JP7742744B2 - Resin composition, molded article, and method for producing molded article - Google Patents

Description

The present invention relates to a resin composition, a molded article, and a method for producing a molded article. In particular, it relates to a resin composition containing a polyamide resin and a maleic anhydride-modified polyphenylene ether resin.

Polyphenylene ether resins are widely used because they have excellent mechanical properties, electrical properties and heat resistance, and also have excellent dimensional stability, but when used alone, they are poor in moldability, for example.
Therefore, in order to improve moldability, various techniques have been proposed for blending polyphenylene ether resins with polyamide resins to produce polymer alloys, which are used in a variety of applications as metal substitutes for electrical and electronic components, automotive parts, and the like.

For example, Patent Document 1 discloses a resin composition comprising (a) a polyamide, (b) a polyamide having a higher amide group concentration than the (a) polyamide, (c) a polyphenylene ether-based resin, and (d) a compatibilizer for the (a) polyamide, the (b) polyamide, and the (c) polyphenylene ether-based resin, wherein the morphology of the resin composition is characterized in that the (a) polyamide forms a continuous phase, the (b) polyamide, and the (c) polyphenylene ether-based resin form dispersed phases, and 50% or more of the dispersed phases formed by the (c) polyphenylene ether-based resin have a particle size of 3.0 μm or less, and 60% or more of the dispersed phases formed by the (c) polyphenylene ether-based resin are surrounded by the continuous phase formed by the (a) polyamide.

Japanese Patent Application Laid-Open No. 2020-139110

As mentioned above, polymer alloys in which polyphenylene ether resins are blended with polyamide resins are known, but with recent technological advances, new resin compositions with high mechanical strength and low water absorption are required.
Furthermore, if it becomes possible to sufficiently crystallize a resin composition containing a xylylenediamine-based polyamide resin and a polyphenylene ether resin, which have excellent performance properties, even at a low mold temperature during molding, and to obtain molded products with good appearance, further expansion of applications can be expected.
The present invention aims to solve such problems, and to provide a resin composition that can give molded articles that have low water absorption, good appearance, high strength, and high rigidity even when the mold temperature is 100°C or lower, as well as a molded article formed from the resin composition and a method for producing the resin composition.

In light of the above-mentioned problems, the present inventors have conducted research and found that the above-mentioned problems can be solved by using a xylylenediamine-based polyamide resin, polyamide 6, and polyamide 66 as polyamide resins and adjusting the compounding ratio of the polyamide resin and the maleic anhydride-modified polyphenylene ether resin.
Specifically, the above problems were solved by the following means.
<1> A resin composition comprising a polyamide resin and a maleic anhydride-modified polyphenylene ether resin, wherein the polyamide resin comprises polyamide 6, polyamide 66, and a xylylene diamine-based polyamide resin, wherein the xylylene diamine-based polyamide resin comprises diamine-derived structural units and dicarboxylic acid-derived structural units, wherein 70 mol % or more of the diamine-derived structural units are derived from xylylene diamine and more than 50 mol % of the dicarboxylic acid-derived structural units are derived from sebacic acid, and wherein the mass ratio of the polyamide resin to the maleic anhydride-modified polyphenylene ether resin is 80/20 to 60/40.
<2> The resin composition according to <1>, wherein the xylylenediamine contains 50 to 100 mol% of metaxylylenediamine and 0 to 50 mol% of paraxylylenediamine.
<3> Further, the resin composition according to <1> or <2>, further comprising 40 to 200 parts by mass of reinforcing fibers per 100 parts by mass of the thermoplastic resin component containing the polyamide resin and the maleic anhydride-modified polyphenylene ether resin.
<4> The resin composition according to any one of <1> to <3>, wherein the crystallization peak heat quantity of a molded product at a mold temperature of 90 ° C., measured according to differential scanning calorimetry, is 1.0 J / g or less.
<5> The resin composition according to any one of <1> to <4>, which is for a housing of a fishing reel.
<6> A molded article formed from the resin composition according to any one of <1> to <5>.
<7> The molded article according to <6>, which is a housing for a fishing reel.
<8> A method for producing a molded article, comprising molding the resin composition according to any one of <1> to <5> using a mold having a mold temperature of 100°C or less.

The present invention makes it possible to provide a resin composition that can be used at a mold temperature of 100°C or less to produce molded articles that have low water absorption, good appearance, and high strength and rigidity, as well as a molded article formed from the resin composition and a method for producing the resin composition.

Hereinafter, an embodiment of the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only this embodiment.
In this specification, the word "to" is used to mean that the numerical values before and after it are included as the lower limit and upper limit.
In this specification, various physical properties and characteristic values are those at 23° C. unless otherwise specified.
If the standards shown in this specification differ depending on the year and the measurement method, etc., they will be based on the standards as of January 1, 2021, unless otherwise stated.

The resin composition of the present embodiment comprises a polyamide resin and a maleic anhydride-modified polyphenylene ether resin, the polyamide resin comprising polyamide 6, polyamide 66, and a xylylene diamine-based polyamide resin, the xylylene diamine-based polyamide resin comprising diamine-derived structural units and dicarboxylic acid-derived structural units, 70 mol % or more of the diamine-derived structural units being derived from xylylene diamine, and more than 50 mol % of the dicarboxylic acid-derived structural units being derived from sebacic acid, and the mass ratio of the polyamide resin to the maleic anhydride-modified polyphenylene ether resin being 80/20 to 60/40.
By using such a composition, it is possible to obtain a resin composition which has low water absorption, good appearance, and can be used to produce molded articles with high strength and high rigidity at a mold temperature of 100° C. or less.
Maleic anhydride-modified polyphenylene ether resins are known to have low water absorption. However, when only maleic anhydride-modified polyphenylene ether resins are used, the mechanical properties are poor and the appearance of the molded product is poor. Therefore, it has been considered to blend a xylylenediamine-based polyamide resin with the maleic anhydride-modified polyphenylene ether resin.
As a xylylenediamine-based polyamide resin with low water absorption, one in which more than 50 mol% of the dicarboxylic acid-derived structural units are derived from sebacic acid is considered. Such polyamide resins have a lower water absorption than, for example, xylylenediamine-based polyamide resins (e.g., MXD6) in which the dicarboxylic acid component is derived from adipic acid. However, xylylenediamine-based polyamide resins in which more than 50 mol% of the dicarboxylic acid-derived structural units are derived from sebacic acid have the problem that the mold temperature during molding is relatively high. For example, if the mold temperature is 100°C or less, many resins do not crystallize sufficiently.
Therefore, in order to promote crystallization, it has been considered to blend polyamide 66. However, molded articles obtained by blending polyamide 66 have poor appearance. Under these circumstances, the present inventors have succeeded in obtaining a resin composition that further blends polyamide 6 to improve appearance, and that can produce molded articles with low water absorption, good appearance, high strength, and high rigidity at a mold temperature of 100°C or less.

<Polyamide resin>
The polyamide resin used in this embodiment includes polyamide 6, polyamide 66, and xylylenediamine-based polyamide resin.
In this embodiment, by blending polyamide 6, the appearance of the resulting molded article can be improved.
Here, polyamide 6 is a polyamide obtained by ring-opening polycondensation of ε-caprolactam, but may contain other monomer units within the scope of the present invention. For example, 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less of the monomer units constituting polyamide 6 may be monomer units derived from other monomers.

Furthermore, in this embodiment, by blending polyamide 66, the crystallization peak heat quantity of the resin composition at 90°C can be reduced, and even if the mold temperature during molding of the resin composition is low, the crystallization of the thermoplastic resin component can be sufficiently advanced.
Here, polyamide 66 is a polyamide obtained by polycondensation of adipic acid and hexamethylenediamine, but may contain other monomer units within the scope of the present invention. For example, 5% by mass or less, preferably 3% by mass or less, and more preferably 1% by mass or less of the monomer units constituting polyamide 66 may be monomer units derived from other monomers.

Furthermore, in this embodiment, by using a xylylenediamine-based polyamide resin (hereinafter sometimes referred to as a "specific xylylenediamine-based polyamide resin") that contains diamine-derived structural units and dicarboxylic acid-derived structural units, in which 70 mol % or more of the diamine-derived structural units are derived from xylylenediamine and more than 50 mol % of the dicarboxylic acid-derived structural units are derived from sebacic acid, the water absorption rate of the resulting molded product can be reduced and good molding can be achieved even at a low mold temperature.

In the specific xylylenediamine-based polyamide resin, preferably 80 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and even more preferably 99 mol % or more of the diamine-derived structural units are derived from xylylenediamine.
The xylylenediamine preferably contains metaxylylenediamine and/or paraxylylenediamine, more preferably contains 50 to 100 mol % of metaxylylenediamine and 0 to 50 mol % of paraxylylenediamine, and even more preferably contains 50 to 90 mol % of metaxylylenediamine and 10 to 50 mol % of paraxylylenediamine.
The total amount of metaxylylenediamine and/or paraxylylenediamine in the xylylenediamine is preferably 95 to 100 mol %, more preferably 99 to 100 mol %.

Diamines other than xylylenediamine that can be used as raw diamine components for xylylenediamine-based polyamide resins include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethylhexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine; 1,3-bis(aminomethyl)silane; Examples include alicyclic diamines such as cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane; and diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene. These can be used alone or in combination of two or more.

In the xylylenediamine-based polyamide resin used in this embodiment, preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 99 mol% or more of the dicarboxylic acid-derived structural units are derived from sebacic acid.

Examples of the dicarboxylic acid component other than sebacic acid include linear aliphatic dicarboxylic acids other than sebacic acid, such as adipic acid and dodecanedioic acid; phthalic acid compounds, such as isophthalic acid, terephthalic acid, and orthophthalic acid; and isomers of naphthalenedicarboxylic acid, such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. These can be used alone or in combination of two or more.

The xylylenediamine-based polyamide resin in this embodiment is primarily composed of diamine-derived structural units and dicarboxylic acid-derived structural units, but does not completely exclude other structural units. Needless to say, it may also contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, "primary component" refers to the structural units that, among the structural units constituting the xylylenediamine-based polyamide resin, the total number of diamine-derived structural units and dicarboxylic acid-derived structural units is the largest among all structural units. In this embodiment, the total of diamine-derived structural units and dicarboxylic acid-derived structural units in the xylylenediamine-based polyamide resin preferably accounts for 90% or more of all structural units, more preferably 95% or more, and even more preferably 98% or more.

In the resin composition of this embodiment, the mass ratio of polyamide 6 to polyamide 66 (polyamide 6/polyamide 66) is preferably 0.5 or greater, more preferably 1.5 or greater, even more preferably 2.0 or greater, even more preferably 3.0 or greater, and may be 4.0 or greater. By setting the mass ratio at or above the lower limit, the appearance of the resulting molded article tends to be further improved. Furthermore, the mass ratio of polyamide 6 to polyamide 66 (polyamide 6/polyamide 66) is preferably 12.0 or less, more preferably 9.0 or less, even more preferably 8.0 or less, even more preferably 7.0 or less, and may be 6.0 or less. By setting the mass ratio at or below the upper limit, the water absorption of the resulting molded article tends to be lower.

In the resin composition of this embodiment, the mass ratio of the specific xylylenediamine-based polyamide resin to polyamide 66 (specific xylylenediamine-based polyamide resin/polyamide 66) is preferably 0.3 or more, more preferably 1.0 or more, even more preferably 2.0 or more, and even more preferably 2.5 or more. By making it equal to or greater than the lower limit, the appearance of the obtained molded article tends to be improved and the water absorption rate tends to be lower. Furthermore, the mass ratio of the specific xylylenediamine-based polyamide resin to polyamide 66 (specific xylylenediamine-based polyamide resin/polyamide 66) is preferably 7.0 or less, more preferably 6.0 or less, even more preferably 5.0 or less, and may be 4.0 or less. By making it equal to or less than the upper limit, the crystallization of the molded article tends to be faster.
When two or more specific xylylenediamine-based polyamide resins are contained, the total amount thereof is preferably within the above range.

In the resin composition of this embodiment, the mass ratio of the specific xylylenediamine-based polyamide resin to polyamide 6 (specific xylylenediamine-based polyamide resin/polyamide 6) is preferably 0.2 or more, more preferably 0.4 or more, and even more preferably 0.5 or more. By making the mass ratio equal to or greater than the lower limit, the water absorption rate of the obtained molded article tends to be low. Furthermore, the mass ratio of the specific xylylenediamine-based polyamide resin to polyamide 6 (specific xylylenediamine-based polyamide resin/polyamide 6) is preferably 2.0 or less, more preferably 1.5 or less, even more preferably 1.0 or less, and even more preferably 0.8 or less. By making the mass ratio equal to or less than the upper limit, the appearance of the obtained molded article tends to be improved.
When two or more specific xylylenediamine-based polyamide resins are contained, the total amount thereof is preferably within the above range.

The resin composition of the present embodiment may or may not contain a polyamide resin other than polyamide 6, polyamide 66, and the xylylenediamine-based polyamide resin. The other polyamide resin may be an aliphatic polyamide resin or a semi-aromatic polyamide resin, and an aliphatic polyamide resin is preferred.
Examples of aliphatic polyamide resins include polyamide 10, polyamide 610, polyamide 11, polyamide 12, and the like.
Examples of semi-aromatic polyamide resins include polyamide 6T, polyamide 9T, polyamide 10T, polyamide 6I, polyamide 9I, polyamide 6T/6I, and polyamide 9T/9I.
The content of the other polyamide resin in the resin composition of this embodiment is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 1 part by mass or less, based on 100 parts by mass of the entire polyamide resin. The lower limit of the content of the other polyamide resin may be 0 part by mass.

The resin composition of this embodiment preferably contains polyamide resin in a total amount of 25% by mass or more of the resin composition, more preferably 28% by mass or more, and even more preferably 30% by mass or more. The upper limit of the polyamide resin content is preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 37% by mass or less.

<Maleic anhydride modified polyphenylene ether resin>
The resin composition of this embodiment contains the maleic anhydride-modified polyphenylene ether resin in a mass ratio of the polyamide resin to the maleic anhydride-modified polyphenylene ether resin of 80/20 to 60/40. By blending the maleic anhydride-modified polyphenylene ether resin, the water absorption rate of the resulting molded article can be reduced.
The maleic anhydride-modified polyphenylene ether resin is a polyphenylene ether resin modified with maleic anhydride.
In the present embodiment, the amount of maleic anhydride in the maleic anhydride-modified polyphenylene ether resin is preferably 0.01 to 1.0 mass %, more preferably 0.3 to 0.7 mass %, calculated as the amount of maleic acid. By adjusting the amount within this range, the resulting molded article can achieve high mechanical strength.
Here, the amount of maleic anhydride in the maleic anhydride-modified polyphenylene ether resin refers to the mass of the maleic anhydride used to modify the polyphenylene ether resin and which reacts with the polyphenylene ether resin, converted into the amount of maleic acid.

Examples of polyphenylene ether resins include poly(2,6-dimethyl-1,4-phenylene) ether, poly(2,6-diethyl-1,4-phenylene) ether, poly(2,6-dipropyl-1,4-phenylene) ether, poly(2-methyl-6-ethyl-1,4-phenylene) ether, and poly(2-methyl-6-propyl-1,4-phenylene) ether, with poly(2,6-dimethyl-1,4-phenylene) ether being particularly preferred.
The polyphenylene ether resin preferably has an intrinsic viscosity of 0.2 to 0.6 dL/g, more preferably 0.3 to 0.5 dL/g, measured in chloroform at 30°C. By adjusting the intrinsic viscosity to 0.2 dL/g or more, impact resistance tends to be further improved, while by adjusting the intrinsic viscosity to 0.6 dL/g or less, moldability and appearance tend to be further improved. Note that the intrinsic viscosity within the above range may be adjusted by using two or more polyphenylene ether resins having different intrinsic viscosities in combination.

In the resin composition of this embodiment, the polyamide resin and the maleic anhydride-modified polyphenylene ether resin are blended so that the mass ratio of the polyamide resin to the maleic anhydride-modified polyphenylene ether resin is 80/20 to 60/40. In this embodiment, the mass ratio of the polyamide resin to the maleic anhydride-modified polyphenylene ether resin is preferably 80/20 to 65/35, more preferably 80/20 to 70/30, and even more preferably 78/22 to 72/28.
The resin composition of the present embodiment may contain only one maleic anhydride-modified polyphenylene ether resin, or may contain two or more maleic anhydride-modified polyphenylene ether resins. When two or more maleic anhydride-modified polyphenylene ether resins are contained, the total amount is preferably in the above range.

In the resin composition of the present embodiment, the total of the polyamide resin and the maleic anhydride-modified polyphenylene ether resin preferably accounts for 90% by mass or more of the thermoplastic resin components contained in the resin composition, more preferably 95% by mass or more, and even more preferably 99% by mass or more.
Furthermore, the total proportion of the thermoplastic resin components (polyamide resin, maleic anhydride-modified polyphenylene ether resin, and other resins blended as necessary) in the resin composition is preferably 35% by mass or more, and more preferably 40% by mass or more, and is preferably 75% by mass or less, more preferably 65% by mass or less, and even more preferably 55% by mass or less.

<Reinforced fiber>
The resin composition of the present embodiment preferably contains reinforcing fibers.
The reinforcing fibers may be organic or inorganic, with inorganic reinforcing fibers being preferred.
The reinforcing fibers are preferably plant fibers, carbon fibers, glass fibers, alumina fibers, boron fibers, ceramic fibers, aramid fibers, etc., more preferably selected from carbon fibers and glass fibers, and even more preferably glass fibers.

Glass fibers are typically obtained by melt spinning commonly available glass such as E-glass, C-glass, A-glass, S-glass, and alkali-resistant glass, but any material that can be made into glass fiber can be used, and there are no particular limitations. In the present invention, it is preferable to use E-glass.

The glass fiber is preferably surface-treated with a surface treatment agent such as a silane coupling agent, such as gamma-methacryloxypropyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, or gamma-aminopropyltriethoxysilane. The amount of surface treatment agent attached is preferably 0.01 to 1% by mass of the glass fiber. If necessary, the glass fiber may also be surface-treated with a lubricant such as a fatty acid amide compound or silicone oil, an antistatic agent such as a quaternary ammonium salt, a resin with film-forming properties such as an epoxy resin or urethane resin, or a mixture of a resin with film-forming properties with a heat stabilizer or flame retardant.

The glass fibers used in the resin composition of this embodiment are commercially available. Examples of commercially available products include T-275H, T-286H, T-756H, T-289, T-289DE, T-289H, and T-296GH manufactured by Nippon Electric Glass (NEG); DEFT2A manufactured by Owens Corning; HP3540 manufactured by PPG; CSG3PA-810S and CSG3PA-820 manufactured by Nitto Boseki Co., Ltd.; and EFH50-31 manufactured by Central Glass Fiber Co., Ltd. (all trade names).

The cross section of the reinforcing fiber may be either circular or non-circular (e.g., elliptical, oval, rectangular, rectangular with semicircular sides joined to both short sides, cocoon-shaped, etc.), and is preferably circular. When a reinforcing fiber having a circular cross section is used in the present invention, the effect of improving flame retardancy and mechanical strength is particularly remarkable.
The circular shape here includes not only a perfect circle in the geometrical sense, but also what is normally called a circle in the technical field of the present invention.
Examples of reinforcing fibers having a non-circular cross section include the flat reinforcing fibers described in paragraphs 0048 to 0052 of JP 2012-214819 A, the contents of which are incorporated herein by reference.

The reinforcing fibers in the resin composition of this embodiment preferably have a number average fiber length (cut length) of 100 μm or more, more preferably 150 μm or more, and even more preferably 200 μm or more. The upper limit is preferably 10 mm or less, more preferably 8 mm or less, and even more preferably 5 mm or less.

The number average fiber diameter of the reinforcing fibers used in the resin composition of this embodiment is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 5 μm or more. The upper limit is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less.

The content of the reinforcing fiber (preferably glass fiber) in the resin composition of this embodiment is preferably 40 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 100 parts by mass or more, even more preferably 110 parts by mass or more, and even more preferably 120 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin component. The upper limit of the content of the reinforcing fiber is preferably 200 parts by mass or less, more preferably 180 parts by mass or less, more preferably 150 parts by mass or less, or even 130 parts by mass or less, relative to 100 parts by mass of the total thermoplastic resin component.
The content of reinforcing fibers (preferably glass fibers) in the resin composition of this embodiment is preferably 25% by mass or more of the resin composition, more preferably 35% by mass or more, and even more preferably 45% by mass or more. The upper limit of the content is preferably 65% by mass or less, more preferably 50% by mass or less. By making the content equal to or greater than the lower limit, mechanical strength tends to be significantly improved. On the other hand, by making the amount of reinforcing fibers equal to or less than the upper limit, moldability tends to be further improved.
The molded article of the present invention may contain only one type of reinforcing fiber or two or more types. When two or more types are contained, the total amount is preferably within the above range.

<Nucleating agent>
The resin composition of the present embodiment may contain a nucleating agent to adjust the crystallization rate. The type of nucleating agent is not particularly limited, but talc, boron nitride, mica, kaolin, barium sulfate, silicon nitride, and molybdenum disulfide are preferred, talc and boron nitride are more preferred, and talc is even more preferred.
When the resin composition of the present embodiment contains a nucleating agent, the content thereof is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin component. The upper limit of the content is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, even more preferably 6 parts by mass or less, and even more preferably 4 parts by mass or less.
The resin composition of the present embodiment may contain only one type of nucleating agent, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

<Release Agent>
The resin composition of the present embodiment may contain a release agent.
Examples of the release agent include aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic carboxylic acid amides, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, polysiloxane-based silicone oils, and waxes.
The wax is preferably a polyolefin wax, a ketone wax, an amide wax, an ester wax, or a paraffin wax, and more preferably a ketone wax.
For details of the release agent, please refer to the descriptions in paragraphs 0034 to 0039 of JP-A-2017-115093 and paragraphs 0068 to 0091 of JP-A-2018-184575, the contents of which are incorporated herein by reference.

When the resin composition of the present embodiment contains a release agent, the content thereof is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.2 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin component, and the content is preferably 5.0 parts by mass or less, more preferably 4.0 parts by mass or less, and even more preferably 3.0 parts by mass or less.
The resin composition of the present embodiment may contain only one type of release agent, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

<Coloring Agent>
The resin composition of the present embodiment may contain a colorant.
Examples of colorants include inorganic pigments (black pigments such as carbon black, red pigments such as iron oxide red, orange pigments such as molybdate orange, and white pigments such as titanium oxide), and organic pigments (yellow pigments, orange pigments, red pigments, blue pigments, green pigments, etc.).
The content of the colorant is preferably 0.01 to 2% by mass of the resin composition. The resin composition may contain one type of colorant or two or more types. When two or more types are contained, the total amount is preferably in the above range.

<Other ingredients>
The resin composition of this embodiment may contain other components within the scope of this embodiment. Examples of such additives include light stabilizers, antioxidants, heat stabilizers, flame retardants, flame retardant aids, ultraviolet absorbers, fluorescent brighteners, anti-dripping agents, antistatic agents, anti-fogging agents, anti-blocking agents, flow improvers, weather resistance improvers, light resistance improvers, plasticizers, dispersants, and antibacterial agents. These components may be used alone or in combination of two or more. The content of these components is preferably 5% by mass or less of the resin composition.
In the resin composition of this embodiment, the contents of the polyamide resin, maleic anhydride-modified polyphenylene ether resin, and other components blended as necessary are adjusted so that the total of each component is 100% by mass. In the resin composition of this embodiment, the total of the polyamide resin, maleic anhydride-modified polyphenylene ether resin, reinforcing fiber, nucleating agent, release agent, and colorant preferably accounts for 90% by mass or more of the resin composition, more preferably 95% by mass or more, and even more preferably 98% by mass or more.

<Physical Properties of Resin Composition>
The resin composition of the present embodiment preferably exhibits excellent crystallization when molded at a low mold temperature.
Specifically, the crystallization peak heat quantity of a molded article of the resin composition of this embodiment, measured by differential scanning calorimetry at a mold temperature of 90°C, is preferably 1.5 J/g or less, more preferably 1.0 J/g or less, and even more preferably less than 1.0 J/g. Such a low crystallization peak heat quantity can be achieved by blending polyamide 66 or the like.
In this embodiment, it is preferable that the bending properties are excellent. Such excellent bending properties are achieved by using a xylylenediamine-based polyamide resin.
Specifically, the resin composition of this embodiment, when molded to a thickness of 4 mm, preferably has a bending strength of 330 MPa or more, more preferably 335 MPa or more, and even more preferably 348 MPa or more, in accordance with ISO 178. There is no particular upper limit to the bending strength, but a practical upper limit is, for example, 500 MPa or less, or even 450 MPa or less.
Furthermore, the resin composition of this embodiment, when molded to a thickness of 4 mm, preferably has a flexural modulus of 10.0 GPa or more, more preferably 14.0 GPa or more, and even more preferably 16.0 GPa or more, in accordance with ISO 178. There is no particular upper limit to the flexural modulus, but a flexural modulus of 40.0 GPa or less is practical, and even a flexural modulus of 35.0 GPa or less will fully satisfy the required performance.

The resin composition of this embodiment preferably has excellent impact resistance. Specifically, when the resin composition of this embodiment is molded into an ISO test piece with a thickness of 4 mm, the notched Charpy impact strength according to ISO-179 is preferably 12 kJ/ ^m² or more, and more preferably 13 kJ/ ^m² or more. There is no particular upper limit for the notched Charpy impact strength, but a value of 25 kJ/ ^m² or less is practical, and even a value of 22 kJ/ ^m² or less will fully satisfy the required performance.

The resin composition of this embodiment preferably has a low saturated water absorption. For example, the saturated water absorption when immersed in 70°C warm water is preferably 3.0% or less, more preferably 2.5% or less, even more preferably 2.4% or less, even more preferably 2.3% or less, and even more preferably 2.2% or less. The ideal lower limit is 0%, but 0.1% or more is practical. Such a low saturated water absorption can be achieved by using a maleic anhydride-modified polyphenylene ether resin or a xylylene diamine-based polyamide resin.
The crystallization peak, flexural strength, flexural modulus, notched Charpy impact strength, and saturated water absorption are measured according to the descriptions in the examples below.

<Method of producing resin composition>
The resin composition of this embodiment can be produced by a known method for producing a thermoplastic resin composition.
In one embodiment of the method for producing the resin composition of the present embodiment, a polyamide resin, a maleic anhydride-modified polyphenylene ether resin, and other components that are optionally blended are preferably blended and kneaded together. An example of such a resin composition is pellets.
Specifically, a polyamide resin, a maleic anhydride-modified polyphenylene ether resin, and other components added as needed may be premixed using various mixers such as a tumbler or a Henschel mixer, and then melt-kneaded using a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, or a kneader. The reinforcing filler is preferably fed midway through the extruder to prevent it from being crushed during kneading. Alternatively, two or more components selected from each component may be premixed and kneaded.

<Molded product>
The molded article of this embodiment is formed from the resin composition of this embodiment.
The method for producing the molded article of this embodiment is not particularly limited.
For example, the molded product of this embodiment may be obtained by melt-kneading the components and then directly molding them using various molding methods, or by melt-kneading the components and pelletizing them, then melting them again and molding them using various molding methods.

The method for molding the molded article is not particularly limited, and any conventionally known molding method can be used, such as injection molding, injection compression molding, extrusion molding, profile extrusion, transfer molding, blow molding, gas-assisted blow molding, blow molding, extrusion blow molding, IMC (in-mold coating molding), rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, and pressure molding.
The resin composition of this embodiment is preferably used in a molding method using a mold, and particularly preferably used in a low-temperature mold molding method. An example of a method for producing a molded article of this embodiment is a method for producing a molded article that includes molding the resin composition of this embodiment using a mold at a mold temperature of 100°C or less (preferably 80 to 100°C).

The shape of the molded product of this embodiment is not particularly limited and can be selected appropriately depending on the application and purpose of the molded product. Examples include plate-like, plate-like, rod-like, sheet-like, film-like, cylindrical, ring-like, circular, elliptical, gear-like, polygonal, irregularly shaped, hollow, frame-like, box-like, and panel-like shapes.

The application field of the molded product of this embodiment is not particularly limited, and it can be widely used in transportation equipment parts such as automobiles, general machine parts, precision machine parts, electronic and electrical equipment parts, office automation equipment parts, building materials and housing-related parts, medical devices, leisure and sporting goods, play equipment, medical supplies, daily necessities such as food packaging films, defense and aerospace products, etc.
In particular, the molded article of this embodiment has low water absorption and excellent mechanical strength, making it suitable for use as a housing for a fishing reel.

The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, processing details, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.
If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

1. Raw material polyamide resin (PA)
<Synthesis of MP10>
Sebacic acid (manufactured by CASDA) was placed in a jacketed reactor equipped with a stirrer, a partial condenser, a thermometer, a dropping tank, and a nitrogen gas inlet tube, and the inside was thoroughly purged with nitrogen. After heating and melting at 170°C, a mixed amine of metaxylylenediamine and paraxylylenediamine (molar ratio: 70:30) (manufactured by Mitsubishi Gas Chemical Company, Inc., MPXDA) was gradually added dropwise to the contents while stirring, so that the molar ratio to sebacic acid became 1:1, and the temperature was raised to 240°C. After completion of the dropwise addition, the temperature was raised to 260°C and continued for 20 minutes. Thereafter, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After completion of the reaction, a pressure of 0.2 MPa was applied to the reactor with nitrogen gas, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization vessel. After water cooling, it was pelletized using a pelletizer.

<Synthesis of PXD10>
Sebacic acid (manufactured by CASDA) was placed in a jacketed reactor equipped with a stirrer, a partial condenser, a thermometer, a dropping tank, and a nitrogen gas inlet tube, and the contents were thoroughly purged with nitrogen. After heating and melting at 170°C, paraxylylenediamine (manufactured by Showa Denko, PXDA) was gradually added dropwise to a molar ratio of 1:1 to sebacic acid while stirring the contents, and the temperature was raised to 290°C. After completion of the dropwise addition, the temperature was raised to 300°C and continued for 20 minutes. Thereafter, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued for 20 minutes. After completion of the reaction, a pressure of 0.2 MPa was applied to the reactor with nitrogen gas, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization vessel. After water cooling, it was pelletized using a pelletizer.

<Synthesis of MXD10>
Sebacic acid (manufactured by CASDA) was placed in a jacketed reactor equipped with a stirrer, a partial condenser, a thermometer, a dropping tank, and a nitrogen gas inlet tube, and the contents were thoroughly purged with nitrogen. After heating and melting at 170°C, metaxylylenediamine (manufactured by Mitsubishi Gas Chemical Company, Inc., MXDA) was gradually added dropwise to the contents while stirring, so that the molar ratio to sebacic acid was 1:1, and the temperature was raised to 240°C. After completion of the dropwise addition, the temperature was raised to 260°C and continued for 20 minutes. Thereafter, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After completion of the reaction, a pressure of 0.2 MPa was applied to the reactor with nitrogen gas, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization vessel. After water cooling, it was pelletized using a pelletizer.

MXD6: Polyamide obtained by polycondensation of metaxylylenediamine and adipic acid, manufactured by Mitsubishi Gas Chemical Company, Inc., product number: #6000
PA66: Toray Industries, Inc., CM3001-N
PA6: 1013B, manufactured by Ube Industries, Ltd.

Maleic anhydride modified polyphenylene ether resin (PPE-1)
100 parts by mass of powdered unmodified polyphenylene ether resin ("Iupiace PX-100L" manufactured by Mitsubishi Engineering-Plastics Corporation), 0.5 parts by mass of maleic anhydride (first-grade reagent), and 6 parts by mass of a styrene-based resin ("Septon 8006" manufactured by Kuraray Co., Ltd., SEBS, styrene ratio 33% by mass) were thoroughly mixed in a super mixer, and the resulting mixture was melt-kneaded in a twin-screw extruder ("TEX30XCT" manufactured by The Japan Steel Works, Ltd.) and pelletized to obtain a modified polyphenylene ether resin (PPE-1) containing 6% by mass of SEBS.

<Nucleating agent>
Talc: Hayashi Kasei Micron White 5000S

<Reinforced fiber>
GF: Circular cross-section glass fiber, manufactured by Nippon Electric Glass Co., Ltd., T-275H, E-glass, chopped strand, number average fiber diameter 10 μm

<Release Agent>
Light Amide WH-255: Kyoeisha Chemical Co., Ltd., higher fatty acid amide

<Black colorant>
Carbon black: carbon black masterbatch, manufactured by Mitsubishi Chemical, carbon black #45 (furnace black, DBP absorption capacity 53 cm ³ /100 g)

2. Examples 1 to 10 and Comparative Examples 1 to 6
<Compound>
Each component was weighed (the amount of each component is shown in parts by mass) to obtain the composition shown in Tables 2 to 4 below, and then dry-blended. The components were then fed into a twin-screw extruder (Shibaura Machine Co., Ltd., TEM26SS) from the base of the screw using a twin-screw cassette weighing feeder (Kubota, CE-W-1-MP). Glass fiber was fed into the twin-screw extruder from the side using a vibrating cassette weighing feeder (Kubota, CE-V-1B-MP), and melt-kneaded with the thermoplastic resin components to obtain a resin composition (pellets). The extruder temperature was set to 280°C. For Example 9, the temperature was set to 300°C.

<Flexural strength and flexural modulus>
The pellets obtained above were dried at 120°C for 4 hours, and then injection-molded into ISO tensile test specimens (4 mm thick) using an injection molding machine (NEX140III, manufactured by Nissei Plastic Industrial Co., Ltd.) at a cylinder temperature of 280°C and a mold temperature of 130°C. The cylinder temperature for Example 9 was 300°C.
The flexural strength (unit: MPa) and flexural modulus (unit: GPa) were measured using the above ISO tensile test specimens (4 mm thick) in accordance with ISO 178. The results are shown in Tables 2 to 4.

<Notched Charpy impact strength>
The notched Charpy impact strength (unit: kJ/ ^m2 ) was measured using the above ISO tensile test pieces (4 mm thick) with a 1J hammer in an environment of 23°C and 50% humidity in accordance with ISO 179-1 and 2. The results are shown in Tables 2 to 4.

<Saturated water absorption rate (in 70℃ warm water)>
The pellets obtained above were dried at 120°C for 4 hours, and then plate test pieces of 100 x 100 mm x 2 mm thick were produced using an injection molding machine (manufactured by Nissei Plastic Industrial Co., Ltd., "NEX80") under conditions of a cylinder temperature of 280°C and a mold temperature of 90°C. The cylinder temperature was 300°C for Example 9. The produced plate was immersed in 70°C warm water, and the immersion was terminated when the mass change was saturated. The mass change rate relative to the initial mass was calculated as the saturated water absorption.
(% saturated water absorption) = {(mass after saturated water absorption) - (initial mass)} / (initial mass) x 100

<Appearance (mold temperature 90°C)>
The pellets were dried at 120°C for 3 hours and then injection molded into flat plates of 60 x 60 x 1 mmt using an injection molding machine (NEX140III, manufactured by Nissei Plastic Industrial Co., Ltd.) at a cylinder temperature of 280°C and a mold temperature of 90°C. The cylinder temperature for Example 9 was 300°C. Five experts evaluated the resulting molded products and rated them by majority vote as follows:
A: There is no lifting of reinforcing fibers on the surface of the molded article, and the surface is glossy.
B: There is more lifting than A, but less lifting than C. For example, there is lifting of reinforcing fibers on part of the surface of the molded article.
C: Reinforcing fibers are present on most of the surface of the molded article.

<DSC crystallization peak heat quantity (J/g) of molded product>
The DSC crystallization peak heat quantity (J/g) of a molded product of 60 mm x 60 mm x 1 mm thick at a mold temperature of 90°C was measured as follows.
The molded product was crushed and placed in the measuring pan of a differential scanning calorimeter, and heated to 300°C at a rate of 10°C/min in a nitrogen atmosphere, and the crystallization peak heat quantity (J/g) during the heating process was measured.
The differential scanning calorimeter used was a DSC7020 manufactured by Seiko Instruments Inc.

<Overall rating>
The overall evaluation was based on the following criteria.

As is clear from the above results, the present invention has produced a resin composition that, at a mold temperature of 100°C or less, can produce molded articles with low water absorption, good appearance, high strength, and high rigidity.

Claims (8)

It contains a polyamide resin and a maleic anhydride-modified polyphenylene ether resin,
the polyamide resin contains polyamide 6, polyamide 66, and a xylylenediamine-based polyamide resin;
the xylylenediamine-based polyamide resin contains diamine-derived structural units and dicarboxylic acid-derived structural units, wherein 70 mol% or more of the diamine-derived structural units are derived from xylylenediamine, and more than 50 mol% of the dicarboxylic acid-derived structural units are derived from sebacic acid;
a mass ratio of the polyamide resin to the maleic anhydride-modified polyphenylene ether resin is 80/20 to 60/40;
a mass ratio of polyamide 6 to polyamide 66 (polyamide 6/polyamide 66) of 0.5 or more and 12.0 or less;
a mass ratio of the xylylenediamine-based polyamide resin to polyamide 66 (xylylenediamine-based polyamide resin/polyamide 66) of 0.3 or more and 7.0 or less;
A resin composition , wherein the mass ratio of the xylylenediamine-based polyamide resin to polyamide 6 (xylylenediamine-based polyamide resin/polyamide 6) is 0.2 or more and 2.0 or less . The resin composition according to claim 1, wherein the xylylenediamine contains 50 to 100 mol% metaxylylenediamine and 0 to 50 mol% paraxylylenediamine. The resin composition according to claim 1 or 2 further comprises 40 to 200 parts by mass of reinforcing fibers per 100 parts by mass of the thermoplastic resin component containing the polyamide resin and maleic anhydride-modified polyphenylene ether resin. The resin composition according to any one of claims 1 to 3, wherein the crystallization peak heat quantity of a molded article of the resin composition at a mold temperature of 90°C, measured by differential scanning calorimetry, is 1.0 J/g or less. The resin composition according to any one of claims 1 to 4, which is used for the housing of a fishing reel. A molded article formed from the resin composition described in any one of claims 1 to 5. The molded product according to claim 6, which is a housing for a fishing reel. A method for producing a molded product, comprising molding the resin composition described in any one of claims 1 to 5 using a mold at a mold temperature of 100°C or less.