JPH04258668A - Polyphenylene sulfide resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a polyphenylene sulfide (hereinafter abbreviated as PPS) resin composition that has improved whiteness and has sufficient mechanical strength for practical use, and is used in heat-resistant tableware and other applications. It is applied to electric/electronic parts, automobile parts, and mechanical parts that require high whiteness.

0002

[Prior Art] PPS resin has extremely high heat resistance, chemical resistance, electrical properties, and flame resistance, and when reinforced with reinforcing fillers, it has excellent mechanical strength, rigidity, It is known to exhibit dimensional stability and is widely used in various molding applications such as electrical/electronic parts, automobile parts, and even mechanical parts.

Such PPS resins are generally made by thermally crosslinking linear uncrosslinked polymers with relatively low molecular weights in the presence of oxygen, but even uncrosslinked polymers can be used without crosslinking if they have a sufficiently high molecular weight. used in

[0004] The PPS resin, particularly the crosslinked polymer, has a deep brown color, while the uncrosslinked polymer has a brownish-gray color, making it unsuitable for applications that require whiteness. Furthermore, it is a molding material that is extremely difficult to adjust to various colors such as red, yellow, and blue.

[0005] As a measure to whiten the PPS, it is common to add a coloring pigment, that is, titanium oxide.
When titanium oxide is added to PPS resin, the whiteness is improved, but the mechanical strength is drastically reduced, making it impractical.Not only does it become impractical, but it also suffers from severe discoloration, especially yellowing, due to ultraviolet rays, making it an impractical molding material. It can only happen.

[0006]

[Problems to be Solved by the Invention] The purpose of the present invention is to
The object of the present invention is to provide a PPS resin composition that achieves whitening of S resin and has practically sufficient mechanical properties.

[0007]

[Means for Solving the Problems] The present invention is based on ASTM
The present invention provides a PPS resin composition characterized in that zinc sulfide is added to a PPS resin having a viscosity of 1000 g/10 minutes or less as measured by the melt flow rate measurement method of D-1238-86.

The greatest feature of the composition of the present invention is that the decrease in mechanical strength due to the improvement in whiteness is extremely small. Furthermore, there is very little discoloration due to ultraviolet rays or sunlight. These features are completely unattainable by adding titanium oxide, a conventional coloring agent.

[0009]

[Constitution] The PPS resin used in the present invention has the general formula

00
10]

[Chemical formula 1]

It is preferable that the composition contains 90 mol % or more of the structural unit represented by the following formula; if the amount is less than 90 mol %, it is difficult to obtain a composition with excellent properties.

Methods for polymerizing this polymer include a method in which P-dichlorobenzene is polymerized in the presence of sulfur and sodium carbonate, a method in which P-dichlorobenzene is polymerized in the presence of sulfur and sodium carbonate, a method in which P-dichlorobenzene is polymerized in the presence of sulfur and sodium carbonate, and a method in which P-dichlorobenzene is polymerized in the presence of sodium sulfide, sodium bisulfide and sodium hydroxide, or hydrogen sulfide and sodium hydroxide in a polar solvent. Examples include polymerization in the presence of P-chlorothiophenol, and self-condensation of P-chlorothiophenol.
- A method in which dichlorobenzene is reacted is suitable.

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. If it is less than 10 mol% as a copolymer component, it is a meta bond.

001
4]

[Case 2]

[0015] Ether bond

[0016]

[Chemical formula 3]

[0017] Sulfone bond

[0018]

[C4]

[0019] Sulfide ketone bond

[0020]

[C5]

[0021] Biphenyl bond

[0022]

[C6]

Substituted phenyl sulfide bond

[0024]

[C7]

[0025] Here, R is alkyl, nitro, phenyl,
alkoxy group), trifunctional phenyl sulfide bond

[0026]

[Chemical formula 8]

[0027] Even if the copolymerization component is contained, it may be contained as long as it does not significantly affect the crystallinity, but the content of the copolymerization component is preferably 5 mol % or less. In particular, when a trifunctional or more functional phenyl, biphenyl, naphthyl sulfide bond, etc. is selected as a copolymerization component, the amount is preferably 3 mol % or less, more preferably 1 mol % or less.

Such a PPS resin can be produced by a general manufacturing method, such as (1) reaction of a halogen-substituted aromatic compound with an alkali sulfide (US Pat. No. 2,513,188, Japanese Patent Publication No. 44
-27671 and Special Publication No. 45-3368)
(2) Condensation reaction of thiophenols in the presence of an alkali catalyst or copper salt (US Patent No. 327416)
(3) Those synthesized by a condensation reaction of an aromatic compound with sulfur chloride in the presence of a Lewis acid catalyst (see Japanese Patent Publication No. 46-27255, Belgian Patent No. 29437), etc. and can be arbitrarily selected depending on the purpose.

[0029] The PPS resin used in the present invention is ASTM
In the melt flow test method of D-1238-86,
1000 g/10 minutes or less is selected, and both uncrosslinked and crosslinked polymers are used. Low viscosity P where the viscosity of such resin is 1000 g/10 minutes or more
In the case of PS resin, the mechanical strength of the polymer itself is so low that it cannot be put to practical use.

[0030] The zinc sulfide added in the present invention is preferably a powder having a chemical composition of substantially 90 wt % or more of ZnS and an average particle size of 1 μm or less. Commercially available zinc sulfide products include SACHTLEBEN, Germany;
CHEMIE GMBH's Sachtolith (
Sactris) can be obtained.

In the present invention, the addition ratio of the PPS resin and zinc sulfide is preferably 4 to 100 parts by weight per 100 parts by weight of the PPS resin. When the amount of zinc sulfide added is 4 to 100 parts by weight, the whitening effect is high and the moldability is also good. More preferably, the amount of zinc sulfide is 8 to 80 parts by weight per 100 parts by weight of the PPS resin.

Fibrous reinforcing materials that can be used in the present invention include glass fiber, asbestos fiber, silica fiber,
Examples include inorganic fibrous materials such as silica/alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, and metal fibrous materials such as stainless steel, aluminum, and titanium. Particularly typical fibrous reinforcing agents are glass fibers or carbon fibers.

Note that high melting point organic fibrous substances such as aramid fibers, polyamides, fluororesins, and acrylic resins can also be used.

Powdered inorganic fillers that can be used in the composition of the present invention include barium sulfate, calcium sulfate, talc, kaolin, clay, bentonite, sericite, zeolite, wollastonite, PMF, ferrite, and calcium silicate. , aluminum silicate, calcium carbonate, dolomite, antimony trioxide, titanium oxide,
Iron oxide, graphite, molybdenum disulfide, silica, quartz powder,
Examples include milled glass, glass beads, glass balloons, silicon carbide, silicon nitride, boron nitride, and various metal powders.

[0035] Examples of plate-shaped inorganic fillers that can be used in the composition of the present invention include mica, mica, glass flakes, and various metal foils.

The composition of the present invention may also contain antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, crystal nucleating agents, colorants, silane coupling agents,
There are no restrictions due to the addition of a mold release agent or the like.

Furthermore, the composition of the present invention may contain thermosetting resins and other thermoplastic resins such as epoxy resins, phenoxy resins, silicone resins, polyimides, ABS, polyphenylene ethers, etc., to the extent that the objects of the present invention are not impaired.
Polyamide, polycarbonate, polysulfone, polyethersulfone, polyarylate, polyacetal, polyetherketone, polyetheretherketone,
One or more types of polybutylene terephthalate, polyethylene terephthalate, liquid crystal polymer, polyamideimide, polyetherimide, fluororesin, etc. can be blended.

The compositions of the present invention can be prepared by various known methods. For example, the PPS resin and the zinc sulfide to be added in the present invention may be mixed in advance in a Henschel mixer or tumbler, and then fed into a single-screw or twin-screw extrusion kneader, melt-kneaded at 260 to 360°C, and granulated. It can be obtained by Further, other fibrous reinforcing materials, powdery or plate-like inorganic fillers, and various additives may be added as necessary during mixing.

The composition of the present invention can be applied to various uses such as heat-resistant tableware, electric/electronic parts, mechanical parts, and automobile parts that require high whiteness.

[0040]

[Examples] The present invention will be further explained below with reference to Examples. The test values for each characteristic shown in this example are based on the following methods and standards.

<Mechanical strength> From granulated pellets, 3
A mm thick specimen for bending test and a 3 mm thick specimen for Izod impact strength measurement were prepared, and the bending strength (based on ASTM D-790) was measured.

<Color tone> From granulated pellets, 100×
A color tone measurement sheet of 50 x 2 mm was prepared, and a standard plate (L = 96.
The color tone L was measured based on 9).

<Outdoor exposure> Place the color tone measurement sheet outdoors.
After exposure for 00 days, changes in color tone were visually determined.

(Reference example) [Synthesis of PPS resin] 70% of N-methylpyrrolidone was placed in a 50L scale autoclave.
, sodium sulfide nonahydrate was charged at a molar ratio of 0.99, sodium benzoate 0.60, and sodium hydroxide at a molar ratio of 0.15 (50 molar scale), and the temperature was raised to 210°C in a nitrogen stream to give a dehydration rate of 110%. Dehydrated until. After cooling the system to 160°C, P-dichlorobenzene was charged at a molar ratio of 10, the system was sealed, and the system was pressurized with nitrogen to an internal pressure of 25 kg/cm2.

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/cm2. Next, the system was cooled and depressurized, and the contents were poured into a large amount of water to recover the flaky polymer. The polymer was washed repeatedly with hot water and acetone, and the final yield was 70% in the form of off-white flakes.

[0046] When this was measured by the melt flow test method of ASTM D-1238-86, it was found to be 700g/10
It was a minute. This polymer will be referred to as "A" polymer.

Next, according to the above synthesis conditions, 1300 g
An off-white flaky polymer was obtained after 10 minutes. This will be referred to as "B" polymer. Furthermore, 3000g/1
A "C" polymer of 0 minutes was obtained.

[0048] The above uncrosslinked polymer B was placed in a ribbon blender and stirred at 260°C while blowing air.
The PPS resin was crosslinked to obtain 200 g/10 min of polymer, which is designated as "D" polymer. Polymer C was similarly crosslinked to obtain a crosslinked polymer "E" of 600 g/10 min.

(Examples 1 to 6 and Comparative Examples 1 to 5) Using each of the PPS resins synthesized in the reference examples, the raw materials shown in Table 1 were uniformly mixed in the proportions shown in the table, and then a 35 mmφ biaxial The mixture was melt-kneaded using an extruder at 320°C to obtain pellets.

Further, after uniformly mixing 70 parts by weight of the polymer A synthesized in Reference Example, 30 parts by weight of glass fiber, and 100 parts by weight of zinc sulfide or titanium oxide, the mixture was melt-kneaded at 320°C in a 35 mmφ twin-screw extruder. Masterbatch pellets of zinc sulfide or titanium sulfide were obtained.

The pellets were directly prepared, and the masterbatch pellets were dry blended with Comparative Example 1 pellets in the proportions shown in Table 1 using an in-line screw injection molding machine at a cylinder temperature of 320°C, a mold temperature of 150°C,
Test specimens for evaluation of bending strength and color tone were molded at an injection pressure of 1000 kgf/cm 2 and medium injection speed, and both properties were evaluated. The results are shown in Table 1.

[0052]

[Table 1]

[0053]

[Effects of the Invention] The composition of the present invention has improved whiteness.

Claims (3)

[Claims] 1. A polyphenylene sulfide resin composition characterized by adding zinc sulfide to a polyphenylene sulfide resin having a viscosity of 1000 g/10 minutes or less in the melt flow rate measurement method of ASTM D-1238-86. thing. [Claim 2] Polyphenylene sulfide resin 1
2. The resin composition according to claim 1, wherein 4 to 100 parts by weight of zinc sulfide is added to 00 parts by weight. 3. The resin composition according to claim 1, comprising a fibrous reinforcing material and/or a powdery inorganic filler.