composition, Izod strength and bending strength were measured, and the results are shown in Table 1. Both measurements are based on ASTM D2
56 and ASTM D790.

Further, using a sample obtained by cutting from the central portion of the test piece, the temperature was raised at a heating rate of 5 ° C./min to 40
The linear expansion coefficient of MD and TD at ° C was measured. The ratio of linear expansion coefficients (TD / MD) was calculated in order to evaluate the anisotropy and is shown in Table 1.

[0054]

According to the present invention, it is possible to provide a resin composition having a small anisotropy of linear expansion coefficient, excellent mechanical strength, heat resistance and flame retardancy. Since the resin composition of the present invention has the above-mentioned features, it can be particularly suitably used for sealing electronic parts such as ICs.

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 81/00-81/10 C08K 3/00-13/08

Claims (3)

(57) [Claims] 1. A polyarylene sulfide resin composition comprising an amino group-containing polyarylene sulfide, silica, an epoxysilane coupling agent, and a zinc oxide whisker having a three-dimensional structure. 2. The polyarylene sulfide resin composition according to claim 1, wherein the polyarylene sulfide contains 0.1 mol% or more of an arylene sulfide unit containing an amino group. 3. The polyarylene sulfide resin composition according to claim 1, wherein the polyarylene sulfide resin composition is an IC encapsulating resin composition.