JPH0345655A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PURPOSE:To reduce the corrosion of metal and to improve the water resistance and moisture-resistant insulating characteristics by incorporating Zn(OH)2 into a polyphenylene sulfide resin. CONSTITUTION:100 pts.wt. polyphenylene sulfide resin is mixed with 0.01-10 pts.wt. Zn(OH)2 and, if necessary, a filler (e.g. glass fibers), a lubricant (e.g. graphite), an antioxidant, a heat stabilizer, an ultraviolet absorber, a nucleating agent, etc. The mixture is melt compounded at 260-360 deg.C and granulated.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention is directed to a polyphenylene sulfide for molding (hereinafter referred to as (abbreviated as PPS)) relates to a resin composition.

"Conventional technology" PPS resin has extremely high heat resistance, chemical resistance, electrical properties, and flame resistance, and by strengthening it with reinforcing fillers, it has excellent mechanical strength, rigidity, and dimensions. It is known to exhibit stability and is widely used in various molding applications such as electrical/electronic parts, automobile parts, and even mechanical parts.

However, PPS resin generates metal corrosive gas at high temperatures and when melted, which may corrode the mold or molding machine during molding, or when molded products are aged at temperatures above 100°C but below their melting point. However, there are problems such as corrosion of metal parts of assembled parts using the molded product or corrosion of insert metal parts. For example, when PPS resin is used for a relay base, problems such as corrosion of the metal contacts of the relay, resulting in contact failure, and deterioration of solder adhesion at the metal insert portion due to corrosion occur.

Regarding this problem, a conventional method of adding an alkali metal hydroxide or carbonate (US Pat. No. 4,017,450) has been proposed.
method of adding hydroxides, oxides, and aromatic carboxylates of group metals (Japanese Patent Application Laid-open No. 10985-1985)
No. 0) are known.

However, in both cases, sufficient effects were not obtained;
In particular, it can be said that no effect is seen at all in preventing silver corrosion, for example, when PPS resin is aged at temperatures above 100°0 and below its melting point. Furthermore, since all of the additives themselves are water-soluble, or have hygroscopic properties even if they are not water-soluble, the addition of the above-mentioned compounds reduces water resistance, and even if the additives are reinforced with glass fiber, etc. The current situation is that when used as an insulating material, the insulation properties under high humidity conditions are significantly reduced.

In addition, a composition for encapsulating electronic components in which zinc oxide is added to PPS resin and a method for preventing color shift thereof (Japanese Patent Laid-Open No. 59
-181408) is also known, but this method
In addition to not being sufficiently effective against mold corrosion during PS melting, there is no effect at all on preventing metal (especially silver) corrosion when aging at temperatures above l00'C and below the melting point. .

``Problems to be Solved by the Invention'' The purpose of the present invention is to utilize the excellent properties of PPS resin, without deteriorating its water resistance and insulation properties under high humidity when used as an insulating material. In particular, it is an object of the present invention to provide a polyphenylene sulfide resin composition that significantly reduces metal corrosion during molding, corrosion of metal parts of assembled parts using the molded product, and corrosion of insert metal parts.

"Means for Solving the Problems" That is, the present invention provides a PPS resin composition characterized in that zinc hydroxide is added to a PPS resin.

The most important feature of the composition of the present invention is that it has significantly reduced corrosion resistance to the metal parts of the molding die and the assembled parts using the molded product, as well as the insert metal parts, and has particularly good water resistance. Furthermore, when used as an insulating material, it has excellent insulating properties under humid conditions. As mentioned above, many of the hydroxides and carbonates of Group IA of the periodic table are readily soluble in water, and many of the hydroxides and oxides of Group I of the periodic table are hygroscopic.

On the other hand, zinc hydroxide added in the present invention is poorly soluble in water, and has an extremely high ability to capture metal corrosive gases from PPS resin.

In addition, the conventional method had no effect on metal (particularly silver) corrosion when heat aging PP5I precepts and molded products thereof at temperatures below the melting point, whereas the hydroxide added in the present invention Zinc has an outstanding effect in preventing corrosion of metal molds and the like during melting, and also in preventing metal (particularly silver) S corrosion during heat aging below the melting point.

Therefore, the composition of the present invention significantly reduces metal corrosive gases generated by PPS resins, has significantly improved water resistance, and furthermore, when used as an insulating material, can be used for long-term humid conditions. It is considered to have extremely excellent insulation properties, as exemplified by the volume resistivity retention capacity shown below.

A polymer containing 90 mol% or more of the structural unit represented by is preferable; if the amount is less than 90 mol%, it is difficult to obtain a composition with excellent properties. Examples include polymerization in the presence of sodium sulfide, sodium bisulfide and sodium hydroxide, or hydrogen sulfide and sodium hydroxide in a polar solvent, and self-condensation of P-chlorothiophenol. A suitable method is to react sodium sulfide with P-dichlorobenzene in an amide solvent such as , N-methylpyrrolidone or dimethylacedoago, or a sulfonic solvent such as sulfolane. At this time, in order to adjust the degree of polymerization, it is a preferable method to add an alkali metal salt of carboxylic acid or sulfonic acid, or to add alkali hydroxide. As a copolymerization component, the copolymerization component may be 10% by mole (indicating tro-, phenyl, or alkoxy groups), or trifunctional as long as it does not significantly affect the crystallinity of the polymer, but preferably the copolymerization component is 5% by mole or less. In particular, when trifunctional or more functional phenyl, biphenyl, naphthyl sulfide bonds, etc. are selected for copolymerization, the amount is preferably 3 mol % or less, more preferably 1 mol % or less.

Such PPS resins can be produced by common manufacturing methods, such as (1) reaction of a halogen-substituted aromatic compound with an alkali sulfide (U.S. Pat. No. 2,513,188, Japanese Patent Publication No. 44-27671).
(2) Condensation reaction of thiophenols in the coexistence of an alkali catalyst or copper salt, etc. (U.S. Pat. No. 3,274,165, British Patent No. 11)
60660) (3) Condensation reaction of aromatic compounds with sulfur chloride in the coexistence of a Lewis acid catalyst (Japanese Patent Publication No. 46-2
No. 7255, Belgian Patent No. 29437), and can be arbitrarily selected depending on the purpose.

Zinc hydroxide added in the present invention can be used as a commercially available reagent, and the amount added is 0.01 to 1O2 per 100 parts by weight of PPS resin.
Parts by weight.

If the amount added is within this range, the effect of reducing metal corrosive gas will be large, the melt flowability of the composition will be good, and the strength will be maintained high.

Various reinforcing materials and fillers can be added to the &1ltc product of the present invention in order to improve mechanical properties. Examples of reinforcing materials and fillers that can be used in the present invention include glass fiber, carbonate Fiber, calcium titanate, potassium titanate, silicon carbide, aramid fiber, ceramic fiber,
Metal fiber, silicon nitride, barium sulfate, calcium sulfate, kaolin, clay, bentonite, sericite, zeolite, mica, mica, talc, wollastonite, P
MF ferrite, calcium silicate, calcium carbonate, dolomite, antimony trioxide, titanium oxide, iron oxide,
There are milled glass, glass beads, glass balloons, etc.

Furthermore, the composition of the present invention can contain lubricants and stabilizers thereof, such as graphite, molybdenum disulfide, and polytetrafluoroethylene.

In addition, the composition of the present invention may contain an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant, a crystal nucleating agent, a coloring agent, a silane coupling agent, and a mold release agent within a range that does not impair the purpose of the present invention. not be constrained by what you do.

Furthermore, the composition of the present invention may contain thermosetting resins and other thermoplastic resins such as epoxy resins, silicone resins, polyimides, polyphenylene ethers, polyamides, polycarbonates, polysulfones, polyether ketones, etc., to the extent that the objects of the present invention are not impaired. A small amount of one or more of polyester, polyarylate, polyacetal, polyetherketone, polyetheretherketone, polybutylene terephthalate, polyethylene terephthalate, liquid crystal polyester, polyamideimide, polyetherimide, etc. can be blended.

The composition of the present invention can be prepared by various known methods. For example, the PPS resin and the compound to be added in the present invention are mixed in advance in a Henschel mixer or tumbler, and then mixed in a l-screw or twin-screw extrusion kneader, etc. supplying 260
It can be obtained by melt-kneading and granulating at a temperature of 360°C to 360°C.

Further, other reinforcing materials, fillers, and various additives may be added as necessary during mixing.

The &[I acid of the present invention is applicable to various uses such as electric/electronic parts, mechanical parts, and automobile parts, but especially when used as an insulating material, it can be used for switch parts, relay parts, It is useful as an industrial material such as connectors.

"Example" The present invention will be further explained below with reference to Examples.

The test values for each characteristic shown in this example were obtained using the following method.
This is based on the standards.

As shown in FIG. 1, 100 g each of the granulated pellets 2 were placed in a metal closed container 1, and placed on a 20-mesh wire mesh 3 fixed by a metal plate 4 therein. 5%, Cr:
5KD-11 steel material block 5, which is a high alloy tool steel having a composition of 12.0%, Mo: 1.0%: V: 0.4%
(surface roughness of 3 μm or less) and heat-treated at 340° C. for 6 hours. After heat treatment, 5KD-11 steel block 5
The steel was taken out and placed in a constant temperature and humidity chamber at 70°C/95% RH (relative humidity) for 6 hours, and then the corrosion state of the steel was observed.

Water resistance〉 The granulated pellets were molded into dumbbell specimens for tensile testing with the same thickness of 1.6 cm, and the specimens were heated at 120°C, 12kgf/C-
After pressure treatment for 30 hours under the conditions of (
After PCT), the tensile strength was measured and compared with the initial strength. (Tensile strength conforms to ASTM D-638) Insulating properties> ASTM D- 1.6n+m thicker than granulated pellets
A disk for 257 was formed, and the specimen was heated at 120°C and 12kgf.
/am'' for 30 hours under pressure pressure treatment (after PCT), the volume resistivity value was measured and compared with the initial value. (Volume resistivity measurement was performed using ASTM D-25.
7) Reference Example 1 (Synthesis of PPS resin) In a 501 scale autoclave, 70 moles of N-methylpyrrolidone, 0.99 moles of sodium sulfide nonahydrate, 0.60 moles of sodium benzoate, and 1.15 moles of sodium hydroxide were added. (50 molar scale) in a nitrogen stream at a ratio of 21
The temperature was raised to 0°C and dehydration was carried out to a dehydration rate of 110%.

After cooling the system to 160°C, ρ-dichlorobenzene was charged at a molar ratio of 10, and after sealing, the internal pressure was increased to 25 kg/c with nitrogen.
It was pressurized to -.

The temperature was controlled while taking into consideration the heat generated by polymerization, and the temperature was raised to 270"C, and polymerization was carried out with stirring for 5 hours. The internal pressure had risen to 17 kg/ca+".

Next, the system was cooled, the pressure was released, and the contents were poured into a large amount of water to recover flaky polymer. The polymer was washed repeatedly with hot water and acetone, and the final yield was 70% in the form of white flakes.

Put 20 PPS resin powder into a ribbon blender,
The PPS was stirred at 270"C while blowing air to partially crosslink the PPS in the powder state, and finally the specific year was 0.
It was heat-treated until it reached 3.

Examples 1 to 6 and Comparative Examples 1 to 6 Using the PPS resin that bottomed out in Reference Example 1, the raw materials shown in Table 1 were mixed uniformly in the proportions shown in the table, and then mixed in a 35 mmφ twin screw extruder. The mixture was melt-kneaded at 320°C to obtain pellets. This pellet was used to evaluate metal corrosion. In addition, this pellet was molded using an in-line screw type 3-ounce injection molding machine, with a cylinder temperature of 320°C and a mold temperature of 1.
A test piece for evaluating water resistance and insulation properties was molded at an injection pressure of 50 "C1" of 1000 kgf/cm and a medium injection speed, and both properties were evaluated. The results are shown in Table 1.

Examples 7 to 10 and Comparative Examples 7 to 9 Using the PPS resin synthesized in Reference Example 1, the raw materials shown in Table 2 were mixed uniformly in the proportions shown in the table, and then heated at 320°C in a 35 mmφ twin-screw extruder. The mixture was melted and kneaded to obtain pellets. This pellet was used to evaluate metal corrosion.

Furthermore, the pellets were molded using an in-line screw type 3-ounce injection molding machine, with a cylinder temperature of 320°C, a mold temperature of 150°C, and an injection pressure of 100,100O/cm.
A dumbbell for tensile testing with a thickness of 1.6 was molded at medium injection speed, and water resistance was evaluated. The results are shown in Table 2.

/ "Effects of the Invention" The MS product of the present invention significantly reduces metal corrosive gas generated from PPS resin, thereby improving the metal parts of molds and assembled parts using molded products thereof, as well as metal inserts. It greatly reduces corrosion of parts and the like, and furthermore, it has good water resistance and excellent moisture resistance and insulation properties when used as an insulating material.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a closed metal container containing pellets of the composition in a metal corrosion test.

Claims (1)

[Claims] 1. A polyphenylene sulfide resin composition characterized in that 0.01 to 10 parts by weight of zinc hydroxide is added to 100 parts by weight of the polyphenylene sulfide resin.