JP3075796B2 - High dielectric resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high dielectric resin composition.

[0002]

2. Description of the Related Art Fine ceramic products have unique and excellent characteristics or functions not found in metal materials and polymer materials as one of new materials, and have been used in various industrial fields and attracted attention. Above all, highly dielectric porcelains have grown greatly in the electric and electronic related industrial fields, and the dielectric materials are various materials generally composed of alkaline earth metal titanates represented by barium titanate. This alkaline earth metal titanate is usually synthesized from a compound which becomes titanium oxide by heating and a compound which becomes an alkaline earth metal oxide by heating, and has the general formula MO · nT
An isomer having an element ratio of M / Ti represented by iO ₂ (where M is an alkaline earth metal and n is a real number of 1 to 12) of 1 or more is known. When these are molded into a dielectric porcelain, various methods are adopted. That is, to form a relatively thick, large, cylindrical, or other irregularly shaped porcelain, press molding is performed by a dry press or the like, and for a thin plate or the like, a green sheet is formed by extrusion molding or roll rolling molding. After being manufactured and punched into a predetermined shape by a punching press or the like, these primary molded products are
It is obtained by firing at 00 to 1400 ° C. However, the process of obtaining a final product is extremely complicated and long, such as performing cutting for finishing after cooling, which is not suitable for mass production.

[0003] In order to solve these problems, a high dielectric material obtained by injection molding a resin composition obtained by kneading a synthetic resin capable of being injection-molded and a powder material mainly composed of an alkaline earth metal titanate is used. Various resin molded articles have been proposed. Injection molding of the resin composition in this manner simplifies complicated molding processing, and economically advantageously provides a highly dielectric product. However, in order to impart a desired high dielectric constant to such a molded article, it is necessary to increase the amount of the alkaline earth metal titanate, which is a dielectric, to the resin material. The melt viscosity of the product becomes extremely high, making it unsuitable for injection molding. That is, in the case of a composition having a remarkably high melt viscosity, a molded article having a small thickness or a molded article having a long flow length cannot be molded.

[0004]

As described above, in the prior art, there is a problem that a high dielectric resin composition having a high dielectric constant and excellent moldability cannot be obtained. It has been a problem to obtain a high dielectric resin composition which does not cause any problem in injection molding even if the amount of the alkaline earth metal titanate is sufficiently increased in order to improve the efficiency.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides barium titanate as a thermoplastic resin.
In 5 resin composition containing by weight percent, the resin sets
The product contains 0.1 to 4% by weight of polyolefin resin
A means for forming a high dielectric resin composition is employed.
The details are described below.

First, as the thermoplastic resin in the present invention, polyarylene sulfide resin, urethane resin,
Polytetrafluoroethylene, chlorotrifluoroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, vinylidene fluoride resin, ethylene-tetrafluoroethylene copolymer, ethylene -Chlorofluoroethylene copolymer, vinyl chloride resin, vinylidene chloride resin, polyethylene (low density, high density or ultra high molecular weight), chlorinated polyolefin, polypropylene, modified polyolefin, water-crosslinked polyolefin, ethylene-vinyl acetate copolymer, Ethylene-ethyl acrylate copolymer, polystyrene,
ABS resin, polyamide, methacrylic resin, polyacetal, polycarbonate, cellulose resin, polyvinyl alcohol, polyurethane elastomer, polyimide, polyetherimide, polyamideimide, ionomer resin, polyphenylene oxide, methylpentene polymer, polyallyl sulfone, polyallyl ether,
Examples thereof include polyether ketone, polysulfone, wholly aromatic polyester, polyethylene terephthalate, polybutylene terephthalate, thermoplastic polyester elastomer, and blends of various polymer substances. Of these, polyarylene sulfide is particularly preferable. It is. The reason why polyarylene sulfide is preferable is that the melt viscosity of the polymer can be reduced and the filler can be filled at a high rate.In addition, the mechanical strength when reinforced is excellent, the water absorption is small, and the heat resistance is low. This is because they are highly flame-retardant and humbly have these various properties required for a highly dielectric material. A typical example of polyarylene sulfide is polyphenylene sulfide, such as Ryton PPS manufactured by Philips in the United States. This Ryton PPS becomes a crosslinked polymer at the time of molding, but a linear PPS resin having no crosslinked structure or a PPS resin having an intermediate structure between linear and crosslinked structures can also be used.

Next, the barium titanate in the present invention is not particularly limited as long as it has a high dielectric constant. In order to enhance the dielectric properties of these barium titanates, commercially available barium titanate powder is fired at a high temperature and used by pulverizing it or adding a magnesium compound or other additives when producing barium titanate powder. May be used, or the mixing ratio of titanium and barium may be changed. Further, the shape of barium titanate may be fibrous, spherical, columnar, flaky, or the like, and is not particularly limited. However, fibrous one is preferable in terms of dielectric constant and strength.

Further, in the present invention, in addition to the thermoplastic resin and barium titanate, magnesium titanate, calcium titanate, calcium zirconate, calcium stannate and the like are used in order to change the Curie point of barium titanate. It may be added. Further, other fillers may be added as long as they do not adversely affect the original purpose and effect of the present invention. As a specific example of the filler,
Glass fiber, carbon fiber, graphite fiber, wollastonite, potassium titanate whisker, silicone carbide whisker, sapphire whisker, heat-resistant inorganic single fiber such as steel wire, copper wire, stainless wire, tungsten core wire or carbon fiber etc. Or heat conductive inorganic composite fiber such as so-called boron fiber or silicon carbide fiber on which silicon carbide or the like is deposited, heat resistant organic fiber such as aromatic amide fiber, graphite or heat conduction of metal such as zinc, aluminum, magnesium or oxide or the like. Inorganic powder for improving heat insulation such as inorganic powder for improvement, glass beads, silica balloon, diatomaceous earth, asbestos, magnesium carbonate, etc., inorganic powder for improving lubricity such as molybdenum disulfide, graphite, carbon, mica, talc, and oxidation Iron, cadmium sulfide, Ren cadmium, can be cited a number of such coloring inorganic pigments such as carbon black.

The polyolefin resin contained in the resin composition of the present invention is not particularly limited, but is preferably a polyethylene resin. The polyethylene resin may be either high-density or low-density, and can be used regardless of the melt flow rate. However, in the case of a resin requiring a particularly high molding temperature in injection molding of a thermoplastic resin, a resin having a large melt flow rate is more desirable. This polyolefin resin has a sufficient effect in the range of 0.1 to 4% by weight in the resin composition. If the amount is less than 0.1% by weight, the uniform dispersibility during preliminary mixing or extrusion kneading is poor, and the reproducibility of the effect is poor. On the other hand, if it exceeds 4% by weight, it may cause gas generation during kneading or molding.

The form at the time of blending the polyolefin resin is not particularly limited, but it is preferable that the polyolefin resin is a powder in terms of easy handling.

[0011]

In the high dielectric resin composition, the dielectric constant is increased by the highly filled barium titanate in the thermoplastic resin, and the melt viscosity of the composition is decreased by the blended polyolefin resin. Molded articles are easily obtained by injection molding. In addition, since the melt viscosity is low, the fibers are less likely to be broken during kneading even when fibrous barium titanate is added, and the properties of barium titanate can be effectively exerted. Excellent in dielectric constant, withstand voltage, and mechanical properties.

[0012]

EXAMPLES The raw materials used in Examples and Comparative Examples are collectively shown as follows. Abbreviations are shown in [].

Polyphenylene sulfide resin [PPS] (Tosoh Sosa Steel: PPS140) Polybutylene terephthalate resin [PBT] (Mitsubishi Rayon: Tuffpet N1030) Polyethylene resin powder [PE] (Mitsui Petrochemical Co., Ltd .: HIZEX 2100JP) ) Barium titanate fiber [BaTiO ₃ -F] (BaTi having an average fiber length of 15 μm and an average fiber diameter of 0.2 μm)
O ₃ ) Barium titanate powder [BaTiO ₃ -P] Powdered barium titanate KYORIX BT-S (manufactured by Kyoritsu Ceramics Co., Ltd.) is calcined at 1400 ° C. for 6 hours and then pulverized (average particle size 1 μm).

[0014]

[Table 1]

Examples 1 to 5 and Comparative Examples 1 and 2 Additives were added to the thermoplastic resin at the ratios shown in Table 1, mixed thoroughly with a Henschel mixer, and fed to a twin-screw extruder. The pellets were extruded and granulated under the melt-mixing conditions and injection conditions shown in the table, and the pellets were supplied to an injection molding machine to injection-mold a disk-shaped test piece having a diameter of 70 mm and a thickness of 3.8 mm. In molding, the raw materials were sufficiently dried, and the dielectric constant was measured at 25 ° C. and 1 MHz using a disk-shaped test piece according to JIS K6911.

Under the injection conditions shown in Table 1, the inner diameter was 11 m.
A cylindrical specimen having a diameter of 13 mm and an outer diameter of 13 mm and a length of 47 mm was formed with a single point gate having a diameter of 0.5 mm, and flowability was evaluated. The test results are summarized in the table. The fluidity was evaluated as ○ (good fluidity), ×
(Short shot with poor fluidity) was shown in two-step evaluation.

As is clear from the numerical values in Table 1, Comparative Example 1
In Comparative Example 2, although the fluidity is good, the dielectric constant is low, and in Comparative Example 2, the dielectric constant is high, but the fluidity is poor and a thin long product cannot be molded. On the other hand, Examples 1 to 5 had a high dielectric constant and good fluidity, and were suitable for injection molding.

[0018]

As described above, the highly dielectric resin composition of the present invention has excellent dielectric properties and can be injection-molded, so that it can be used to mold even very complicated shapes. In addition, there are many advantages such as extremely high productivity. Therefore, it is an excellent material for electric and electronic parts such as capacitors, and the significance of the present invention can be said to be very large.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI (C08L 101/00 23:00) (56) References JP-A-58-222125 (JP, A) JP-A-63-264671 ( JP, A) JP-A-57-65741 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08

Claims (2)

(57) [Claims] (1) barium titanate is added to a thermoplastic resin;
In 5 resin composition containing by weight percent, the resin sets
A highly dielectric resin composition wherein the composition contains 0.1 to 4% by weight of a polyolefin resin. 2. The high dielectric resin composition according to claim 1, wherein the main component of the thermoplastic resin is a polyarylene sulfide resin.