JP2018162412A - Thermoplastic polyimide resin composition, ultrasonic welded article, office equipment component, automobile component, and aircraft component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic polyimide resin composition that ensures excellent weld strength when ultrasonic-welding the thermoplastic polyimide resin composition to metal.SOLUTION: A thermoplastic polyimide resin composition contains thermoplastic polyimide resin, fluorine resin, and graphite, with an MFR of 3 g/10 min or more and a linear expansion coefficient in TD direction of 10×10/K-40×10/K.SELECTED DRAWING: None

Description

  The present disclosure relates to a thermoplastic polyimide resin composition, an ultrasonic weld, an office equipment part, an automobile part, and an aircraft part.

  A material in which a resin member and a metal member are joined is used for parts used in office equipment, automobiles, aircraft, industrial equipment, and the like. In addition, various parts are being reduced in weight, and for example, a metal material (for example, aluminum, aluminum alloy, etc.) that is lightweight and excellent in strength is used as a metal member of the various parts.

For example, a resin composition containing a thermoplastic resin (hereinafter also referred to as a thermoplastic resin composition) is applied to the resin member to be joined to the metal member. When a resin composition containing a thermoplastic resin is required to have heat resistance, for example, a resin composition containing a thermoplastic polyimide resin having high heat resistance (hereinafter also referred to as a thermoplastic polyimide resin composition) may be used. .
The thermoplastic polyimide resin composition has excellent characteristics such as heat resistance and self-lubricity, and thus may be applied to sliding portions with various metal members, for example. Therefore, a sliding member formed using a thermoplastic polyimide resin composition as a material has been developed in accordance with use conditions (for example, see Patent Document 1).
Such a sliding member has a metal member such as aluminum or an aluminum alloy as a base material, and may be joined to the base material for use.

JP 2007-192242 A

  By the way, as a method of joining a resin member using a thermoplastic resin composition and a metal member (for example, aluminum, aluminum alloy, etc.), a member to be welded in a state where the surface of the resin composition is as low as possible. Attempts have been made to perform welding by applying a temperature necessary for welding in a short time in the vicinity of the surface. Examples of such a welding method include ultrasonic welding by an ultrasonic welding method.

  In the ultrasonic welding method, ultrasonic energy generated from an ultrasonic oscillator is converted into mechanical vibration energy, and the converted mechanical vibration energy is applied to the bonding surface (welding between the resin member and the metal member using the thermoplastic resin composition). Surface). The transmitted vibrational energy is generated by generating frictional heat in the vicinity of the surfaces of the resin member and metal member to be welded to melt the thermoplastic resin composition.

  However, when a thermoplastic polyimide resin composition is used as the thermoplastic resin composition for forming the resin member, when the resin member and the metal member are ultrasonically welded, the welding strength between the resin member and the metal member is low. There was. Therefore, further improvement is required for the thermoplastic polyimide resin composition in order to improve the welding strength when the resin member and the metal member formed using the thermoplastic polyimide resin composition are ultrasonically welded. Yes.

  The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a thermoplastic polyimide resin composition that provides excellent welding strength when ultrasonically welding a thermoplastic polyimide resin composition and a metal. To provide things.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have solved the above-mentioned problems by including a thermoplastic polyimide resin, a fluororesin, and graphite, and controlling the linear expansion coefficient within a specific range. I found out that I could do it.

  That is, the following aspects are included in the means for solving the above problems.

<1> thermoplastic polyimide resin include fluororesin, and the graphite, and a MFR of 3 g / 10min or higher, the thermal linear expansion coefficient in the TD direction is ^{10 × 10 -6 / K~40 × 10} -6 / K Plastic polyimide resin composition.

<2> The thermoplastic polyimide according to <1>, comprising 40 to 80 parts by mass of the thermoplastic polyimide resin, 5 to 30 parts by mass of the fluororesin, and 15 to 30 parts by mass of the graphite. Resin composition.

<3> The thermoplastic polyimide resin composition according to <1> or <2>, wherein the graphite has an average particle size of 5 μm to 20 μm.

<4> An ultrasonic welded product of the resin molded body of the thermoplastic polyimide resin composition according to any one of <1> to <3> and aluminum or an aluminum alloy.

<5> An office equipment part comprising the ultrasonic weld described in <4>.

<6> Automobile parts provided with the ultrasonic weld according to <4>.

<7> An aircraft part provided with the ultrasonic weld according to <4>.

  According to the thermoplastic polyimide resin composition according to the present disclosure, there is provided a thermoplastic polyimide resin composition capable of obtaining excellent welding strength when the thermoplastic polyimide resin composition and a metal are ultrasonically welded.

Hereinafter, an example of an embodiment of the thermoplastic polyimide resin composition according to the present disclosure will be described in detail.
In addition, the numerical range shown using "to" in this specification shows the range which includes the numerical value described before and behind "to" as a minimum value and a maximum value, respectively.

<Thermoplastic polyimide resin composition>
The thermoplastic polyimide resin composition according to the present disclosure contains a fluororesin and graphite in the thermoplastic polyimide resin. And when the thermoplastic polyimide resin composition according to the present disclosure has the specific values shown below for the linear expansion coefficient and MFR in the TD direction, the thermoplastic polyimide resin composition and the metal are ultrasonically welded. The welding strength is excellent.

(Linear expansion coefficient of thermoplastic polyimide resin composition)
Thermoplastic polyimide resin composition of the present disclosure, the linear expansion coefficient in the TD direction is ^{10 × 10 -6 / K~40 × 10} -6 / K.
By linear expansion coefficient in the TD direction of the thermoplastic polyimide resin composition is in the range of ^{10 × 10 -6 / K~40 × 10} -6 / K, a thermoplastic polyimide resin composition and the aluminum, a metal such as aluminum alloy The welding strength when the member is ultrasonically welded is excellent. This is thought to be because the welding strength increases because the linear expansion coefficient in the TD direction of the thermoplastic polyimide resin composition approximates the linear expansion coefficient of a metal member such as aluminum or aluminum alloy.

A preferred range of the linear expansion coefficient in the TD direction of the thermoplastic polyimide resin composition of the present disclosure is a ^{20 × 10 -6 / K~40 × 10} -6 / K.
Further, from the viewpoint of excellent welding strength of the metal member welded product obtained by ultrasonic welding, often linear expansion coefficient in the MD direction is ^{10 × 10 -6 / K~40 × 10} -6 / K, 20 × it is preferably ^{10 -6 / K~40 × 10 -6 /} K.
Here, in this specification, the MD direction represents the direction in which the resin composition flows when the resin composition is molded. The TD direction represents a direction orthogonal to the direction in which the resin composition flows when the resin composition is molded.

Note that it is difficult to control the linear expansion coefficient in the TD direction to the above range even if the thermoplastic polyimide resin composition includes, for example, PAN-based carbon fibers. In addition, when carbon fibers such as PAN are included, a difference occurs in the linear expansion coefficient between the TD direction and the MD direction, and anisotropy tends to occur in the linear expansion coefficient.
On the other hand, since the thermoplastic polyimide resin composition according to the present disclosure can control the linear expansion coefficient in the TD direction to the above range by using graphite, it is welded by ultrasonic welding with a metal member. It is considered that the welding strength of the object is excellent.
Furthermore, not only the linear expansion coefficient in the TD direction but also the linear expansion coefficient in the MD direction can be similarly controlled within the above range. For this reason, the use of graphite makes it difficult for anisotropy to occur in the coefficient of linear expansion. It is considered that the welding strength is excellent.
Therefore, in the thermoplastic polyimide resin composition according to the present disclosure, the linear expansion coefficient in the TD direction falls within the above range depending on the combination of the thermoplastic polyimide resin, the fluororesin, and the graphite. It is considered that the weld strength of the welded product obtained by ultrasonically welding the molded resin molded body and a metal member such as aluminum or aluminum alloy is excellent.

(MFR of thermoplastic polyimide resin composition)
The thermoplastic polyimide resin composition according to the present disclosure has an MFR of 3 g / 10 min or more. If the MFR is less than 3 g / 10 min, the flowability of the thermoplastic polyimide resin composition is too low, so that the moldability is lowered. Moreover, when the fluidity | liquidity of a thermoplastic polyimide resin composition is low, even if the linear expansion coefficient of a resin composition is the above-mentioned range, it is thought that the dispersibility of the graphite in a thermoplastic polyimide resin composition falls. Therefore, by setting the MFR of the thermoplastic polyimide resin composition to 3 g / 10 min or more, the dispersibility of graphite in the thermoplastic polyimide resin composition is increased, and the thermoplastic polyimide resin composition and a metal such as aluminum or aluminum alloy are increased. It is considered that the welding strength when the member is ultrasonically welded is excellent.
The MFR of the thermoplastic polyimide resin composition is preferably 5 g / 10 min or more. Although the upper limit of MFR is not specifically limited, For example, it is mentioned that it is 40 g / 10min or less.

  Hereinafter, each component of the polyimide resin composition according to the present disclosure will be described.

(Thermoplastic polyimide resin)
In this specification, a thermoplastic polyimide resin is a resin having a polyimide bond as a repeating unit, and represents a polyimide resin having a weighted deflection temperature of 200 ° C. or higher.

  The thermoplastic polyimide resin is not particularly limited as long as the above conditions are satisfied. A preferable example of the thermoplastic polyimide resin is a polyimide resin having a repeating unit represented by the following chemical formula (1).

In the chemical formula (1), X represents a direct bond, —SO ₂ —, —CO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ —, or —S—, and R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogenated alkyl group, a halogenated alkoxy group, or a halogen atom, and Y represents (A) in the following chemical formula (2), A group selected from the group consisting of (B), (C), and (D) is shown.

  The thermoplastic polyimide resin having a repeating unit represented by the chemical formula (1) is an aromatic ether diamine represented by the following chemical formula (7) and an aromatic tetracarboxylic dianhydride represented by the following chemical formula (8). The product can be produced by reacting the product with a raw material in the presence or absence of an organic solvent and imidizing the resulting polyamic acid chemically or thermally. These specific production methods can utilize the conditions of known polyimide resin production methods.

  However, in the chemical formula (7), X has the same meaning as X in the chemical formula (1).

  In the chemical formula (8), Y represents a group selected from the group consisting of (A), (B), (C), and (D) in the chemical formula (2).

In chemical formula (1) and chemical formula (7), the groups represented by R ¹ , R ² , R ³ and R ⁴ are a hydrogen atom, an alkyl group, an alkoxy group, a halogenated alkyl group, a halogenated alkoxy group, or a halogen atom. is there. Among these, a hydrogen atom is preferable.

Examples of the alkyl group represented by R ¹ , R ² , R ³ , and R ⁴ include an alkyl group having 1 to 4 carbon atoms. Specific examples include alkyl groups such as a methyl group and an ethyl group.
Examples of the alkoxy group represented by R ¹ , R ² , R ³ , and R ⁴ include an alkoxy group having 1 to 4 carbon atoms. Specific examples include alkyl groups such as methoxy group and ethoxy group.
The halogenated alkyl group represented by R ¹ , R ² , R ³ , R ⁴ is a group in which a halogen atom (a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, etc.) is substituted on an alkyl group having 1 to 4 carbon atoms. Is mentioned. Specific examples include a fluoromethyl group and a trifluoromethyl group.
The halogenated alkoxy group represented by R ¹ , R ² , R ³ , or R ⁴ is a group in which a halogen atom (a chlorine atom, a fluorine atom, a bromine atom, an iodine atom, or the like) is substituted on an alkoxy group having 1 to 4 carbon atoms. Is mentioned. Specific examples include a fluoromethoxy group.
Examples of the halogen atom represented by R ¹ , R ² , R ³ , or R ⁴ include a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom.

In chemical formula (1) and chemical formula (7), X represents a direct bond, —SO ₂ —, —CO—, —C (CH ₃ ) ₂ —, —C (CF ₃ ) ₂ — or —S—. Among these, X is preferably a direct bond, —SO ₂ —, —CO—, or —C (CH ₃ ) ₂ —.

  In chemical formula (1) and chemical formula (8), Y is a tetravalent aromatic group selected from the group consisting of (A), (B), (C), and (D) in chemical formula (2). Among these, Y is preferably (A) in the chemical formula (2). That is, it is preferable to use pyromellitic dianhydride as the aromatic tetracarboxylic dianhydride.

  It is more preferable that the thermoplastic polyimide resin composition according to the present disclosure uses a thermoplastic polyimide resin having a repeating unit represented by the following chemical formula (3) as the thermoplastic polyimide resin.

  In addition, the thermoplastic polyimide resin which has a repeating unit represented by the said Formula (3) can be purchased as Mitsui Chemicals, Inc. make: brand name AURUM (trademark).

  In the thermoplastic polyimide resin composition according to the present disclosure, the aromatic ether diamine or aromatic tetracarboxylic dianhydride that is a raw material of the thermoplastic polyimide resin can be used singly or in combination. Other copolymer components may be included as long as the purpose of the thermoplastic polyimide resin composition is not impaired. In addition, a plurality of polyimide resins obtained from different monomers may be arbitrarily polymer blended within a range that does not impair the purpose of the thermoplastic polyimide resin composition according to the present disclosure.

  In the thermoplastic polyimide resin composition according to the present disclosure, a thermoplastic polyimide resin in which the thermoplastic composition polyimide resin has repeating units represented by the following chemical formula (4) and the following chemical formula (5) is also preferable.

However, m and n are molar ratios of the copolymer, and m / n = 4 to 99 (mol% / mol%). m / n is preferably 5 to 99, more preferably 6 to 99.
m and n each represents 1 or more.

  The thermoplastic polyimide resin having a repeating structural unit represented by the above chemical formula (4) and chemical formula (5) is prepared by using an aromatic solvent such as an aromatic ether diamine and an aromatic tetracarboxylic dianhydride as raw materials. The reaction can be performed in the presence or absence, and the resulting polyamic acid can be chemically or thermally imidized for production. These specific production methods can utilize the known conditions for producing polyimide.

  In the thermoplastic polyimide resin composition according to the present disclosure, a thermoplastic polyimide resin in which the thermoplastic polyimide resin has a repeating unit represented by the following chemical formula (6) is also given as a preferred example.

  The thermoplastic polyimide resin having a repeating structural unit represented by the above chemical formula (6) is obtained by using the corresponding aromatic ether diamine and aromatic tetracarboxylic dianhydride as raw materials in the presence or absence of an organic solvent. The resulting polyamic acid can be produced by chemically or thermally imidizing by reacting under the following conditions. These specific production methods can utilize the known conditions for producing polyimide.

In the thermoplastic polyimide resin composition according to the present disclosure, the thermoplastic polyimide resin is a melt-moldable resin. The logarithmic viscosity of the thermoplastic polyimide resin is not particularly limited, but is preferably in the range of 0.35 dl / g to 1.30 dl / g, and preferably in the range of 0.40 dl / g to 1.20 dl / g. .
When the logarithmic viscosity is 0.35 dl / g or more, a decrease in mechanical strength due to a small molecular weight of the thermoplastic polyimide resin tends to be suppressed. Further, when the logarithmic viscosity is 1.30 dl / g or less, a decrease in fluidity of the resin composition due to an excessively high molecular weight of the thermoplastic polyimide resin is suppressed. In particular, when a resin molded body is produced by a molding method such as injection molding or extrusion molding using the resin composition of the present disclosure, it can have appropriate fluidity.

  The measurement of the logarithmic viscosity of the polymer in the thermoplastic polyimide resin composition according to the present disclosure was performed by heating to 200 ° C. with a solvent having a concentration of 0.5 g / 100 ml in a mixed solvent of parachlorophenol / phenol (90/10 mass ratio). Thereafter, it is cooled to 35 ° C. and measured. The definition of the logarithmic viscosity is described in “Polymer Handbook” published by Asakura Shoten, edited by the Japan Society for Analytical Chemistry, 1995, first edition, P58.

(Fluorine resin)
In the thermoplastic polyimide resin composition according to the present disclosure, examples of the fluororesin include at least one selected from the group consisting of the following (a) to (f).
(A) In the molecule, a tetrafluoroethylene resin having a repeating structural unit represented by the chemical formula-(CF ₂ CF ₂ )-(b) In the molecule, chemical formula-(CF ₂ CF ₂ )-and chemical formula- In the molecule of tetrafluoroethylene resin-hexafluoropropylene copolymer resin (c) having a repeating structural unit represented by [CF (CF ₃ ) CF ₂ ] —, chemical formula − (CF ₂ CF ₂ ) and chemical formula − _{[CF (OC m F2 m + 1} ) CF 2 ] (wherein, m is a positive integer) tetrafluoroethylene having a repeating structural unit represented by - the perfluoroalkyl vinyl ether copolymer resin (d) in the molecule, formula - _(CF 2 CF 2) - and the formula - _(CH 2 CH ₂₎ - to repeat tetrafluoroethylene-ethylene copolymer resin having a structural unit (e) in the molecule represented by the formula - (C ₂ CH ₂₎ - and the formula - (CFClCF ₂₎ - Table with - ethylene copolymer resin (f) in the molecule, the formula _{- - (CF 2 CH 2)} 3 fluorinated ethylene chloride having a repeating structural unit represented by Vinylidene fluoride resin having a repeating structural unit

(Graphite)
In the thermoplastic polyimide resin composition according to the present disclosure, the graphite is not particularly limited, and examples thereof include artificial graphite and natural graphite (flaky graphite, scaly graphite, earthy graphite). The graphite preferably has a high carbon purity, and more preferably has a fixed carbon purity of 95% or more.

The average particle diameter of the graphite is preferably 5 μm to 20 μm (preferably 10 μm to 20 μm) in terms of excellent welding strength when the resin member and the metal member are ultrasonically welded.
In the specification, the average particle diameter of graphite is measured by a laser diffraction method.

  The total content of the thermoplastic polyimide resin, the fluororesin, and the graphite is preferably 95% by mass or more, and may be 100% by mass with respect to the entire resin composition.

(Other additives)
In the polyimide resin composition according to the present disclosure, if necessary, within the range that does not impair the characteristics of the polyimide resin composition according to the present disclosure (for example, 5% by mass or less (including 0% by mass)), the following Ingredients may be included.

  The thermoplastic polyimide resin composition according to the present disclosure includes, as necessary, carbon fiber, glass fiber, potassium titanate fiber, boric acid within a range that does not impair the characteristics of the thermoplastic polyimide resin composition according to the present disclosure. You may contain at least 1 sort (s) from the group which consists of aluminum fiber, metal fiber, ceramic fiber, boron fiber, silicon carbide fiber, asbestos fiber, rock wool fiber, and aramid fiber.

  Further, in the thermoplastic polyimide resin composition according to the present disclosure, if necessary, mica, synthetic mica, wollastonite, talc, silicone oil, as long as the characteristics of the polyimide resin composition according to the present disclosure are not impaired. , Fluorinated oil, glass beads, molybdenum disulfide, clay, silica, alumina, diatomaceous earth, hydrated alumina, shirasu balloon, carbon nanotube, calcium carbonate, hydrotalcite, filler, lubricant, mold release agent, stable You may contain at least 1 sort (s) of a coloring agent, a coloring agent, a crystal nucleating agent, etc.

  Furthermore, the thermoplastic polyimide resin composition according to the present disclosure may include various liquid crystal polymers and thermoplastic resins (for example, polyetherimide) within a range that does not impair the characteristics of the polyimide resin composition according to the present disclosure. , Polyether nitrile, polyether ketone, polyether ether ketone, polyether ketone ketone, polyether ketone ether ketone ketone, polyamide imide, polyether sulfone, polysulfone, polyarylate and / or polyphenylene sulfide), thermosetting resin (for example, , Epoxy resin, polybenzimidazole resin, polyimide resin, and the like).

(Composition ratio of thermoplastic polyimide resin composition)
The thermoplastic polyimide resin composition according to the present disclosure contains a thermoplastic polyimide resin, a fluororesin, and graphite. The thermoplastic polyimide resin composition preferably has the following composition in that it has excellent welding strength when ultrasonically welded to a metal member. Moreover, by setting it as the following compositions, it becomes easy to control the linear expansion coefficient and MFR in a TD direction to the above-mentioned range.

  The thermoplastic polyimide resin may be contained in the range of 40 parts by mass to 80 parts by mass in 100 parts by mass of the total amount of the thermoplastic polyimide resin, the fluororesin, and the graphite. The preferable range of the content of the thermoplastic polyimide resin is 50 parts by mass to 75 parts by mass, and more preferably 60 parts by mass to 75 parts by mass.

  The fluororesin is preferably contained in the range of 5 to 30 parts by mass in 100 parts by mass of the total amount of thermoplastic polyimide resin, fluororesin, and graphite. A preferable range of the content of the fluororesin is 10 parts by mass to 20 parts by mass.

  Graphite is preferably contained in a range of 15 to 30 parts by mass in 100 parts by mass of the total amount of thermoplastic polyimide resin, fluororesin, and graphite. A preferred range for the graphite content is 15 to 20 parts by mass.

(Method for producing thermoplastic polyimide resin composition)
The manufacturing method of the thermoplastic polyimide resin composition according to the present disclosure is not particularly limited, and a known manufacturing method can be applied. For example, a mixture containing a thermoplastic polyimide resin, a fluororesin, and graphite may be continuously melted and kneaded using a single-screw or multi-screw extruder, or melted by a batch method such as a kneading roll or Brabender. You may knead.
What is necessary is just to determine as temperature (cylinder temperature) in the case of melt-kneading according to the melting | fusing point etc. of the resin component contained in a thermoplastic polyimide resin composition.

(Molding of thermoplastic polyimide resin composition)
The thermoplastic polyimide resin composition according to the present disclosure is not particularly limited, and all known molding methods can be used. For example, a molding method may be mentioned in which molding is performed by injection molding. It can be applied to various uses by molding by injection molding. It can also be used by cutting the molded product obtained by injection molding to finish it into a final shape. In addition, it is also possible to perform molding by a conventionally known method such as extrusion molding, compression molding, and transfer molding.
For example, in the case of molding by injection molding, the writing conditions such as cylinder temperature, injection pressure, mold temperature, etc. may be determined according to the shape of the thermoplastic polyimide resin composition, resin molded body, and the like.

<Ultrasonic welded material>
The thermoplastic polyimide resin composition according to the present disclosure is excellent in welding strength when ultrasonically welded to a metal such as aluminum or an aluminum alloy. Therefore, it is good also as a welded product (ultrasonic welded product) obtained by ultrasonically welding a resin molded body of a thermoplastic polyimide resin composition and aluminum or an aluminum alloy.

Specifically, ultrasonic welding converts an electrical signal from an ultrasonic oscillator into electrical energy of a 20 kHz sine wave by the oscillator. This high-frequency electrical energy is converted into mechanical vibration energy, amplified, and then transmitted to the welded resin molded body and metal joint through a resonator called a horn. Friction heat is generated at the interface between the resin molded body and the metal by the transmitted vibration energy and pressure, and welding is performed by melting the resin component of the resin molded body. For this reason, ultrasonic welding is advantageous in that it can be welded in a short time without becoming high temperature.
The apparatus for ultrasonic welding is not particularly limited, and examples thereof include Branson 2000X series.

  The welding strength of a welded product obtained by ultrasonically welding a resin molded body of a thermoplastic polyimide resin composition and aluminum or an aluminum alloy is preferably 50 kgf or more, and preferably 60 kgf. A method for measuring the welding strength will be described later.

Examples of a method for obtaining an ultrasonic weld of a resin molded body obtained by molding a thermoplastic polyimide resin composition and aluminum or an aluminum alloy include the following methods.
Thermoplastic polyimide resin include fluororesin, and the graphite, and a MFR of 3 g / 10min or higher, the thermoplastic polyimide resin linear expansion coefficient in the TD direction is ^{10 × 10 -6 / K~40 × 10} -6 / K A step of obtaining a resin molded body by molding the composition, and superposing the resin molded body and aluminum or aluminum alloy, applying ultrasonic vibration to the joint between the resin molded body and aluminum or aluminum alloy, And a step of welding the metal formed body. Specifically, first, a thermoplastic polyimide resin composition according to the present disclosure is molded to prepare a resin molded body. Moreover, the metal molded object which shape | molded aluminum or aluminum alloy is prepared. Next, the resin molded body and the metal molded body are superposed and ultrasonic vibration is applied to the joint between the resin molded body and the metal molded body, thereby obtaining a welded product of the resin molded body and the metal molded body. It is done.

  Aluminum or aluminum alloy is not particularly limited, and a known material may be used. The surface of aluminum or aluminum alloy may be subjected to various surface treatments such as plating treatment, thermal spraying treatment, anodizing treatment, chemical conversion treatment, or rough surface forming treatment.

(Application of ultrasonic weld)
The ultrasonic welded material according to the present disclosure is excellent in ultrasonic weldability between a resin molded body of a thermoplastic polyimide resin composition and a metal member such as aluminum or aluminum alloy, so that it is an automobile part, office equipment part, aircraft part, industrial It can be applied to various parts in a wide range of fields such as machine parts.
The ultrasonic welded material according to the present disclosure includes, for example, a gear, a thrust washer, a seal ring, a piston ring, a turbo seal part (abre seal), a wear ring, a guide roller, a retainer, a bush, a transport device, and various other slides. It can be applied to a moving member.

  Hereinafter, the present disclosure will be specifically described by way of examples. However, the present disclosure is not limited to these examples. Note that “part” means “part by mass” unless otherwise specified.

In the following examples and comparative examples, the resin compositions were evaluated in the following manner.
The results of each evaluation are shown in Table 1.

[Linear expansion coefficient]
Using a 6 mm × 3 mm × 70 mm rectangular injection molded product, the linear expansion coefficient was measured in the flow direction (MD) and the right angle direction (TD) by TMA / SS120 manufactured by Seiko Electronics Co., Ltd.

[Tensile strength]
Based on ASTM D638, ASTM No. 1 dumbbell was used, and a tensile strength test was performed at a test speed of 5 mm / min.

[Bending strength and flexural modulus]
Based on ASTM D790, a bending test was performed at a test speed of 1.5 mm / min and a measurement temperature of 23 ° C., and a flexural modulus was measured.

[Fluidity (MFR)]
Based on JIS K7210 (2014), the measurement was performed under the conditions of a test temperature of 420 ° C. and a load of 2.16 kgf.

[Weld strength]
A resin molded body sample (inner diameter: 50 mm, outer diameter: 70 mm, height: 50 mm) obtained by molding a thermoplastic polyimide resin composition into a cylindrical shape by injection molding described later was prepared. In addition, an aluminum alloy molded sample (inner diameter 70 mm, outer diameter 110 mm, height 50 mm) in which an aluminum alloy (ADC-12) was formed into a cylindrical shape was prepared.
The resin molded body sample is inserted into the aluminum alloy molded sample, and ultrasonic waves are applied from above the resin molded body sample using ultrasonic welding tester (Branson 2000xdt) under welding conditions of pressure 400 kPa and amplitude 100%. Welding was performed. Thereafter, a load was applied from the lower surface of the molded body sample, and the maximum stress until the resin molded body sample was detached from the aluminum alloy molded sample was defined as the welding strength.

<Example 1>
70 parts by mass of a thermoplastic polyimide resin having a repeating structural unit represented by the chemical formula (3) (manufactured by Mitsui Chemicals, Inc., trade name: Aurum (registered trademark) PD450) and fluororesin (Asahi Glass Fluoropolymers, Inc.) , Trade name Aflon PTFE L-180) 10 parts by mass was dry blended using a mixer. Thereafter, using a twin screw extruder, 20 parts by mass of graphite (manufactured by Nippon Graphite Co., Ltd., trade name: ACP, average particle size: 15 μm) is supplied from the side feeder, extruded at 400 ° C. to 420 ° C. and granulated to obtain pellets. It was. The obtained pellets were supplied to an injection molding machine (cylinder temperature of 400 ° C. to 420 ° C., injection pressure of 230 MPa, mold temperature of 190 ° C.), and the test pieces defined in each test method described above were molded.

<Comparative Examples 1-4>
A test piece was molded in the same manner as in Example 1 except that the compositions of the thermoplastic polyimide resin, the fluororesin, and the graphite were changed to the ratios shown in Table 1.

<Comparative Examples 5 and 6>
Graphite was changed to PAN-based carbon fiber (trade name Besfight HTA-C6-UH, manufactured by Toho Tenax Co., Ltd.), and the ratios of thermoplastic polyimide resin, fluororesin, and PAN-based carbon fiber are shown in Table 1. A test piece was molded in the same manner as in Example 1 except that.

  As shown in Table 1, the thermoplastic polyimide resin, fluororesin, and graphite are included, and at least one of the linear expansion coefficient and MFR of the thermoplastic polyimide resin composition is a specified range of the thermoplastic polyimide resin composition according to the present disclosure. It can be seen that the comparative example exceeding 10 has poor welding strength. Moreover, it turns out that the welding strength is inferior in the comparative example using PAN-based carbon fiber instead of graphite in the thermoplastic polyimide resin composition according to the present disclosure.

Claims (7)

Thermoplastic polyimide resin include fluororesin, and the graphite, and a MFR of 3 g / 10min or higher, the thermoplastic polyimide resin linear expansion coefficient in the TD direction is ^{10 × 10 -6 / K~40 × 10} -6 / K Composition.   The thermoplastic polyimide resin composition according to claim 1, comprising 40 to 80 parts by mass of the thermoplastic polyimide resin, 5 to 30 parts by mass of the fluororesin, and 15 to 30 parts by mass of the graphite. .   The thermoplastic polyimide resin composition according to claim 1 or 2, wherein the graphite has an average particle size of 5 µm to 20 µm.   The ultrasonic welded product of the resin molded object of the thermoplastic polyimide resin composition of any one of Claims 1-3, and aluminum or aluminum alloy.   An office equipment part comprising the ultrasonic weld according to claim 4.   An automobile part provided with the ultrasonic weld according to claim 4.   An aircraft part comprising the ultrasonic weld according to claim 4.