JPH04168159A - Pps resin composition - Google Patents

Abstract

PURPOSE:To provide a PPS resin composition having excellent thermal stability, mechanical property and impact resistance and having a large practical use as a molding material by adding a specific ethylenic copolymer to polyphenylene sulfide resin in a specific dispersing state. CONSTITUTION:A resin composition comprises (A) polyphenylene sulfide resin having a melting viscosity of preferably 100-10000 poises, more preferably 1000-5000 poires, and (B) an ethylenic copolymer comprising 50-90wt.%, preferably 60-85wt.%. of ethylene, 5-49wt.%, preferably 7-45wt.%, of an alpha,beta-unsaturated carboxylic acid alkyl ester, and 0.5-10wt.%, preferably 1-8wt.%, of maleic anhydride, and having a melt index of 0.1-1000, preferably 0.2-500, in an A/B weight ratio of 50/50 to 98/2, the component B being distributed in the component A as a dispersing phase in an inter-particular surface distance of <=0.2mum, preferably <=0.1mum.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a polyphenylene sulfide resin composition with improved impact resistance properties.

More specifically, the present invention relates to a polyphenylene sulfide resin composition with improved impact resistance, which is made by containing a specific ethylene copolymer in a specific dispersion state in a polyphenylene sulfide resin.

(Prior Art) The field of application of engineering plastics has been expanding more and more in recent years, and in particular, their use in the automobile, electrical, and electronic fields has increased significantly. Along with this, user demands for plastics have become more diverse and sophisticated, and meeting these demands has become a technological challenge.

However, these diversified and highly functional demands cannot be fully met with a single material alone, and therefore polymer alloys have recently been actively used to meet these demands.

A resin composition comprising a polyphenylene sulfide resin (hereinafter referred to as PPS) and an elastomer is a known polymer alloy, and was developed against the background of the above-mentioned requirements. In other words, PPS is known as a resin with excellent flame retardancy, heat resistance, and chemical resistance, but its impact strength is not necessarily satisfactory, and for this reason, alloying with elastomers has improved impact resistance. trying to improve.

However, the elastomer dispersed in such a resin composition does not necessarily have an optimal dispersion state, and a sufficient effect of improving impact resistance cannot be obtained.

(Problems to be Solved by the Invention) In view of the above circumstances, an object of the present invention is to obtain a polyphenylene sulfide resin composition that maintains the excellent features of PPS and has improved impact resistance.

(Means for Solving the Problems) As a result of intensive study of this object, the present inventors added 50 to 90% of ethylene to the polyphenylene sulfide resin (A).
* f %, α,β-unsaturated carboxylic acid alkyl ester 5-49% by weight and maleic anhydride 0.5-10
% by weight of an ethylene copolymer (B), in which component (B) is dispersed in component (A) with a distance between particle surfaces of 0.2 μm or less. The inventors have discovered that a composition achieves the above objects and have arrived at the present invention.

The present invention will be explained in detail below.

P P S (A) used in the present invention is a polymer containing 70 mol% or more, more preferably 90 mol% or more of repeating units represented by the structural formula:.

If the content of the repeating unit is less than 70 mol%, the heat resistance will be lowered, which is not preferable.

PPS generally includes a polymer with a relatively small molecular weight obtained by the production method typified by Japanese Patent Publication No. 45-3368, and a polymer with an essentially low molecular weight obtained by the production method typified by Japanese Patent Publication No. 52-12240. There are linear polymers with relatively high molecular weight, etc., and in the polymer obtained by the method described in Japanese Patent Publication No. 45-3368, after polymerization, it can be heated in an oxygen atmosphere or treated with peroxide. It is also possible to increase the degree of polymerization and use it by adding a crosslinking agent such as PPS and heating it, and in the present invention, it is possible to use PPS obtained by any method.

Furthermore, less than 30 mol% of the repeating units of PPS can be composed of repeating units having the following structural formula, etc.

The melt viscosity of PPS used in the present invention is not particularly limited as long as it is possible to obtain molded products, but in terms of the toughness of PPS itself, it is 100 poise or more, and in terms of moldability it is 10,000 poise or more. Poise or less is more preferably used. Particularly preferred is a range of 1,000 to 5,000 poise.

Furthermore, for the purpose of controlling the degree of crosslinking of PPS, common peroxide crosslinking agents and crosslinking accelerators such as thiophosphinic acid metal salts described in JP-A-59-131650,
or JP-A-58-204045, JP-A-58-
It is also possible to incorporate crosslinking inhibitors such as dialkyltin dicarboxylate and aminotriazole described in JP-A No. 204046 and the like.

In the present invention, polyphenylene sulfide resin (A
) contains a copolymer (B) of ethylene, α, β-unsaturated carboxylic acid alkyl ester, and maleic anhydride, and the proportion thereof is such that the proportion of component (B) forms a dispersed phase in PPS. There is no particular restriction, and in order to obtain the desired effect, it is preferable to mix the components in a weight ratio of (A)/(B) = 50,150 to 98/2. This is because when the amount of component (B) exceeds this range, PPS loses its inherent heat resistance.
Also, if the amount decreases, it becomes difficult to obtain the desired effect.

In the present invention, a copolymer of ethylene, α, β-unsaturated carboxylic acid alkyl ester, and maleic anhydride is used.
Among them, the monomer component is ethylene 50 to 90% by weight,
Preferably 60 to 85% by weight, α,β-unsaturated carboxylic acid alkyl ester 5 to 49% by weight, preferably 7 to 85% by weight.
45% by weight and maleic anhydride in an amount of 0.5 to 10% by weight, preferably 1 to 8% by weight.

α,β-Unsaturated carboxylic acid alkyl ester is an unsaturated carboxylic acid having 3 to 8 carbon atoms, such as acrylic acid,
Alkyl esters such as methacrylic acid, specific examples include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, and methacrylate. Methyl acid, ethyl methacrylate,
Examples include methacrylic 11n-propyl, isopropyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, and isobutyl methacrylate. Among these, ethyl acrylate, n-butyl acrylate, and methyl methacrylate are particularly preferred. .

As a guideline for the molecular weight of these copolymers (B), 190
The melt index value under a load of 2.16 kg can be used.The copolymer used (B
) has a melt index value in the range of 0.1 to 1000, preferably 0.2 to 500, more preferably 1 to 100.

These copolymers (B) are commercially available from Jumei CPF Chemical Industry Co., Ltd. under the name "Bondine".

PPS (A) and ethylene copolymer (B) of the present invention
In the composition, the ethylene copolymer (B) is distributed as a dispersed phase, and the interparticle surface distance is 0°2 μm.
It is important that the thickness is not more than 0.1 μm, and in order to obtain a higher impact resistance improvement effect, it is preferably 0.1 μm or less.

The distance between the particle surfaces of the ethylene copolymer (B) in the present invention is defined as follows.

A composition consisting of PPS and ethylene copolymer was stained with ruthenium tetroxide, osmium tetroxide, etc. by a conventional method, cut into thin sections, and observed with a transmission electron microscope.
Take the average particle size d of the dyed phase.

The average particle diameter d refers to the circular phase 5 of each particle calculated from a photograph of an arbitrary 15 x 15 μm field of a thin section, or by printing it onto a photograph from a negative and reading it into an image diffraction device.
Take the number average value of the diameter. However, the arbitrary field of view at this time is
If a skin phase and a core phase are present in the composition, the core phase view is used.

Furthermore, when inputting a photograph to the image diffraction device, if the dyed boundary is unclear, the photograph is traced and this diagram is used to input the data to the image diffraction device.

Assuming that the particle diameter is uniform and that the particle is arranged squarely, the distance between the particle surfaces can be calculated from the average particle diameter d obtained above using the formula below, and this value is taken as the distance between the particle surfaces here. .

L=d((π/6φ)"3-1) φ: Volume fraction of ethylene copolymer, melt kneading in the present invention is performed using a kneader, a roll mill, an extruder, etc., which are commonly used for kneading resin melts. The kneading can be carried out using a known device.Types of extruders include single-screw, twin-screw, co-kneader, etc., but the composition of the present invention can be obtained using any of the extruders. A twin-screw extruder is preferably used because the stronger the kneading, the better the particle dispersion and the smaller the particle diameter.

The mixing temperature is higher than the melting point of PPS, and sufficient kneading is possible within the commonly used range of 280 to 340'C. Further, it is preferable that PPS be pre-dried as a pre-treatment and cross-talk be performed in an inert gas atmosphere.

Further, in order to improve the dispersion state of the ethylene copolymer (B) and reduce the distance between particle surfaces, a polyfunctional compatibilizer is usually used. Examples of this polyfunctional compatibilizer include compounds having amino groups, hydroxyl groups, carboxyl groups, isocyanate groups, carbodiimide groups, epoxy groups, maleic anhydride groups, etc. in the molecule, and among these, compounds having isocyanate groups are mentioned. Preferably used.

Furthermore, in the resin composition of the present invention, an inorganic and/or organic filler can be added to the resin portion as necessary to improve rigidity and the like.

Suitable fillers include glass fiber, carbon fiber, metal fiber, aramid fiber, potassium titanate, asbestos, silicon carbide, ceramic, silicon nitride, barium sulfate, calcium sulfate, kaolin, clay, pyrophyllite,
bentonite, sericite, zeolite, mica, mica, nephelinsinite, talc, atalpulgite,
Wollastonite, PMF, ferrite, calcium silicate, calcium carbonate, magnesium carbonate, dolomite, zinc oxide, titanium oxide, magnesium oxide, iron oxide,
Mention may be made of reinforcing fillers such as molybdenum disulfide, graphite, gypsum, glass beads, glass powder, glass balloons, quartz, and quartz glass.

The resin composition of the present invention may further contain an aromatic hydroxy derivative such as 2-ethylhexyl-p-hydroxybenzoate, as long as the structure of the composition is maintained.
In addition to sulfonic acid amide, a plasticizer such as benzenesulfonamide, a small amount of a mold release agent, a coupling agent, a coloring agent, a lubricant, a heat stabilizer, a weather stabilizer, a foaming agent, and a rust preventive agent are added. Also good.

The resin composition of the present invention can be prepared by various known methods. For example, there is a method in which the raw materials are mixed uniformly in advance in a mixer such as a tumbler 1 or a Henschel mixer, and then fed into a -screw or twin-screw extruder, melt-kneaded, and then prepared as pellets.

The melt-kneading temperature is preferably 280 to 320°C; if it is less than 280°C, the melting of PPS may become insufficient, and if it exceeds 320°C, the ethylene copolymer C
Care must be taken as thermal deterioration and gelation of B) may occur.

In the present invention, the Izot impact strength is determined by ASTM D
-256.

(Example) The present invention will be explained in further detail by giving examples below, but the present invention is not limited thereto.

Examples 1 to 9 After drying PPS powder (T-4 manufactured by Torblen ■) at 140°C for 3 hours, the temperature was lowered to 50°C, and PPS, ethylene copolymer, and 4,4'-diphenylmethane diisocyanate were blended. After mixing in a Henschel mixer in a nitrogen atmosphere for 5 minutes,
BT-40” twin screw extruder, cylinder 1 degree: 290
Pelletized at ~300°C.

In addition, when glass fiber was blended, the pelletized pellets were melt-kneaded with the glass fiber again using an extruder. The obtained pellets are heated to a cylinder temperature of 240°C in the hopper part, 290°C in the center, and 300°C in the tip part.
In step C, the mold temperature was set at 140°C, a test piece was obtained by a normal injection molding method, and the Izod impact strength was measured.

This test piece was stained with ruthenium tetroxide, thin sections were cut, and transmission electron micrographs were taken. For observation, a 1200EX ■ transmission electron microscope manufactured by JEOL ■ was used.

Furthermore, for image analysis, IP-1000 manufactured by Asahi Kasei Kogyo
Images were input from the above-mentioned electron microscope using an image analysis device. The results obtained are shown in Tables 1 and 2.

Comparative Examples 1 to 3 After drying PPS powder (Tovren T-4) at 140°C for 3 hours, the temperature was lowered to 50°C, PPS and ethylene copolymer were blended, and the powder was dried in a Henschel mixer in a nitrogen atmosphere for 5 minutes. After mixing, ``BT'' manufactured by Plastic Engineering Research Institute ■
-40” twin screw extruder, cylinder temperature: 290-30
Pelletized at 0°C.

In addition, when glass fiber was blended, the pelletized pellets were melt-kneaded with glass fiber again using an extruder. The obtained pellets are heated to a cylinder temperature of 240°C in the hopper part, 290°C in the center part, 300°C in the tip part.
In step C, the mold temperature was set at 140°C, a test piece was obtained by a normal injection molding method, and the Izont impact strength was measured.

This test piece was stained with ruthenium tetroxide, thin sections were cut, and transmission electron micrographs were taken. For the observation, a 1200Ex■ transmission electron microscope manufactured by JEOL Ltd. was used.

Furthermore, an IP-1000 image analysis device manufactured by Asahi Kasei Kogyo Co., Ltd. was used for image analysis, and images were input from the above-mentioned electron microscope. The results obtained are shown in Tables 1 and 2.

Table 1 PPS;)-Bren-Kasuken rT-4J MDI, 4,4'-diphenylmethane diisocyanate ethylene copolymer 1: To resident CDF to Ceramics r Bondine χ8390 J ethylene copolymer 2;
Resident CPF (manufactured by En "Bondine FX8000"
j Ethylene copolymer 3; Resident CPF (Jitoku Rpondyne TX8030 J Table 2 Glass fiber: Nippon Electric Glass rT-717J (fiber diameter 13 μm, fiber length 3 mm) (Effects of the invention) PPS of the present invention The resin composition has excellent thermal stability and mechanical properties, and has a good dispersion state of the ethylene copolymer component.
It is a resin composition with excellent impact resistance, and is a highly practical molding material with excellent physical properties as an engineering plastic.

(1 idiot)

Claims (1)

[Scope of Claims] Polyphenylene sulfide resin (A) contains 50 to 90% by weight of ethylene, 5 to 49% by weight of α,β-unsaturated carboxylic acid alkyl ester, and 0.5 to 10% by weight of maleic anhydride. In the resin composition containing the copolymer (B), the component (B) is (
A) A resin composition in which the particles are dispersed in the component so that the distance between the particle surfaces is 0.2 μm or less.