JP2013098330A - Member for direct ignition coil, coil, and direct ignition coil - Google Patents

Abstract

A direct ignition coil member having excellent insulation and rigidity at high temperatures is provided.
A liquid crystal polyester having a repeating unit represented by the following formula (1), the following formula (2) and the following formula (3) as a forming material, the repeating unit having an m-phenylene group in the liquid crystal polyester. Is 0 mol% or more and 6.5 mol% or less with respect to the total amount of all repeating units.
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(Ar ¹ : phenylene group, naphthylene group, biphenylylene group; Ar ² , Ar ³ : phenylene group, naphthylene group, biphenylylene group, group represented by the following formula (4); X, Y: oxygen atom, imino group)
(4) -Ar ⁴ -Z-Ar ^5-
(Ar ⁴ , Ar ⁵ : phenylene group, naphthylene group; Z: oxygen atom, sulfur atom, carbonyl group, sulfonyl group, alkylidene group)
[Selection figure] None

Description

  The present invention relates to a direct ignition coil member, a coil, and a direct ignition coil.

  As an ignition coil used for ignition of an internal combustion engine such as an automobile engine, an ignition coil that is inserted into a plug hole provided in each cylinder of the internal combustion engine and connected to the ignition plug in the plug hole is known. . In this specification, an ignition coil of the type inserted into the plug hole as described above and directly connected to the spark plug is referred to as a “direct ignition coil”.

  The direct ignition coil has a structure in which a secondary coil wound around a secondary bobbin is arranged around a central core, and a primary coil wound around a primary bobbin is arranged around the secondary coil. When the engine is ignited, a voltage of 300 to 500 V is generated in the primary coil by switching of the igniter, and a voltage of 25 to 35 kV is generated in the secondary coil by electromagnetic induction. As a result, a high voltage is applied to the spark plug connected to the spark plug coil to generate a discharge spark between the electrodes of the spark plug and ignite the air-fuel mixture in the cylinder.

  Since such a direct ignition coil is mounted in a plug hole of an internal combustion engine that becomes high temperature, high heat resistance is required. On the other hand, since the size is limited corresponding to the size of the plug hole, the casing and each component of the direct ignition coil are required to be downsized.

  As a material for such a direct ignition coil, a liquid crystal polyester excellent in fluidity and heat resistance has been studied. For example, Patent Documents 1 to 3 propose a coil bobbin and a casing made of liquid crystal polyester.

Japanese Patent Laid-Open No. 10-289831 Japanese Patent Laid-Open No. 11-307359 JP 2000-188227 A

  As described above, the direct ignition coil is used in a high temperature environment. Therefore, when the structural member such as a casing constituting the direct ignition coil has low rigidity in a high temperature environment, there is a risk of warping or deformation. Further, since the direct ignition coil is exposed to a high voltage of 35 kV in a high temperature environment, if the withstand voltage in the high temperature environment is weak, dielectric breakdown may occur and reliability may be reduced. Therefore, a member used for the direct ignition coil (hereinafter sometimes referred to as a member for the ignition coil) such as a bobbin and a casing constituting the direct ignition coil is an insulating member having both high heat resistance and insulation resistance. Is required.

  In the above-mentioned patent document, the examination on the problem expected as described above is not sufficiently disclosed, and there is room for examination on a direct ignition coil having a constituent member using liquid crystal polyester.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the member for direct ignition coils excellent in the insulation and rigidity under high temperature. Another object of the present invention is to provide a direct ignition coil having such a member for direct ignition coil and having excellent insulation and rigidity at high temperature and high reliability at high temperature.

In order to solve the above problems, the present invention includes a liquid crystal polyester having a repeating unit represented by the following formula (1), the following formula (2) and the following formula (3) as a forming material, Provided is a direct ignition coil member in which the content of repeating units having an m-phenylene group is 0 mol% or more and 6.5 mol% or less with respect to the total amount of all repeating units.
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4). X And Y each independently represents an oxygen atom or an imino group (—NH—), and each hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently a halogen atom or a carbon number. (It may be substituted with an alkyl group of 1 to 10 or an aryl group of 6 to 20 carbon atoms.)
(4) -Ar ⁴ -Z-Ar ^5-
(Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)

In the present invention, the Ar ¹ is a p-phenylene group or a 2,6-naphthylene group, the Ar ² is a p-phenylene group, an m-phenylene group, or a 2,6-naphthylene group, and the Ar ³ is a p-phenylene group or a 4,4′-biphenylylene group, and X and Y are preferably oxygen atoms.

  In the present invention, the liquid crystalline polyester is represented by the formula (2), wherein the repeating unit represented by the formula (1) is 30 mol% or more and 80 mol% or less with respect to the total amount of all repeating units. It is desirable to have 10 to 35 mol% of repeating units and 10 to 35 mol% of repeating units represented by the formula (3).

  In the present invention, it is desirable to use a composition containing the liquid crystalline polyester and glass fiber as a forming material.

  In this invention, it is desirable that content of the said glass fiber is 10 to 100 mass parts with respect to 100 mass parts of said liquid crystalline polyester.

  The present invention is a coil having a bobbin and a conducting wire wound around a winding part of the bobbin, wherein the bobbin is the above-described member for a direct ignition coil, and the thickness of the winding part is 0. Provided is a coil that is 2 mm or more and 1.5 mm or less.

  The present invention is a direct ignition coil having a coil having a bobbin and a conducting wire wound around a winding part of the bobbin, and a housing that houses the coil, and the bobbin and the housing At least one of them provides a direct ignition coil which is the above-described direct ignition coil member.

  ADVANTAGE OF THE INVENTION According to this invention, the member for direct ignition coils excellent in the insulation and rigidity under high temperature can be provided. Further, it is possible to provide a coil having such a direct ignition coil member and having excellent insulation and rigidity at high temperatures. Furthermore, a direct ignition coil with high reliability at high temperatures can be provided.

It is a schematic sectional drawing which shows the direct ignition coil of this embodiment.

  FIG. 1 is a schematic cross-sectional view showing a direct ignition coil 100 of the present embodiment. The direct ignition coil 100 is used by being directly connected to an ignition plug 200 indicated by a broken line in the drawing in a plug hole provided in an internal combustion engine (engine) (not shown).

  The direct ignition coil 100 includes a primary coil 1, a secondary coil 2 inserted into the primary coil 1, a columnar core 3 inserted into the secondary coil 2, and a housing for housing these. And a body 4. Further, the direct ignition coil 100 is connected to a switching circuit (igniter) (not shown) and receives a control signal, and an output for outputting a high voltage generated in the direct ignition coil 100 to the spark plug 200. Part 6 is provided.

  The primary coil 1 has a primary bobbin 11 and a conductive wire 12 wound around a winding part 11 a of the primary bobbin 11. The conducting wire 12 is electrically connected to a terminal 51 provided in the input unit 5. Further, the primary coil 1 is insulated by covering the conductive wire 12 with a sealant 15.

  The secondary coil 2 includes a secondary bobbin 21 and a conductive wire 22 wound around a winding part 21 a of the secondary bobbin 21. The conducting wire 22 is electrically connected to the high voltage terminal 61 of the output unit 6. Further, the secondary coil 2 is insulated by covering the conductive wire 22 with a sealant 25.

  Magnets 31 and 32 having a polarity opposite to the direction of the magnetic flux generated when the core 3 is excited by the primary coil 1 and the secondary coil 2 are attached to both ends of the core 3. The outer periphery of the core 3 is covered with an insulating material (not shown).

  The input unit 5 is provided on the upper end side of the housing 4. A control signal input from a terminal 51 provided in the input unit is input to the primary coil 1 via an internal control circuit 52.

  The output unit 6 is provided at the lower end of the housing 4. The spring 62 provided in the output unit 61 is electrically connected to the secondary coil 2 via the high voltage terminal 61 and is electrically connected to the spark plug 200 in the plug hole.

  In such a direct ignition coil 100, when a control signal is supplied via the input unit 5 by switching of an igniter (not shown), a voltage of 300 to 500 V is generated in the primary coil 1 and further 2 by electromagnetic induction. A high voltage of 25 to 35 kV is generated in the secondary coil 2. The generated high voltage is applied to the spark plug 200 via the high voltage terminal 61 and the spring 62. The spark plug 200 to which the high voltage is applied discharges at the discharge terminal and ignites the air-fuel mixture in the engine.

The direct ignition coil member of the present embodiment includes a liquid crystal polyester having a repeating unit represented by the following formula (1), the following formula (2), and the following formula (3) as a forming material, m in the liquid crystal polyester -Content of the repeating unit which has a phenylene group is 0 mol% or more and 6.5 mol% or less with respect to the total amount of all the repeating units.
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4). X And Y each independently represents an oxygen atom or an imino group (—NH—), and each hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently a halogen atom or a carbon number. (It may be substituted with an alkyl group of 1 to 10 or an aryl group of 6 to 20 carbon atoms.)
(4) -Ar ⁴ -Z-Ar ^5-
(Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)

  In the direct ignition coil 100 described above, the primary bobbin 11, the secondary bobbin 21, and the housing 4 correspond to the direct ignition coil member of the present embodiment.

  Further, the coil of the present embodiment is a coil having a bobbin and a conductive wire wound around the bobbin winding part, and the bobbin is the above-mentioned direct ignition coil member, Thickness is 0.2 mm or more and 1.5 mm or less. In the direct ignition coil 100 described above, the primary coil 1 and the secondary coil 2 correspond to the coils of this embodiment.

As described above, the direct ignition coil 100 according to the present embodiment is a direct ignition coil having a coil having a bobbin and a conductive wire wound around a winding portion of the bobbin, and a casing that houses the coil. And at least any one of the said bobbin and the said housing | casing is the above-mentioned member for direct ignition coils.
Hereinafter, it demonstrates in order.

(Liquid crystal polyester)
The liquid crystal polyester constituting the direct ignition coil member such as the primary bobbin 11, the secondary bobbin 21, and the housing 4 of the present embodiment is a liquid crystal polyester that exhibits liquid crystallinity in a molten state and melts at a temperature of 450 ° C. or lower. It is preferable that The liquid crystal polyester may be a liquid crystal polyester amide, a liquid crystal polyester ether, a liquid crystal polyester carbonate, or a liquid crystal polyester imide. The liquid crystal polyester is preferably a wholly aromatic liquid crystal polyester using only an aromatic compound as a raw material monomer.

In the present embodiment, as the liquid crystalline polyester, a repeating unit represented by the following formula (1) (hereinafter sometimes referred to as “repeating unit (1)”) and a repeating unit represented by the following formula (2): A unit (hereinafter sometimes referred to as “repeating unit (2)”) and a repeating unit represented by formula (3) (hereinafter sometimes referred to as “repeating unit (3)”). In the liquid crystal polyester, the content of the repeating unit having an m-phenylene group is 0 mol% or more and 6.5 mol% or less with respect to the total amount of all repeating units.
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4). X And Y each independently represents an oxygen atom or an imino group (—NH—), and each hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently a halogen atom or a carbon number. (It may be substituted with an alkyl group of 1 to 10 or an aryl group of 6 to 20 carbon atoms.)
(4) -Ar ⁴ -Z-Ar ^5-
(Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)

  Here, in this specification, the “total amount of all repeating units” means the mass equivalent amount of each repeating unit by dividing the mass of each repeating unit constituting the liquid crystal polyester by the formula amount of each repeating unit ( Mole) and the sum of them.

  Thereby, the skeleton of the liquid crystal polyester constituting the ignition coil member becomes rigid, and the ignition coil member is excellent in rigidity at high temperatures and hardly undergoes deformation such as warpage. In addition, the liquid crystalline polyester having such a skeleton has a mesogen portion that crystallizes and tends to have a high density, so that it has excellent insulation at high temperatures and is not susceptible to dielectric breakdown even if the distance between adjacent terminals is short. A member for use can be obtained.

  As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned.

  Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-hexyl group, 2-ethylhexyl group, An n-octyl group and n-decyl group are mentioned, The carbon number is 1-10 normally.

  Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group, and the number of carbon atoms is usually 6 to 20. .

When the hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is substituted with these groups, the number is as follows for each group represented by Ar ¹ , Ar ² or Ar ³ . Each of them is usually 2 or less, preferably 1 or less.

  Examples of the alkylidene group include a methylene group, an ethylidene group, an isopropylidene group, an n-butylidene group, and a 2-ethylhexylidene group, and the number of carbon atoms is usually 1 to 10.

When the liquid crystalline polyester has a repeating unit containing an m-phenylene group, the m-phenylene group may be contained in any of the repeating unit (1) to the repeating unit (3).
The content of the repeating unit having an m-phenylene group is preferably 6 mol% or less, more preferably 4 mol% or less, still more preferably 3 mol% or less, based on the total amount of all repeating units. In addition, the smaller the content of the repeating unit having an m-phenylene group, the more easily the insulation of the ignition coil member is improved. However, if the content is too small, the liquid crystal polyester is difficult to be molded. The content of the unit is preferably 1 mol% or more with respect to the total amount of all repeating units.

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. As the repeating unit (1), Ar ¹ is a p-phenylene group (repeating unit derived from p-hydroxybenzoic acid), and Ar ¹ is a 2,6-naphthylene group (6-hydroxy-2). -Repeating units derived from naphthoic acid) are preferred.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. As the repeating unit (2), Ar ² is a p-phenylene group (a repeating unit derived from terephthalic acid), Ar ² is an m-phenylene group (a repeating unit derived from isophthalic acid), Ar ² In which is a 2,6-naphthylene group (a repeating unit derived from 2,6-naphthalenedicarboxylic acid) is preferred.

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxylamine or aromatic diamine. As the repeating unit (3), Ar ³ is a p-phenylene group (a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ is a 4,4′-biphenylylene group. Those (4,4′-dihydroxybiphenyl, 4-amino-4′-hydroxybiphenyl or repeating units derived from 4,4′-diaminobiphenyl) are preferred.

  The content of the repeating unit (1) is 30 mol% or more, preferably 30 mol% or more and 80 mol% or less, more preferably 40 mol% or more and 70 mol% or less, further preferably, based on the total amount of all repeating units. Is 45 mol% or more and 65 mol% or less.

  The content of the repeating unit (2) is not more than 35 mol%, preferably not less than 10 mol% and not more than 35 mol%, more preferably not less than 15 mol% and not more than 30 mol%, more preferably based on the total amount of all repeating units. Is 17.5 mol% or more and 27.5 mol% or less.

  The content of the repeating unit (3) is not more than 35 mol%, preferably not less than 10 mol% and not more than 35 mol%, more preferably not less than 15 mol% and not more than 30 mol%, more preferably based on the total amount of all repeating units. Is 17.5 mol% or more and 27.5 mol% or less.

  The higher the content of the repeating unit (1), the easier it is to improve the melt fluidity, heat resistance, strength and rigidity. However, if it is too much, the melting temperature and melt viscosity are likely to increase, and the temperature required for molding increases. easy.

  The ratio between the content of the repeating unit (2) and the content of the repeating unit (3) is expressed as [content of repeating unit (2)] / [content of repeating unit (3)] (mol / mol). The ratio is usually 0.9 / 1 to 1 / 0.9, preferably 0.95 / 1 to 1 / 0.95, and more preferably 0.98 / 1 to 1 / 0.98.

  In addition, liquid crystalline polyester may have 2 or more types of repeating units (1)-(3) each independently. The liquid crystalline polyester may have repeating units other than the repeating units (1) to (3), but the content of repeating units other than the repeating units (1) to (3) is the sum of all repeating units. It is 10 mol% or less, preferably 5 mol% or less, based on the amount.

  Such a liquid crystal polyester includes a monomer (aromatic hydroxycarboxylic acid) that gives a repeating unit (1), a monomer (aromatic dicarboxylic acid) that gives a repeating unit (2), and a monomer (aromatic that gives a repeating unit (3)). Group diol, aromatic hydroxylamine or aromatic diamine) can be produced by polymerization (polycondensation). In that case, it adjusts so that the quantity of the monomer containing m-phenylene group may be 0 mol% or more and 6.5 mol% or less with respect to the total amount of all the monomers.

  Here, the aromatic hydroxycarboxylic acid, the aromatic dicarboxylic acid, the aromatic diol, the aromatic hydroxyamine, and the aromatic diamine are each independently replaced with a part or all of the polymerizable derivative. Also good.

  Examples of polymerizable derivatives of a compound having a carboxyl group such as aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid include those obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group (ester), carboxyl Examples include those obtained by converting a group into a haloformyl group (acid halide), and those obtained by converting a carboxyl group into an acyloxycarbonyl group (acid anhydride).

  Examples of polymerizable derivatives of hydroxyl group-containing compounds such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxyamines include those obtained by acylating hydroxyl groups and converting them to acyloxyl groups (acylated products) ).

  Examples of polymerizable derivatives of amino group-containing compounds such as aromatic hydroxyamines and aromatic diamines include those obtained by acylating an amino group and converting it to an acylamino group (acylated product).

  Moreover, it is preferable to manufacture liquid crystalline polyester by melt-polymerizing a monomer and solid-phase-polymerizing the obtained polymer (prepolymer). Thereby, liquid crystalline polyester with high heat resistance and high melt tension can be manufactured with good operability. Melt polymerization may be carried out in the presence of a catalyst. Examples of this catalyst include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide, , N, N-dimethylaminopyridine, N-methylimidazole, and the like, and nitrogen-containing heterocyclic compounds are preferably used.

  The liquid crystal polyester has a flow initiation temperature of preferably 280 ° C. or higher, more preferably 290 ° C. or higher, further preferably 295 ° C. or higher, and usually 380 ° C. or lower, preferably 350 ° C. or lower. As the flow start temperature is higher, the heat resistance and melt tension are more likely to be improved. However, if the flow start temperature is too high, a high temperature is required for melting, and thermal deterioration tends to occur during molding.

The flow start temperature is also called flow temperature or flow temperature, and is 4 ° C / min under a load of 9.8 MPa (100 kg / cm ² ) using a capillary rheometer having a nozzle with an inner diameter of 1 mm and a length of 10 mm. This is a temperature at which the melt viscosity shows 4800 Pa · s (48,000 poise) when the heated melt of liquid crystal polyester is extruded from the nozzle at a temperature rising rate, and is a measure of the molecular weight of the liquid crystal polyester (Naoyuki Koide) Ed., “Liquid Crystal Polymer—Synthesis / Molding / Application—”, CMC Co., Ltd., June 5, 1987, p. 95).

  The material for forming the ignition coil member of the present embodiment may be used as a liquid crystal polyester composition by blending one or more other components such as a filler, an additive, and a resin other than the liquid crystal polyester with the liquid crystal polyester. Good.

  The filler may be a fibrous filler, a plate-like filler, or a spherical or other granular filler other than the fibrous and plate-like materials. The filler may be an inorganic filler or an organic filler.

  Examples of the fibrous inorganic filler include glass fibers; ceramic fibers such as silica fibers, alumina fibers, and silica alumina fibers. In addition, whiskers such as potassium titanate whisker, barium titanate whisker, wollastonite whisker, aluminum borate whisker, silicon nitride whisker, and silicon carbide whisker are also included.

  Examples of fibrous organic fillers include polyester fibers and aramid fibers.

  Examples of the plate-like inorganic filler include talc, mica, graphite, wollastonite, glass flake, barium sulfate, and calcium carbonate. Mica may be muscovite, phlogopite, fluorine phlogopite, or tetrasilicon mica.

  Examples of the particulate inorganic filler include silica, alumina, titanium oxide, glass beads, glass balloons, boron nitride, silicon carbide and calcium carbonate.

  The blending amount of these fillers is preferably 0 to 100 parts by mass with respect to 100 parts by mass of the liquid crystalline polyester.

  In particular, it is preferable to add glass fiber to the liquid crystal polyester so that the strength of the ignition coil member is easily improved.

  The amount of the glass fiber is preferably 10 parts by mass or more and 100 parts by mass or less, more preferably 30 parts by mass or more and 100 parts by mass or less, and further preferably 30 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the liquid crystalline polyester. is there. If the amount of glass fiber is too small, the effect of improving the strength is insufficient, and if it is too large, anisotropy tends to occur.

  The glass fiber has a number average fiber diameter of preferably 25 μm or less, more preferably 20 μm or less, and a number average fiber length of preferably 500 μm or less, more preferably 300 μm or less. The number average fiber diameter and the number average fiber length of the glass fiber can be measured by observing with an electron microscope.

  Examples of additives include antioxidants, heat stabilizers, ultraviolet absorbers, antistatic agents, surfactants, flame retardants, and colorants. It is preferable that the compounding quantity of an additive is 0 to 5 mass parts with respect to 100 mass parts of liquid crystalline polyester.

  Examples of resins other than liquid crystal polyester include polypropylene, polyamide, polyester other than liquid crystal polyester, thermoplastic resin other than liquid crystal polyester such as polysulfone, polyphenylene sulfide, polyether ketone, polycarbonate, polyphenylene ether, and polyetherimide; and phenol resin And thermosetting resins such as epoxy resins, polyimide resins, and cyanate resins. It is preferable that the compounding quantity of resin other than liquid crystalline polyester is 0 to 20 mass parts with respect to 100 mass parts of liquid crystalline polyester.

  The liquid crystal polyester composition is preferably prepared by melt-kneading the liquid crystal polyester and other components used as necessary using an extruder and extruding the mixture into pellets. As the extruder, one having a cylinder, one or more screws arranged in the cylinder, and one or more supply ports provided in the cylinder is preferably used, and further one place provided in the cylinder What has the above vent part is used more preferably.

  The ignition coil member is preferably molded by a melt molding method, more preferably by an injection molding method.

  When the ignition coil member is a bobbin such as the primary bobbin 11 and the secondary bobbin 21 of FIG. 1, the thickness of the winding part is preferably 0.2 mm or more and 1.5 mm or less, and 0.4 mm or more and 1 mm or less. More preferred. If the winding portion is thin, the resin does not flow during molding, and molding defects tend to occur, and the strength tends to be insufficient. In addition, if the winding part is thick, the bobbin becomes large, so that the direct ignition coil having the bobbin becomes large and heavy, and does not meet the needs for miniaturization and weight reduction.

  The direct spark plug can be obtained by using the above-described ignition coil member that is excellent in insulation and rigidity at high temperatures.

  The ignition coil member (direct ignition coil member) configured as described above has excellent insulation and rigidity at high temperatures.

  The coil as described above is excellent in insulation and rigidity at high temperatures.

  Furthermore, according to the direct spark plug as described above, the reliability is high, and even if it is inserted into the plug hole of the engine that becomes high temperature, it can be suitably used.

  In this embodiment, the primary bobbin 11, the secondary bobbin 21, the housing 4 and the like are exemplified as the direct ignition coil member used for the direct ignition coil. However, the direct ignition coil member of the present invention is applied. The member which can be done is not restricted to these.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

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

  In this example, liquid crystalline polyester was used in which isophthalic acid was used as a monomer for providing a repeating unit containing an m-phenylene group and the usage rate of isophthalic acid was changed. Then, as a model sample of a member for direct ignition coil, after forming a flat test piece using such liquid crystal polyester, each liquid crystal polyester is used by measuring the heat resistance and electric resistance of the test piece. The heat resistance and electric resistance of the molded body were confirmed.

[Flow start temperature]
The flow start temperature of the liquid crystal polyester was measured using a flow tester (“CFT-500 type” manufactured by Shimadzu Corporation). About 2 g of liquid crystalline polyester was filled in a cylinder of a flow tester equipped with a die having a nozzle having an inner diameter of 1 mm and a length of 10 mm, and under a load of 9.8 MPa (100 kg / cm ² ), the heating rate was 4 ° C./min. The liquid crystal polyester was melted and the melt viscosity was measured while extruding from the nozzle, and the temperature showing a viscosity of 4800 Pa · s (48000 poise) was defined as the flow start temperature.

[Synthesis Example 1: Liquid crystalline polyester (1)]
In a reactor equipped with a stirrer, torque meter, nitrogen gas inlet tube, thermometer and reflux condenser, p-hydroxybenzoic acid 828.8 g (6.0 mol), terephthalic acid 473.4 g (2.85 mol) , 24.9 g (0.15 mol) of isophthalic acid, 558.6 g (3.0 mol) of 4,4′-dihydroxybiphenyl and 1347.6 g (13.2 mol) of acetic anhydride were added and stirred under a nitrogen gas stream. While raising the temperature from room temperature to 150 ° C. over 15 minutes, the mixture was refluxed at 150 ° C. for 3 hours.

  Next, while distilling off by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 150 ° C. to 320 ° C. over 2 hours and 50 minutes, and when an increase in torque was observed, the contents were taken out from the reactor. And cooled to room temperature.

  The obtained solid was pulverized by a pulverizer, heated from room temperature to 250 ° C. over 1 hour in a nitrogen gas atmosphere, heated from 250 ° C. to 320 ° C. over 5 hours, and heated at 320 ° C. for 3 hours. By holding, after carrying out solid phase polymerization, it cooled and obtained powdery liquid crystalline polyester (1).

  This liquid crystalline polyester (1) is composed of 50 mol% of repeating units derived from p-hydroxybenzoic acid, 23.75 mol% of repeating units derived from terephthalic acid, and isophthalic acid, based on the total amount of all repeating units. It has 1.25 mol% of repeating units derived from (a repeating unit containing an m-phenylene group) and 25 mol% of repeating units derived from 4,4′-dihydroxybiphenyl. It was 380 degreeC when the flow start temperature was measured.

[Synthesis Example 2: Liquid crystalline polyester (2)]
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 994.5 g (7.2 mol) of p-hydroxybenzoic acid and 358.8 g (2.16 mol) of terephthalic acid , 39.9 g (0.24 mol) of isophthalic acid, 446.9 g (2.4 mol) of 4,4′-dihydroxybiphenyl, 1347.6 g (13.2 mol) of acetic anhydride and 0.20 g of 1-methylimidazole. The mixture was heated from room temperature to 150 ° C. over 30 minutes with stirring under a nitrogen gas stream and refluxed at 150 ° C. for 60 minutes.

  Next, 0.9 g of 1-methylimidazole was added, the temperature was raised to 320 ° C. over 2 hours and 50 minutes while distilling out by-product acetic acid and unreacted acetic anhydride, and when an increase in torque was observed, The contents were removed from the reactor and cooled to room temperature.

  The obtained solid was pulverized by a pulverizer, heated from room temperature to 250 ° C. over 1 hour in a nitrogen gas atmosphere, heated from 250 ° C. to 305 ° C. over 5 hours, and then heated at 305 ° C. for 3 hours. By holding, after carrying out solid-phase polymerization, it cooled and obtained powdery liquid crystal polyester (2).

  This liquid crystal polyester (2) is derived from 60 mol% of repeating units derived from p-hydroxybenzoic acid, 18 mol% of repeating units derived from terephthalic acid, and from isophthalic acid, based on the total amount of all repeating units. 2 mol% of repeating units and 20 mol% of repeating units derived from 4,4′-dihydroxybiphenyl. The flow starting temperature was measured and found to be 357 ° C.

[Synthesis Example 3: Liquid Crystalline Polyester (3)]
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 994.5 g (7.2 mol) of p-hydroxybenzoic acid and 299.0 g (1.8 mol) of terephthalic acid 99.7 g (0.6 mol) of isophthalic acid, 446.9 g (2.4 mol) of 4,4′-dihydroxybiphenyl, 1347.6 g (13.2 mol) of acetic anhydride and 0.18 g of 1-methylimidazole. The mixture was heated from room temperature to 150 ° C. over 30 minutes with stirring under a nitrogen gas stream and refluxed at 150 ° C. for 30 minutes.

  Next, 2.4 g of 1-methylimidazole was added and the temperature was raised from 150 ° C. to 320 ° C. over 2 hours and 50 minutes while distilling out by-product acetic acid and unreacted acetic anhydride, and an increase in torque was observed. At that time, the contents were removed from the reactor and cooled to room temperature.

  The obtained solid was pulverized by a pulverizer, heated from room temperature to 250 ° C. over 1 hour in a nitrogen gas atmosphere, heated from 250 ° C. to 295 ° C. over 5 hours, and heated at 295 ° C. for 3 hours. By holding, after carrying out solid phase polymerization, it cooled and obtained powdery liquid crystalline polyester (3).

  This liquid crystal polyester (3) is derived from 60 mol% of repeating units derived from p-hydroxybenzoic acid, 15 mol% of repeating units derived from terephthalic acid, and from isophthalic acid, based on the total amount of all repeating units. 5 mol% of repeating units and 20 mol% of repeating units derived from 4,4′-dihydroxybiphenyl. It was 330 degreeC when the flow start temperature was measured.

[Synthesis Example 4: Liquid crystalline polyester (4)]
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 994.5 g (7.2 mol) of p-hydroxybenzoic acid and 239.2 g (1.44 mol) of terephthalic acid , 159.5 g (0.96 mol) of isophthalic acid, 446.9 g (2.4 mol) of 4,4′-dihydroxybiphenyl, 1347.6 g (13.2 mol) of acetic anhydride and 0.18 g of 1-methylimidazole The mixture was heated from room temperature to 150 ° C. over 30 minutes with stirring under a nitrogen gas stream and refluxed at 150 ° C. for 30 minutes.

  Next, 2.4 g of 1-methylimidazole was added and the temperature was raised from 150 ° C. to 320 ° C. over 2 hours and 50 minutes while distilling out by-product acetic acid and unreacted acetic anhydride, and an increase in torque was observed. At that time, the contents were removed from the reactor and cooled to room temperature.

  The obtained solid was pulverized by a pulverizer, heated in a nitrogen gas atmosphere from room temperature to 220 ° C. over 1 hour, heated from 220 ° C. to 240 ° C. over 30 minutes, and then at 240 ° C. for 10 hours. By holding, after carrying out solid phase polymerization, it cooled and obtained powdery liquid crystal polyester (4).

  This liquid crystal polyester (4) is derived from 60 mol% of repeating units derived from p-hydroxybenzoic acid, 12 mol% of repeating units derived from terephthalic acid, and from isophthalic acid, based on the total amount of all repeating units. 8 mol% of repeating units and 20 mol% of repeating units derived from 4,4′-dihydroxybiphenyl. The flow starting temperature was measured and found to be 290 ° C.

[Glass fiber]
The following were used as glass fibers.
Glass fiber (1): “REV8” manufactured by Nippon Sheet Glass Co., Ltd. (number average fiber diameter 13 μm, number average fiber length 70 μm)
Glass fiber (2): “EFH75-01” (number average fiber diameter 11 μm, number average fiber length 75 μm) of Central Glass Co., Ltd.

Example 1
100 parts by mass of liquid crystalline polyester (1) and 67 parts by mass of glass fiber (1) were mixed and produced at a cylinder temperature of 390 ° C. using a twin-screw extruder (“PCM-30” from Ikekai Tekko Co., Ltd.). Granulated to obtain a pellet-like liquid crystal polyester composition. The obtained liquid crystal polyester composition was injection molded to obtain molded bodies of 64 mm × 64 mm × thicknesses 0.5, 1.0 and 1.6 mm. About the obtained molded object, the dielectric breakdown voltage and the curvature of the molded object were measured with the following method.

[Dielectric breakdown voltage]
About the obtained molded object, according to JISC2110, the dielectric breakdown voltage of room temperature, 100 degreeC, and 200 degreeC was measured by the short time destruction test method. As for the electrodes used for the measurement, the upper electrode is a spherical electrode having a diameter of 20 mm, and the lower electrode is a disk-shaped electrode having a diameter of 25 mm.

  The dielectric breakdown voltage in this example is the minimum voltage (effective value) at which the molded body is destroyed when a voltage is applied to the molded body that is an insulating material in accordance with the above method. It expresses as a breakdown voltage with respect to the unit thickness of a molded object (unit: kV / mm). The measurement result of this example was determined as the average value (arithmetic average value) of the values measured for the five molded bodies (n = 5).

[War of molded body]
The warping of the molded body was obtained by heating the obtained molded body having a thickness of 0.5 mm at 250 ° C. for 5000 hours in a nitrogen atmosphere and then pressing one of the four corners of the molded body with a finger. The apex on the corner side was determined by measuring the lift from the surface on which the molded body was placed. About one molded object, four values obtained by measuring about each vertex were averaged, and it was set as the value of the curvature of a molded object.

  The measurement limit of warpage by the above method is about 2 mm, and the detection limit in the above method is set to 3 mm or less by taking a measurement error of 1 mm at maximum.

(Example 2)
A molded body was obtained in the same manner as in Example 1 except that 100 parts by mass of the liquid crystalline polyester (2) and 67 parts by mass of the glass fiber (2) were mixed and the cylinder temperature at the time of pellet processing was 360 ° C. . About the obtained molded object, it carried out similarly to Example 1, and measured the dielectric breakdown voltage and the curvature of the molded object.

(Example 3)
A molded body was obtained in the same manner as in Example 1 except that 100 parts by mass of the liquid crystalline polyester (3) and 67 parts by mass of the glass fiber (2) were mixed and the cylinder temperature at the time of pellet processing was 340 ° C. . About the obtained molded object, it carried out similarly to Example 1, and measured the dielectric breakdown voltage and the curvature of the molded object.

(Comparative Example 1)
A molded body was obtained in the same manner as in Example 1 except that 100 parts by mass of the liquid crystalline polyester (4) and 67 parts by mass of the glass fiber (2) were mixed and the cylinder temperature at the time of pellet processing was 300 ° C. . About the obtained molded object, it carried out similarly to Example 1, and measured the dielectric breakdown voltage and the curvature of the molded object.

  With respect to Examples 1 to 3 and Comparative Example 1, measurement results of dielectric breakdown voltage and warpage are shown in Table 1 below.

  As a result of the measurement, from the measurement result of the warpage of the 0.5 mm-thick molded body, the molded body of Comparative Example 1 is more warped than the molded bodies of Examples 1 to 3, and is likely to deform under high temperature conditions. I understood. Moreover, it turned out that the curvature of Example 1, 2 is smaller than 3 mm among Examples 1-3, and has heat resistance higher than Example 3. FIG.

  Moreover, from the measurement result of the dielectric breakdown voltage for the 0.5 mm-thick molded body, it was found that the molded body of Comparative Example 1 had lower electric resistance than the molded body of Examples 1 to 3 at any temperature. .

  Furthermore, from the measurement result of the dielectric breakdown voltage at room temperature, the withstand voltage decreases rapidly between Example 3 (the isophthalic acid content of the liquid crystal polyester is 5 mol%) and Comparative Example 1 (8 mol%). Was confirmed. Based on Example 1 (1.25 mol%), the withstand voltage of 90% or more of Example 1 can be maintained if the isophthalic acid content is 6.5 mol% or more. It was found that a high withstand voltage can be realized.

  From these results, the usefulness of the present invention was confirmed.

DESCRIPTION OF SYMBOLS 1 ... Primary coil, 2 ... Secondary coil, 3 ... Core, 4 ... Housing, 5 ... Input part, 6 ... Output part, 11 ... Primary bobbin, 11a ... Winding part, 12 ... Conductor, 15 ... Sealing Stop agent, 21 ... secondary bobbin, 21a ... winding part, 22 ... conducting wire, 25 ... sealant, 31, 32 ... magnet, 51 ... terminal, 52 ... control circuit, 61 ... high pressure terminal, 62 ... spring, 100 ... Direct ignition coil, 200 ... Ignition plug

Claims (7)

The liquid crystal polyester having a repeating unit represented by the following formula (1), the following formula (2) and the following formula (3) is included as a forming material, and the content of the repeating unit having an m-phenylene group in the liquid crystal polyester is A member for a direct ignition coil that is 0 mol% or more and 6.5 mol% or less with respect to the total amount of all repeating units.
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4). X And Y each independently represents an oxygen atom or an imino group (—NH—), and each hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently a halogen atom or a carbon number. (It may be substituted with an alkyl group of 1 to 10 or an aryl group of 6 to 20 carbon atoms.)
(4) -Ar ⁴ -Z-Ar ^5-
(Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.) The Ar ¹ is a p-phenylene group or a 2,6-naphthylene group, the Ar ² is a p-phenylene group, an m-phenylene group or a 2,6-naphthylene group, and the Ar ³ is p- The direct ignition coil member according to claim 1, wherein the member is a phenylene group or a 4,4′-biphenylylene group, and the X and the Y are oxygen atoms.   The liquid crystalline polyester has a repeating unit represented by the formula (1) of 30 mol% or more and 80 mol% or less and a repeating unit represented by the formula (2) of 10 mol based on the total amount of all repeating units. The direct ignition coil member according to claim 1 or 2, wherein the repeating unit represented by the formula (3) is 10 mol% or more and 35 mol% or less.   The direct ignition coil member according to any one of claims 1 to 3, wherein a composition containing the liquid crystal polyester and glass fiber is used as a forming material.   5. The direct ignition coil member according to claim 4, wherein a content of the glass fiber is 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the liquid crystal polyester. A coil having a bobbin and a conductive wire wound around a winding part of the bobbin,
The said bobbin is a member for direct ignition coils of any one of Claim 1 to 5, The thickness of the said winding part is 0.2 mm or more and 1.5 mm or less. A direct ignition coil having a coil having a bobbin and a conductive wire wound around a winding part of the bobbin, and a housing for housing the coil,
6. The direct ignition coil according to claim 1, wherein at least one of the bobbin and the housing is the member for direct ignition coil according to claim 1.

Images