JPH0798901B2 - Polyphenylene sulfide composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a composition comprising polyphenylene sulfide (hereinafter abbreviated as PPS) having a bound chlorine content of 500 ppm or less in a polymer and an inorganic filler. The composition of the present invention has excellent electrical properties and is particularly useful as a coating material or sealing material for electric and electronic parts.

[Conventional technology]

As a conventional PPS composition for molding, PPS having a low degree of polymerization produced by the method disclosed in JP-B-45-3368.
There is known a composition in which a material having an apparent melt viscosity increased by oxidative crosslinking is used as a raw material polymer and a filler is added thereto.

On the other hand, by using an auxiliary agent at the time of polymerization or by copolymerizing polyhalobenzene having 3 or more halogens in the molecule, PPS which has not been oxidatively crosslinked and has a high molecular weight is used as a raw material polymer, and a filler is added to this. Additive compositions are also known.

However, if the above-mentioned compositions are to be applied to the fields of electric and electronic parts, the deterioration of electric characteristics due to a large amount of sodium and chlorine such as salt in PPS becomes a serious obstacle. That is, when PPS containing a large amount of sodium and chlorine is used to seal electronic components such as ICs, the insulation of the circuit may be reduced due to moisture absorption, or the electrodes or lead frame may be corroded and broken. It may cause the deterioration of the characteristics of the element such as the above and the failure.

Therefore, as a method for improving these drawbacks, a method of extracting the PPS powder several times with hot water so that the amount of sodium that can be extracted with water is 100 ppm or less is known.
-156342. However, according to the study by the present inventors, in this method, the amount of sodium extracted was such that the amount of sodium adhering to the surface of the polymer particles or the surface layer was extremely small, even though the extraction was repeated for an extremely long time. There is still only 1000 pp in the polymer.
There was sodium above m, and the removal effect was poor. Furthermore, when the chlorine content in PPS purified by this method was quantified, it was found to be about 2000 to 3000 ppm, and no chlorine reducing effect was found in PPS.

Further, JP-A-59-219331 discloses a method of heating PPS in an aromatic solvent to reduce the sodium content. According to this method, the sodium content can be reduced, but chlorine was contained in the treated polymer in an amount of about 2000 to 3000 ppm, and no removal effect was observed.

Thus, even if attempts were made to purify PPS by conventional techniques, the sodium content could be reduced, but the chlorine content could not be reduced. It is not yet of satisfactory purity for use as a coating or sealing material for parts.

[Problems to be solved by the invention]

The present invention, as a result of earnest research to answer these demands,
PPS, which does not substantially contain ionic bond chlorine in PPS and has extremely reduced not only sodium content but also covalent bond chlorine content, is used as a raw material polymer, and a composition obtained by adding an inorganic filler to it is prepared. The inventors have found that they have excellent applicability in the fields of electric and electronic parts, and have completed the present invention.

[Means for solving problems]

That is, the present invention relates to a PPS composition prepared by treating PPS with a combined chlorine content in the polymer of 500 ppm or less as a raw material polymer and adding an inorganic filler to the raw material polymer. The bound chlorine referred to in the present invention is a covalent chlorine directly bonded to a carbon atom, and does not mean an ionic chlorine contained in a polymer as NaCl or the like. In addition, in this covalent chlorine,
It does not contain chlorine of dichlorobenzene as a residual monomer. The amount of covalently bound chlorine contained in such a polymer is determined by quantifying the total amount of covalently bound chlorine and ionicly bound chlorine by ion chromatography, etc.
roscopy for Chemical Analysis), the ratio of covalently bound chlorine to ionicly bound chlorine was determined and quantified.

PPS used in the present invention has been purified to a high degree of purity, substantially free of ionic bond chlorine in PPS,
500ppm not only for sodium content but also for combined chlorine content
Below, it is preferably reduced to 100 ppm or less. The phrase "substantially free of ionic bond chlorine" means that the content of ionic bond chlorine in PPS is about 100 ppm or less.

The PPS used in the present invention is at least 90 mol%
Or more, more preferably 95 mol% or more It is a poly (P-phenylene sulfide) composed of structural units, and the remaining structural units may be copolymerizable units such as ortho and metaphenylene sulfides, biphenyl sulfides, 2,6-naphthalene sulfides, diphenyl sulfone sulfides. Examples thereof include diphenyl ketone sulfide and trivalent or tetravalent phenylene sulfide introduced by copolymerizing a monomer having three or more halogens in the molecule. Further PPS used in the present invention
May be oxidatively crosslinked by heat treatment in the presence of oxygen.

In addition, the PPS used in the present invention uses a high-performance flow tester (die: hole diameter 0.5 mm, hole length 2 mm) at 300 ° C, 10 k
The melt viscosity measured by g-load is preferably in the range of 10 to 50,000 poise.

The high-purity PPS used in the composition of the present invention is disclosed in the method of Japanese Patent Application No. 60-245318 and Japanese Patent Application No. 60-277913 previously filed by the present inventor, that is, Japanese Patent Publication No. 45-3368. After producing PPS by a known method as described above, PPS and the alkali metal salt of the mercapto group-containing compound or the mercapto group-containing compound or disulfide thus produced and PPS are dissolved with a base as necessary. It is produced by heat treatment in the solvent to be obtained. That is, polyphenylene sulfide and a mercapto group-containing compound represented by the general formula (1) (R is a hydrocarbon group or a heterocyclic compound residue,
Is a hydrogen atom or an alkali metal, A is a carboxyl group or a hydroxyl group, a substituted or unsubstituted amino group or a nitro group, x is an integer of 1 to 6, and y is an integer of 0 to 6) and a general formula ( Disulfide represented by 2) (A _x R-S-S-R'A) _y (2) (R and R'are a hydrocarbon group or a heterocyclic compound residue, and R and R'are the same. A is a carboxyl group, a hydroxyl group, a substituted or unsubstituted amino group or a nitro group, and x and y are integers of 0 to 6) and a base, if necessary, with polyphenylene sulfide. Is produced by heat treatment in a solvent capable of dissolving. For example, PPS produced by a known method, a mercapto group-containing compound such as 2-mercaptobenzimidazole, and a base such as sodium hydroxide in N-methylpyrrolidone are used in an amount of 220 to 260
It is a method such as reacting at 0 ° C for 0.5 to 10 hours. By such a treatment, not only the sodium content in PPS but also the combined chlorine content can be reduced to 500 ppm or less, further 100 ppm or less.

The PPS composition of the present invention can be obtained by blending the high-purity PPS obtained by the above method and the inorganic filler. The inorganic filler can be used, for example, in the form of powder, granules or fibers. Some examples of inorganic fillers that can be used in the present invention are glass fiber, asbestos fiber, ceramic fiber, carbon fiber, glass beads, glass powder, talc, silica, clay, mica, alumina, calcium sulfate, carbonic acid. Examples thereof include calcium, potassium titanate, iron oxide, zinc oxide and titanium oxide. The amount of these inorganic fillers added is 5 to 85% by weight, preferably 10 to
80% by weight. If the addition amount is too small, a sufficient filling effect cannot be obtained, and if the addition amount is too large, problems such as poor moldability and brittleness when formed into a molded product are not preferable.

The PPS composition of the present invention obtained as described above can be molded into various molded products, films, sheets, pipes, etc. by injection molding, transfer molding, extrusion molding, etc.
In particular, it is extremely useful for coating electric and electronic parts and as a sealing material.

〔Example〕

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

The sodium content in the PPS used in the following examples and comparative examples is about 0.5 g of a sample, which is deionized after wet decomposition with about 10 ml of sulfuric acid and about 10 ml of nitric acid in a quartz beaker. A solution prepared by adding water to a constant amount was determined by atomic absorption spectrometry. The combined chlorine content in PPS is about 30 m.
After ashing a sample of g by the flask combustion method, N / 100NaOH
After absorption and deionized water were added to aq and adjusted to a fixed amount, the liquid was measured by ion chromatography and the total amount of chlorine was quantified.
The ratio of covalent bond chlorine and ionic bond chlorine was obtained by (Shimadzu ESCA-750), and covalent bond chlorine was quantified from these values. ESCA was measured at a energy of 8 KV and 30 mA using a Mg target as an X-ray source.

The melt viscosity of PPS was measured with a Koka type flow tester (die; hole diameter 0.5 mm, hole length 2 mm) at 300 ° C. under a load of 10 kg.

Example 1 Into a 15 l autoclave was added Na ₂ S.2.9H ₂ O 14.6 mol, N-
Add 4.9 l of methylpyrrolidone and stir under a nitrogen stream to 210
The temperature was raised to 0 ° C., and 340 g of a distillate mainly composed of water was distilled off. After that, the system was cooled to 170 ° C, 14.5 mol of P-dichlorobenzene was added, the system was sealed under a nitrogen stream, and the temperature was raised.
Polymerization was carried out at 250 ° C for 3 hours. After completion of the polymerization, N-methylpyrrolidone was distilled and recovered under reduced pressure, and then the polymer was washed with water, dried and isolated. The yield of the obtained polymer is 1490.
g, melt viscosity was 210 poise, and sodium and chlorine contents in the polymer were 2200 ppm and 2900 ppm, respectively.

Next, 1400 g of this PPS, 0.65 mol of 2-mercaptobenzimidazole, 0.65 mol of NaOH, and 5.0 l of N-methylpyrrolidone were added to 1 part.
The autoclave having a capacity of 5 l was charged, the system was replaced with nitrogen, and the temperature was raised to carry out a reaction at 260 ° C. for 1 hour. After completion of the reaction, N-methylpyrrolidone was distilled and recovered under reduced pressure.
Water was added and the polymer was washed at 200 ° C. for 4 hours, dried and isolated. The yield of the obtained polymer was 1330 g and the melt viscosity was 20.
4 poise, sodium content in polymer is 56pp
The content of m and bound chlorine was less than 100 ppm.

The high-purity PPS thus obtained was heated at 260 ° C. for 3 hours in the presence of oxygen to obtain a melt viscosity of 3070 poise, and 60 parts by weight of this PPS and glass fiber (diameter 13 μm, length 3 mm chopped 40 parts by weight of strand) were uniformly mixed in a V blender, and then kneaded into pellets at a cylinder temperature of 310 ° C. in an extruder having a screw diameter of 40 mm. Next, using an injection molding machine, the pellets were heated to a cylinder temperature of 310 ° C. and an injection pressure of 800 kg.
/ cm ² and mold temperature of 135 ° C were injected into the metal fittings into which aluminum metal fittings were previously inserted.

10 samples were taken out from the obtained molded product at 80 ℃, 95
It was left to stand in% RH atmosphere for 1000 hours, and the corrosion state of aluminum metal fittings was examined. As a result, corrosion of aluminum metal fittings was 0 out of 10 samples.

Example 2 Polymerized and highly purified PPS by the same method as in Example 1
(Melt viscosity 200 poise, sodium content 40ppm, bound chlorine content 100ppm or less) was heat-treated at 230 ° C for 2 hours in the presence of oxygen to make the melt viscosity 550 poise, and then 35 parts by weight of this PPS and glass fiber (diameter 35 parts by weight of chopped strands (13 μm, length 3 mm) and 30 parts by weight of calcium carbonate were kneaded and pelletized in the same manner as in Example 1. Using this pellet, insert molding was performed by injection molding in the same manner as in Example 1,
A moisture resistance test was conducted on the obtained molded product under the same conditions as in Example 1. As a result, the corrosion of the aluminum metal fittings was 0 out of 10 samples.

Example 3 Polymerization was carried out in the same manner as in Example 1 to obtain a melt viscosity of 230
Poise, sodium content 2400ppm, chlorine content 3000ppm
1520 g of PPS was obtained. Next, 1400 g of this PPS, 0.65 mol of phenyl disulfide, 0.65 mol of NaOH, and 5.0 l of N-methylpyrrolidone were added to 1 part.
The autoclave having a volume of 5 l was charged, the system was replaced with nitrogen, and the temperature was raised to carry out a reaction at 200 ° C. for 2 hours. After completion of the reaction, N-methylpyrrolidone was distilled and recovered under reduced pressure, water was added, and the polymer was washed at 200 ° C. for 4 hours, dried and isolated. The yield of the obtained polymer was 1300 g and the melt viscosity was 10
It is 5 poise and the sodium content in the polymer is 23 pp
The content of m and bound chlorine was less than 100 ppm.

The high-purity PPS thus obtained was heated at 260 ° C. for 4 hours in the presence of oxygen to obtain a melt viscosity of 3140 poise,
In the same manner as in Example 1, 60 parts by weight of S and 40 parts by weight of glass fiber (chopped strand having a diameter of 13 μm and a length of 3 mm) were kneaded and pelletized. Using this pellet, insert molding was performed by injection molding in the same manner as in Example 1, and the obtained molded product was subjected to a moisture resistance test under the same conditions as in Example 1. as a result,
Corrosion of aluminum metal fittings was 0 out of 10 samples.

Comparative Example 1 Polymerization was carried out by the same known method as in Example 1 to obtain a melt viscosity of 21
0 poise, sodium content 2000ppm, chlorine content 2800ppm
I got 1500g of PSS. After heat-treating this PPS at 260 ° C for 3 hours in the presence of oxygen to make the melt viscosity 3140 poise,
In the same manner as in Example 1, 60 parts by weight of S and 40 parts by weight of glass fiber (chopped strand having a diameter of 13 μm and a length of 3 mm) were kneaded and pelletized. Using this pellet, insert molding was performed by injection molding in the same manner as in Example 1, and the obtained molded product was subjected to a moisture resistance test under the same conditions as in Example 1. as a result,
Corrosion of aluminum metal fittings was found in all 10 of the 10 samples.

〔The invention's effect〕

As is clear from the above description, the PPS composition of the present invention has excellent applicability in the fields of electric and electronic parts.
It is extremely useful for coating electronic parts and as a sealing material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-106929 (JP, A) JP 61-220446 (JP, A) JP 62-150752 (JP, A) JP 62- 185717 (JP, A)

Claims (1)

[Claims] 1. (N: 20 or more) as a constituent unit
A poniphenylene sulfide composition comprising 15 to 95% by weight of polyphenylene sulfide which is 500 ppm or less and 5 to 85% by weight of an inorganic filler.