JPH10237303A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition having a high dielectric constant and a low dielectric loss tangent and useful as a material for electronic and electric parts treated in high frequency zones by including polyphenylene sulfide resin having a specific melt viscosity, rutile type titanium dioxide, a fibrous filler, etc. SOLUTION: This resin composition comprises (A) 10-65wt.% of polyphenylene sulfide resin having a melt viscosity of 100-2000 poises at 300 deg.C, (B) 30-85wt.% of rutile type titanium dioxide having an average particle diameter of 0.01-1μm and a purity of >=90%, (C) 5-40wt.% of a fibrous filler, one or more other inorganic fillers or their mixture (wherein the total amount of the components B and C is <=90wt.%), has excellent dielectric characteristics comprising a specific dielectric constant of >=6 and a dielectric loss tangent of <=0.003 in a high frequency zone of >=1 giga hertz, and is good in moldability such as injection moldability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyphenylene sulfide resin composition having excellent dielectric properties and good moldability such as injection molding, and more particularly, it has a high dielectric constant and a low dielectric loss tangent. High frequency band (GHz band)
The present invention relates to a polyphenylene sulfide resin composition which is effective as a material for electronic and electric parts handled in the above.

[0002]

2. Description of the Related Art The frequency band handled in the field of information and communication has shifted to higher frequency bands, and a number of devices handling the gigahertz (hereinafter referred to as GHz) band, such as satellite broadcasting and mobile phones, have appeared. Global Positionio is one of the systems for transmitting information using the GHz band.
Ning System (hereinafter referred to as GPS)
It has become familiar since it was applied to car navigation systems. A radio wave receiving antenna (hereinafter, referred to as a GPS antenna) for car navigation is a microstrip antenna which is a kind of a planar antenna. The resonance frequency (f ₀ ) of this antenna is given by equation (1). f ₀ = C / 2dε ^1/2 (1) where C: speed of light ε: dielectric constant of the antenna substrate d: length (mm) of one side of the electrode on the antenna substrate.

In the case of GPS, f ₀ (1.5754 GH
Since z) and C are constant, the size (d) of the GPS antenna depends on the dielectric constant of the substrate according to equation (1). The dielectric properties required for the GPS antenna include a high dielectric constant (ε), a low dielectric loss tangent (tan δ), and ε,
The value of tan δ is summarized in three points that the value of tan δ is hardly affected by temperature and humidity fluctuations. As is clear from equation (1), securing a high dielectric constant is indispensable for miniaturization of the GPS antenna. Further, the lower the value of tan δ, the higher the gain is obtained, and the S / N
It is also advantageous from the viewpoint of the ratio (Signal Noise Ratio).

At present, various ceramics are used for the dielectric substrate of the GPS antenna. Ceramics can easily secure a high dielectric constant, which is advantageous for miniaturization of an antenna, but is disadvantageous from the viewpoint of yield because the dielectric constant is affected by the firing step. From this point, it is preferable that the dielectric material is made of resin and the substrate is manufactured by injection molding for the purpose of simplifying the working process and ensuring stable performance. For example, JP-A-8-41247 proposes a resin composition in which a fibrous metal titanate is filled in a synthetic resin, but the resin composition generally has a large dielectric loss tangent and is not suitable for high frequency applications.

[0005]

SUMMARY OF THE INVENTION The present invention provides a polyphenylene sulfide resin composition having a high dielectric constant, a low dielectric loss tangent, and excellent in processability such as injection molding for high frequency electric and electronic parts.

[0006]

According to the present invention, there is provided (a) 300
A polyphenylene sulfide resin having a melt viscosity at 100 ° C. of 100 to 2000 poise; (b) a rutile-type titanium oxide; (c) a polyphenylene sulfide resin composition comprising a fibrous filler, another inorganic filler, or a mixture thereof; In the embodiment, the component (a) is 10 to 65% by weight, the component (b) is 30 to 85% by weight, and the component (c) is 5 to 65% by weight.
40% by weight (however, the sum of (b) and (c) is 90% by weight
The rutile-type titanium oxide has an average particle size of 0.01 μm or more and 1 μm or less, a purity of the rutile-type titanium oxide of 90% or more, and a relative dielectric constant of 6 GHz or more in a high-frequency band of 6 GHz or more. As described above, the dielectric loss tangent is 0.0
The polyphenylene sulfide resin composition is 03 or less.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The polyphenylene sulfide (hereinafter, referred to as PPS) resin as the component (a) used in the present invention is excellent as an engineering plastic such as heat resistance, dimensional stability, low water absorption, rigidity, chemical resistance, moldability, and flame retardancy. Since it has properties, it is suitably used for electric and electronic parts for injection molding. As the PPS resin, a general formula

FIG. Preferably, the composition contains at least 70 mol% of the structural unit represented by the formula. If the amount is less than 70 mol%, it is difficult to obtain a composition having excellent properties. As a polymerization method of the PPS resin, a method of reacting sodium sulfide with p-dichlorobenzene in an amide solvent such as N-methylpyrrolidone or dimethylacetamide or a sulfone solvent such as sulfolane is suitable.
At this time, an alkali metal salt of a carboxylic acid or a sulfonic acid is added to adjust the degree of polymerization, or an alkali hydroxide, an alkali metal carbonate, or an alkaline earth metal oxide is added.

If the amount of the copolymer component is less than 30 mol%, a meta bond, an ortho bond, an ether bond, a sulfone bond, a biphenyl bond, or a substituted phenylene sulfide bond (where the substituent is an alkyl group, a nitro group, a phenyl group) , An alkoxy group, a carboxylic acid group, a metal base of a carboxylic acid), a trifunctional bond or the like, as long as it does not greatly affect the crystallinity of the polymer. Good.

[0010] The PPS resin is usually used in the presence of oxygen in the range of 200 to
It is used after adjusting the melt viscosity by thermal crosslinking at a temperature of 250 ° C., but the PPS used in the present invention is not limited to such a crosslinking type, and a linear type or a branched type is used. I can do it. Desirable melt viscosity is 3
100-2000 poise at 00 ° C, more preferably 20 poise
The range is from 0 to 1500 poise. If the melt viscosity is lower than 100 poise, the mechanical strength of the material decreases, and
If the poise is higher than the poise, the moldability decreases. When the filler is compounded at a high concentration as in the present invention, it is desirable to use a filler having a relatively low viscosity within the above range in consideration of extrusion processability and moldability.

[0011] Titanium oxide (TiO ₂ ) is mainly used as a white pigment, and is one of the inorganic pigments that are currently produced in large quantities along with black carbon black. Its excellent optical properties (large refractive index) In addition to this, it has a feature of having a high dielectric constant. Titanium oxide is classified into three types, anatase type, rutile type, and brookite type, depending on its crystal type. Of these, two are industrially produced, the anatase type and the rutile type. The sulfuric acid method and the chlorine method are available as production methods.The sulfuric acid method is a method in which the raw material ilmenite is digested with sulfuric acid to extract and separate the titanium component, hydrolyze it, and then calcine and pulverize it to produce titanium oxide. Yes, the crystal form of the obtained titanium oxide is determined depending on the conditions of the firing step (anatase type or rutile type). on the other hand,
The chlorine method is a method using chlorine instead of sulfuric acid, and generally produces rutile titanium oxide.

The titanium oxide used in the present invention is of the rutile type, and the use of the anatase type does not lead to a significant improvement in the dielectric constant. Average particle size is 0.01μ
m or more and 1 μm or less, more preferably 0.05 μm or more and 0.5 μm or less. Average particle size is 0.0
If it is less than 1 μm, a problem of moldability occurs, and if it exceeds 1 μm, the mechanical strength of the material decreases. The purity of the rutile type titanium oxide used is 90% or more, more preferably 92% or more. When the purity is less than 90%, the effect of improving the dielectric constant of the material is small. The compounding amount of the rutile type titanium oxide is 30 to 85% by weight, more preferably 40 to 80% by weight. If it is less than 30% by weight, the effect of improving the dielectric constant of the material is small, and if it is more than 85% by weight, the moldability is reduced.

A fibrous filler which is the component (c) of the present invention,
Other inorganic fillers are used to improve various physical properties such as mechanical strength, heat resistance, dimensional stability, and electrical properties of the material (b)
Used in combination with ingredients. Examples of the fibrous filler include glass fiber, carbon fiber, asbestos fiber, silica fiber, silica / alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and stainless steel. Inorganic fibrous materials such as fibrous materials of metals such as aluminum, titanium, copper, and brass can be used.

Other inorganic fillers include carbon black, quartz powder, glass beads, glass powder, glass flake, calcium silicate, aluminum silicate,
Silicates such as clay, mica, diatomaceous earth, wollastonite, metal oxides such as iron oxide, zinc oxide and alumina; carbonates of metals such as calcium carbonate and magnesium carbonate; metals such as calcium sulfate and barium sulfate Sulfates, etc.
Examples include silicon carbide, silicon nitride, boron nitride, and various metal powders. These fillers can be used in combination of two or more of fibrous fillers and other inorganic fillers. In use, it is desirable to modify the particle surface with a surface treatment agent. Examples of the surface treatment agent include functional compounds such as epoxy compounds, isocyanate compounds, silane compounds, titanate compounds, and the like. The filler may be surface-treated with these compounds in advance or used at the same time as mixing the materials.

The content of these fillers is 5 to 40% by weight, more preferably 10 to 30% by weight. 5% by weight
When the amount is less than the above, the effect of improving various properties is small, and when the amount is more than 40% by weight, the moldability is significantly reduced. In particular, in the case of a fibrous filler, this tendency is strong, and anisotropy tends to be exhibited when the molded product shrinks. Therefore, it is desirable to keep the content within the above-mentioned range. The total of the rutile-type titanium oxide and the filler is 90% by weight or less. When the total amount exceeds 90% by weight, there is a problem that workability deteriorates. Further, the composition of the present invention generally contains a thermoplastic resin, and known substances added to the thermosetting resin, that is, stabilizers such as antioxidants and ultraviolet absorbers, antistatic agents, flame retardants, dyes and the like. A coloring agent such as a pigment, a lubricant, and the like can be appropriately added as needed.

The resin composition obtained by blending them has a relative dielectric constant of 6 or more in a high frequency band of 1 GHz or more and a dielectric loss tangent of 0.003 or less. If the relative dielectric constant in the high frequency band is less than 6, it is disadvantageous for miniaturization of communication device parts, and if the dielectric loss tangent exceeds 0.003, there is a problem that signals are converted into heat and energy loss increases.

The method for producing the composition according to the present invention is not limited. For example, the components may be weighed, then mixed by a blender, a mixer or the like, and melt-kneaded by an extruder to form pellets. Then, the glass fibers may be kneaded and pelletized by quantitatively supplying them with a side feeder. The pellet-shaped molding material thus obtained is
It is usually molded into a desired shape by a widely used thermoplastic resin molding machine, injection molding machine, injection compression molding machine or the like and used.

[0018]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. The components used in Examples 1 to 8 and Comparative Examples 1 to 8 are as shown below. PPS resin: manufactured by Toprene Co., Ltd. Product name: K-1 Rutile type titanium oxide: manufactured by Ishihara Sangyo Co., Ltd. Product name: Thai-Hook CR-80 Glass fiber: manufactured by Nippon Sheet Glass Co., Ltd. Product name: RES03-TP29 Calcium carbonate: Shiraishi calcium Co., Ltd. Product name Whiten P-30

The above components were blended with the compositions (% by weight) shown in Tables 1 and 2, and melt-kneaded with a twin-screw kneader to form pellets. After the obtained molding material was dehumidified and dried at 140 ° C. for 5 hours, the cylinder temperature was 300 ° C. and the injection pressure was 1200 kg / using an injection molding machine (TOSHIBA MACHINE IS80EPN).
Molding was performed under the conditions of cm ² , medium injection speed, and mold temperature of 140 ° C. to produce various test pieces. Using each test piece, the bending strength, the relative dielectric constant, and the dielectric loss tangent were measured. Flexural strength is A
The measurement was performed by the STM test method (D790), and the dielectric properties were measured by the triplate line resonator method (loss separation method). Further, the fluidity of the material was measured by a Koka flow (JIS K7210) (300 ° C., pressure load 50 kg). The results are shown in Tables 1 and 2.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

According to the present invention, the dielectric properties (high dielectric constant,
A PPS resin composition having excellent low dielectric loss tangent and excellent moldability can be provided. Such a resin composition can be used for electric / electronic parts handling a high frequency band, for example, a substrate use of a GPS antenna.

Claims (5)

[Claims] (1) a melt viscosity at 300 ° C. of 10
A polyphenylene sulfide resin composition comprising a polyphenylene sulfide resin having 0 to 2000 poise, (b) rutile-type titanium oxide, (c) a fibrous filler, another inorganic filler, or a mixture thereof. 2. Component (a) is 10 to 65% by weight, (b)
30 to 85% by weight of component, 5 to 40% by weight of component (c)
The polyphenylene sulfide resin composition according to claim 1, wherein the polyphenylene sulfide resin composition is blended (provided that the total of (b) and (c) is 90% by weight or less). 3. The polyphenylene sulfide resin composition according to claim 1, wherein the average particle size of the rutile type titanium oxide is 0.01 μm or more and 1 μm or less. 4. The polyphenylene sulfide resin composition according to claim 1, wherein the purity of the rutile type titanium oxide is 90% or more. 5. The polyphenylene sulfide resin composition according to claim 1, wherein the relative dielectric constant in a high frequency band of 1 GHz or more is 6 or more and the dielectric loss tangent is 0.003 or less.