JPH041029B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyphenylene sulfide composition with excellent moldability. Polyphenylene sulfide (hereinafter abbreviated as PPS) has excellent properties as an engineering plastic, such as excellent chemical resistance, heat resistance, and electrical insulation, and is used for various purposes, mainly injection molding. ing. However, various improvements are required before PPS can be used in a wider range of applications. That is, firstly, the melt viscosity of PPS is extremely low. For this reason, it is difficult to obtain good strands during extrusion molding to produce pellets, which causes problems in terms of stable supply of pellets to the feeder during injection molding. Furthermore, as a matter of course, so-called extrusion-molded products such as sheets, films, pipes, etc. that require higher extrusion moldability cannot be obtained. Increasing the degree of crosslinking may be considered as a method of increasing the melt viscosity of PPS, but as the degree of crosslinking increases, the viscosity stability during extrusion molding decreases, making it difficult to obtain stable and good molded products. The second problem is the presence of pores in the molded product due to gas generated when PPS is melted. Although the cause of this is not very clear, it is presumed that the main cause is volatilization or decomposition of low molecular weight components present in the polymer. The presence of such pores deteriorates the mechanical properties and electrical properties of PPS molded products. Furthermore, the gas components are mainly organic, with small amounts of SO ₂ and H ₂ S.
Also exists and causes corrosion of metal materials. Thirdly, PPS for injection molding has a high degree of brown coloration, and if you want to apply various colors depending on the application, a large amount of white filler is required, which results in a loss of mechanical strength of PPS. . The present inventors conducted various research studies to improve these shortcomings of PPS, and as a result, they discovered that a composition of a specific PPS with a low degree of crosslinking and an epoxy resin solved the above-mentioned shortcomings, and the present invention reached. That is, the present invention has a melt viscosity (V) of 10 or more at 300°C under a shear rate of 200 (sec) ^-1 ,
A polyphenylene sulfur containing PPS and 0.01 to 40 parts by weight of an epoxy resin as essential components, which is 100,000 poise or less and whose relationship between the non-Newtonian coefficient (N) and V satisfies the following formula (1). ide composition. Formula (1) 0.8≦N≦1.33+0.000047×V The PPS used in the present invention has the general formula

It is preferable that the composition contains 70 mol% or more of the structural unit represented by the formula; if the amount is less than 70 mol%, it is difficult to obtain the present composition with excellent properties. The polymerization method for this polymer includes a method of polymerizing p-dichlorobenzene in the presence of sulfur and soda carbonate;
Methods include polymerization in the presence of sodium sulfide or sodium bisulfide and sodium hydroxide or hydrogen sulfide and sodium hydroxide in a polar solvent, self-condensation of p-chlorothiophenol, etc. N-methylpyrrolidone, dimethylacetamide, etc. A suitable method is to react sodium sulfide with p-dichlorobenzene in an amide solvent such as sulfolane or a sulfone 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. If it is less than 30 mol% as a copolymer component, it is a meta bond.

[Formula] Ortho bond

[Formula] Ether bond

[Formula] Sulfone bond

[Formula] biphenyl join

[Formula] Substituted phenyl Sulfide bond (

[Formula] where R represents an alkyl group, a nitro group, a phenyl group, an alkoxy group, a carboxylic acid group or a metal base of a carboxylic acid), trifunctional bond

[Reference example 1]

98.4 g of sodium sulfide (60% purity) and 4.7 g of sodium hydroxide were added to 3080 g of N-methylpyrrolidone, heated to 205°C while dehydrating, and then 1113g of paradichlorobenzene and N-methylpyrrolidone were added.
510 g was added and heated under pressure at 260° C. for 5 hours, cooled, washed with water and dried. The obtained PPS has a melt viscosity of
It was 37 poise, and the non-Newtonian coefficient was 0.95. This is called Polymer A. The melt viscosity and non-Newtonian coefficient of Polymer A thermally crosslinked in air at a temperature of 270°C for 3 hours, 4 hours, 5 hours and 6 hours, respectively, were 1800 poise and 1.17 (Polymer B) and 3600.
poise and 1.42 (Polymer C), 4300 poise and 1.63 (Polymer D), 5500 poise and 1.80 (Polymer E). Also, polymer A at 260℃,
The melt viscosity and non-Newtonian coefficient of those thermally crosslinked in air for 5, 7 and 9 hours were 300 poise and 1.13 (Polymer F), 1010, respectively.
poise and 1.31 (Polymer G), 2000 poise and 1.54 (Polymer H). [Reference Example 2] 984 g of sodium sulfide (60% purity), 47 g of sodium hydroxide, and 765 g of lithium acetate dihydrate were mixed with N-
After adding it to 3080g of methylpyrrolidone and heating it up to 205℃ while dehydrating, p-dichlorobenzene
1113 g of N-methylpyrrolidone and 510 g of N-methylpyrrolidone were added thereto, heated under pressure at 230°C for 2 hours and at 265°C for 3 hours, cooled, washed with water, and dried. The obtained PPS has a melt viscosity of
It was 3980 poise and the non-Newtonian coefficient was 1.21. This will be referred to as Polymer I. The melt viscosity and non-Newtonian coefficient of Polymer I thermally crosslinked at 270°C in air for 3 hours and 4 hours, respectively, were 6800 poise and 1.57 (Polymer J), 7800 poise and 1.73 (Polymer K).
It was hot. [Reference Example 3] 984 g of sodium sulfide (60% purity), 47 g of sodium hydroxide, and 765 g of lithium acetate dihydrate were mixed with N-
After adding it to 3080g of methylpyrrolidone and heating it up to 205℃ while dehydrating, p-dichlorobenzene
1113g, 1,2,4-trichlorobenzene 2.2g,
Add 510g of N-methylpyrrolidone and heat at 230°C under pressure.
After heating for 2 hours at 265°C and 3 hours at 265°C and cooling, the mixture was washed with water and dried. The obtained PPS has a melt viscosity of 13500
The Pois non-Newtonian coefficient was 1.84.
This will be referred to as Polymer L. [Example 1] Polymers A, B, C, prepared in Reference Example 1
D, E, F, G, H and Ryton P-4, Ryton R-6, Dainippon Ink & Chemicals Co., Ltd.'s novolac type epoxy resin Epicron N-695, the same company's bisphenol A type epoxy resin Epicron
After uniformly pre-mixing 4050 in the ratio shown in Table 1, it was heated to 290-300℃ in a co-rotating 50mm twin-screw vented extruder.
Then, the mixture was melted and kneaded to obtain pellets. Table 1 also shows the change in melt viscosity before and after melt-kneading. The pellets were put into a 40 mm single screw extruder and extruded at a cylinder temperature and a die temperature of 290 to 300°C to form a sheet-like molded product with a thickness of 2.5 mm and a width of 150 mm. The surface condition and internal condition of the obtained sheet are also listed in Table 1. Various test pieces were cut out from this sheet and their physical properties were measured. The results are also listed in Table 1. As is clear from Table 1, by using the composition of the present invention, the melt viscosity of PPS increases, and molded products with smooth surfaces, no bubbles inside, and excellent mechanical strength can be obtained. is clear. [Example 2] Polymers A and D prepared from Reference Examples 1 and 2
and I, resin Epicron N-695, glass fiber Glasslon CS-03MA497 manufactured by Asahi Glass Co., Ltd., and talc were premixed in a tumbler for 5 minutes at the mixing ratio shown in Table 2, and heated at 280 to 290°C in a 40 mm single screw extruder. Pellets were obtained by melt-kneading. This pellet was molded using a 3-ounce injection molding machine to prepare a test piece for measuring physical properties. At the same time, spiral flow was measured. The results are also listed in Table 2. From here too,
It is clear that the composition of the present invention increases the melt viscosity of PPS, reduces coloring, and provides injection molded products with excellent mechanical strength. [Example 3] Polymers I, J, and L obtained in Reference Examples 1 and 2 and epoxy resin Epicron N-670 manufactured by Dainippon Ink and Chemicals Co., Ltd. were mixed in a tumbler at the ratio shown in Table 3 for 50 minutes. After mixing for a minute, extruded pellets were obtained in a 40 mm single screw extruder at a cylinder temperature and a die temperature of 300-310°C. Next, this pellet is extruded using a single screw extruder with a screw diameter of 30 mm at a cylinder temperature and a die temperature of 290 to 295°C and a screw rotation speed of 30 to 40 rpm to obtain a pellet with a thickness of 300 microns and a width of 300 microns.
A 10cm sheet was produced. All of the obtained sheets were pale yellow and transparent, had no air bubbles, and did not break even when bent. Polymers E and K for comparison
The compositions shown in Table 3 were melt-kneaded using Ryton R-6 and Ryton R-6, and extruded under the same conditions. However, in both cases, the films had many small holes and uneven striped patterns were observed on the surface. In addition, this sheet was dark brown and had poor flexibility and easily cracked when bent.

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[Table] Resin length.

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Claims (1)

[Claims] 1. Melt viscosity (V) at 300°C at a shear rate of 200 (seconds) ^-1 is 10 or more and 100,000 poise or less, and the non-Newtonian coefficient (N) and V A polyphenylene sulfide composition comprising 100 parts by weight of polyphenylene sulfide and 0.01 to 40 parts by weight of a novolak type epoxy resin as essential components, characterized in that the relationship satisfies the following formula (1). Formula (1) 0.8≦N≦1.33＋0.000047×V