JPH0841341A - Polyphenylene sulfide resin composition and molded product for light reflection - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a polyphenylene sulfide resin composition excellent in surface smoothness and rigidity of a molded article and a molded article for light reflection excellent in surface smoothness and rigidity obtained by molding the same. Composition: 40 to 60% by weight of polyphenylene sulfide resin having a melt viscosity of 300 to 4000 poise, 10 to 20% by weight of potassium titanate whisker, and an average particle size of 1.
A polyphenylene sulfide resin composition comprising 30 to 50% by weight of calcium carbonate having a particle size of ˜7 μm, and a light reflection molded article obtained by molding the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyphenylene sulfide resin composition and a light-reflecting molded article obtained by molding the same. More specifically, the present invention relates to a polyphenylene sulfide resin having excellent surface smoothness and rigidity. The present invention relates to a composition and a molded article for light reflection, which is obtained by molding the composition and has excellent surface smoothness and rigidity.

[0002]

2. Description of the Related Art Polyphenylene sulfide resin is being developed into electric / electronic equipment parts materials and automobile equipment parts materials by taking advantage of its excellent heat resistance, chemical resistance, dimensional stability and mechanical strength. . However, since the polyphenylene sulfide resin is insufficient in heat resistance and mechanical strength when used alone, the fibrous reinforcing material and / or
Alternatively, by adding an inorganic filler, the heat resistance and the mechanical strength are increased for use.

As a development of a polyphenylene sulfide resin as a material for automobile equipment parts, it has been proposed to use it as a lamp reflector for automobiles, which is required to have a high degree of surface smoothness. For example, JP-A-63-243162 (polyphenylene sulfide resin, resin composition comprising about 5 to 40% by weight of inorganic fiber and about 15 to 70% by weight of silica fume), JP-A-2-244501 (polyphenylene sulfide resin). Resin compositions comprising 10% by weight or less of glass fiber and 40 to 70% by weight of filler) and the like. However, JP-A-63-243162
The composition disclosed in No. 1 does not have sufficient surface smoothness,
The composition disclosed in JP-A-2-244501 has a markedly reduced surface smoothness due to the addition of glass fibers, and
When glass fiber is not added, the rigidity is low, so that the molded product is largely deformed at a high temperature, which causes a problem that the optical axis is changed in the use as a lamp reflector for automobiles. Furthermore, Japanese Patent Laid-Open No. 2-24
The composition disclosed in No. 4501 causes a significant decrease in the surface smoothness of the molded product when the average particle size of the filler used is large, and when the filler alone is used, the surface smoothness of the molded product is excellent. It is impossible to achieve both the property and the rigidity. These are major obstacles to the practical use of lamp reflectors for automobiles.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a polyphenylene sulfide resin composition having excellent surface smoothness and rigidity of a molded article, and a molded article for light reflection excellent in surface smoothness and rigidity obtained by molding the same. Is provided.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above problems, and as a result, completed the present invention.

That is, the present invention has a melt viscosity of 300 to 4
Polyphenylene sulfide resin 40 with 000 poise
~ 60 wt%, potassium titanate whiskers 10-20
The present invention relates to a polyphenylene sulfide resin composition comprising 30% to 50% by weight of calcium carbonate having an average particle size of 1 to 7 μm, and a light reflection molded article obtained by molding the same.

Hereinafter, the present invention will be described in detail. The polyphenylene sulfide resin used in the present invention has a melt viscosity (measured with a high-performance flow tester using a die having a diameter of 1 mm and a length of 2 mm under the conditions of a measurement temperature of 300 ° C. and a load of 10 kg) of 300 to 4000 poise. , And particularly preferably a polyphenylene sulfide resin in the range of 1000 to 3500 poise, even if it is a linear one,
Even if the degree of polymerization is increased by curing by heat treatment in an oxygen atmosphere or by adding heat treatment such as adding peroxide, heat treatment in a non-oxidizing inert gas is also performed. It may be a mixture of these structures. If the melt viscosity is less than 300 poise, strength is reduced and a large amount of gas is generated, which is not preferable. On the other hand, when it exceeds 4000 poise, the fluidity is remarkably lowered and the surface smoothness of the molded article is lowered, which is not preferable. A polyphenylene sulfide resin having a melt viscosity in the range of 1000 to 3500 poises has particularly excellent strength and fluidity of a molded product and has a small amount of gas generation.
preferable.

Further, the above polyphenylene sulfide resin may be one in which ions are reduced by performing deionization treatment (acid washing, hot water washing, etc.).

Further, the polyphenylene sulfide resin used in the present invention has, as its constitutional unit,

[0010]

Embedded image

It is preferable to contain 70 mol% or more, more preferably 90 mol% or more. If the constituent unit is less than 30 mol%, preferably less than 10 mol%, the m-phenylene sulfide unit,

[0012]

Embedded image

An o-phenylene sulfide unit,

[0014]

[Chemical 3]

A phenylene sulfide sulfone unit,

[0016]

[Chemical 4]

Phenylene sulfide ketone unit,

[0018]

[Chemical 5]

A phenylene sulfide ether unit,

[0020]

[Chemical 6]

A diphenylene sulfide unit,

[0022]

[Chemical 7]

It does not matter if it contains a copolymerized unit such as

As the potassium titanate whiskers used in the present invention, commercially available products can be used. The potassium titanate whiskers used preferably have an average fiber diameter of 1 μm or less and an average fiber length of 30 μm or less in view of rigidity, strength, fluidity and the like.

The amount of potassium titanate whiskers used in the present invention is 10 to 20% by weight. If the blending amount is less than 10% by weight, the effect of improving the rigidity is small, which is not preferable. On the other hand, when it exceeds 20% by weight, the surface smoothness of the molded article is deteriorated and the potassium titanate whiskers are expensive, which is not preferable because of its low commercial utility value.

Further, the potassium titanate whiskers used in the present invention are preferably used after being pretreated with a coupling agent such as a silane type or titanium type in order to improve strength and fluidity. In particular, it is preferable to use an aminosilane coupling agent that is effective in improving strength and fluidity.

The average particle diameter (D50) of the calcium carbonate used in the present invention is 1 to 7 μm, preferably 2 to 5 μm. If the average particle size exceeds 7 μm, the surface smoothness of the molded product deteriorates, which is not preferable. On the other hand, when the thickness is less than 1 μm, the strength and the fluidity decrease, which is not preferable. The average particle diameter of 2 to 5 μm is preferable because the surface smoothness, strength and fluidity of the molded product are particularly excellent. The amount of calcium carbonate used in the present invention is 30 to 50.
% By weight, preferably 33 to 45% by weight. If the blending amount is less than 30% by weight, the heat resistance is significantly deteriorated, which is not preferable. On the other hand, when it exceeds 50% by weight, the surface smoothness and fluidity of the molded product are deteriorated, which is not preferable. When the compounding amount is 33 to 45% by weight, the surface smoothness, heat resistance and fluidity of the molded product are particularly excellent, which is preferable.

In particular, in the present invention, the combination of a two-component filler consisting of potassium titanate whiskers and calcium carbonate having an average particle size of 1 to 7 μm satisfies rigidity, fluidity, heat resistance and surface smoothness. A polyphenylene sulfide resin composition has been found.

The resin composition of the present invention contains talc, barium sulfate, calcium sulfate, kaolin, clay, pyroferrite, bentonite, cerilite, nepheline sinite, attapulgite, wollastonite, within a range not departing from the object of the present invention. Fillers such as ferrite, calcium silicate, magnesium carbonate, dolomite, antimony trioxide, zinc oxide, titanium oxide, magnesium oxide, iron oxide, molybdenum disulfide, graphite, gypsum, glass beads, glass balloons, glass powder, silica, etc. 1
You may use together 1 or more types. If necessary, these can be used after being pretreated with a coupling agent such as a silane-based or titanium-based coupling agent.

Further, the resin composition of the present invention is a thermoplastic elastomer such as olefin, styrene, urethane, ester, fluorine, amide, acrylic or the like, polybutadiene, within the range not departing from the object of the present invention. Rubber components such as polyisoprene, polychloroprene, polybutene, styrene butadiene rubber and hydrogenated products thereof, acrylonitrile butadiene rubber, ethylene propylene copolymer, ethylene propylene ethylidene norbornene copolymer, nylon 6, nylon 66, nylon 46, Polyamide resins such as nylon 610, nylon 11 and nylon 12, polyethylene terephthalate, polybutylene terephthalate, polyester resins such as polyacrylate, polystyrene, poly α-methyl styrene, polyvinyl acetate, polyvinyl chloride. , Polyacrylic acid ester, polymethacrylic acid ester, polyacrylonitrile, polyurethane, polyacetal, polyphenylene oxide,
Polycarbonate, polysulfone, polyether sulfone, polyallyl sulfone, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, polyether ketone, polyether ether ketone, polyamide imide, polyimide, silicone resin, phenoxy resin,
One or more kinds of resins such as a homopolymer such as a fluororesin and a melt-processible resin forming an anisotropic melt phase, a random or block, a graft copolymer and a mixture thereof or a modified product thereof may be used in combination. .

Further, the resin composition of the present invention is a conventionally known release agent, lubricant, heat stabilizer, antioxidant, ultraviolet absorber, crystal nucleating agent, foaming agent within the range not impairing the object of the present invention. One or more additives such as a rust preventive agent, an ion trap agent, a flame retardant, a flame retardant aid, a coloring agent such as a dye or a pigment, and an antistatic agent may be used in combination.

As a method for producing the polyphenylene sulfide resin composition of the present invention, a conventionally used heating and melting method can be used. For example, V-blender,
After mixing with various blenders such as Henschel mixer,
Examples of the method include heating, melting and mixing with a kneader, a mill, or a single-screw or twin-screw extruder. Furthermore, the composition obtained is
It can be molded using an injection molding machine, an extrusion molding machine, a transfer molding machine, or a compression molding machine.

Further, since the molded product obtained by molding the resin composition of the present invention is particularly excellent in surface smoothness and rigidity, it is excellent in light reflection performance and is stable in the optical axis such as a lamp reflector for automobiles. It can be used as a light-reflecting molded article that solves the above-mentioned conventional problems.

[0034]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 3 Polyphenylene sulfide resin (PPS, manufactured by Tosoh Sustille Co., Ltd., melt viscosity 1900 poise), potassium titanate whiskers (average fiber diameter 0.6 μm, average fiber length 20 μm, aminosilane coupling) After using the agent) and calcium carbonate (average particle size 4 μm) in the proportions shown in Table 1, they were melt-kneaded at 300 ° C. using a twin-screw extruder and pelletized. Then, in order to evaluate the strength and rigidity of the molded product, we made a test piece with an injection molding machine,
Flexural strength and flexural modulus measurements (ASTM D790
Compliant). Further, in order to evaluate the surface smoothness of the molded product, a disk (102 mmφ, thickness 2 mm) was prepared by an injection molding machine, and the maximum mirror surface height (Rma) of the molded product was measured.
x) was measured (according to JIS B0601), and a fluorescent lamp was reflected on the mirror surface of the molded product, and the presence or absence of distortion of the reflected image was visually determined. ◯ means good, and x means bad. Further, in order to evaluate fluidity, pellets of the resin composition obtained by the above method are used, and melt flow rate (MFR) is measured (according to ASTM D1238,
The measurement temperature was 315 ° C. and the load was 5 kg). Table 2 shows the respective measurement results.

The composition thus obtained was excellent in strength, rigidity and surface smoothness, and a sufficiently satisfactory light reflecting molded article could be obtained.

Comparative Examples 1 to 6 Polyphenylene sulfide resins (PP having different melt viscosities)
S, manufactured by Tosoh Sustain Co., Ltd., potassium titanate whiskers (average fiber diameter 0.6 μm, average fiber length 20)
μm, aminosilane-based coupling agent used), glass fiber (average fiber diameter 4 μm, 3 mm chopped strand product), and calcium carbonate having different average particle sizes in the proportions shown in Table 1, and the same operations and evaluations as in Example I went.
Table 2 shows the respective measurement results.

The composition thus obtained does not satisfy all of the characteristics, although it may satisfy the characteristics of strength, rigidity and surface smoothness, and a satisfactory light reflecting molded article may be obtained. I couldn't get it.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

As is clear from the above description, a polyphenylene sulfide resin having a limited melt viscosity is used in combination with potassium titanate whiskers in a limited amount and calcium carbonate in a limited average particle size and amount. It is possible to obtain a polyphenylene sulfide resin composition which is excellent in surface smoothness and rigidity of a molded product by blending the above. Furthermore, since the molded product for light reflection obtained by molding this is excellent in rigidity and surface smoothness,
It can be obtained as a light-reflecting molded article such as a lamp reflector for automobiles having excellent light-reflecting performance and a stable optical axis.

[0042]

Claims (2)

[Claims] 1. A polyphenylene sulfide resin having a melt viscosity of 300 to 4000 poise, 40 to 60% by weight, potassium titanate whiskers 10 to 20% by weight, and calcium carbonate having an average particle size of 1 to 7 μm, 30 to 50% by weight. A polyphenylene sulfide resin composition comprising: 2. A light-reflecting molded article obtained by molding the resin composition according to claim 1.