JP3295847B2 - Polyarylene sulfide resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a metal part (for example, a silver-plated terminal) having excellent mechanical strength, corrosion of a mold at the time of molding, and an assembly part using the molded product. Etc.) and a polyarylene sulfide (hereinafter abbreviated as PAS) resin composition having reduced corrosion.

"Conventional technology" PAS resin has extremely high heat resistance, chemical resistance, electrical properties, and combustion resistance, and has excellent mechanical strength, rigidity, It is known to exhibit dimensional stability and is widely used for various molding applications such as electric / electronic parts, automobile parts, and mechanical parts.

However, PAS resin generates a metal corrosive gas at high temperature and at the time of melting, so that a mold or a molding machine is corroded at the time of molding, or when a molded product is subjected to aging treatment at a temperature of 100 ° C or higher and lower than the melting point, There are problems such as corrosion of metal parts (for example, silver-plated terminals, etc.) of the assembled parts using the molded products or corrosion of the insert metal parts.

For example, when a PAS resin is used for a relay base, troubles such as corrosion of a silver contact of the relay causing a contact failure and deterioration of solder adhesiveness in an insert metal portion due to corrosion have occurred.

In other words, there are currently two types of problems of metal corrosion caused by PAS resin: corrosion of molds and the like when the PAS resin is melted, and corrosion of silver-plated terminals and the like during aging below the melting point. I have.

Regarding such a problem, a method of adding a hydroxide or carbonate of an alkali metal has been conventionally known (US Pat. No. 4,017,450).
And a method of adding a hydroxide, oxide or aromatic carboxylate of a Group _A metal of the Periodic Table II (JP-A-62-109850).

However, in each case, a sufficient effect cannot be obtained, and it can be said that there is no effect particularly in preventing silver corrosion when the PAS resin is aged at a temperature of 100 ° C. or higher and lower than the melting point. In addition, all additives themselves are water-soluble,
Or because it has hygroscopicity even if it is not water-soluble, the water resistance is reduced by the addition of the above compounds, and when used for insulating materials reinforced with glass fiber etc., the insulating properties under humid conditions It is the present situation that causes a drastic reduction.

Further, a method of adding γ-alumina to a PAS resin is known (Japanese Patent Application Laid-Open No. 62-241962). However, according to this method, there is no effect on corrosion of a mold or the like during melting of the PAS resin. A composition which can be recognized and has no effect on corrosion of silver-plated terminals and the like during aging at a temperature lower than the melting point, although no reduction in water resistance and insulation properties under humid conditions is observed. , A decrease in strength is observed.

Further, a composition for encapsulating electronic parts in which general zinc oxide is added to a PAS resin and a method for preventing color shift thereof (Japanese Patent Application Laid-Open No. 59-181408) are known. In the composition to be added, in addition to not being able to obtain a sufficient effect on mold corrosion during melting of the PAS resin and corrosion of silver-plated terminals during aging below the melting point, the biggest problem is that in the case of a small amount of added composition, Even the strength is greatly reduced.

"Problems to be Solved by the Invention" The object of the present invention is to significantly reduce both corrosion of a mold and the like during melting of a PAS resin and corrosion of a silver-plated terminal and the like during aging at or below the melting point, and It is an object of the present invention to provide a polyarylene sulfide resin composition which retains good insulating properties under humid conditions even when used as an insulating material and has excellent mechanical strength.

"Means for Solving the Problems" The present invention provides a PAS resin composition characterized by adding a specific zinc compound to a PAS resin.

That is, the present invention relates to a PAS resin having at least 80
PAS resin characterized by adding a zinc-based compound having a chemical composition of ZnO by weight% and an average particle size of 0.1 μm or less (air permeation method) and a specific surface area of 30 m ² / g or more (BET method). It provides a composition.

The most significant features of the composition of the present invention are, first of all, the corrosion of the mold and the like when the PAS resin is melted, and the corrosion of the silver plated terminals and the like when the PAS resin and its molded product are aged below the melting point. Is greatly reduced.

Conventional methods, for example, the Periodic Table I _A group hydroxides, carbonates, Periodic Table II _A group hydroxides, the addition of such oxides, PAS
The purpose is to reduce the metal corrosive gas during resin melting, and its effect is not sufficient.

Furthermore, these conventional methods have no corrosion-preventing effect on metal (especially silver) corrosive gas when a PAS resin or a molded article thereof is heat-aged at a temperature lower than the melting point for a long time.

On the other hand, the specific zinc-based compound added in the present invention is derived from its inherent properties (chemical composition, particle size, specific surface area, etc.) and, in addition to preventing corrosion of a mold and the like at the time of PAS resin melting, It has an outstanding effect on preventing metal (especially silver) corrosion during heat aging below the melting point.

A second feature of the composition of the present invention is that it has good water resistance and excellent insulating properties even when used as an insulating material.

As described above, hydroxides and carbonates of Group _A of the periodic table are often readily soluble in water, and hydroxides of Group _{A of the} periodic table II,
Many oxides are also hygroscopic.

On the other hand, the specific zinc compound added in the present invention is hardly soluble in water and has extremely low water absorption.

Therefore, the composition of the present invention has remarkably improved water resistance, and furthermore, when used for an insulating material, has an extremely excellent insulating property typified by a long-term high-humidity volume resistivity holding capacity. It is excellent.

A third feature of the composition of the present invention is that it has excellent mechanical strength.

In a conventional method, for example, a method of adding γ-alumina, when a large amount is added for the purpose of preventing corrosion of a mold or the like at the time of melting, the tensile strength, bending strength, impact strength, and the like are reduced. In addition, for example, in a method of adding general zinc oxide, a significant decrease in strength is caused even with a very small amount of addition.

On the other hand, the composition of the present invention does not show a decrease in strength due to the addition of the specific zinc compound.

PAS resin used in the present invention It is preferable that the composition contains 90 mol% or more of the structural unit represented by the formula. If the amount is less than 90 mol%, it is difficult to obtain a composition having excellent characteristics. In particular, polyphenylene sulfide (PPS) is preferably used. Examples of the polymerization method of this polymer include a method of polymerizing p-dichlorobenzene in the presence of sulfur and sodium carbonate, a method of polymerizing sodium sulfide or sodium hydrogen sulfide in a polar solvent in the presence of sodium hydroxide, and a method of polymerizing p-chlorobenzene. Self-condensation of luthiophenol and the like can be mentioned. A suitable method is to react sodium sulfide with p-dichlorobenzene in an amide solvent such as N-methylpyrrolidone or dimethylacetamide or a sulfone solvent such as sulfolane. At this time, it is preferable to add an alkali metal salt of carboxylic acid or sulfonic acid or to add an alkali hydroxide in order to adjust the degree of polymerization. If less than 50 mol% as a copolymer component, a meta bond Ether bond Sulfone bond Biphenyl bond Sulfide ketone bond Substituted phenyl sulfide bond Wherein R represents an alkyl group, a nitro group, a phenyl group, a carboxyl group, a metal base of a carboxylic acid, an alkoxy group or an amino group.
Preferably it is at most 40 mol%. Also, a trifunctional bond Including And 5 mol% or less, more preferably 3 mol% or less.

Such a PAS resin can be produced by a general production method, for example, (1) the reaction of a halogen-substituted aromatic compound with an alkali sulfide (U.S. Pat. No. 2,513,188, Japanese Patent Publication No. 44-27671 and Japanese Patent Publication No.
(2) Condensation reaction of thiophenols in the presence of an alkali catalyst or a copper salt (US Pat. No. 32
No. 74165, British Patent No. 1160660) (3) The aromatic compound is synthesized by a condensation reaction with sulfur chloride in the presence of a Lewis acid catalyst (JP-B-46-27255, Belgian Patent No. 29439). And can be arbitrarily selected according to the purpose.

The specific zinc-based compound to be added in the present invention means that at least 80% by weight has a chemical composition of ZnO, an average particle size of 0.1 μm or less (air permeation method), and a specific surface area of 30 m ² / g or more (B
ET method).

In the case of a zinc-based compound in which the weight fraction of ZnO in the chemical composition is less than 80% by weight, the ability to capture metal corrosive gas is undesirably reduced. As the preferred zinc compound used in the present invention, the range of ZnO weight fraction is 85-9.
5% by weight.

When the average particle size measured by the air permeation method exceeds 0.1 μm, or the specific surface area measured by the BET method is 30 m ² /
When the amount is less than g, the metal corrosive gas capturing ability is similarly reduced, which is not preferable.

The specific zinc compound to be added in the present invention is produced by, for example, the following method.

That is, a 20-degree Baume soda ash solution is added to a 20-degree Baume zinc chloride solution to precipitate a basic zinc carbonate, which is washed with water, dried and "calcined" at 600 ° C. If the "calcination" temperature is too high, the particles grow in a hexagonal system, and the particle size increases, which is not preferable.

In this method, for example, when the "calcination" treatment is performed completely (up to 100% by weight in chemical composition) under a high "calcination" temperature,
A general zinc oxide having a hexagonal system is formed, and becomes a compound having, for example, an average particle size of about 0.5 μm (air permeation method) and a specific surface area of about 4 to 5 m ² / g (BET method). It is not preferable because not only the capturing ability is reduced but also the mechanical strength of the added composition is significantly reduced.

Examples of the specific zinc-based compound to be added in the present invention include, for example, those commonly known as active zinc white and wet-process zinc white. The addition amount of the specific zinc compound in the present invention is 0.01 to 100 parts by weight of the PAS resin.
10 parts by weight is preferable, and within such an addition amount, the effect of reducing the metal corrosive gas is large, and the melt flowability of the composition is good, and the composition has high strength.

In order to improve the mechanical properties, various fibrous reinforcing materials and / or powdery or plate-like inorganic fillers can be added to the composition of the present invention.

As the fibrous reinforcement that can be used in the present invention,
Glass fiber, carbon fiber, asbestos fiber, silica fiber,
Inorganic fibrous substances such as silica / alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, and fibrous materials of metals such as stainless steel, aluminum and titanium. Particularly typical fibrous reinforcing agents are glass fibers or carbon fibers. In addition, aramid fibers, and high-melting-point organic fibrous substances such as polyamide, fluorine resin, and acrylic resin can also be used.

Barium sulfate, calcium sulfate, talc, kaolin, clay, bentonite, sericite, zeolite, wollastonite, PMF, ferrite, calcium silicate, aluminum silicate , Calcium carbonate, dolomite, antimony trioxide, titanium oxide, iron oxide, graphite, molybdenum disulfide, silica, quartz powder, milled glass, glass beads, glass balloons, other silicon carbide,
Examples include silicon nitride, boron nitride, various metal powders, and the like.

Examples of the plate-like inorganic filler that can be used in the composition of the present invention include mica, mica, glass flake, and various metal foils.

Further, the composition of the present invention is an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant, as long as the object of the present invention is not impaired.
There is no restriction by adding a nucleating agent, a coloring agent, a silane coupling agent, a release agent, and the like.

Further, the composition of the present invention, a thermosetting resin and other thermoplastic resins within a range that does not impair the purpose of the present invention, for example, epoxy resin, silicone resin, polyimide, ABS, polyphenylene ether, polyamide, polycarbonate, polysulfone, One or more kinds of polyethersulfone, polyarylate, polyacetal, polyetherketone, polyetheretherketone, polybutyleneterephthalate, polyethyleneterephthalate, liquid crystal polymer, polyamideimide, polyetherimide, fluorine resin and the like can be blended.

The composition of the present invention can be prepared by various known methods. For example, a PAS resin and a specific zinc compound to be added in the present invention are mixed in advance with a Henschel mixer or a tumbler, and then supplied to a single-screw or twin-screw extruder and melt-kneaded at 260 to 360 ° C. It can be obtained by granulating.

In addition, at the time of mixing, other fibrous reinforcing materials, powdery or plate-like inorganic fillers, and various additives may be added as necessary.

The composition of the present invention is applied to various applications such as electric / electronic parts, mechanical parts, and automobile parts, and particularly when used for insulating materials, switch parts,
Useful as industrial materials such as relay parts and connectors.

"Example" Hereinafter, the present invention will be further described with reference to examples. In addition, the test values of each characteristic shown in this example are based on the following methods and standards.

<Metallic corrosiveness> (Silver corrosiveness during heat aging below the melting point) As shown in Fig. 1, granules (1) dried at 120 ° C for 3 hours and pelletized (1) are each 50g in a glass pressure bottle (2). Get in,
Silver plating plate (3) (plating thickness: 7μm, weight: 20)
g) is completely buried, sealed with a metal fixing jig (4), and heated at 180 ° C. for 50 hours. After the heat treatment, the corrosion state of the silver plated plate (3) is observed.

<Mechanical strength> 3mm thick bending test specimen and 3mm from granulated pellet
Thick Izod impact strength test specimens were prepared and flexural strength (ASTM D
-790) and Izod impact strength (ASTM D-256).

<Moisture resistance insulation property> (Water resistance when used as an insulating material) A 1.6 mm thick disk for ASTM D-257 was formed from the granulated pellets, and the specimen was heated at 120 ° C and 2 kgf / cm ^2. After the pressure cooker treatment (after PCT) for 30 hours under the conditions described above, the volume resistivity was measured and compared with the initial value.

(Volume resistivity measurement is based on ASTM D-257) Reference Example 1 (Synthesis of PPS resin) N-methylpyrrolidone at a molar ratio of 70, sodium sulfide nonahydrate 0.99, sodium benzoate in a 50-scale autoclave 0.60 and sodium hydroxide were charged at a molar ratio of 0.15 (50 molar scale), and the temperature was raised to 210 ° C. in a nitrogen stream to perform dehydration to 110%.

After the system was cooled to 160 ° C, P-dichlorobenzene was charged at a molar ratio of 10 and sealed, and the internal pressure was increased to 25 kg / cm ² with nitrogen. The temperature was controlled while taking into account the heat generated by the polymerization, and the temperature was raised to 270 ° C., and the polymerization was performed with stirring for 5 hours. The internal pressure had risen to 17 kg / cm ² .

Then, after cooling the system, release the pressure, pour the contents into a large amount of water,
The flaky polymer was recovered. The polymer was repeatedly washed with hot water and acetone, and finally became white flakes with a yield of 70%. This PPS resin powder was put into a ribbon blender, and stirred at 270 ° C. while blowing air thereinto, partially crosslinked PPS in a powder state, and heat-treated until the intrinsic viscosity finally became 0.3.

Examples 1 to 6 and Comparative Examples 1 to 6 Using the PPS resin synthesized in Reference Example 1, after uniformly mixing the raw materials shown in Table 1 in the proportions shown in the table, the mixture was heated to 320 ° C. with a 35 mmφ twin screw extruder. To obtain a pellet.

The metal corrosion was evaluated using the pellets. In addition, using an in-line screw type injection molding machine, the pellets were tested at a cylinder temperature of 320 ° C, a mold temperature of 150 ° C, an injection pressure of 1000 kgf / cm ² , a medium injection speed, and mechanical strength and moisture-proof insulation properties. Was molded and both properties were evaluated. Table 1 shows the results.

[Effect of the Invention] The composition of the present invention has significantly reduced both corrosion of a mold and the like during melting of a PAS resin and corrosion of a silver-plated terminal and the like during aging below the melting point, and has excellent water resistance. Even when used as an insulating material, it retains good insulating properties under humid conditions and has excellent mechanical strength.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which the composition of each of the pellets of Examples and Comparative Examples of the present invention is tested for silver corrosion resistance due to heat aging below the melting point. (1) Pellet resin composition (2) Glass pressure bottle (3) Silver plated plate (4) Fixing jig

Claims (4)

(57) [Claims] 1. A zinc-based compound having a chemical composition of ZnO at least 80% by weight based on a polyarylene sulfide resin and having an average particle diameter of 0.1 μm or less and a specific surface area of 30 m ² / g or more. A polyarylene sulfide resin composition comprising: 2. The resin composition according to claim 1, wherein 0.01 to 10 parts by weight of a zinc compound is added to 100 parts by weight of the polyarylene sulfide resin. 3. The resin composition according to claim 1, further comprising a fibrous reinforcing material. 4. The composition according to claim 1, further comprising a powdery or plate-like inorganic filler.