JPH03143958A - Polyphenylene sulfide resin composition - Google Patents

Abstract

PURPOSE:To improve the anticorrosiveness to a metal by compounding a polyphenylene sulfide resin with a specific fine particle calcium carbonate. CONSTITUTION:100 pts.wt. polyphenylene sulfide resin contg. 70mol% or higher, pref. 90mol% or higher, repeating units of the formula is compounded with 0.1-10 pts.wt., pref. 0.5-5 pts.wt., fine particle calcium carbonate surface-treated if necessary and having a mean particle diameter of 0.5mum or lower and a BET specific surface area of 15m<2> or higher, and, if necessary, with a filler, plasticizer, release agent, coupling agent, lubricant, blowing agent, thermoplastic resin, thermoset resin, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polyphenylene sulfide resin composition that has improved corrosion resistance to metals.

[Prior art and problems to be solved by the invention] Polyphenylene sulfide resin is attracting attention as a component for electric/electronic equipment and automobile equipment due to its excellent heat resistance and chemical resistance. It is widely used in fields where chemical resistance is required.

Polyphenylene sulfide ( Hereinafter, it is coated or sealed with PPS (hereinafter abbreviated as PPS).

However, when these parts are exposed to high temperatures, PP
A problem arises in that corrosive gas is generated from the S resin, corroding electrode lead frames, lead wires, and the like. This is an obstacle in applying PPS resin molded products to the electrical and electronic fields, especially to fields in which they come into contact with metal materials.

In order to improve these drawbacks, attempts have been made to reduce the corrosivity of PPS resins using various additives.

For example, U.S. Pat. No. 4,017,450 discloses the addition of alkali metal carbonates, silicates, and hydroxides, but these effects are not sufficient and are said to have a negative effect on electrical properties. I have a problem.

Furthermore, lithium carbonate, which has relatively good performance, has the economic problem of being expensive and the problem of deterioration of mechanical properties due to addition.

Also, U.S. Pat. No. 4,115. No. 344 discloses the addition of ureas, hydrazines, and amino acids, but since these compounds decompose at processing temperatures, their effects are poor, and the problem is that the amount of gas generated increases. have.

[Means for Solving the Problems] As a result of intensive study of the above problems, the inventors found that PP
The inventors have discovered that the addition of a specific calcium carbonate to S resin is effective in improving the corrosivity of PPS resin to metals, and have arrived at the present invention.

That is, the present invention provides (a) 0.1 to 10 parts by weight of fine calcium carbonate having an average particle diameter of 0.5 μ or less and a BET specific surface area of 15 bo/g or more, based on 100 parts by weight of the polyphenylene sulfide resin; This invention relates to a polyphenylene sulfide resin composition with improved corrosion resistance to metals, which is characterized by comprising:

The details of the present invention will be explained below.

The PPS resin referred to in the present invention is a resin copolymerized with other components as long as it contains 70 mol% or more, preferably 90 mol% or more of a structure having a repeating unit represented by the general formula. Alternatively, a portion thereof may have a crosslinked structure. Other components in this case include - -SS- (wherein R is an alkyl group, a phenyl group, a nitro group, a carboxyl group, a nitrile group, or an amino group.

It is an alkoxyl group, a hydroxyl group, or a sulfone group. ) Mudo can be mentioned.

The fine calcium carbonate in the present invention has an average particle diameter of 0.5μ or less, preferably 0.5μ or less. 1μ or less and a BET specific surface area of 15α/g or more, preferably
Examples include fine light calcium carbonate with a concentration of 25 rf/g or more.

Those with an average particle diameter larger than 0.5 μ° or BET
A material having a specific surface area smaller than 15 rrl''/g is not preferable because it has a poor effect of reducing corrosion to metals.

Historically, the fine calcium carbonate used in the present invention can be used after surface treatment with resin acid, lignin, etc. in order to improve dispersibility in resin.

Further, the content of fine calcium carbonate is 0.1 to 10 parts by weight, preferably 0.5 parts by weight, based on 5100 parts by weight of PP.
~5 parts by weight.

If the content of fine calcium carbonate is less than 0.1 parts by weight, the effect of improving corrosion resistance to metals is poor, and if it is more than 10 parts by weight, there is a risk of a decrease in mechanical strength, which is not preferable.

Various fillers can be added to the PPS resin composition in the present invention.

Examples of fillers include fibrous fillers such as glass fiber, carbon fiber, ceramic fiber, and metal fiber, whiskers such as potassium titanate, mica, calcium carbonate, silica, talc, calcium sulfate, kaolin, clay, glass peas, and glass. These include powder fillers such as powder, and these can be used alone or in combination.

In addition, plasticizers, mold release agents, silane-based and titanate-based coupling agents, lubricants, heat-resistant stabilizers, weather-resistant stabilizers, crystal nucleating agents, blowing agents, ion trapping agents, flame retardants, etc. are added as necessary. It may also be added.

Furthermore, various thermosetting resins and thermoplastic resins, such as epoxy resins, cyanate ester resins, phenol resins, polyimides, silicone resins, polyester resins, nylon, polyphenylene oxide, polycarbonates, polysulfones, and polyethersulfones, can be added as necessary. ,
It is also possible to use a mixture of one or more of homopolymers, random, block, and graft copolymers such as polyetherketone, polyetheretherketone, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, and fluororesin.

As a method for producing the PPS resin composition of the present invention, a conventional heating melt mixing method can be used.

For example, there is a method in which the mixture is mixed in a blender such as a Blender Guchenschel mixer, and then heated and melt-mixed in a kneader mill, a two-screw extruder, or a twin-screw extruder.

Furthermore, the obtained composition can be molded using an injection molding machine, an extrusion molding machine, a transfer molding machine, or a compression molding machine.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

Reference Example The method for producing the PPS resin used in the Examples and Comparative Examples of the present invention is as follows.

Internal volume 53 equipped with agitator, dehydration tower and jacket
N-methylpyrrolidone 1101 and sodium sulfide (purity: Na 2 S 60 wt%) 61.
1 kg was charged and heated with stirring using a shake soto, and dehydration was carried out through a dehydration tower until the internal temperature reached about 200°C. At this time, a distillate of 13.51 mainly consisting of water was distilled off. Next, 70.0 kg of p-dichlorobenzene
and N-methylpyrrolidone 481 were added, the temperature was raised to 250°C, and the mixture was further reacted at 250°C for 3 hours.

After the reaction was completed, the reaction mixture was transferred to a solvent recovery vessel equipped with a stirrer, a jacket, and a vacuum line.

At that time, 31 portions of N-methylpyrrolidone were added.

Subsequently, the distillate 2101 mainly consisting of N-methylpyrrolidone was distilled off by heating under reduced pressure.

Subsequently, water 2001 was added to make a water slurry, and the mixture was heated to 80°C.
After heating and stirring for 15 minutes, the polymer was recovered by centrifugation.

Furthermore, the polymer was returned to the solvent recovery vessel, water 2001 was added thereto, heated and stirred at 100°C for 30 minutes, and after cooling, the polymer powder was recovered using a centrifuge.

Note that this operation was repeated twice.

The obtained polymer was transferred to a jacketed ribbon blender and dried. A part of this PPS was sampled and the melt viscosity was increased using a flow tester (dice; 0.5
When measured at 300° C. with a glare load of 110 mm, it was 27 Pa, s.

Further, the polymer was cured at 250° C. for 4 hours while stirring with a ribbon blender under a stream of air.

The melt viscosity of the obtained polymer was 280 Pa.s.

Example 1 53.0 kg of PP obtained in the reference example, 2.1 kg of chopped strands with a fiber diameter of 13 μ as glass fiber and a cut length of 3 m11, and an average particle size of 0.05 μ, BET
Mix 51 g of fine calcium carbonate with a specific surface area of 34 ni'/g [manufactured by Shiraishi Kogyo ■] in a V-Blengu, and beat for 45 minutes.
A pelletized resin composition was obtained by melt extrusion using an L/D-3.0 twin-screw extruder.

As shown in Figure 1, 10 g of the obtained resin composition was placed in a weighing device, a silver plate placed in a petri dish was placed inside, and the temperature was heated at 150°C.
After heating in an oven for 500 hours, the degree of corrosion of the silver plate was determined visually and by measuring the lightness index using a color difference meter [manufactured by Suga Test Instruments ■]. No discoloration was observed, and the lightness index (L)
There were 26.

In addition, the brightness index of the silver plate was 24 in a blank test in which the silver plate alone was heat-treated without adding the resin composition.

In addition, in order to confirm the influence of fine calcium carbonate on the mechanical strength of the resin composition, the bending strength of the obtained resin composition was measured according to ASTM-D790.
It was MPa.

Comparative Example 1 The same operation as in Example 1 was performed except that fine calcium carbonate was not added.

The silver plate turned gray and had a lightness index (L) of 45. Moreover, the bending strength of the composition was 250 MPa.

Comparative Example 2 Except that 50 g of lithium carbonate [special reagent grade; manufactured by Wako Pure Chemical Industries, Ltd.] was added instead of fine calcium carbonate.
The same operation as in Example 1 was performed.

The silver plate was slightly discolored to gray, and the lightness index (L) was 33.

Further, the bending strength of the obtained composition was 235 MPa, and it was observed that the mechanical strength decreased due to the addition of lithium carbonate.

Examples 2 to 6 The same operation as in Example 1 was performed except for changing the fine calcium carbonate having different particle sizes and BET specific surface areas and the amount of addition thereof.

The results are shown in Table 1.

Comparative Examples 3 and 4 Instead of fine calcium carbonate, heavy calcium carbonate (particle size 4μ, BE
T specific surface area 1. The same procedure as in Example 1 was carried out except that 2rrI'/g) was used and the amount added was changed.

The results are shown in Table 1.

Comparative Example 5.6 The same operation as in Example 1 was carried out except that light calcium carbonate, which was outside the scope of the present invention, was used.

The results are shown in Table 1.

[Effects of the Invention] As is clear from the above explanation, the PPS resin composition of the present invention has significantly improved corrosion resistance to metals,
It also has excellent mechanical strength and has high industrial value.

[Brief explanation of the drawing]

FIG. 1 shows Examples 1 to 6. FIG. 2 is a schematic diagram of a test to examine the corrosivity of resin compositions of Comparative Examples 1 to 5 to metals. 1; Oven 150℃, 2; Weighing bottle 3; Petri dish, 4; Silver plate (25X 25X O, 2m
mouth) 5; Sample (resin composition)

Claims (1)

[Scope of Claims] 1) a) 100 parts by weight of polyphenylene sulfide resin b) 0.1 to 100 parts by weight of fine calcium carbonate having an average particle diameter of 0.5 μ or less and a BET specific surface area of 15 m^2/g or more
A polyphenylene sulfide resin composition comprising 10 parts by weight of the above a) and b).