JP2015081331A - Resin composition and coating material prepared using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition and coating material that have a low relative dielectric constant and excellent tensile elongation (tenacity), and prevent the occurrence of surface peeling.SOLUTION: A mixture comprising, based on 100 pts.mass of polyarylene sulfide resin, 35-85 pts.mass of polytetrafluoroethylene with a melt viscosity of 100-1000 Pa s, is melted and kneaded to obtain a resin composition.

Description

  The present invention relates to a resin composition containing a polyarylene sulfide resin and a coating material using the same.

In recent years, in the automobile field, the development of hybrid cars and electric cars has been accelerated, and the demand for high efficiency motors is expanding. There is an increasing demand for higher density of insulating materials (wire coating materials, motor insulators, etc.) used around motors such as hybrid vehicles, and it is necessary to reduce the thickness of the insulating material to meet these requirements. There is. Since the limit value of the film thickness of the insulating material with respect to the applied voltage depends on the dielectric constant (relative dielectric constant), it is essential to reduce the relative dielectric constant of the insulating material in order to reduce the thickness.
On the other hand, since the insulating material for the above-mentioned uses is used under a high voltage, there is a concern that dielectric breakdown may occur when the thickness is reduced, so that excellent dielectric breakdown characteristics are required.

  Polyarylene sulfide resin (hereinafter also referred to as “PAS resin”) represented by polyphenylene sulfide resin (hereinafter also referred to as “PPS resin”) has high heat resistance, mechanical properties, chemical resistance, dimensional stability, Since it has flame retardancy, it is widely used for electrical and electronic equipment parts materials, automotive equipment parts materials, chemical equipment parts materials and the like. Thus, although PAS resin has various performances, it cannot satisfy the above required performance alone, and it is difficult to use it as an insulating material around a motor of a hybrid vehicle or the like.

  On the other hand, fluororesins represented by tetrafluoroethylene resin (hereinafter also referred to as “PTFE resin”) have an extremely low coefficient of friction, high heat resistance, insulation and chemical resistance, and are non-adhesive. It has been used in various fields for many years as an engineering plastic with excellent properties.

Conventionally, attempts have been made to bring out the desired performance by mixing the above-described PAS resin and fluororesin (see, for example, Patent Documents 1 to 3).
Patent Document 1 discloses a resin composition obtained by blending a PAS resin, an amorphous resin, and a fluororesin. By blending a predetermined ratio of fluororesin with the PAS resin, the original PAS resin is disclosed. In addition to performance, it provides slidability.
Patent Document 2 discloses a resin composition obtained by blending a PPS resin, a PTFE resin, and an inorganic filler. By blending a predetermined proportion of PTFE resin into the PPS resin, the original performance of the PPS resin is disclosed. While maintaining the above, it provides electrical insulation.
Patent Document 3 discloses a resin composition obtained by blending a PAS resin, a fluororesin, another specific graft copolymer, and a filler, and blending a predetermined proportion of PTFE resin with the PPS resin. As a result, the friction characteristics and slidability are improved while maintaining the original performance of the PPS resin.

JP 2006-273999 A JP 2009-30030 A Japanese Patent Laid-Open No. 5-78574

  However, when the above resin composition is molded into a thin wall, it has not been possible to achieve both low dielectric constant and excellent tensile elongation (toughness) and surface peeling characteristics.

  The present invention has been made in view of the above-described conventional problems, and the object thereof is a resin composition having a low relative dielectric constant, excellent tensile elongation (toughness), and hardly causing surface peeling, and a coating using the same. To provide materials.

The present invention for solving the above problems is as follows.
(1) A resin composition obtained by melt-kneading a mixture containing 35 to 85 parts by mass of a tetrafluoroethylene resin having a melt viscosity of 100 to 1000 Pa · s with respect to 100 parts by mass of a polyarylene sulfide resin.
(2) The resin composition as described in (1) above, wherein the polyarylene sulfide resin has a weight average molecular weight of 50,000 to 200,000.
(3) The resin composition according to the above (1) or (2), which is used as a coating material for electric wires obtained by coating a conductor with a coating material.
(4) A coating material comprising the resin composition according to any one of (1) to (3) above.
(5) A coating material formed by molding the resin composition according to any one of (1) to (3) above.

  According to the present invention, it is possible to provide a resin composition and a coating material having a low relative dielectric constant, excellent tensile elongation (toughness), and hardly causing surface peeling.

It is a figure which shows the result of the heat aging evaluation in Example 1, 4 and 7 with a graph.

The resin composition of the present invention contains polyarylene sulfide resin and tetrafluoroethylene resin, and 35 to 85 mass of tetrafluoroethylene resin having a melt viscosity of 100 to 1000 Pa · s with respect to 100 mass parts of polyarylene sulfide resin. The resin composition of the present invention is characterized by being obtained by melt-kneading a mixture containing parts. The resin composition of the present invention contains a predetermined amount of a predetermined PTFE resin relative to the PAS resin, so that the relative dielectric constant is low and the tensile elongation ( It has excellent toughness and exhibits the effect that surface peeling hardly occurs.
Below, each component is explained in full detail.

[Polyarylene sulfide resin (PAS resin)]
The PAS resin is a polymer compound mainly composed of-(Ar-S)-(where Ar is an arylene group) as a repeating unit, and a PAS resin having a generally known molecular structure is used in the present invention. can do.

  Examples of the arylene group include a p-phenylene group, m-phenylene group, o-phenylene group, substituted phenylene group, p, p′-diphenylene sulfone group, p, p′-biphenylene group, p, p′-. A diphenylene ether group, p, p′-diphenylenecarbonyl group, naphthalene group and the like can be mentioned. The PAS resin may be a homopolymer consisting only of the above repeating units, or a copolymer containing the following different types of repeating units may be preferable from the viewpoint of processability and the like.

  As the homopolymer, a polyphenylene sulfide resin using a p-phenylene sulfide group as a repeating unit and a p-phenylene group as an arylene group is preferably used. In addition, as the copolymer, among the arylene sulfide groups composed of the above-mentioned arylene groups, two or more different combinations can be used, and among them, a combination including a p-phenylene sulfide group and an m-phenylene sulfide group is particularly preferably used. It is done. Of these, those containing 70 mol% or more, preferably 80 mol% or more of p-phenylene sulfide groups are suitable from the viewpoint of physical properties such as heat resistance, moldability and mechanical properties. Further, among these PAS resins, a high molecular weight polymer having a substantially linear structure obtained by condensation polymerization from a monomer mainly composed of a bifunctional halogen aromatic compound can be particularly preferably used. Two or more different molecular weight PAS resins may be mixed and used.

  In addition to the linear PAS resin, a partial branched or crosslinked structure is formed by using a small amount of a monomer such as a polyhaloaromatic compound having 3 or more halogen substituents when performing condensation polymerization. Examples thereof include a polymer obtained by heating a polymer having a low molecular weight and a linear structure polymer having a low molecular weight at a high temperature in the presence of oxygen or the like to increase the melt viscosity by oxidative crosslinking or thermal crosslinking, thereby improving moldability.

The melt viscosity (310 ° C., shear rate 1216 sec ⁻¹ ) of the PAS resin as the base resin used in the present invention is preferably 600 Pa · s or less, including the above mixed system, and is in the range of 20 to 300 Pa · s. Those having a good balance between mechanical properties and fluidity are particularly preferred.

  In the present invention, the weight average molecular weight of the PAS resin is preferably 50,000 to 200,000, more preferably 60000 to 150,000, and even more preferably 70000 to 100,000. Heat aging resistance can be improved as the said weight average molecular weight is 50000-200000.

[Tetrafluoroethylene resin (PTFE resin)]
As the PTFE resin, one having a melt viscosity (360 ° C., shear rate 1216 sec ⁻¹ ) of 100 to 1000 Pa · s is used. If the melt viscosity of the PTFE resin exceeds 1000 Pa · s, the cohesiveness tends to deteriorate, and if it is less than 100 Pa · s, surface peeling tends to occur. When the melt viscosity of PTFE resin is low, the low-viscosity PTFE resin completely melted in the PAS resin moves to the surface layer of the kneaded product or molded product when kneaded and molded with a resin having high heat resistance such as PAS resin. It is estimated that the surface layer causes peeling. Further, even when the PTFE resin does not move to the surface layer, it is estimated that such a layer also causes peeling when it stays in the kneaded product or the molded body and forms a film-like layer near the surface layer. By using a PTFE resin having a melt viscosity in the above range, such surface peeling can be suppressed.

  PTFE resin contains 35-85 mass parts with respect to 100 mass parts of PAS resin. If it is less than 35% by mass, the effect of reducing the relative dielectric constant cannot be exhibited, and if it exceeds 85 parts by mass, the tensile elongation (toughness) tends to decrease. The content of the PTFE resin is preferably 40 to 85 parts by mass, and more preferably 50 to 85 parts by mass with respect to 100 parts by mass of the PAS resin.

  The PTFE resin used in the present invention is not particularly limited as long as it is generally used in the field of the resin composition. For example, KT-400M, KT-600M, KTL-450A manufactured by Kitamura Co., Ltd. KTL-610, KTL-620, etc. are mentioned.

[Other ingredients]
In the resin composition of the present invention, in addition to the above-mentioned components, known substances generally added to thermoplastic resins, that is, lubricants, nucleating agents, flame retardants, flame retardant aids, as long as the effects of the present invention are not hindered. , Antioxidants, metal deactivators, other anti-aging agents, UV absorbers, stabilizers, plasticizers, pigments, dyes, colorants, antistatic agents, foaming agents, other polymers such as resins, and additives You may mix | blend an agent etc.

The coating material of the present invention comprises the above-described resin composition of the present invention. Specifically, the coating material is used for a coating material for an electric wire obtained by coating a coating material on a conductor, a motor insulator, an insulating coating, an electric wire coating, an insulating electric wire, an insulating film, and the like.
There is no limitation in particular as a method of producing a coating material using the resin composition of this invention, A well-known method is employable. For example, the resin composition can be produced by melting and mixing various additives as required, and coating the obtained composition on the conductor surface using an extruder or the like according to a conventional method. As a means for mixing the composition, compoundable equipment such as an extruder, a Henschel mixer, a kneader, a shaft kneader, a Banbury mixer, and a roll mill can be used.
Further, the diameter and material of the conductor are not particularly limited, and can be appropriately determined according to the application. Further, the thickness of the coating layer obtained by coating the resin composition is not particularly limited, and can be appropriately determined in consideration of the conductor diameter and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

[Examples 1-9, Comparative Examples 1-2]
The details of each PAS resin component used in Examples and Comparative Examples are as follows.
PAS resin 1: PPS resin, Kureha, Fortron KPS W214A, weight average molecular weight (Mw): 64000)
PAS resin 2: PPS resin, Kureha, Fortron KPS W220A, weight average molecular weight (Mw): 80000)
-PAS resin 3: PPS resin Kureha, Fortron KPS W300, weight average molecular weight (Mw): 95000)
The weight average molecular weight (Mw) of each PAS resin was measured as follows.

(Measurement of weight average molecular weight (Mw) of PAS resin)
1-chloronaphthalene was used as a solvent, and each PAS resin was heated and dissolved in an oil bath at 230 ° C. for 10 minutes, and then purified by high-temperature filtration as necessary to prepare a 0.05 mass% concentration solution. Using a UV detector (detection wavelength: 360 nm, manufactured by Senshu Kagaku Co., Ltd., SSC-7000), high-temperature GPC measurement was performed, and the molecular weight was calculated in terms of standard polystyrene.

The details of each PTFE resin component used in Examples and Comparative Examples are as follows.
PTFE resin 1: manufactured by Kitamura Co., Ltd., KT-400M (melt viscosity: 711 Pa · s (shear rate: 1216 sec ⁻¹ , 360 ° C.))
PTFE resin 2: manufactured by Kitamura Co., Ltd., KTL-450A (melt viscosity: 323 Pa · s (shear rate: 1216 sec ⁻¹ , 360 ° C.))
PTFE resin 3: manufactured by Kitamura Co., Ltd., KTL-610 (melt viscosity: 170 Pa · s (shear rate: 1216 sec ⁻¹ , 360 ° C.))
PTFE resin 4: manufactured by Sumitomo 3M, Dinion TF9205 (melt viscosity: 58 Pa · s (shear rate: 1216 sec ⁻¹ , 360 ° C.))
The melt viscosity of each PTFE resin was measured as follows.

(Measurement of melt viscosity of PTFE resin)
A capillary rheometer (Capillograph 1B, manufactured by Toyo Seiki Co., Ltd.) was used, and a melt viscosity at a barrel temperature of 360 ° C. and a shear rate of 1216 sec ⁻¹ was measured using a 1 mmφ × 20 mmL / flat die as a capillary.

<Preparation of pellet (resin composition)>
As shown in the Examples and Comparative Examples in Table 1 below, the above raw material components were dry blended, then charged into a twin screw extruder having a cylinder temperature of 320 ° C., melt-kneaded, and pelletized (resin composition).
Moreover, the melt viscosity of each said pellet was measured as follows.

(Measurement of melt viscosity of pellets)
Using a capillary rheometer (Capillograph 1B, manufactured by Toyo Seiki Co., Ltd.), a melt viscosity at a barrel temperature of 310 ° C. and a shear rate of 1000 sec ⁻¹ was measured using a 1 mmφ × 20 mmL / flat die as a capillary.

In the table, the numerical value of each component means “part by mass”.

  Moreover, various test pieces were produced from each of the pellets using an injection molding machine (FANUC Co., Ltd., ROBOSHOT S-2000i100t), and the following evaluations were performed.

<Measurement of relative permittivity>
Using each of the above pellets, a flat plate test piece of 80 mm × 80 mm × 1 mmt was produced by injection molding at a cylinder temperature of 335 ° C. and a mold temperature of 150 ° C., and an LCR meter (Yokogawa Hewlett-Packard Co., Ltd., 4284A ) And a dielectric measurement electrode (manufactured by Yokogawa Hewlett-Packard Co., Ltd., HP16451B), the relative dielectric constant at a measurement frequency of 1 kHz was measured according to IEC60250. The measurement results are shown in Table 2.

<Measurement of surface peelability>
Using each of the above pellets, a plate test piece of 80 mm × 80 mm × 1 mmt was produced by injection molding at a cylinder temperature of 335 ° C. and a mold temperature of 150 ° C., and the surface according to JIS K5400-8.5 (JIS D0202) The peelability was measured. The measurement results are shown in Table 2.

<Measurement of tensile strength>
Using each of the above pellets, a dumbbell test piece having a cylinder temperature of 335 ° C. and a mold temperature of 150 ° C. and a thickness of 1 mmt is prepared, and tensile strength (TS) and tensile elongation (TE) are measured according to ASTM D638. Measured (tensile speed 50 mm / min). The measurement results are shown in Table 2.

<Measurement of heat aging resistance>
For each of the pellets of Examples 1, 4 and 7, the same test piece as that used in the measurement of the tensile strength was prepared and left for 500, 1000 and 1500 hours in an oven set at 200 ° C. And about each taken out test piece, tensile elongation (TE) was measured according to ASTM D638 (tensile speed 50 mm / min). The value obtained by the measurement of the tensile strength was used as the initial value, and the ratio (percentage) of the tensile elongation (TE) after the lapse of the predetermined time with respect to the initial value was defined as the retention rate. The result of the retention of tensile elongation (TE) is shown in FIG.

  Hereinafter, evaluation of each measurement result will be shown.

<Evaluation of relative dielectric constant>
From the results of Table 2, all of the resin compositions of Examples and Comparative Example 2 showed a low relative dielectric constant of 3.0 or less. On the other hand, the resin composition of Comparative Example 1 showed a high relative dielectric constant of 3.2.

<Evaluation of surface peelability>
From the result of Table 2, it was shown that the resin composition of each Example and the comparative example 1 has the outstanding surface peelability. On the other hand, it was shown that the resin composition of Comparative Example 2 was inferior in surface peelability.

<Evaluation of tensile strength>
From the results of each Example and Comparative Example 2 in Table 2, it is shown that although there is no significant difference in tensile strength, the tensile elongation is improved in the resin composition of each Example as compared with Comparative Example 2. It was done. In particular, it was shown that the tensile elongation of the resin composition is remarkably improved by using a PTFE resin having a high melt viscosity (a high molecular weight).

<Evaluation of heat aging resistance>
From the result of FIG. 1, it was shown that the heat aging resistance of the resin composition is remarkably improved by using a PAS resin having a large weight average molecular weight.

From the said result, in the resin composition of Examples 1-9, it was shown that the low dielectric constant, the outstanding tensile elongation (toughness), and surface peelability are compatible. Furthermore, it was shown that when a PAS resin having a large molecular weight is included, the heat aging resistance is also excellent. On the other hand, the comparative example 1 which does not contain PTFE resin did not obtain good results for the relative dielectric constant. Moreover, the comparative example 2 containing PTFE resin with low melt viscosity did not obtain a favorable result about surface peelability and tensile elongation.
From the above, it can be seen that a low relative dielectric constant, excellent tensile elongation (toughness) and surface releasability can be achieved by blending a PTFE resin having a melt viscosity specified in the present invention with a PAS resin. Moreover, it turns out that heat aging resistance can be provided in addition to the said characteristic by using PAS resin with a large molecular weight.

Claims (5)

  A resin composition obtained by melt-kneading a mixture containing 35 to 85 parts by mass of a tetrafluoroethylene resin having a melt viscosity of 100 to 1000 Pa · s with respect to 100 parts by mass of a polyarylene sulfide resin.   The resin composition according to claim 1, wherein the polyarylene sulfide resin has a weight average molecular weight of 50,000 to 200,000.   The resin composition of Claim 1 or 2 used for the coating | covering material of the electric wire which coat | covers a coating | covering material to a conductor.   The coating material which comprises the resin composition as described in any one of Claims 1-3.   The coating material formed by shape | molding the resin composition as described in any one of Claims 1-3.