Polyamide resin compositions and their uses

Abstract

To provide a polyamide resin composition with excellent fluidity. [Solution] A polyamide resin composition is prepared by blending a fatty acid metal salt having 3 to 6 carbon atoms with a polyamide resin. The fatty acid metal salt may be at least one salt selected from monovalent metal salts and divalent metal salts. The fatty acid of the fatty acid metal salt may have a hydroxyl group. The number of carbon atoms of the fatty acid metal salt may be 4 to 6. The fatty acid metal salt may be a hydroxybutyrate metal salt. The fatty acid metal salt may be a 3-hydroxybutyrate metal salt. The polyamide resin may contain an aliphatic polyamide resin. The polyamide resin composition may further contain a resin reinforcing material.

Description

Technical Field

[0001] The present disclosure relates to a polyamide resin composition and its uses.

Background Art

[0002] Polyamide resins are used in various technical fields because of their excellent mechanical properties and heat resistance.

[0003] International Publication No. 2016 / 139826 (Patent Document 1) discloses a polyamide resin composition containing a compound having a 9,9-bisarylfluorene skeleton as a fluidity improver.

[0004] Japanese Patent No. 4678979 (Patent Document 2) discloses a glass fiber reinforced polyamide resin composition containing 20 to 170 parts by mass of glass fiber, 0.01 to 5 parts by mass of a higher fatty acid amide compound, and 0.001 to 5 parts by mass of a higher fatty acid metal salt having an acid value of 0.5 mgKOH / g or less with respect to 100 parts by mass of the polyamide resin.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Polyamide resins have high melt viscosity due to strong intermolecular hydrogen bonding, resulting in low fluidity and moldability. For example, polyamide resins have a relatively high melting point, requiring heating at a temperature higher than the melting point for molding. Furthermore, the melt viscosity of polyamide resins is highly temperature-dependent, and the decomposition temperature is close to the melting point, requiring strict temperature control. Therefore, a method of adding plasticizers to relax intermolecular hydrogen bonding, thereby lowering the melt viscosity of polyamide resins and improving moldability, is known. However, the addition of plasticizers degrades the mechanical properties of polyamide resins. Therefore, it is difficult to improve moldability while suppressing the degradation of mechanical properties.

[0007] In contrast, the polyamide resin composition described in Patent Document 1 is a composition that achieves both mechanical properties and fluidity (melt flow rate), but its fluidity is not sufficient and does not have sufficient fluidity when injection molding into a mold having a cavity with a fine shape and flow channel. Furthermore, the glass fiber reinforced polyamide resin composition described in Patent Document 2 also does not have high fluidity.

[0008] Therefore, the object of this disclosure is to provide polyamide resin compositions with excellent fluidity (particularly melt fluidity) and their applications. [Means for solving the problem]

[0009] As a result of diligent research to solve the aforementioned problems, the inventors discovered that fluidity can be improved by incorporating fatty acid metal salts having 3 to 6 carbon atoms into polyamide resins, and thus completed the present invention (or present disclosure).

[0010] In other words, this disclosure includes the following aspects:

[0011] Embodiment [1]: A polyamide resin composition comprising a polyamide resin and a fatty acid metal salt having 3 to 6 carbon atoms.

[0012] Embodiment [2]: The polyamide resin composition of Embodiment [1], wherein the fatty acid metal salt is at least one salt selected from monovalent metal salts and divalent metal salts.

[0013] Embodiment [3]: A polyamide resin composition according to Embodiment [1] or [2], wherein the fatty acid constituting the fatty acid metal salt has a hydroxyl group.

[0014] Embodiment [4]: ​​A polyamide resin composition according to any of Embodiments [1] to [3], wherein the fatty acid metal salt has 4 to 6 carbon atoms.

[0015] Embodiment [5]: A polyamide resin composition according to any of Embodiments [1] to [4], wherein the fatty acid metal salt is a hydroxybutyrate metal salt.

[0016] Embodiment [6]: A polyamide resin composition according to any of Embodiments [1] to [5], wherein the fatty acid metal salt is a 3-hydroxybutyrate metal salt.

[0017] Embodiment [7]: A polyamide resin composition according to any of Embodiments [1] to [6], wherein the polyamide resin comprises an aliphatic polyamide resin.

[0018] Embodiment [8]: A polyamide resin composition according to any of Embodiments [1] to [7], further comprising a resin reinforcing material.

[0019] Embodiment [9]: A molded article comprising any of the polyamide resin compositions of Embodiments [1] to [8].

[0020] Embodiment

[10] : A molded body according to Embodiment [9], which is at least one selected from the group consisting of automotive components, office automation (OA) equipment components, electrical or electronic components, mechanical components, containers, packaging materials, fibers and fiber structures.

[0021] Embodiment

[11] : A fluidity improving agent for improving the fluidity of a polyamide resin, comprising a fatty acid metal salt having 3 to 6 carbon atoms.

[0022] Embodiment

[12] : A method for improving the fluidity of a polyamide resin by blending it with a fatty acid metal salt having 3 to 6 carbon atoms.

[0023] This disclosure may also achieve the following secondary objectives (solve problems):

[0024] Another object of this disclosure is to provide polyamide resin compositions with excellent fluidity while maintaining (or significantly reducing) mechanical properties, and applications thereof.

[0025] In this specification and in the claims, the number of carbon atoms in substituents, etc., is defined as C1, C6, C 10 It is sometimes indicated in these ways. For example, "C1 alkyl group" means an alkyl group with 1 carbon atom, and "C 6-10 The term "aryl group" refers to an aryl group with 6 to 10 carbon atoms.

[0026] Furthermore, when "X~Y" is used to indicate a numerical range in this specification and the claims, it may include the end numbers X and Y. [Effects of the Invention]

[0027] This disclosure provides polyamide resin compositions with excellent fluidity and their applications. [Modes for carrying out the invention]

[0028] [Polyamide resin] The polyamide resin composition of this disclosure comprises a polyamide resin. Conventional polyamide resins can be used as the polyamide resin. The polyamide resin may be formed of at least one monomer component selected from the group consisting of aliphatic monomers, alicyclic monomers, and aromatic monomers.

[0029] In this specification and in the claims, the monomer having a carboxyl group, such as a dicarboxylic acid described later, may also be an amide-forming derivative, such as an acid halide such as an acid chloride, or an acid anhydride.

[0030] Examples of aliphatic monomers include aliphatic diamines, aliphatic dicarboxylic acids, aliphatic aminocarboxylic acids, lactams, and the like.

[0031] Examples of aliphatic diamines include C alkylene diamines such as tetramethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, nonamethylenediamine, 2-methyloctamethylenediamine, trimethylhexamethylenediamine, decamethylenediamine, dodecamethylenediamine, etc. 2-20 alkylene diamine (linear or branched C 2-20 alkylene diamine), etc. Among these, C 4-16 alkylene diamine is preferred, and C 6-12 alkylene diamine is particularly preferred.

[0032] Examples of aliphatic dicarboxylic acids include saturated aliphatic dicarboxylic acids (alkanedicarboxylic acids), unsaturated aliphatic dicarboxylic acids, and the like.

[0033] Examples of alkanedicarboxylic acids (linear or branched alkanedicarboxylic acids) include C alkanedicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, etc. 1-20 alkane-dicarboxylic acid, etc. Among these, C 2-16 alkane-dicarboxylic acid is preferred, and C alkanedicarboxylic acids such as adipic acid, sebacic acid, 1,10-decanedicarboxylic acid, etc. 4-12 alkane-dicarboxylic acid is particularly preferred.

[0034] Examples of unsaturated aliphatic dicarboxylic acids include C alkenedicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, etc. 2-10 alkene-dicarboxylic acid, etc.

[0035] Examples of aliphatic aminocarboxylic acids include aminocarboxylic acids such as 6-aminohexanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, etc. 2-20 alkyl-carboxylic acid, etc. Among these, amino C 3-16Alkyl carboxylic acids are preferred, and amino C 5-11 Alkyl carboxylic acids are particularly preferred.

[0036] The lactam may be any lactam corresponding to the aliphatic aminocarboxylic acid, such as 4- to 13-membered ring lactams like ε-caprolactam and ω-laurolactam. Of these, 7- to 13-membered ring lactams are preferred.

[0037] Alicyclic monomers only need to have an alicyclic skeleton (or an aliphatic hydrocarbon ring skeleton). Examples of alicyclic monomers include alicyclic diamines, alicyclic dicarboxylic acids, and alicyclic aminocarboxylic acids.

[0038] Examples of alicyclic diamines include diaminocycloalkanes, bis(aminoalkyl)cycloalkanes, and bis(aminocyclohexyl)alkanes.

[0039] Examples of diaminocycloalkanes include diaminocyclohexane and other diamino-C 5-10 Examples include cycloalkanes.

[0040] Examples of bis(aminoalkyl)cycloalkanes include bis(aminomethyl)cyclohexane and other bis(aminoC 1-4 Alkyl)C 5-10 Examples include cycloalkanes.

[0041] Examples of bis(aminocyclohexyl)alkanes include bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, and other bis(aminocyclohexyl)C 1-6 Alkanes; such as bis(4-amino-3-methylcyclohexyl)methane, bis(4-amino-3,5-dimethylcyclohexyl)methane, 2,2-bis(4-amino-3-methylcyclohexyl)propane, etc. (bis(amino-mono or tri-C)) 1-6 Alkyl-C 5-10 Cycloalkyl)C 1-6 Alkanes are one example.

[0042] Examples of alicyclic dicarboxylic acids include cycloalkanedicarboxylic acids, crosslinked cyclic cycloalkanedicarboxylic acids, cycloalkenedicarboxylic acids, and crosslinked cyclic cycloalkenedicarboxylic acids.

[0043] Examples of cycloalkanedicarboxylic acids include C1,4-cyclohexanedicarboxylic acid. 5-10 Examples include cycloalkane-dicarboxylic acids.

[0044] Examples of crosslinked cyclic cycloalkanedicarboxylic acids include decalindicarboxylic acid, norbornanedicarboxylic acid, adamantanedicarboxylic acid, tricyclodecanedicarboxylic acid, and other bi or tricycloalkanedicarboxylic acids.

[0045] Examples of cycloalkenedicarboxylic acids include C15, such as cyclohexenedicarboxylic acid. 5-10 Examples include cycloalkene-dicarboxylic acids.

[0046] Examples of cross-linked cyclic cycloalkenedicarboxylic acids include bi- or tricycloalkenedicarboxylic acids such as norbornenedicarboxylic acid.

[0047] Examples of alicyclic aminocarboxylic acids include aminocycloalkanecarboxylic acids. Examples of aminocycloalkanecarboxylic acids include aminocyclohexanecarboxylic acid and other aminoC 5-10 Examples include cycloalkane-carboxylic acids.

[0048] Aromatic monomers only need to have an aromatic ring skeleton. Examples of aromatic monomers include aromatic (or aromatic aliphatic) diamines, aromatic (or aromatic aliphatic) dicarboxylic acids, and aromatic (or aromatic aliphatic) aminocarboxylic acids.

[0049] Examples of aromatic (or aromatic aliphatic) diamines include diaminoarenes and bis(aminoalkyl)arenes. Diaminoarenes include diaminoC such as m-phenylenediamine and p-phenylenediamine. 6-14 Examples include arenes. Bis(aminoalkyl)arenes include bis(aminoC) such as m-xylylenediamine. 1-4 Examples include alkylarenes.

[0050] Examples of aromatic (or aromatic aliphatic) dicarboxylic acids include benzenedicarboxylic acids, alkylbenzenedicarboxylic acids, polycyclic allenedicarboxylic acids, diarylalkanedicarboxylic acids, diarylketonedicarboxylic acids, diaryletherdicarboxylic acids, diarylsulfidedicarboxylic acids, and diarylsulfonedicarboxylic acids.

[0051] Examples of benzenedicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid. Examples of alkylbenzenedicarboxylic acids include 4-methylisophthalic acid and 5-methylisophthalic acid. 1-4 Examples include alkylbenzene dicarboxylic acids.

[0052] Examples of polycyclic arenedicarboxylic acids include condensed polycyclic arenedicarboxylic acids and ring-assembled arenedicarboxylic acids.

[0053] Examples of condensed polycyclic arenedicarboxylic acids include naphthalenedicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid; anthracenedicarboxylic acids; and phenantradicarboxylic acids. 10-24 Examples include arene-dicarboxylic acids. Among these, condensed polycyclic C1 10-14 Arene dicarboxylic acids are preferred.

[0054] Examples of ring-assembled allene dicarboxylic acids include 2,2'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and other biphenyldicarboxylic acids. 6-10 Examples include arene-dicarboxylic acids.

[0055] Examples of diarylalkanedicarboxylic acids include diC such as 4,4'-diphenylmethanedicarboxylic acid. 6-10 Aryl C 1-6 Examples include alkane-dicarboxylic acids.

[0056] Examples of diarylketone dicarboxylic acids include di(C) such as 4,4'-diphenylketone dicarboxylic acid. 6-10 Examples include aryl)ketone-dicarboxylic acids.

[0057] Examples of diaryl ether dicarboxylic acids include di(C) such as 4,4'-diphenyl ether dicarboxylic acid. 6-10 Examples include aryl) ether-dicarboxylic acids.

[0058] Examples of diarylsulfide dicarboxylic acids include di(C)(4,4'-diphenylsulfide dicarboxylic acid. 6-10 Examples include aryl sulfide dicarboxylic acids.

[0059] Diaryl sulfone dicarboxylic acids include di(C) such as 4,4'-diphenyl sulfone dicarboxylic acid. 6-10 Examples include aryl)sulfone-dicarboxylic acids.

[0060] Examples of aromatic aminocarboxylic acids include aminoarenecarboxylic acids. Examples of aminoarenecarboxylic acids include aminobenzoic acid and other amino C 6-12 Examples include arene-carboxylic acids.

[0061] Polyamide resins can be formed by using these monomer components individually or in combination of two or more. For example, they may be formed by polymerization of diamines and dicarboxylic acids, polymerization of aminocarboxylic acids and / or lactams, or polymerization of diamines and dicarboxylic acids with aminocarboxylic acids and / or lactams. Furthermore, polyamide resins may be homopolyamides formed from a single monomer (a single diamine and dicarboxylic acid, a single aminocarboxylic acid, or a single lactam), or copolyamides formed by copolymerization of multiple monomers. Typical polyamide resins include aliphatic polyamide resins, alicyclic polyamide resins, and aromatic polyamide resins.

[0062] Aliphatic polyamide resins only need to be formed from aliphatic monomer units. Examples of aliphatic polyamide polymers include homopolyamides of aliphatic diamines and aliphatic dicarboxylic acids such as polyamide 46, polyamide 66, polyamide 610, and polyamide 612; homopolyamides of aliphatic aminocarboxylic acids and / or corresponding lactams such as polyamide 6, polyamide 11, and polyamide 12; and copolymers (copolyamides) of multiple aliphatic monomers such as copolyamide 6 / 66, copolyamide 6 / 11, and copolyamide 66 / 12.

[0063] Alicyclic polyamide resins only need to have alicyclic monomer units, and may be formed by combining aliphatic monomers and alicyclic monomers. Examples of alicyclic polyamide resins include homopolyamides of alicyclic diamines and aliphatic dicarboxylic acids, such as polymers of diaminomethylcyclohexane and adipic acid.

[0064] Aromatic polyamide resins only need to have at least aromatic monomer units. Examples of aromatic polyamide resins include semi-aromatic polyamide resins formed from aromatic monomers and aliphatic or alicyclic monomers, and fully aromatic polyamide resins formed from aromatic monomers and not containing aliphatic or alicyclic monomers.

[0065] Examples of semi-aromatic polyamide resins include homopolyamides of aromatic (or aromatic aliphatic) diamines and aliphatic dicarboxylic acids, such as polyamide MXD6 (polymer of m-xylylenediamine and adipic acid); polyamide 6T (polymer of hexamethylenediamine and terephthalic acid); polyamide 9T (polymer of nonamethylenediamine and terephthalic acid); polyamide 10T (polymer of decamethylenediamine and terephthalic acid); polyamide 12T (polymer of dodecamethylenediamine and terephthalic acid); and polyamide M5T (polymer of 2-methylpentamethylenediamine and terephthalic acid). Examples include homopolyamides of aliphatic diamines and aromatic dicarboxylic acids, such as polymers with phthalic acid, polyamide M8T (polymer of 2-methyloctamethylenediamine and terephthalic acid), polyamide 6I (polymer of hexamethylenediamine and isophthalic acid), and polymers of trimethylhexamethylenediamine and terephthalic acid; and copolymers containing at least an aliphatic diamine and an aromatic dicarboxylic acid, such as copolyamide 6T / 66, copolyamide 6T / M5T, copolyamide 6T / 6I, copolyamide 6T / 6I / 6, and copolyamide 6T / 6I / 66.

[0066] Examples of fully aromatic polyamide resins include homopolyamides of aromatic diamines and aromatic dicarboxylic acids, such as polymers of m-phenylenediamine and isophthalic acid, and polymers of p-phenylenediamine and terephthalic acid.

[0067] In this specification and in the claims, the " / " in "copolyamide" means that the monomers (units) described before and after it are used as copolymer components (copolymer units) to form the copolyamide. That is, copolyamide 6 / 66 means that it is a copolymer having units that form polyamide 6 and units that form polyamide 66.

[0068] The polyamide resin may be a polyamide having an N-alkoxymethyl group, or a polymerized fatty acid polyamide resin using dimer acid, which is a dimer of an unsaturated higher fatty acid, as the polymerization component. The polyamide resin may also be crystalline or amorphous, and may be a transparent polyamide resin (amorphous transparent polyamide resin). From the viewpoint of the mechanical properties of the molded product, a crystalline resin is preferred.

[0069] These polyamide resins may be used individually or in combination of two or more. Among these polyamide resins, aliphatic polyamide resins are preferred. Furthermore, the polyamide resin is preferably formed from monomers containing aliphatic monomers having, for example, about 4 to 12 carbon atoms, preferably 6 to 11, more preferably 6 to 9 carbon atoms, and in particular, aliphatic polyamide resins formed from aliphatic monomers having the aforementioned number of carbon atoms and alkylene groups are preferred. Typical preferred aliphatic polyamide resins are homopolyamides of aliphatic diamines and aliphatic dicarboxylic acids such as polyamide 46, polyamide 66, polyamide 610, and polyamide 612; and homopolyamides of aliphatic aminocarboxylic acids and / or corresponding lactams such as polyamide 6, polyamide 11, and polyamide 12.

[0070] The number-average molecular weight Mn of polyamide resins (especially aliphatic polyamide resins) is, for example, 7,000 to 1,000,000, preferably in the following increments: 10,000 to 750,000, 20,000 to 700,000, 30,000 to 600,000, and 50,000 to 500,000.

[0071] In this specification and in the claims, the number-average molecular weight of polyamide resins can be measured using gel permeation chromatography (GPC) and evaluated as the molecular weight in terms of polystyrene.

[0072] The proportion of polyamide resin (especially aliphatic polyamide resin) may be 10% by mass or more in the polyamide resin composition, and preferably in the following increments: 30-99.99% by mass, 50-99.95% by mass, 70-99.93% by mass, 80-99.92% by mass, 90-99.9% by mass, 95-99.8% by mass, 99-99.7% by mass, and 99.3-99.6% by mass.

[0073] [Fatty acid metal salts with 3 to 6 carbon atoms] The polyamide resin composition disclosed herein is a fatty acid metal salt (hereinafter referred to as "C") having 3 to 6 carbon atoms (total carbon number). 3-6 By incorporating a fatty acid metal salt (also called a "fatty acid metal salt") into a polyamide resin, the fluidity of the polyamide resin can be improved. Therefore, C 3-6 Fatty acid metal salts may also be used as fluidity improvers for polyamide resins.

[0074] C 3-6 The fatty acids (aliphatic monocarboxylic acids) that constitute the fatty acid metal salt are not particularly limited as long as they have 3 to 6 carbon atoms. 3-6 Examples of fatty acids include linear or branched C2 compounds such as propanoic acid, butanoic acid (butyric acid), dimethylacetic acid (isobutyric acid), pentanoic acid (valeric acid), hexanoic acid (caproic acid), and 3-methylbutanoic acid. 3-6 Alkanic acid (C 2-5 Examples include alkanes and carboxylic acids. Of these, C is chosen because it is easier to improve the fluidity of polyamide resins. 4-5 Alkano acids are preferred, and linear C4 alkano acids are particularly preferred.

[0075] C 3-6 Fatty acids may have a hydroxyl group. 3-6Examples of fatty acids include 2-hydroxypropanoic acid (lactic acid), 3-hydroxypropanoic acid, 2-hydroxybutanoic acid (2-hydroxybutyric acid), 3-hydroxybutanoic acid (3-hydroxybutyric acid), 4-hydroxybutanoic acid, 3-hydroxy-3-methylbutanoic acid, 2-hydroxypentanoic acid (2-hydroxyvaleric acid), 3-hydroxypentanoic acid, 5-hydroxypentanoic acid, 2-hydroxy-2-methylpentanoic acid, 3-hydroxyhexanoic acid, and 6-hydroxyhexanoic acid. The above fatty acids do not necessarily have hydroxyl groups, but it is preferable that they have hydroxyl groups in order to improve the fluidity of the polyamide resin and / or impart to the polyamide resin a boiling point that can withstand kneading.

[0076] These C 3-6 Fatty acids (fatty acids with 3 to 6 carbon atoms that may have hydroxyl groups) can be used alone or in combination of two or more types.

[0077] These C 3-6 Fatty acids (which may have a hydroxyl group) 3-6 Among fatty acids, hydroxy C is chosen because it easily improves the fluidity of polyamide resins. 4-6 Alkanic acid is preferred, and hydroxy C 4-5 Alkano acids are more preferred, hydroxybutyric acid is more preferred, and 3-hydroxybutyric acid is most preferred.

[0078] 3-hydroxybutyric acid (3HB or BHB) may be an optical isomer (R-isomer or S-isomer) or a racemic mixture, but from the viewpoint of biodegradability and other factors, it is preferable to contain at least the R-isomer (R-3-hydroxybutyric acid or D-β-hydroxybutyric acid).

[0079] The proportion of the R-isomer in 3HB, particularly the optical purity (enantiomer or optical isomer excess), is, for example, 50% ee or more (e.g., 80% ee or more), preferably 90% ee or more (e.g., 95-100% ee), and more preferably 98-100% ee (e.g., 99-100% ee, especially substantially 100% ee).

[0080] Furthermore, 3HB may be used in combination with the R-isomer [(R)3HB] and the S-isomer [(S)3HB] and / or a racemic mixture, but the mass proportion of the R-isomer in 3HB is preferably 10% by mass or more, more preferably 50% by mass or more, more preferably 90% by mass or more, and most preferably 100% by mass.

[0081] Commercially available 3HB can be used. Examples of commercially available 3HB include chemically synthesized 3HB and 3HB produced by fermentation using microorganisms.

[0082] Examples of metal salts include alkali metal salts such as sodium, potassium, and lithium salts; alkaline earth metal salts such as magnesium and calcium salts; Group 12 metal salts such as zinc and cadmium salts; and Group 13 metal salts such as aluminum salts. These metal salts can be used individually or in combination of two or more types.

[0083] Among these metal salts, 1-2 valent metal salts (at least one selected from monovalent and divalent metal salts) such as alkali metals, alkaline earth metals, and Group 12 metals of the periodic table are also preferred because they easily improve the fluidity of polyamide resins. At least one salt selected from the group consisting of Ca, Mg, Na, and Zn is preferred, at least one salt selected from the group consisting of Ca, Mg, and Na is more preferred, and Mg salts and / or Ca salts are more preferred because they easily improve fluidity to a high degree, with Mg salts being the most preferred.

[0084] Polyamide resins (especially aliphatic polyamide resins) and C 3-6 fatty acid metal salt (which may have a hydroxyl group C) 3-6 The ratio (mass ratio) of fatty acid metal salts (especially 3HB salts) is, for example, that of polyamide resin / C 3-6The fatty acid metal salt can be selected from a range of approximately 10 / 90 to 99.99 / 0.01, preferably in the following increments: 30 / 70 to 99.99 / 0.01, 50 / 50 to 99.95 / 0.05, 70 / 30 to 99.93 / 0.07, 80 / 20 to 99.92 / 0.08, 90 / 10 to 99.9 / 0.1, 95 / 5 to 99.8 / 0.2, 99 / 1 to 99.7 / 0.3, and 99.3 / 0.7 to 99.6 / 0.4. 3-6 When the proportion of fatty acid metal salts is above the lower limit, the fluidity of polyamide resins is easily improved, C 3-6 When the proportion of fatty acid metal salts is below the upper limit, the mechanical properties of the polyamide resin composition are more easily maintained.

[0085] When using a polyamide resin composition as a masterbatch, the polyamide resin (especially aliphatic polyamide resin) and C 3-6 fatty acid metal salt (which may have a hydroxyl group C) 3-6 The ratio (mass ratio) of fatty acid metal salts (especially 3HB salts) to polyamide resin / C 3-6 The fatty acid metal salt can be selected from a range of approximately 10 / 90 to 99 / 1, preferably in the following increments: 20 / 80 to 93 / 7, 30 / 70 to 95 / 5, and 40 / 60 to 90 / 10.

[0086] C 3-6 Fatty acid metal salts can also be used as flow improvers for polyamide resins. The flow improver of this disclosure is C 3-6 It is sufficient if it contains a fatty acid metal salt, but C 3-6 It is preferable that the material be composed solely of fatty acid metal salts.

[0087] [Other fatty acids or their salts] The polyamide resin compositions disclosed herein may be C as long as they do not impair the effects of the disclosure. 3-6 It may contain fatty acids other than fatty acid metal salts or their salts (other fatty acids or their salts).

[0088] Other fatty acids or their salts include formic acid or its salts, acetic acid or its salts, glycolic acid or its salts, C 3-6 Fatty acids (which may have a hydroxyl group)3-6 fatty acids), C 3-6 Salts of fatty acids and amines, C 3-6 Salts of fatty acids and basic amino acids, C 7-24 Examples include fatty acids (fatty acids with a total of 7 to 24 carbon atoms, which may have hydroxyl groups) or their salts. These other fatty acids or their salts can be used individually or in combination of two or more.

[0089] C 3-6 As for fatty acids, the above C 3-6 C of fatty acid metal salts 3-6 C is an example of a fatty acid. 3-6 Examples include fatty acids.

[0090] C 7-24 Examples of fatty acids include heptanoic acid, 6-hydroxyheptanoic acid, 3-hydroxyheptanoic acid, 7-hydroxyheptanoic acid, octanoic acid, 3-hydroxyoctanoic acid, 8-hydroxyoctanoic acid, nonanoic acid, 3-hydroxynonanoic acid, 9-hydroxynonanoic acid, decanoic acid, 3-hydroxydecanoic acid, 10-hydroxydecanoic acid, etc. 7-12 Examples include alkanic acids.

[0091] Glycolic acid and C 7-24 As the fatty acid salt, a metal salt is preferred. Among metal salts, at least one salt selected from the group consisting of Ca, Mg, Na, and Zn is preferred, at least one salt selected from the group consisting of Ca, Mg, and Na is more preferred, Mg salts and / or Ca salts are more preferred, and Mg salts are most preferred.

[0092] These other fatty acids or their salts can be used alone or in combination of two or more. Among these, hydroxy-C fatty acids such as 6-hydroxyheptanoic acid and 3-hydroxyheptanoic acid are used. 7-9 Metal salts of alkanic acids are preferred.

[0093] The proportion of other fatty acids or their salts may be 10 parts by mass or less (0 to 10 parts by mass) per 100 parts by mass of the polyamide resin, preferably 5 parts by mass or less, more preferably 1 part by mass or less, more preferably 0.1 parts by mass or less, even more preferably 0.01 parts by mass or less, and most preferably 0 parts by mass. In the polyamide resin composition of this disclosure, C 3-6 Since the fluidity can be improved by the fatty acid metal salt, other fatty acids or their salts may not be substantially present, and it is particularly preferable that they are not present at all.

[0094] Furthermore, the polyamide resin composition of this disclosure is C 3-6 As an impurity of fatty acid metal salts, hydroxy C 3-6 It may contain fatty acids and their oligomers. In that case, hydroxy C 3-6 The proportion of fatty acids and their oligomers is C 3-6 For every 100 parts by mass of the fatty acid metal salt, the amount may be, for example, 10 parts by mass or less, preferably 0.001 to 5 parts by mass, more preferably 0.01 to 3 parts by mass, and more preferably 0.01 to 1 part by mass.

[0095] [Resin reinforcement material] The polyamide resin composition of this disclosure may further contain a resin reinforcing material (resin strengthening material or resin filler) because it is easy to improve mechanical properties such as flexural strength, flexural modulus, tensile strength, and impact strength.

[0096] Examples of resin reinforcing materials include granular (non-fibrous) reinforcing materials and fibrous reinforcing materials.

[0097] Examples of granular reinforcing materials include carbonaceous materials such as carbon black and graphite; metal oxides such as calcium oxide, magnesium oxide, barium oxide, iron oxide, copper oxide, titanium oxide, and aluminum oxide (alumina); metal silicates such as calcium silicate and aluminum silicate; metal carbides such as silicon carbide and tungsten carbide; metal nitrides such as titanium nitride, aluminum nitride, and boron nitride; metal carbonates such as magnesium carbonate and calcium carbonate; metal sulfates such as calcium sulfate and barium sulfate; and mineral materials such as zeolite, diatomaceous earth, calcined diatomaceous earth, activated clay, silica, talc, mica, kaolin, sericite, bentonite, montmorillonite, smectite, and clay.

[0098] Examples of fibrous reinforcing materials include organic fibers and inorganic fibers. Examples of organic fibers include cellulose fibers, modified or unmodified cellulose fibers (fibers of cellulose or its derivatives) such as cellulose acetate fibers, and polyester fibers such as polyalkylene arylate fibers. Examples of inorganic fibers include glass fibers, carbon fibers, boron fibers, wollastonite, and metal fibers such as whiskers. Examples of carbon fibers include polyacrylonitrile (PAN) carbon fibers, isotropic pitch carbon fibers, mesophase pitch carbon fibers, and vapor-grown carbon fibers.

[0099] These resin reinforcing materials can be used individually or in combination of two or more. Among these, C is particularly likely to increase the viscosity of the resin composition and acts as a fluidity improver. 3-6 Fibrous reinforcing materials are preferred because fatty acid metal salts can act effectively on them. Among fibrous reinforcing materials, modified or unmodified cellulose fibers and inorganic fibers are preferred, inorganic fibers are more preferred, glass fibers and carbon fibers are even more preferred, and glass fibers are most preferred.

[0100] Examples of glass components used to form glass fibers include E glass (alkali-free electrical insulating glass), S glass (high-strength glass), C glass (chemical glass), A glass (general-purpose alkali-containing glass), and YM-31-A glass (high-elasticity glass). Of these, E glass, C glass, and S glass are preferred from the viewpoint of mechanical properties, with E glass being particularly preferred. Glass fibers formed from these glass components can be used individually or in combination of two or more types.

[0101] The fibrous reinforcing material may take the form of short or long fibers, depending on the application, and may also be a fabric such as a woven, knitted, or nonwoven material. These fibrous reinforcing materials can be used alone or in combination of two or more types. Short fibers are preferred because they easily improve fluidity.

[0102] The average fiber length of the fibrous reinforcing material (or, in the case of a fabric, the average fiber length of the fibers constituting the fabric) may be selected from a range of approximately 0.1 to 10 mm, and preferably in the following increments: 0.2 to 8 mm, 0.5 to 6 mm, and 1 to 4 mm. Furthermore, the average fiber length of the fibrous reinforcing material in the polyamide resin composition or molded article may be shorter than before mixing due to the effects of mixing (kneading) when preparing the resin composition and shear force during molding, for example, 0.05 to 5 mm, preferably 0.1 to 3 mm, and more preferably 0.2 to 1 mm.

[0103] The average fiber diameter (filament diameter) of the fibrous reinforcing material may be on the order of nanometers. Examples of such fibrous reinforcing materials include modified or unmodified cellulose nanofibers, carbon nanotubes, carbon nanocoils, and carbon nanofibers. From the viewpoint of mechanical strength, the average fiber diameter (filament diameter) may be selected from the order of microns, for example, in the range of about 1 to 200 μm, preferably 3 to 100 μm, more preferably 4 to 30 μm, and particularly 5 to 15 μm.

[0104] The cross-sectional shape of the fibrous reinforcing material can be circular, elliptical, polygonal, etc. Furthermore, the fibrous reinforcing material may be subjected to conventional surface treatments, including treatment with surface treatment agents such as sizing agents and silane coupling agents.

[0105] The ratio of polyamide resin to resin reinforcing material can be selected from a range of approximately 99 / 1 to 20 / 80, preferably in increments of 90 / 10 to 30 / 70, 80 / 20 to 35 / 65, 70 / 30 to 40 / 60, 60 / 40 to 45 / 55, and 55 / 45 to 45 / 55. When the ratio of resin reinforcing material is above the lower limit, it tends to improve mechanical properties, and when it is below the upper limit, it tends to improve fluidity.

[0106] [Other ingredients] The polyamide resin composition of this disclosure may further contain various additives as needed. These additives may include aliphatic polycarboxylic acids or their salts, which may have hydroxyl groups; colorants such as dyes and pigments; conductive agents; flame retardants; plasticizers; lubricants; stabilizers; mold release agents; antistatic agents; dispersants; flow regulators; leveling agents; defoaming agents; surface modifiers; stress reducers; carbon materials; and the like. Examples of stabilizers include antioxidants, ultraviolet absorbers, and heat stabilizers. These additives may be used individually or in combination of two or more.

[0107] The total proportion of the other components may be 30 parts by mass or less (0 to 30 parts by mass) per 100 parts by mass of the polyamide resin, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and more preferably 5 parts by mass or less.

[0108] The proportion of aliphatic polycarboxylic acid or its salt, which may have a hydroxyl group, may be 30 parts by mass or less (0 to 10 parts by mass) per 100 parts by mass of polyamide resin, preferably 5 parts by mass or less, more preferably 3 parts by mass or less, more preferably 0.1 parts by mass or less, even more preferably 0.01 parts by mass or less, and most preferably 0 parts by mass.

[0109] [Methods for preparing polyamide resin compositions and their properties] The polyamide resin composition disclosed herein comprises a polyamide resin and C 3-6 The polyamide resin composition can be prepared by mixing fatty acid metal salts (flow improvers) with other components such as resin reinforcing agents and additives as needed, using conventional methods such as dry mixing or melt kneading. The polyamide resin composition may also be in the form of pellets or other similar materials.

[0110] When melt-kneading, the kneading temperature is, for example, 105 to 350°C, preferably 200 to 320°C, more preferably 220 to 300°C, more preferably 240 to 280°C, and most preferably 250 to 270°C.

[0111] Conventional methods for melt-mixing include mixing rollers, kneaders, Banbury mixers, and extruders (such as single-screw or twin-screw extruders). Of these methods, kneaders and twin-screw extruders capable of applying high shear force are preferred.

[0112] Mixing can be carried out in air or under an inert gas atmosphere (such as nitrogen or argon), and in an open system, but it is usually carried out in a closed mixing system.

[0113] The polyamide resin composition disclosed herein has excellent fluidity. The melt flow rate (MFR) of the polyamide resin composition disclosed herein is C 3-6 When the MFR of a polyamide resin alone without added fatty acid metal salts (hereinafter simply referred to as "blank") is set to 100, it may be 110 or higher, and preferably in the following increments: 110-1000, 130-800, 150-500, 180-400, and 200-300. The MFR of the blank is, for example, 5-100 g / 10 min, preferably in the following increments: 7-60 g / 10 min and 8-50 g / 10 min.

[0114] The polyamide resin compositions disclosed herein may also be able to improve fluidity without excessively degrading mechanical properties.

[0115] The tensile strength of the polyamide resin composition disclosed herein may be, for example, about 80 to 120, preferably 85 to 115, more preferably 90 to 110, and particularly 95 to 105, when the tensile strength of the blank is set to 100. The tensile strength of the blank is, for example, 10 to 300 MPa, preferably in stages below, 30 to 200 MPa, 40 to 150 MPa, 45 to 100 MPa, and 50 to 90 MPa.

[0116] The flexural strength of the polyamide resin composition disclosed herein may be, for example, about 90 to 150, preferably 95 to 140, more preferably 100 to 130, and particularly 105 to 120, when the flexural strength of the blank is set to 100. The flexural strength of the blank is, for example, 10 to 300 MPa, preferably, in stages, 20 to 200 MPa, 30 to 150 MPa, 35 to 130 MPa, and 40 to 110 MPa.

[0117] The flexural modulus of the polyamide resin composition disclosed herein may be, for example, about 90 to 150, preferably 95 to 130, and particularly 100 to 120, when the flexural modulus of the blank is set to 100. The flexural modulus of the blank is, for example, 500 to 5000 MPa, preferably in stages below, 700 to 4000 MPa, 800 to 3500 MPa, 900 to 3000 MPa, and 1000 to 2800 MPa.

[0118] In this specification and in the claims, MFR, tensile strength, flexural strength, and flexural modulus can be measured by the methods described in the examples below.

[0119] [Molded body] The polyamide resin composition of this disclosure has excellent fluidity while maintaining mechanical properties, and therefore can form molded articles with excellent mechanical properties with high moldability (or productivity). The shape of the molded article is not particularly limited and can be selected according to the application, and may be a one-dimensional structure such as a linear, thread-like or fibrous structure, a two-dimensional structure such as a film-like, sheet-like or plate-like structure, or a three-dimensional structure such as a block-like, rod-like, tubular or hollow structure.

[0120] Molded articles can be manufactured using conventional molding methods such as compression molding, injection molding, injection compression molding, extrusion molding, transfer molding, blow molding, pressure molding, and casting molding. [Examples]

[0121] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to these examples. The raw materials, equipment used in the examples, and methods for evaluating the polyamide resin compositions prepared in the examples are as follows.

[0122] [Raw materials] (Additives) BPEF(registered trademark): 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene, manufactured by Osaka Gas Chemical Co., Ltd. BHB-Na: D-β-hydroxybutyrate sodium salt, manufactured by Osaka Gas Co., Ltd. "OKETOA (registered trademark)" BHB-Mg: D-β-hydroxybutyrate magnesium salt, manufactured by Osaka Gas Co., Ltd. "OKETOA (registered trademark)" BHB-Ca: D-β-hydroxybutyrate calcium salt, manufactured by Osaka Gas Co., Ltd. "OKETOA (registered trademark)" DL-Calcium Lactate: "Calcium Lactate Pentahydrate, Wako Grade 1," manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Calcium stearate: Manufactured by Tokyo Chemical Industry Co., Ltd. Trisodium citrate (3Na citrate): "Trisodium citrate, Wako Grade 1" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Disodium maleate (2Na maleate): "Disodium maleate" manufactured by Tokyo Chemical Industry Co., Ltd. Disodium fumarate (2Na fumarate): "Disodium fumarate" manufactured by Tokyo Chemical Industry Co., Ltd.

[0123] (Polyamide (PA) resin) PA66: Polyamide 66, manufactured by Asahi Kasei Corporation as "Leona(registered trademark) 1300S" PA11: Polyamide 11, manufactured by ARKEMA, "Rilsan(registered trademark) BMNO"

[0124] [Equipment used] Melt flow rate tester: "Melt Flow Index Tester IMC-1540C" manufactured by Imoto Seisakusho Co., Ltd. Tensile testing machine: Instron "Universal Testing Machine Model 5982" Impact testing machine: "Digital Impact Testing Machine IT Type" manufactured by Toyo Seiki Seisakusho Co., Ltd. Twin-screw compounding extruder: TEM-26SX manufactured by Shibaura Machinery Co., Ltd. Injection molding machine: "NEX50III" manufactured by Nissei Plastic Industrial Co., Ltd.

[0125] [MFR] Using a melt flow rate tester, measurements were taken in accordance with JIS K 7210-1 Method A, with a holding time of 5 minutes. For PA66, the temperature was 270°C and the test load was 1.2 kg. For PA11, the temperature was 220°C and the test load was 1.2 kg.

[0126] [Tensile test] Tensile strength (maximum tensile strength) and tensile elongation were measured using a tensile testing machine in accordance with JIS K 7161-1,-2, at a test speed of 5 mm / min. The test specimens were formed using an injection molding machine with a mold temperature of 80°C and a cylinder temperature of 275°C.

[0127] [Bending test] The bending strength and bending modulus were measured in accordance with JIS K 7171. The bending modulus was calculated using the tangential method. The test specimens were molded using an injection molding machine at a mold temperature of 80°C and a cylinder temperature of 275°C.

[0128] [Charpy impact test] The Charpy impact strength was measured using an impact testing machine in accordance with JIS K 7111. The test specimens were molded using an injection molding machine at a mold temperature of 80°C and a cylinder temperature of 275°C.

[0129] [Examples 1-8 and Comparative Examples 1-6] The polyamide resin and additives (without additives in Comparative Example 1) were melt-kneaded in a twin-screw extruder at a temperature of 270°C, a screw rotation speed of 300 rpm, and a discharge rate of 6 kg / h to prepare the resin composition, according to the mass ratios shown in Table 1. The MFR of the obtained resin composition was measured, and the results of tensile tests, bending tests, and Charpy impact tests are shown in Table 1.

[0130] [Table 1]

[0131] As is clear from the results in Table 1, compared to Comparative Example 1 which did not contain additives, C was used as a flow improver. 3-6 The polyamide resin compositions of Examples 1 to 8, which incorporated fatty acid metal salts, maintained mechanical properties such as tensile strength, tensile elongation, flexural strength, flexural modulus, and Charpy impact strength, while also improving fluidity (MFR).

[0132] Furthermore, compared to Comparative Examples 2-6, which contained BPEF, calcium stearate, trisodium citrate, disodium maleate, or disodium fumarate as fluidity improvers, the same amount of C 3-6 Examples 1-2 and 5, which incorporated fatty acid metal salts, also maintained mechanical properties while improving fluidity.

[0133] In Examples 1-2, 5, and 8, the same amount of C was used. 3-6 Although fatty acid metal salts were included, the BHB salts used in Examples 1-2 and 5, which are C4 fatty acid metal salts, were used to improve fluidity more effectively than the calcium lactate used in Example 8, which is a C3 fatty acid metal salt. Among Examples 1-2 and 5, BHB-Mg showed the greatest improvement in fluidity.

[0134] [Examples 9-11 and Comparative Examples 7-8] The polyamide resin and additives (without additives in Comparative Example 7) were melt-kneaded in a twin-screw extruder at a temperature of 250°C, a screw rotation speed of 300 rpm, and a discharge rate of 6 kg / h to prepare the resin composition, according to the mass ratios shown in Table 2. The MFR of the obtained resin composition was measured, and the results of tensile tests, bending tests, and Charpy impact tests are shown in Table 2.

[0135] [Table 2]

[0136] As is clear from the results in Table 2, compared to Comparative Example 7 which did not contain additives, C was used as a flow improver. 3-6 In the polyamide resin compositions of Examples 9 to 11, which incorporated fatty acid metal salts, mechanical properties were maintained while fluidity was improved.

[0137] Furthermore, compared to Comparative Example 8, which contained BPEF as a fluidity improver, the same amount of C 3-6 Examples 9-11, which incorporated fatty acid metal salts, also maintained mechanical properties while improving fluidity. [Industrial applicability]

[0138] The polyamide resin composition disclosed herein can significantly improve the fluidity (or moldability), such as melt flowability, without excessively reducing the mechanical strength of the polyamide resin, thereby effectively improving moldability. Typical applications include, for example, utilizing the excellent properties of polyamide resins such as abrasion resistance, lubricity, heat resistance, and chemical resistance, they can be used in a wide range of applications such as fibers or fiber structures (yarns; ropes; nets; woven fabrics, nonwoven fabrics, knitted fabrics, etc.), films, containers, daily necessities (stationery, household parts, etc.), clothing materials, cosmetic components, medical (medical / treatment) components, automotive parts, electrical / electronic components, machinery parts, building components, construction / civil engineering materials, and sports / leisure-related components. In particular, they can be suitably used as in-vehicle components, office automation (OA) equipment components, electrical / electronic components, machinery components, containers, packaging materials, fibers, and fiber structures. More specifically, it can be used in applications such as automotive lenses, computer components, 3D printer parts, ropes, tire cords, fishing nets, fishing lines, filter cloths, clothing cores, food containers, tableware (plates, spoons, forks, straws, etc.), packaging films, garbage bags, radiator tanks, manifolds, piping tubes and pipes, hoses, air cleaners, clutch components, connectors (including electrical circuit connectors, etc.), switches, gears, pulleys, cams, bushings, rollers, bearings, housings, casings, wire insulation, door rollers, rail components, casters, shoes, shuttlecocks, reels, and more.

Claims

1. A polyamide resin composition comprising a polyamide resin and a fatty acid metal salt having 3 to 6 carbon atoms.

2. The polyamide resin composition according to claim 1, wherein the fatty acid metal salt is at least one salt selected from monovalent metal salts and divalent metal salts.

3. The polyamide resin composition according to claim 1 or 2, wherein the fatty acid constituting the fatty acid metal salt has a hydroxyl group.

4. The polyamide resin composition according to claim 1 or 2, wherein the fatty acid metal salt has 4 to 6 carbon atoms.

5. The polyamide resin composition according to claim 1 or 2, wherein the fatty acid metal salt is a hydroxybutyrate metal salt.

6. The polyamide resin composition according to claim 1 or 2, wherein the fatty acid metal salt is a 3-hydroxybutyrate metal salt.

7. The polyamide resin composition according to claim 1 or 2, wherein the polyamide resin comprises an aliphatic polyamide resin.

8. The polyamide resin composition according to claim 1 or 2, further comprising a resin reinforcing material.

9. A molded article comprising the polyamide resin composition according to claim 1 or 2.

10. The molded article according to claim 9, which is at least one selected from the group consisting of automotive components, office automation equipment components, electrical or electronic components, mechanical components, containers, packaging materials, fibers, and fiber structures.

11. A fluidity improving agent for improving the fluidity of polyamide resins, comprising a fatty acid metal salt having 3 to 6 carbon atoms.

12. A method for improving the fluidity of a polyamide resin by blending it with a fatty acid metal salt having 3 to 6 carbon atoms.

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