JPH09279028A - Polyarylene sulfide resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyarylene sulfide resin composition reduced in the formation of burrs, during molding, excellent in moldability and can give moldings excellent in mechanical properties, stability, etc., by mixing a polyarylene sulfide resin with a specified boric acid compound. SOLUTION: This composition is obtained by mixing 100 pts.wt. polyarylene sulfide resin with 0.05-5 pts.wt. boric acid and/or its ester and 0-300 pts.wt. inorganic or organic filler. Although a polyarylene sulfide resin has high heat resistance, mechanical properties, chemical resistance, dimensional stability, etc., it has a drawback that burrs are apt to be formed when it is molded. By adding the above boric acid compound thereto, the obtained composition is reduced in the formation of burrs, emits little gas because of its thermal and chemical stabilities, and has excellent mechanical properties and moldability (flowability).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyarylene sulfide resin composition for molding, particularly for injection molding, and for blow molding. More specifically, burr generation during molding is improved, and it is thermally and chemically stable with less decomposition gas, and has excellent mechanical properties and moldability (fluidity).
And a polyphenylene sulfide resin composition, in particular.

[0002]

2. Description of the Related Art In recent years, electric / electronic equipment parts materials, automobile equipment parts materials, and chemical equipment parts materials have high heat resistance, mechanical properties, chemical resistance, dimensional stability, and flame resistance. There has been a demand for thermoplastic resins. Polyarylene sulfide (hereinafter abbreviated as PAS) resin represented by polyphenylene sulfide (hereinafter abbreviated as PPS) is also one of the resins that meets this demand, and generally improves the physical properties by blending a fibrous reinforcing agent such as glass fiber. , That demand is growing. However, the PAS-based resin or its composition has a drawback that when the resin is molded by injection molding or the like, the resin particularly flows into the joint surface of the mold and so-called burrs are easily generated. It has become to. The burrs of this molded product can be removed by deburring finishing after molding, but depending on the product shape, this finishing requires a great deal of labor and cost. Several proposals have been made so far for methods for reducing the occurrence of burrs in the PAS resin (for example, Japanese Patent Application Laid-Open No. 2-191666, etc.), but these methods are insufficient in the effect of reducing burrs. However, there are problems such as deterioration of mechanical properties and deterioration of molding processability (fluidity), which causes problems in other physical properties. There is a strong demand for a PAS-based resin material that simultaneously satisfies the desired properties.

[0003]

In view of the present situation, the present invention improves the occurrence of burrs particularly during molding, and is superior in other physical properties such as moldability and mechanical properties and stability of molded products.
It is intended to provide an S resin composition.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems of the PAS resin or its composition, and as a result, by adding a specific boric acid compound to the PAS resin, The present invention has been completed by finding that the desired effect of reducing the occurrence of burrs and the like is remarkably brought and other physical properties are also good. That is, the present invention comprises (A) 100 parts by weight of a polyarylene sulfide resin, (B) 0.05 to 5 parts by weight of boric acid and / or borate ester, and (C) 0 to 300 parts by weight of an inorganic or organic filler. The following polyarylene sulfide resin composition has a basic constitution. Further, in the present invention, by further blending 0.005 to 5.0 parts by weight of a crystallization accelerator such as boron nitride, talc and kaolin as the component (D), the effect aimed at by the present invention is more remarkably exhibited. It came to.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, components constituting the composition of the present invention will be described. The base resin used in the composition of the present invention is mainly composed of PAS resin, and is mainly composed of-(Ar-S)-(where Ar is an arylene group) as a repeating unit. As the arylene group, for example,
p-phenylene group, m-phenylene group, o-phenylene group, substituted phenylene group, p, p'-diphenylene sulfone group, p, p'-biphenylene group, p, p'-diphenylene ether group, p, p A'-diphenylenecarbonyl group, a naphthalene group or the like can be used. In this case, among the arylene sulfide groups composed of the above-mentioned arylene groups, in addition to a polymer using the same repeating unit, i.e., a homopolymer, a copolymer containing a heterogeneous repeating unit from the viewpoint of processability of the composition. Is sometimes preferred. As the homopolymer, one having a p-phenylene sulfide group as a repeating unit using a p-phenylene group as an arylene group is particularly preferably used. Further, as the copolymer, a combination of two or more different arylene sulfide groups consisting of the above-mentioned arylene groups can be used. Among them, a p-phenylene sulfide group and an m-
A combination containing a phenylene sulfide group is particularly preferably used. Among them, those containing p-phenylene sulfide groups in an amount of 70 mol% or more, preferably 80 mol% or more are suitable from the viewpoint of physical properties such as heat resistance, moldability and mechanical properties. The m-phenylene sulfide group is 5 to
Those containing 30 mol%, particularly 10 to 20 mol%, are preferable as the copolymer. In this case, the repeating units of the components contained in a block form rather than a random form (for example, those described in JP-A-61-142228) have excellent processability, heat resistance and mechanical properties. It has excellent physical properties and can be preferably used. Further, among these PASs, a high molecular weight polymer having a substantially linear structure, which is obtained by condensation polymerization from a monomer mainly containing a bifunctional halogen aromatic compound, can be particularly preferably used. Such a linear PAS having substantially no branching has excellent fluidity and mechanical properties, but has a large tendency to generate burrs, and is a particularly preferable target resin for the purpose of the present invention. In addition to the linear structure PAS,
A polymer having a partially branched structure or a crosslinked structure formed by using a small amount of a monomer such as a polyhaloaromatic compound having three or more halogen functional groups at the time of polycondensation can be used. It is also possible to use a polymer in which the structural polymer is heated at a high temperature in the presence of oxygen or the like to increase the melt viscosity by oxidative crosslinking or thermal crosslinking to improve the moldability. Above all, the PAS resin as the component (A) has a viscosity at the linear PAS (310 ° C./slipping speed of 1200 sec ⁻¹⁾ .
10 to 300 Pa · s) as a main component, and a part of it (1 to 30% by weight, preferably 2 to 25% by weight) has a relatively high viscosity (300
˜3000 Pa · s, preferably 500 to 2000 Pa · s) is a mixed system with a branched or cross-linked PAS resin in order to improve the generation of burrs at the time of molding, which is the object of the present invention, and to keep various physical properties superior. Is preferred. Melt viscosity of the PAS resin as the base resin used in the present invention (310 ° C, shear rate 1200 sec
^-1 ) is preferably 10 to 500 Pa · s, including the above mixed system. Among them, those in the range of 20 to 300 Pa · s are particularly preferable because they have an excellent balance of mechanical properties and fluidity. If the melt viscosity is too low, the mechanical strength is not sufficient, which is not preferable. Further, when the melt viscosity exceeds 1000 Pa · s, the fluidity of the resin composition during injection molding is poor and the molding operation becomes difficult, which is not preferable.

Next, the present invention is characterized in that the PAS resin as the component (A) is blended with boric acid and / or boric acid ester as the component (B). The boric acid used in the present invention is orthoboric acid, metaboric acid,
Tetraboric acid, boric anhydride, etc. are mentioned, The ester, for example, an alkyl or aryl ester, is also effective, and at least 1 type or more of these is used. Among them, orthoboric acid, boric anhydride, or an alkyl ester thereof is preferably used. Commercially available products can be used as these compounds, or they can be easily prepared by a heating treatment using orthoboric acid or the like as a starting material or a heating mixing treatment with an alcohol. The addition amount of the component (B) such as boric acid is 0.1 parts with respect to 100 parts by weight of the PAS resin as the component (A).
05 to 5 parts by weight, preferably 0.1 to 3 parts by weight. Particularly preferred is 0.1 to 1.0 part by weight. If the amount added is too small, no sufficient effect will be obtained, and if the amount added is too large, it will be difficult to prepare by melt-kneading, which is not preferable. The component (B), such as boric acid, may be added at any time after washing and purifying the crude PAS, and is generally performed at the same time when the filler such as glass fiber or various additives is added to the PAS resin. However, it may be added separately. In this case, the powder or liquid may be added as it is, or may be added (dried) as an aqueous solution or an organic solution.

Next, in the present invention, as the component (C), an organic or inorganic filler is blended in order to obtain a molded article excellent in mechanical strength, rigidity, heat resistance, dimensional stability and electrical properties. Preferably. For this purpose, a fibrous, powdery or plate-like filler is used depending on the purpose. Among these, as the fibrous filler, in addition to organic fibers represented by aramid fibers, glass fibers, asbestos fibers, carbon fibers,
Silica fiber, silica / alumina fiber, zirconia fiber,
Boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, stainless steel, aluminum, titanium, copper,
An inorganic fibrous substance such as a fibrous material of a metal such as brass can be used. Particularly typical fibrous fillers are glass fibers or carbon fibers. On the other hand, as the particulate filler, carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, clay,
Diatomaceous earth, silicates like wollastonite, iron oxide,
Oxides of metals such as titanium oxide, zinc oxide and alumina,
Further, metal carbonates such as calcium carbonate and magnesium carbonate, metal sulfates such as calcium sulfate and barium sulfate, silicon carbide, silicon nitride, various metal powders and the like can be mentioned. Examples of the plate-like filler include various types of mica, glass flakes, metal foils and the like. In addition, hollow fillers such as shirasu balloons, metal balloons and glass balloons may be added from the viewpoint of weight reduction. These fillers can be used alone or in combination of two or more. Fibrous filler,
In particular, the combined use of glass fiber, carbon fiber, or potassium titanate fiber and a granular and / or plate-like filler is a preferable combination particularly in terms of mechanical strength, dimensional accuracy, electrical properties and the like. The amount of the filler used is 300 parts by weight or less, preferably 5 to 250 parts by weight, particularly preferably 10 to 200 parts by weight, per 100 parts by weight of the polyarylene sulfide resin. If it is too small, the mechanical strength is not sufficient, and if it is too large, the molding operation becomes difficult, and the mechanical properties of the molded product are also unfavorable. These fillers are epoxy compounds, isocyanate compounds, silane compounds,
It is preferable to use a functional compound such as a titanate-based compound or a polymer that has been surface-treated or converged. These compounds may be added at the same time when the composition is prepared. In particular, alkoxysilanes such as epoxysilane, aminosilane and mercaptosilane are preferable.

Although not essential in the present invention, as the component (D), the PAS resin of the component (A) 1
By using 0.005 to 5.0 parts by weight of crystallization accelerator (nucleating agent) in combination with 00 parts by weight, solidification at the time of molding is promoted, and the desired effect of suppressing burr generation is more remarkably exhibited. It Specific examples of the crystallization accelerator include fine powders of boron nitride, talc, kaolin, etc. Among them, boron nitride powder is most effective because it exerts a remarkable synergistic effect even in an extremely small amount. . Boron nitride (BN) used here has an average particle size of 0.2 to 10 μm (MP
In general, a hexagonal crystal fine powder of (S method) is preferable. If the particle size is too small, it is difficult to handle, and problems such as uniform blending occur. If the particle size is too large, the desired effect of the present invention decreases, which is not preferable. The amount of finely powdered boron nitride compounded is 2 parts by weight or less per 100 parts by weight of the PAS resin (A), preferably 0.005 to 2 parts by weight, particularly preferably 0.01 parts by weight.
１1 part by weight.

In the composition of the present invention, other thermoplastic resins such as polyvinyl chloride resin, polyvinylidene chloride resin, polyolefin resin (ethylene, propylene and further It is also possible to supplementarily add a small amount of a copolymer or modified polymer having an epoxy group introduced therein, a polycarbonate resin, a polyester resin, a polyamide resin, a natural rubber, a synthetic rubber or the like. Further, additives such as a flame retardant, an antioxidant, an ultraviolet protective agent, a lubricant, a release agent, a foaming agent, a cross-linking agent and a coloring agent may be added.

The composition of the present invention can be prepared by various known methods. By adding the above-mentioned components to the PAS resin, and if necessary, other components, and heating and melting the mixture, a kneading treatment is carried out. Is prepared. For example, the necessary components are mixed in advance by a mixer such as a tumbler or a Henschel mixer, and then the mixture is supplied to a uniaxial or biaxial extruder and melt-kneaded to produce pellets. At this time, all the components may be added simultaneously or separately. The kneading temperature is 5 ° C. to 100 ° C. higher than the melting temperature of the resin component, and particularly preferably 10 ° C. to 60 ° C. higher than the melting point of the resin.

[0011]

INDUSTRIAL APPLICABILITY The polyarylene sulfide composition of the present invention can improve the occurrence of burrs during molding, and is excellent in moldability and mechanical properties.

[0012]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. Examples 1 to 7 and Comparative Examples 1 to 3 (A) For PPS resin (“Fortron KPS” manufactured by Kureha Chemical Industry Co., Ltd.), boric acid as a component (B) and a filler (C). Was added as shown in Table 1, mixed well, and then melted and kneaded in an extruder having a cylinder temperature of 310 ° C. to prepare pellets of the resin composition. Then, using an injection molding machine, perform ASTM at a cylinder temperature of 320 ° C and a mold temperature of 150 ° C.
A tensile test piece was molded according to D638, and the tensile strength and tensile elongation were measured. The burr length was evaluated by using a mold with a disk-shaped cavity in which a burr measuring part with a mold gap of 20 μm in part was provided in a part of the outer circumference. Injection molding was carried out at a temperature of 150 ° C with the minimum pressure required to completely fill the cavity, and the length of burrs generated at that portion was measured with a projection projector. or,
Viscosity is measured using a Capirograph at 310 ℃, 1200 / sec ^-1
Melt viscosity was measured. Table 1 also shows the results when the component (B), such as boric acid, was not added.

[0013]

[Table 1]

Examples 8 to 10 and Comparative Examples 4 to 6 As shown in Table 2, the same evaluation was carried out also when the crystallization accelerator of the component (D) was used.

[0015]

[Table 2]

Claims (10)

[Claims] (A) Polyarylene sulfide resin (A)
A polyarylene sulfide resin composition comprising (B) 0.05 to 5 parts by weight of boric acid and / or boric acid ester and 0 to 300 parts by weight of an inorganic or organic filler with respect to 00 parts by weight. 2. The boric acid and / or boric acid ester as the component (B) is at least one selected from orthoboric acid, metaboric acid, tetraboric acid, boric anhydride, and alkyl or aryl esters of these boric acids. The polyarylene sulfide resin composition according to claim 1, which is 3. The polyarylene sulfide resin composition according to claim 2, wherein the boric acid as the component (B) is at least one of orthoboric acid and boric anhydride. 4. The polyarylene sulfide resin composition according to any one of claims 1 to 3, wherein the polyarylene sulfide resin as the component (A) is mainly a substantially linear polyarylene sulfide resin. 5. A polyarylene sulfide resin as the component (A) has a viscosity of 10 at 310 ° C. and a shear rate of 1200 sec ⁻¹ .
A mixed polyarylene sulfide resin comprising 99 to 70 parts by weight of a substantially linear polyarylene sulfide having a viscosity of 300 to 300 Pa · s and 1 to 30 parts by weight of a branched or crosslinked polyarylene sulfide resin having a viscosity of 300 to 3000 Pa · s. The polyarylene sulfide resin composition according to any one of claims 1 to 4. 6. The polyarylene sulfide resin composition according to claim 1, wherein the filler as the component (C) is a fibrous filler. 7. The polyarylene sulfide resin composition according to claim 1, wherein the filler as the component (C) is a fibrous filler and a powdery and / or plate-like filler. 8. The polyarylene sulfide resin composition according to claim 1, wherein the filler as the component (C) is glass fiber. 9. The polyarylene according to claim 1, further comprising 0.005 to 5.0 parts by weight of a crystallization accelerator as a component (D) in addition to the components (A) to (C). Sulfide resin composition. 10. The polyarylene sulfide resin composition according to claim 9, wherein the crystallization accelerator of the component (D) is at least one fine powder selected from boron nitride, talc and kaolin.