JP2023142871A - Polyamide resin composition, and molded body - Google Patents

Abstract

To provide a polyamide resin composition which can suppress lowering of toughness of the polyamide resin composition while improving flowability in injection molding.SOLUTION: A polyamide resin composition contains a polyamide resin (A) having a melting point of 280°C or higher, 0.1-30 pts.mass of a fatty acid metal salt (B) with respect to 100 pts.mass of the polyamide resin (A), and 0.1-30 pts.mass of a lubricant (C) with respect to 100 pts.mass of the polyamide resin (A). The lubricant (C) contains aliphatic diamide (C1) obtained by reaction of a saturated aliphatic monocarboxylic acid having 10 to 30 carbon atoms in the main chain, and aliphatic diamine having 2 to 12 carbon atoms in the main chain.SELECTED DRAWING: None

Description

The present disclosure relates to a polyamide resin composition and a molded article.

Polyamide resin, which can be heated and melted and molded into a predetermined shape, is used as a material for molding electronic components. As the polyamide resin, aliphatic polyamides such as nylon 6 and nylon 66 are generally used. Although such aliphatic polyamide has good moldability, it does not have sufficient heat resistance as a material for manufacturing surface mount components such as connectors that are exposed to high temperatures such as in a reflow soldering process. Therefore, semi-aromatic polyamide resins are used as polyamide resins having sufficient heat resistance.

Although semi-aromatic polyamide resins have sufficient heat resistance and are excellent in low water absorption, they tend to have low fluidity during injection molding. On the other hand, in order to improve fluidity during injection molding, a lubricant such as a fatty acid metal salt may be added to the polyamide resin composition. For example, flame-retardant polyamide compositions containing a semi-aromatic polyamide resin (A), a flame retardant (B), a fatty acid metal salt (C), and a reinforcing material (D) are known (for example, Patent Document 1).

International Publication No. 2008/126381

As mentioned above, the fluidity during injection molding can be improved by adding a fatty acid metal salt. However, the addition of fatty acid metal salts sometimes reduces the toughness of the polyamide resin composition. In particular, in applications for thin-walled fine-pitch connectors, it is desired that the connector material has high toughness during terminal press-fitting and insertion/extraction operations in order to prevent cracking, whitening, etc. of the product.

In addition, in the above-mentioned applications, there is a demand for further improvement in fluidity during injection molding as the size and thickness of the molded product are further reduced. Therefore, the fluidity was not at a sufficient level just by adding the fatty acid metal salt. That is, it is required to achieve a high degree of both improvement in injection fluidity and improvement in toughness.

In view of these circumstances, the present disclosure provides a polyamide resin composition that can suppress a decrease in toughness of the polyamide resin composition while improving fluidity during injection molding, and a polyamide molded article containing the polyamide resin composition. The purpose is to provide.

The polyamide resin composition of the present disclosure includes a polyamide resin (A) having a melting point of 280° C. or higher as measured by differential scanning calorimetry (DSC), and 0.1 to 0.1 to 100 parts by mass of the polyamide resin (A). The lubricant (C) contains 30 parts by mass of a fatty acid metal salt (B) and 0.1 to 30 parts by mass of a lubricant (C) based on 100 parts by mass of the polyamide resin (A). contains an aliphatic diamide (C1) obtained by reacting a saturated aliphatic monocarboxylic acid having 10 to 30 carbon atoms with an aliphatic diamine having 2 to 12 carbon atoms in the main chain.

The molded article of the present disclosure includes the polyamide resin composition of the present disclosure.

According to the present disclosure, it is possible to provide a polyamide resin composition that can suppress a decrease in toughness of the polyamide resin composition while improving fluidity during injection molding, and a polyamide molded article containing the polyamide resin composition. can.

1. Polyamide Resin Composition The polyamide resin composition of the present disclosure includes a polyamide resin (A), a fatty acid metal salt (B), and a lubricant (C).

1-1. Polyamide resin (A)
The polyamide resin (A) contains a structural unit (a1) derived from a dicarboxylic acid and a structural unit (a2) derived from a diamine.

The structural unit (a1) derived from dicarboxylic acid preferably contains a structural unit derived from terephthalic acid. The content of the structural unit derived from terephthalic acid is preferably 30 to 100 mol%, and preferably 30 to 90 mol%, based on the total number of moles of the structural unit (a1) derived from dicarboxylic acid. More preferably, it is 40 to 80 mol%. When the content of the structural unit derived from terephthalic acid is 30 mol% or more, the melting point (Tm) of the polyamide resin (A) can be sufficiently increased, and the heat resistance and strength can be easily increased.

The structural unit (a1) derived from a dicarboxylic acid may further contain a structural unit derived from a dicarboxylic acid other than terephthalic acid. Examples of dicarboxylic acids other than terephthalic acid include aromatic dicarboxylic acids such as isophthalic acid, 2-methylterephthalic acid, and naphthalenedicarboxylic acid; furandicarboxylic acids such as 2,5-furandicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid. , alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid; malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethyl Included are aliphatic dicarboxylic acids having 4 to 20 carbon atoms such as glutaric acid, 3,3-diethylsuccinic acid, azelaic acid, sebacic acid, and suberic acid. Only one type of structural unit derived from a dicarboxylic acid other than terephthalic acid may be included, or two or more types may be included. Among these, dicarboxylic acid structural units other than terephthalic acid structural units are preferably structural units derived from aliphatic dicarboxylic acids having 4 to 20 carbon atoms, and structural units derived from aliphatic dicarboxylic acids having 4 to 12 carbon atoms. It is more preferable that the structural unit is derived from adipic acid, and from the viewpoint of easily adjusting the glass transition temperature Tg below a certain level, it is even more preferable that the structural unit is derived from adipic acid.

The content of structural units derived from dicarboxylic acids other than terephthalic acid, preferably the content of structural units derived from aliphatic dicarboxylic acids having 4 to 20 carbon atoms, is determined by the total mole of structural units (a1) derived from dicarboxylic acids. The amount is preferably 0 to 70 mol%, more preferably 10 to 70 mol%, and even more preferably 20 to 60 mol%. When the content is more than 0 mol%, the fluidity of the polyamide resin composition can be more easily improved. When the content is 70 mol% or less, the melting point of the polyamide resin (A) will not become too low, and the heat resistance of the polyamide resin composition will not be easily impaired.

The structural unit (a2) derived from diamine preferably contains at least one of a structural unit derived from an aliphatic diamine and a structural unit derived from an alicyclic diamine, and preferably contains a structural unit derived from an aliphatic diamine. is more preferable.

The structural unit derived from an aliphatic diamine is preferably a structural unit derived from an aliphatic diamine having 4 to 15 carbon atoms, preferably 6 to 12 carbon atoms. Examples of aliphatic diamines include 1,4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1 , 11-diaminoundecane, 1,12-diaminododecane, etc., and branched alkylene diamines such as 2-methyl-1,5-diaminopentane, 2-methyl-1,8-diaminooctane, etc. included. Only one type of structural unit derived from aliphatic diamine may be included, or two or more types may be included. Among these, linear alkylene diamines are preferred, and 1,6-diaminohexane is more preferred.

The content of the structural unit derived from the aliphatic diamine is preferably 50 to 100 mol%, and preferably 80 to 100 mol%, based on the total number of moles of the structural unit (a2) derived from the diamine. More preferred. When the content of the structural unit derived from aliphatic diamine is 50 mol% or more, the fluidity of the polyamide resin composition during molding can be more easily improved.

The structural unit derived from an alicyclic diamine is preferably a structural unit derived from an alicyclic diamine having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms. Examples of alicyclic diamines include 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(aminomethyl)cyclohexane, and the like.

The structural unit (a2) derived from diamine may further contain a structural unit derived from other diamines other than those mentioned above. Examples of other diamines include aromatic diamines such as p-phenylene diamine, m-phenylene diamine, 4,4'-diaminobiphenyl, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, and the like.

In a preferable example of the polyamide resin (A), the structural unit (a1) derived from dicarboxylic acid is a structural unit derived from terephthalic acid and the structural unit derived from adipic acid, and the structural unit (a2) derived from diamine. is a polyamide resin whose structural unit is derived from 1,6-hexanediamine.

The molecular ends of the polyamide resin (A) may be capped with an end capping agent.

Examples of terminal capping agents include monocarboxylic acids and monoamines. Examples of monocarboxylic acids include aliphatic monocarboxylic acids having 2 to 30 carbon atoms such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, and caprylic acid; alicyclic monocarboxylic acids such as cyclohexanecarboxylic acid; benzoic acid; Aromatic monocarboxylic acids such as toluic acid, naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid and phenylacetic acid are included. Examples of monoamines include aliphatic monoamines such as butylamine, amylamine, hexylamine, etc.; and araliphatic monoamines such as benzylamine, methylbenzylamine. Among these, since the molecular terminal of the polyamide resin (A) is often an amino group, the terminal capping agent is preferably a monocarboxylic acid.

The glass transition temperature (Tg) of the polyamide resin (A) measured by differential scanning calorimetry (DSC) is preferably 60 to 110°C, more preferably 70°C or more and less than 100°C, and 80 More preferably, the temperature is between 100°C and 100°C. When the Tg of the polyamide resin (A) is 60°C or higher, the molecular mobility of the polyamide resin composition at high temperatures is suppressed, making it easier to improve heat resistance. When the Tg of the polyamide resin (A) is 110° C. or lower, it is easier to increase the solidification rate when the molten polyamide resin composition is cooled, and the cycle time during injection molding can be further shortened.

The polyamide resin (A) preferably has a melting point (Tm) of 280 to 340° C. as measured by a differential scanning calorimeter (DSC). When the melting point of the polyamide resin (A) is 280°C or higher, it is easy to sufficiently increase the mechanical strength and heat resistance of the polyamide resin composition, and when it is 340°C or lower, there is no need to increase the molding temperature excessively. , thermal decomposition of the resin and other components during melt molding can be further suppressed. The melting point of the polyamide resin (A) is more preferably 295 to 330°C.

The melting point (Tm) and glass transition temperature (Tg) of the polyamide resin (A) can be measured using a differential scanning calorimeter (eg, Model DSC220C, manufactured by Seiko Instruments Inc.).

Specifically, about 5 mg of polyamide resin is sealed in an aluminum pan for measurement, and heated from room temperature to 350° C. at a rate of 10° C./min. Hold at 350°C for 3 minutes to completely melt the resin, then cool to 30°C at 10°C/min. After leaving at 30°C for 5 minutes, heating is performed a second time to 350°C at 10°C/min. The temperature (° C.) of the endothermic peak in this second heating is defined as the melting point (Tm) of the polyamide resin, and the displacement point corresponding to the glass transition is defined as the glass transition temperature (Tg).

The melting point and glass transition temperature of the polyamide resin (A) can be adjusted by adjusting the type of dicarboxylic acid or diamine that constitutes the polyamide resin (A). For example, if the content of structural units derived from terephthalic acid is increased, the melting point and glass transition temperature of the polyamide resin (A) tend to increase.

The intrinsic viscosity [η] of the polyamide resin (A) measured in 96.5% sulfuric acid at a temperature of 25°C is preferably 0.7 to 1.6 dl/g, and 0.8 to 1.2 dl. /g is more preferable. When the intrinsic viscosity [η] of the polyamide resin (A) is 0.7 dl/g or more, it is easy to sufficiently increase the mechanical strength of the polyamide resin composition, and when it is 1.6 dl/g or less, the polyamide resin composition Fluidity during molding is less likely to be impaired.

The intrinsic viscosity of the polyamide resin (A) can be measured by the following method. First, about 0.5 g of polyamide resin (A) is dissolved in 50 ml of 96.5% concentrated sulfuric acid. Then, the number of seconds of flow of the obtained solution under the condition of 25° C.±0.05° C. is measured using an Ubbelohde viscometer. Thereafter, the limiting viscosity is calculated based on the following formula.
[η]=ηSP/(C(1+0.205ηSP))

In the above formula, each algebra or variable represents the following.
[η]: Intrinsic viscosity (dl/g)
ηSP: Specific viscosity C: Sample concentration (g/dl)

The above ηSP is determined by the following formula.
ηSP=(t-t0)/t0
t: Number of seconds for sample solution to flow down (seconds)
t0: Number of seconds for blank sulfuric acid flow (seconds)

The polyamide resin can be produced, for example, by polycondensing the above dicarboxylic acid and diamine in a homogeneous solution. Specifically, a lower condensate is obtained by heating a dicarboxylic acid and a diamine in the presence of a catalyst as described in WO 03/085029, and then this lower condensate is It can be produced by applying shear stress to the melt and causing polycondensation.

From the viewpoint of adjusting the intrinsic viscosity of the polyamide resin, the above-mentioned terminal capping agent may be added to the reaction system. The intrinsic viscosity [η] (or molecular weight) of the polyamide resin can be adjusted by the amount of the terminal capping agent added.

The terminal capping agent is added to the reaction system of dicarboxylic acid and diamine. The amount added is preferably 0.07 mol or less, more preferably 0.05 mol or less, per 1 mol of the total amount of dicarboxylic acids.

The content of the polyamide resin (A) is preferably 20 to 90% by mass, more preferably 30 to 70% by mass, based on the polyamide resin composition. When the content of the polyamide resin (A) is within the above range, the heat resistance can be sufficiently increased without impairing the moldability of the polyamide resin composition.

1-2. Fatty acid metal salt (B)
The fatty acid metal salt (B) is used for the purpose of improving the fluidity of the resin composition during injection molding.

The fatty acid constituting the fatty acid metal salt (B) is preferably a higher fatty acid. Examples of higher fatty acids include higher fatty acids having 15 to 30 carbon atoms such as stearic acid, oleic acid, behenic acid, behenic acid, and montanic acid.

Examples of metals constituting the fatty acid metal salt (B) include calcium, magnesium, barium, lithium, aluminum, zinc, sodium, potassium, and the like.

Among these, calcium stearate, magnesium stearate, barium stearate, calcium behenate, sodium montanate, calcium montanate, and the like are preferred. Among these, calcium montanate is more preferred from the viewpoint of making it more compatible with the heat resistance and fluidity of the polyamide resin (A).

The content of the fatty acid metal salt (B) is not particularly limited, but is preferably 0.1 to 30 parts by mass, and preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the polyamide resin (A). is more preferable. When the content is 0.1 part by mass or more, fluidity during molding tends to increase. When the above-mentioned content is 30 parts by mass or less, when solidifying the polyamide resin composition in a molten state, the aggregation of the fatty acid metal salt (B) can be made more difficult to occur, so that a decrease in toughness can be further suppressed.

1-3. Lubricant (C)
The lubricant (C) may be used for the purpose of suppressing aggregation or precipitation of the fatty acid metal salt (B) when cooling the resin composition after molding. Note that the lubricant (C) is different from the fatty acid metal salt (B). The lubricant (C) contains an aliphatic diamide (C1).

As mentioned above, since the fatty acid metal salt (B) is in a liquid state when it is heated and melted, it is easy to reduce the viscosity of the polyamide resin composition and improve the fluidity of the polyamide resin composition. On the other hand, when the molten polyamide resin composition is cooled and solidified, the polyamide resin (A) and the fatty acid metal salt (B) solidify at different timings, so the fatty acid metal salt (B) tends to aggregate. , the toughness of the polyamide resin composition sometimes decreased. Such a phenomenon was particularly likely to occur when the amount of fatty acid metal salt (B) was increased.

On the other hand, by adding aliphatic diamide (C1), the decrease in toughness of the polyamide resin composition can be suppressed. Although the reason for this is not clear, since the aliphatic diamide (C1) has an amide bond, it is easily compatible with the polyamide resin (A). Moreover, since the aliphatic diamide (C1) has an aliphatic chain, it also has an affinity with the fatty acid metal salt (B). That is, the aliphatic diamide can function as a compatibilizer between the polyamide resin (A) and the fatty acid metal salt (B). It is thought that this improves the dispersibility of the fatty acid metal salt (B), thereby suppressing a decrease in the toughness of the polyamide resin composition. Furthermore, since aliphatic diamide (C1) has more aliphatic chains and amide bonds than, for example, aliphatic monoamide, it particularly functions as a compatibilizer between polyamide resin (A) and fatty acid metal salt (B). It is thought that the bleeding of aliphatic diamide (C1) can also be suppressed.

1-3-1. Aliphatic diamide (C1)
Aliphatic diamide (C1) is a diamide compound obtained by reacting a saturated aliphatic monocarboxylic acid and an aliphatic diamine.

Since the saturated aliphatic monocarboxylic acid constituting the aliphatic diamide (C1) does not have an unsaturated structure, it is difficult to react or interact with, for example, the aromatic ring of the polyamide resin (A), which improves fluidity. It is thought to promote this. The saturated aliphatic monocarboxylic acid is preferably a higher saturated fatty acid. The number of carbon atoms in the main chain of the saturated aliphatic monocarboxylic acid is preferably 10 to 30, more preferably 15 to 20. Such a saturated aliphatic monocarboxylic acid has a structure similar to that of the fatty acid constituting the fatty acid metal salt (B), and thus has an affinity with the fatty acid. Examples of saturated aliphatic monocarboxylic acids include lauric acid (C12), stearic acid (C18), behenic acid (C22), and montanic acid (C28).

The number of carbon atoms in the main chain of the aliphatic diamine constituting the aliphatic diamide (C1) is preferably 2 to 12, more preferably 2 to 9. Examples of aliphatic diamines include ethylene diamine, butane diamine, hexamethylene diamine, and the like.

Examples of the aliphatic diamide (C1) include ethylene bis stearamide, ethylene bis lauryl amide, ethylene bis behenylamide, butylene bis stearamide, and the like, with ethylene bis stearamide being preferred. These may be used alone or in combination of two or more.

The content of the aliphatic diamide (C1) is preferably 10 to 100 parts by mass, more preferably 10 to 79.5 parts by mass, based on 100 parts by mass of the lubricant (C). When the content is 10 parts by mass or more, aggregation and precipitation of the fatty acid metal salt (B) can be suppressed when the polyamide resin composition is cooled after molding.

In addition, the content ratio (C1/B) of aliphatic diamide (C1) and fatty acid metal salt (B) is preferably 0.01 to 10 (mass ratio) from the viewpoint of achieving a high level of both fluidity and toughness. It is preferably 0.1 to 5 (mass ratio), and more preferably 0.1 to 5 (mass ratio). When C1/B is at least the lower limit, it is easier to suppress a decrease in the toughness of the polyamide resin composition, and when it is at most the upper limit, it is easier to improve the fluidity of the polyamide resin composition.

1-3-2. Low density polyethylene (C2)
It is preferable that the lubricant (C) further contains low density polyethylene (C2). Low density polyethylene (C2) can be used for the purpose of further increasing the fluidity of the polyamide resin composition and making it easier to disperse the aliphatic diamide (C1) in the vicinity of the fatty acid metal salt (B).

The low density polyethylene (C2) is preferably an ethylene homopolymer, but may also be a copolymer of ethylene and a small amount of α-olefin having 3 to 12 carbon atoms (eg, propylene, etc.). The content of structural units derived from ethylene in the copolymer is preferably 90.0 to 99.9% by mass, more preferably 93.0 to 99.9% by mass. On the other hand, the amount of the structural unit derived from α-olefin having 3 to 12 carbon atoms is preferably 0.1 to 10.0% by mass, preferably 0.1 to 7.0% by mass.

The low density polyethylene (C2) may be high pressure low density polyethylene. High-pressure low-density polyethylene is generally polyethylene obtained by radical polymerizing ethylene under high temperature and high pressure. The manufacturing method is not particularly limited, but includes, for example, a radical polymerization method in which radical polymerization is carried out under conditions of 500 to 2,000 atmospheres and 150 to 300°C. Examples of the polymerization initiator include organic peroxides.

The density of the low density polyethylene (C2) measured according to ASTM D1505 is preferably 900 to 925 kg/m ³ , more preferably 910 to 925 kg/m ³ .

The melt flow rate (MFR) of low density polyethylene (C2) measured in accordance with ASTM D1238 at 190°C and a load of 2.16 kg is preferably 0.1 to 50 g/10 minutes, more preferably 1 to 20 g/10 minutes.

The content of low density polyethylene (C2) is preferably 0 to 90 parts by weight, more preferably 10 to 79.5 parts by weight, based on 100 parts by weight of the lubricant (C). When the content is 10 parts by mass or more, the fluidity during molding is likely to be further enhanced. When the content is 79.5 parts by mass or less, decomposition gas derived from low-density polyethylene (C2) can be sufficiently suppressed, and poor appearance during molding can be suppressed.

1-3-2. Copolymer (C3)
It is preferable that the lubricant (C) further includes a copolymer (C3) having a structural unit derived from an olefin and a structural unit derived from an α,β-unsaturated carboxylic acid ester. The copolymer (C3) can further suppress aggregation of the fatty acid metal salt (B) when the polyamide resin composition is cooled and solidified, and can further suppress a decrease in toughness.

Although the reason is not clear, it is thought to be as follows. Since the copolymer (C3) has a structural unit derived from an olefin, it is easily compatible with the fatty acid metal salt (B) and the low density polyethylene (C2). Furthermore, since the copolymer (C3) has a polar moiety derived from an α,β-unsaturated carboxylic acid ester, it is easily compatible with the polyamide resin (A) and the aliphatic diamide (C1). Thereby, the copolymer (C3) acts as a compatibilizer between the polyamide resin (A) and the fatty acid metal salt (B) and between the aliphatic diamide (C1) and the low density polyethylene (C2). It seems to work. Further, it is thought that the copolymer (C3) tends to reduce the crystallization rate and melt viscosity of the polyamide resin composition when heated and melted.

Examples of the structural units derived from olefins constituting the copolymer (C3) include structural units derived from ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, and the like. Among these, structural units derived from ethylene are preferred.

Examples of structural units derived from α,β-unsaturated carboxylic acid esters constituting the copolymer (C3) include acrylic esters including methyl acrylate, ethyl acrylate, and butyl acrylate, and methacrylate. Contains structural units derived from methacrylic acid esters, including methyl acid, and ethyl methacrylate. Among these, from the viewpoint of heat resistance, structural units derived from acrylic acid C1-C10 alkyl esters such as methyl acrylate and n-butyl acrylate are preferred, and are easier to improve compatibility with low-density polyethylene (C2). From this viewpoint, structural units derived from C4 to C10 alkyl acrylate are more preferred, and structural units derived from n-butyl acrylate are even more preferred. The content of the structural units derived from the α,β-unsaturated carboxylic acid ester is preferably 5 to 70% based on the total of the structural units derived from the olefin and the structural units derived from the α,β-unsaturated carboxylic acid ester. % by mass, more preferably 10 to 50% by mass.

The copolymer (C3) may further contain other structural units than the above-mentioned structural units. Examples of other structural units include α,β-unsaturated carboxylic acid glycidyl esters such as acrylic acid glycidyl ester and methacrylic acid glycidyl ester; Glycidyl ether; Aromatic vinyl compounds such as styrene, α-methylstyrene, 4-methylstyrene, 4-methoxystyrene, chlorostyrene, and 2,4-dimethylstyrene; Unsaturated vinyl esters such as vinyl acetate and vinyl propionate. Contains the derived structural units.

Examples of the copolymer (C3) include ethylene/n-butyl acrylate copolymer, ethylene/methyl acrylate copolymer, and ethylene/ethyl acrylate copolymer, preferably ethylene/n-acrylate copolymer. It is an acid butyl copolymer. These may be used alone or in combination of two or more.

The melting point of the copolymer (C3) measured by differential scanning calorimetry (DSC) is preferably 40 to 120°C, more preferably 50 to 110°C. When the melting point of the copolymer (C3) is within this range, the fluidity of the polyamide resin composition during molding can be further improved.

The melt flow rate (MFR) of the copolymer (C3) measured in accordance with ASTM D1238 at 190°C and a load of 2.16 kg is preferably 1 to 400 g/10 minutes, more preferably 10 ~100g/10 minutes.

The content of the copolymer (C3) is preferably 0 to 80 parts by weight, more preferably 10 to 79.5 parts by weight, based on 100 parts by weight of the lubricant (C). When the content is 10 parts by mass or more, aggregation and precipitation of the fatty acid metal salt (B) when cooling the polyamide resin composition after molding can be further suppressed. When the content is 79.5 parts by mass or less, surface roughness of the molded article due to gas generation due to thermal decomposition of the copolymer (C3) can be further suppressed.

1-3-4. Aromatic carboxylic acid compound (C4)
It is preferable that the lubricant (C) further contains an aromatic carboxylic acid compound (C4). The aromatic carboxylic acid compound (C4) can further improve the fluidity of the polyamide resin composition.

The reason for this is not clear, but the aromatic carboxylic acid compound attacks the amide bonding site of the polyamide resin (A), cleaving the bond, and a reaction occurs in which the aromatic carboxylic acid compound is incorporated into the bond. Conceivable. That is, it is thought that this is because a reaction similar to hydrolysis occurs and the molecular weight of the polyamide resin (A) is appropriately reduced.

The aromatic carboxylic acid compound (C4) is an aromatic carboxylic acid, an anhydride thereof, or an alkyl (having 1 to 3 carbon atoms) ester thereof, and is preferably an aromatic carboxylic acid. The aromatic carboxylic acid has, for example, 7 to 15 carbon atoms.

Examples of the aromatic carboxylic acid compound (C4) include benzoic acid, 1-naphthalenecarboxylic acid, 2-naphthalenecarboxylic acid, 2,3-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and 2,7-naphthalene dicarboxylic acid. acids, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and anhydrides and alkyl C1-3 esters thereof, preferably terephthalic acid and isophthalic acid, more preferably terephthalic acid. be. These may be used alone or in combination of two or more.

The content of the aromatic carboxylic acid compound (C4) is preferably 0 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the lubricant (C). When the content is 0.5 parts by mass or more, fluidity during molding is likely to be further enhanced. When the content is 20 parts by mass or less, a decrease in toughness due to excessive decomposition of the polyamide resin (A) can be sufficiently suppressed.

1-3-5. Common matters The lubricant (C) may be composed only of aliphatic diamide (C1), or may be composed of aliphatic diamide (C1), low density polyethylene (C2), copolymer (C3), and aromatic carboxylic acid compound. Any one or more of (C4) may be combined. Among them, from the viewpoint of achieving a higher degree of both fluidity and toughness of the polyamide resin composition, the lubricant (C) contains an aliphatic diamide (C1) and a low density polyethylene (C2) or a copolymer (C3). It is preferable that it contains an aliphatic diamide (C1), a low density polyethylene (C2), and a copolymer (C3); it is more preferable that it contains an aliphatic diamide (C1), a low density polyethylene (C2), It is more preferable that the copolymer (C3) and the aromatic carboxylic acid compound (C4) are included.

That is, the lubricant (C) contains 10 to 79.5 parts by mass of aliphatic diamide (C1) and 10 to 79.5 parts by mass of low density polyethylene (C2) per 100 parts by mass of the lubricant (C). , 10 to 79.5 parts by mass of the copolymer (C3), and 0.5 to 20 parts by mass of the aromatic carboxylic acid compound (C4).

The content ratio (C2/C1) of low density polyethylene (C2) to aliphatic diamide (C1) is, for example, preferably 0.1 to 10, more preferably 0.2 to 5. When the content ratio is at least the lower limit, it is easy to further improve the fluidity during injection molding while suppressing a decrease in the toughness of the polyamide resin composition. When the content ratio is below the upper limit, the decrease in toughness of the polyamide resin composition can be further suppressed.

The content ratio (C3/(C1+C2)) of the copolymer (C3) to the total amount of aliphatic diamide (C1) and low density polyethylene (C2) is preferably 0.1 to 10, for example, 0. More preferably, it is 2 to 5. When the content ratio is equal to or higher than the lower limit, the aliphatic diamide (C1) and the low-density polyethylene (C2) are easily compatible with each other, and the functions of each component are more easily expressed. When the content ratio is below the upper limit, thickening due to excessive reaction between the copolymer (C3) and the polyamide resin (A) during melting can be easily suppressed.

The content of the lubricant (C) is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the polyamide resin (A). When the content is 0.1 parts by mass or more, aggregation and precipitation of the fatty acid metal salt (B) can be suppressed when the polyamide resin composition is cooled after molding. When the amount is 30 parts by mass or less, the decrease in mechanical strength and toughness of the polyamide resin composition due to the lubricant (C) itself becoming a foreign substance can be further suppressed.

Further, the content ratio (C/B) of the lubricant (C) and the fatty acid metal salt (B) is preferably 0.1 to 10, and 0.2 to 10, from the viewpoint of achieving a high level of both fluidity and toughness. It is more preferably 7 (mass ratio), and even more preferably 0.5 to 5 (mass ratio). When C/B is at least the lower limit, it is easier to suppress a decrease in the toughness of the polyamide resin composition, and when it is at most the upper limit, it is easier to improve the fluidity of the polyamide resin composition.

1-4. Other Components The polyamide resin composition of the present disclosure may further contain other components other than those described above, as long as the effects of the present disclosure are not impaired. Examples of other ingredients include reinforcing agents, crystal nucleating agents, flame retardants, flame retardant aids, corrosion resistance improvers, anti-drip agents, ion scavengers, elastomers (rubbers), antistatic agents, mold release agents, Antioxidants (phenols, amines, sulfur, phosphorus, etc.), heat stabilizers (lactone compounds, vitamin E, hydroquinones, copper halides and iodine compounds, etc.), light stabilizers (benzotriazoles, triazine, etc.) benzophenones, benzoates, hindered amines, oxanilides, etc.), other polymers (polyolefins, olefin copolymers such as ethylene/propylene copolymers, ethylene/1-butene copolymers, propylene/1-butene copolymers, etc.) These include olefin copolymers such as butene copolymers, polystyrene, polyamides, polycarbonates, polyacetals, polysulfones, polyphenylene oxides, fluororesins, silicone resins, and LCP).

1-4-1. Reinforcement material (D)
The reinforcing material (D) can impart high mechanical strength to the polyamide resin composition. Examples of reinforcing materials (D) include fibrous reinforcing materials such as glass fibers, wollastonite, potassium titanate whiskers, calcium carbonate whiskers, aluminum borate whiskers, magnesium sulfate whiskers, zinc oxide whiskers, milled fibers and cut fibers. , as well as particulate reinforcement. Among these, one type may be used alone or two or more types may be used in combination. Among these, from the viewpoint of easily increasing the mechanical strength of the polyamide resin composition, fibrous reinforcing materials such as wollastonite, glass fiber, and potassium titanate whiskers are preferred, and wollastonite or glass fiber is more preferred.

The average fiber length of the fibrous reinforcing material may be, for example, 1 μm to 20 mm, preferably 5 μm to 10 mm, from the viewpoint of moldability, mechanical strength, and heat resistance of the polyamide resin composition. Further, the aspect ratio of the fibrous reinforcing material may be, for example, 5 to 2,000, preferably 30 to 600.

The average fiber length and average fiber diameter of the fibrous reinforcement can be measured by the following method.
1) A polyamide resin composition is dissolved in a hexafluoroisopropanol/chloroform solution (0.1/0.9% by volume), and then filtered to collect the resulting filtrate.
2) Disperse the filtrate obtained in 1) above in water, and measure the fiber length (Li) and fiber diameter (di) of each of 300 arbitrary fibers using an optical microscope (magnification: 50x). The number of fibers having a fiber length of Li is set as qi, and the weight average length (Lw) is calculated based on the following formula, and this is taken as the average fiber length of the fibrous reinforcing material.
Weight average length (Lw) = (Σqi×Li ² )/(Σqi×Li)
Similarly, the number of fibers having a fiber diameter Di is set to ri, and the weight average diameter (Dw) is calculated based on the following formula, and this is set as the average fiber diameter of the fibrous reinforcing material.
Weight average diameter (Dw) = (Σri×Di ² )/(Σri×Di)

The content of the reinforcing material (D) is not particularly limited, but is preferably 1 to 300 parts by weight, more preferably 15 to 100 parts by weight, based on 100 parts by weight of the polyamide resin (A). When the content is within the above range, the mechanical strength of the polyamide resin composition can be further increased while ensuring fluidity during injection molding.

1-4-2. Flame retardant (E)
The flame retardant (E) may be added for the purpose of reducing the flammability of the polyamide resin composition. The type of flame retardant (E) is not particularly limited, but brominated polystyrene and phosphine compounds are preferred.

(brominated polystyrene)
Brominated polystyrene is polystyrene or polyα-methylstyrene that has been brominated. Among these, in brominated polystyrene, some of the hydrogen atoms bonded to the carbon atoms forming the aromatic ring are replaced with bromine atoms, and the hydrogen atoms forming the alkyl chains that form the main skeleton of the polymer are substantially bromine atoms. It is preferable that it is not substituted with. The bromine content of the brominated polystyrene is, for example, 65 to 71% by weight, preferably 67 to 71% by weight.

The term "hydrogen atoms forming the alkyl chains forming the main skeleton of the polymer are not substantially substituted with bromine atoms" means that the proportion of hydrogen atoms forming the alkyl chains forming the main skeleton of the polymer being substituted with bromine atoms is 0 to 0.5% by mass, preferably 0 to 0.2% by mass, more preferably 0 to 0.1% by mass. Such brominated polystyrene has good thermal stability.

The weight average molecular weight (Mw) of the brominated polystyrene is, for example, 1000 to 4800, preferably 2000 to 4500. When Mw is within the above range, high fluidity can be easily obtained during molding without impairing toughness or the like. The weight average molecular weight is a value calculated using gel permeation chromatography (GPC) using a differential refractometer detector at a column temperature of 40°C using chloroform as the mobile phase, and calculated in terms of polystyrene. be.

Further, the melt flow rate (MFR) of brominated polystyrene is 200 to 1000 g/10 minutes, preferably 400 to 900 g/10 minutes. MFR is a value measured at a load of 1200 g, a temperature of 270° C., and an orifice inner diameter of 2.095 mm. MFR can also be measured with a load of 2160 g, a temperature of 220° C., and an orifice inner diameter of 2.095 mm, and the MFR in this case is 4 to 15 g/10 minutes.

Examples of the flame retardant (E) include, for example, SAYTEX HP-3010, SAYTEX HP-3010G, and SAYTEX HP-3010P manufactured by Albemarle Corporation.

(phosphine compound)
The phosphine compound is a phosphinate compound represented by formula (I) or a bisphosphinate compound represented by formula (II), or a polymer thereof.

In formula (I) and formula (II),
R ¹ and R ² are independently a linear or branched alkyl group or aryl group having 1 to 6 carbon atoms,
^R3 is independently a linear or branched alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group having 6 to 10 carbon atoms, or an arylalkylene group having 6 or more and 10 or less carbon atoms,
M is one type selected from the group consisting of Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and protonated nitrogen bases. is an atom or atomic group;
m represents an integer of 1 to 4, n represents an integer of 1 to 4, and x represents an integer of 1 to 4.

Examples of the phosphinate compound represented by formula (I) and the bisphosphinate compound represented by formula (II) include calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, and ethylmethylphosphine. calcium acid, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, Magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, calcium methane di(methylphosphinate), magnesium methane di(methylphosphinate), aluminum di(methylphosphinate) methane , methanedi(methylphosphinic acid) zinc, benzene-1,4-(dimethylphosphinic acid) calcium, benzene-1,4-(dimethylphosphinic acid) magnesium, benzene-1,4-(dimethylphosphinic acid) aluminum, benzene- Zinc 1,4-(dimethylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, and zinc diphenylphosphinate.

Among these, calcium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, aluminum diethylphosphinate, diethylphosphinate Zinc; more preferably aluminum diethylphosphinate.

Examples of commercially available phosphinate compounds represented by formula (I) and bisphosphinate compounds represented by formula (II) include EXOLIT OP1230 ("EXOLIT" is a registered trademark of Clariant), OP1311, and OP1312 manufactured by Clariant. , OP930, and OP935.

The content of the flame retardant (E) is preferably 1 to 100 parts by weight, more preferably 3 to 70 parts by weight, based on 100 parts by weight of the polyamide resin (A). With the above content, the flame retardance can be further improved while ensuring fluidity during injection molding of the polyamide resin composition.

1-4-3. Flame retardant aid (F)
The flame retardant aid (F) may be one that significantly enhances the flame retardant effect when used in combination with the flame retardant (E), and any known ones can be used. Specifically, antimony compounds such as antimony trioxide, antimony tetroxide, antimony pentoxide, and sodium antimonate, 2ZnO.3B ₂ O ₃ , 4ZnO.B ₂ O ₃ .H ₂ O, 2ZnO.3B ₂ O ₃ . Examples include zinc borate such as 3.5H ₂ O, zinc stannate, zinc phosphate, calcium borate, calcium molybdate, etc., and these may be used alone or in combination of two or more types. Among these, sodium antimonate, zinc borate, and zinc phosphate are preferred, and sodium antimonate and zinc borate anhydride (2ZnO.3B ₂ O ₃ ) are preferred.

Further, the flame retardant aid (F) used in the present disclosure is preferably 1 to 20 parts by mass based on 100 parts by mass of the polyamide resin (A).

1-4-4. Others A crystal nucleating agent may be used for the purpose of increasing the crystallinity of the polyamide resin composition. Examples of crystal nucleating agents include metals including sodium 2,2-methylenebis(4,6-di-t-butylphenyl) phosphate, aluminum tris(pt-butylbenzoate), and stearates. Salt-based compounds, sorbitol-based compounds including bis(p-methylbenzylidene) sorbitol, bis(4-ethylbenzylidene) sorbitol, etc., and inorganic substances including talc, calcium carbonate, hydrotalcite, etc. are included. Among these, talc is preferred from the viewpoint of further increasing the crystallinity of the polyamide resin composition.

The content of the crystal nucleating agent is preferably 0.1 parts by mass or more and 5 parts by mass or less, more preferably 0.1 parts by mass or more and 3 parts by mass or less, based on 100 parts by mass of the polyamide resin composition. preferable. When the content of the crystal nucleating agent is within the above range, it is easy to sufficiently increase the degree of crystallinity of the polyamide resin composition, and it is easy to obtain sufficient mechanical strength.

For example, hydrotalcite and zeolite are known as ion trapping agents.

The anti-drip agent is used for the purpose of preventing the resin from melting and liquefying and dripping during combustion. Examples of anti-drip agents include maleated SEBS and the like.

1-5. Physical Properties As described above, the polyamide resin composition of the present disclosure can maintain good toughness. The fracture energy at 23° C., which is an indicator of the toughness of the polyamide resin composition, is, for example, 55 mJ or more, preferably 55 to 70 mJ, although it depends on the composition.

Fracture energy can be measured by bending tests.
Specifically, a strip-shaped test piece with a length of 64 mm, a width of 6 mm, and a thickness of 0.8 mm is produced by injection molding. This is left for 24 hours at a temperature of 23° C. under a nitrogen atmosphere. Next, a bending test is performed using a bending tester (for example, AB5 manufactured by NTESCO) in an atmosphere at a temperature of 23° C. and a relative humidity of 50%. The span (distance between fulcrums) is 26 mm, the bending speed (loading speed) is 5 mm/min, and the energy (toughness) required to break the test piece is measured.
Molding machine cylinder temperature: melting point of polyamide resin +10℃
Injection molding pressure: 2000kg/ ^cm2
Mold temperature: 120℃

The toughness of the polyamide resin composition can be adjusted by changing the composition as described above. For example, by increasing the content of the lubricant (C), the decrease in toughness can be further reduced.

The polyamide resin composition has excellent heat resistance and high toughness required for surface mounting using lead-free solder, as well as high melt fluidity. Therefore, the above polyamide resin composition can be particularly preferably used for electrical and electronic parts.

1-6. Manufacturing method The above polyamide resin composition is prepared by mixing the polyamide resin (A), fatty acid metal salt (B), lubricant (C), and other components as necessary using a known resin kneading method, such as a Henschel mixer, a V blender, or a ribbon. It can be produced by mixing in a blender or tumbler blender, or by melt-kneading in a single-screw extruder, multi-screw extruder, kneader, or Banbury mixer, followed by granulation or pulverization.

In addition, when the lubricant (C) is composed of multiple components, the multiple components may be directly melt-kneaded together with other components other than the lubricant (C); or the multiple components may be melt-kneaded in advance. After pelletizing, the pellets may be melt-kneaded with other ingredients. Among these, from the viewpoint of making it easier to disperse the aliphatic diamide (C1), it is preferable to melt-knead the plurality of components in advance and pelletize them, and then melt-knead them together with other components other than the lubricant (C).

2. Molded object The above polyamide composition can be molded into various molded objects by known molding methods such as compression molding, injection molding, and extrusion molding.

A molded article of the above-mentioned polyamide composition can be used for various purposes. Preferred examples of such applications include electrical and electronic components such as connectors, LED reflectors, switches, sensors, sockets, capacitors, jacks, fuse holders, relays, coil bobbins, resistors, ICs, LED housings, and various cases. Can be mentioned.

Hereinafter, the present disclosure will be described in more detail with reference to Examples, but the scope of the present disclosure is not limited to the description of the Examples.

1. Materials of resin composition 1-1. Polyamide resin (A)
(Preparation of polyamide resin 1)
Terephthalic acid 2475g (14.9mol), 1,6-hexanediamine 2905g (25.0mol), adipic acid 1461g (10.0mol), benzoic acid 73.2g (0.60mol), hypophosphorous acid 5.7 g of sodium monohydrate and 554 g of distilled water were placed in an autoclave with an internal capacity of 13.6 L, and the autoclave was purged with nitrogen. Stirring was started at 190°C, and the internal temperature was raised to 250°C over 3 hours. At this time, the internal pressure of the autoclave was increased to 3.01 MPa. After continuing the reaction for 1 hour, the autoclave was discharged into the atmosphere from a spray nozzle installed at the bottom, and the low condensate was extracted. Thereafter, this low condensate was cooled to room temperature, pulverized with a pulverizer to a particle size of 1.5 mm or less, and dried at 110° C. for 24 hours. The water content of the obtained low condensate was 3600 ppm, and the intrinsic viscosity [η] was 0.14 dl/g.

Next, this low condensate was placed in a plated solid phase polymerization apparatus, and after nitrogen substitution, the temperature was raised to 220° C. over about 1 hour and 30 minutes. Thereafter, the reaction was carried out for 1 hour, and the temperature was lowered to room temperature. The intrinsic viscosity [η] of the obtained prepolymer was 0.48 dl/g. Thereafter, this prepolymer was melt-polymerized in a twin-screw extruder with a screw diameter of 30 mm and L/D = 36 at a barrel setting temperature of 330°C, a screw rotation speed of 200 rpm, and a resin supply rate of 6 kg/h to produce a polyamide resin. 1 was prepared. The melting point (Tm) of the obtained polyamide resin 1 was 320°C, and the glass transition temperature (Tg) was 95°C.

The melting point, glass transition temperature, and intrinsic viscosity [η] of the polyamide resin were measured by the following methods.

(Melting point Tm, glass transition temperature Tg)
The melting point (Tm) and glass transition temperature (Tg) of the polyamide resin were measured using a differential scanning calorimeter model DSC220C, manufactured by Seiko Instruments Inc. Specifically, about 5 mg of polyamide resin was sealed in an aluminum pan for measurement, and heated from room temperature to 350°C at a rate of 10°C/min. To completely melt the resin, it was held at 350°C for 3 minutes and then cooled to 30°C at 10°C/min. After leaving it at 30°C for 5 minutes, it was heated a second time to 350°C at 10°C/min. The temperature (°C) of the endothermic peak in this second heating was defined as the melting point (Tm) of the polyamide resin, and the displacement point corresponding to the glass transition was defined as the glass transition temperature (Tg).

(Intrinsic viscosity [η])
0.5 g of polyamide resin was dissolved in 50 ml of 96.5% sulfuric acid solution. The number of seconds of flow of the obtained solution under the condition of 25° C.±0.05° C. was measured using an Ubbelohde viscometer. Thereafter, the intrinsic viscosity was calculated based on the following formula.
[η]=ηSP/(C(1+0.205ηSP))
[η]: Intrinsic viscosity (dl/g)
ηSP: Specific viscosity C: Sample concentration (g/dl)
ηSP was determined by the following formula.
ηSP=(t-t0)/t0
t: Number of seconds for sample solution to flow down (seconds)
t0: Number of seconds for blank sulfuric acid flow (seconds)

1-2. Fatty acid metal salt (B)
・Calcium montanate (Nitto Kasei Kogyo Co., Ltd. CS-8CP, melting point 125-145℃)

1-3. Lubricant (C)
(1) Components - Aliphatic diamide (C1)
Ethylene bisstearamide: Manufactured by Wako Pure Chemical Industries, Ltd. ・Low density polyethylene (C2)
Low density polyethylene 1: manufactured by NUC Corporation, NUC8008 (density: 918 kg/m ³ , melting point: 108°C, MFR: 4.7 g/10 minutes)
・Copolymer (C3)
Ethylene-n-butyl acrylate copolymer 1: Arkema Corporation 35BA320 (n-butyl acrylate content: 26 to 35% by mass, melting point: 65°C, MFR: 32 to 37 g/10 minutes @ 2.16 kg load, 190 ℃)
・Aromatic carboxylic acid compound (C4)
Terephthalic acid: manufactured by Wako Pure Chemical Industries, Ltd.

(2) Preparation of lubricant Low-density polyethylene 1: 720 g, ethylene bisstearamide: 1440 g, terephthalic acid: 400 g, ethylene-n-butyl acrylate copolymer 1: 1440 g were mixed in a tumbler blender, and a twin-screw extruder ( The mixture was melted and kneaded using a TEX30α (manufactured by Japan Steel Works, Ltd.) at a cylinder temperature of 230°C. Thereafter, it was extruded into strands and cooled in a water bath. Thereafter, the strands were taken up with a pelletizer and cut to obtain a pelletized lubricant.

1-4. Others (Reinforcement material (D))
Glass fiber (manufactured by Central Glass Co., Ltd., ECS03-615, average fiber diameter 9 μm, cut length 3 mm, silane treated product)

(Flame retardant (E))
Brominated polystyrene (manufactured by Albemarle, HP-3010-1)
Bromine content: 68% by mass, Mn: 3400, Mw: 4000, Mw/Mn: 1.2, MFR: 490 g/10 min @ 270°C, 1.2 kg load, MFR: 6 g/10 min @ 220°C, 2 .16kg load

(Flame retardant aid (F))
Sodium antimonate (manufactured by Nippon Seiko Co., Ltd., SA-A)

(ion scavenger)
Hydrotalcite (manufactured by Toda Kogyo Co., Ltd., product name: NAOX-33)

(nucleating agent)
Talc (manufactured by Matsumura Sangyo Co., Ltd., product name: High Filler #100 Hakudo 95)

(Anti-drip agent)
Maleated SEBS (manufactured by Asahi Chemicals, product name: Tuftec M1913)

2. Preparation of polyamide resin composition (Examples 1-2, Comparative Examples 1-3)
The components shown in Table 1 were mixed in a tumbler blender at the compounding ratio shown in the table, and then heated in a twin-screw extruder (TEX30α manufactured by Japan Steel Works) at a cylinder temperature (melting point of polyamide resin (A) (Tm)). )+15)°C and melt-kneaded. Thereafter, it was extruded into strands and cooled in a water bath. Thereafter, the strands were taken up with a pelletizer and cut to obtain a pellet-shaped polyamide resin composition.

(evaluation)
(1) Fluidity Injection molding was performed under the following conditions using a barflow mold with a width of 10 mm and a thickness of 0.5 mm, and the flow length (mm) of the resin in the mold was measured.
Injection molding machine: Tupar TR40S3A (manufactured by Sodick Plastech)
Injection setting pressure: 2000kg/ ^cm2
Cylinder setting temperature: Melting point of each polyamide resin +10℃

(2) Toughness A strip-shaped test piece prepared by injection molding and having a length of 64 mm, a width of 6 mm, and a thickness of 0.8 mm was left at a temperature of 23° C. under a nitrogen atmosphere for 24 hours. Next, a bending test was performed using a bending tester (AB5, manufactured by NTESCO) in an atmosphere at a temperature of 23° C. and a relative humidity of 50%. The span was 26 mm, the bending speed was 5 mm/min, and the energy (toughness) required to break the test piece was measured.
Molding machine: Tupar TR40S3A (manufactured by Sodick Plastic Tech)
Molding machine cylinder temperature: melting point of each polyamide resin +10℃
Injection setting pressure: 2000kg/ ^cm2
Mold temperature: 120℃

(3) Flame retardancy Using a 1/32 inch x 1/2 x 5 inch test piece prepared by injection molding, in accordance with the UL94 standard (UL Test No. UL94 dated June 18, 1991), A vertical combustion test was conducted to evaluate flame retardancy.
Molding machine: Tupar TR40S3A (manufactured by Sodick Plastic Tech)
Molding machine cylinder temperature: melting point of each polyamide resin +10℃
Mold temperature: 120℃

The evaluation results of Examples 1 to 2 and Comparative Examples 1 to 3 are shown in Table 1.

As shown in Table 1, the polyamide resin compositions of Examples 1 and 2 containing the fatty acid metal salt (B) and the aliphatic diamide (C1) were It can be seen that the fluidity is higher and the toughness is higher than the polyamide resin compositions of Comparative Examples 1 to 3 containing only one of them. In particular, the fluidity is higher than expected from the polyamide resin composition of Comparative Example 1 using only the fatty acid metal salt (B) and the polyamide resin composition of Comparative Example 3 using only the aliphatic diamide (C1). It showed liquidity at the level.

The polyamide resin composition of the present disclosure can suppress a decrease in toughness of the polyamide resin composition while improving fluidity during injection molding. It can be suitably used for electrical and electronic components in which components are assembled by surface mounting using high melting point solder such as.

Claims (17)

A polyamide resin (A) having a melting point of 280° C. or higher as measured by differential scanning calorimetry (DSC);
0.1 to 30 parts by mass of fatty acid metal salt (B) based on 100 parts by mass of the polyamide resin (A),
0.1 to 30 parts by mass of a lubricant (C) per 100 parts by mass of the polyamide resin (A),
including;
The lubricant (C) is
Contains an aliphatic diamide (C1) obtained by reacting a saturated aliphatic monocarboxylic acid whose main chain has 10 to 30 carbon atoms and an aliphatic diamine whose main chain has 2 to 12 carbon atoms.
Polyamide resin composition. The lubricant (C) further contains low density polyethylene (C2),
The polyamide resin composition according to claim 1. The lubricant (C) further includes a copolymer (C3) containing a structural unit derived from an olefin and a structural unit derived from an α,β-unsaturated carboxylic acid ester.
The polyamide resin composition according to claim 1 or 2. The lubricant (C) further contains an aromatic carboxylic acid compound (C4),
The polyamide resin composition according to any one of claims 1 to 3. The lubricant (C) is
For 100 parts by mass of the lubricant,
10 to 79.5 parts by mass of the aliphatic diamide (C1),
10 to 79.5 parts by mass of low density polyethylene (C2),
10 to 79.5 parts by mass of a copolymer (C3) containing a structural unit derived from an olefin and a structural unit derived from an α,β-unsaturated carboxylic acid ester,
0.5 to 20 parts by mass of aromatic carboxylic acid compound (C4),
including,
The polyamide resin composition according to any one of claims 1 to 4. The polyamide resin (A) contains a structural unit derived from a dicarboxylic acid and a structural unit derived from a diamine,
The structural units derived from the dicarboxylic acid include 30 to 90 mol% of the structural units derived from terephthalic acid and 10 to 70 mol% of the structural units having 4 carbon atoms, based on the total number of moles of the structural units derived from the dicarboxylic acid. ~ Contains structural units derived from 12 aliphatic carboxylic acids,
The structural unit derived from the diamine includes at least one of a structural unit derived from an aliphatic diamine and a structural unit derived from an alicyclic diamine.
The polyamide resin composition according to any one of claims 1 to 5. The aliphatic diamide (C1) is ethylene bisstearamide,
The polyamide resin composition according to any one of claims 1 to 6. The copolymer (C3) is a copolymer containing a structural unit derived from ethylene and a structural unit derived from a C1-10 acrylic acid alkyl ester.
The polyamide resin composition according to claim 3. The copolymer (C3) contains one or more of ethylene/n-butyl acrylate copolymer, ethylene/methyl acrylate copolymer, and ethylene/ethyl acrylate copolymer,
The polyamide resin composition according to claim 8. The aromatic carboxylic acid compound (C4) is terephthalic acid,
The polyamide resin composition according to claim 4. The content ratio (C/B) of the lubricant (C) and fatty acid metal salt (B) is 0.1 to 10 mass ratio,
The polyamide resin composition according to any one of claims 1 to 10. Further comprising 1 to 300 parts by mass of glass fiber (D) based on 100 parts by mass of the polyamide resin (A),
The polyamide resin composition according to any one of claims 1 to 11. Further comprising 1 to 100 parts by mass of a flame retardant (E) per 100 parts by mass of the polyamide resin (A),
The polyamide resin composition according to any one of claims 1 to 12. The polyamide resin (A) has a glass transition temperature measured by differential scanning calorimetry (DSC) of 60°C or more and less than 100°C.
The polyamide resin composition according to any one of claims 1 to 13. The fracture energy when a bending test was conducted on a rectangular test piece of a polyamide resin composition with a length of 64 mm, a width of 6 mm, and a thickness of 0.8 mm under the conditions of a distance between supports of 26 mm, a loading rate of 5 mm/min, and a temperature of 23 ° C. , 55 mJ or more,
The polyamide resin composition according to any one of claims 1 to 14. Comprising the polyamide resin composition according to any one of claims 1 to 15,
Molded object. Used in electrical and electronic parts,
The molded article according to claim 16.