Polyamide composition

Abstract

To provide a polyamide composition having a reduced carbon footprint (CFP).SOLUTION: A polyamide composition comprising (A) a polyamide, wherein the polyamide (A) includes structural units derived from (B) hexamethylenediamine, and the hexamethylenediamine (B) contains hexamethylenediamine produced from saccharides using microorganisms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyamide composition. [Background technology]

[0002] Polyamides have excellent strength, heat resistance, chemical resistance, and specific gravity. Because they have a lower specific gravity than metals, they have traditionally been used as a metal substitute for automotive mechanical parts.

[0003] Fossil fuel-derived raw materials, which have traditionally been used in chemical manufacturing processes, are at risk of depletion and are considered to be a contributing factor to global warming. Therefore, in recent years, there has been a desire to switch to renewable raw materials, such as biomass-derived raw materials. As part of the switch to renewable raw materials, technology using metabolically modified microorganisms through genetic engineering is expected to be a new chemical manufacturing process. For example, it has been suggested that hexamethylenediamine can be produced by genetically modified microorganisms into which exogenous nucleic acids have been introduced (Patent Document 1).

[0004] Biomass refers to organic resources derived from living organisms. Even if plastic made from this material is incinerated, it does not increase net carbon dioxide emissions, which include the carbon dioxide absorbed in the process of producing the biomass. Therefore, the carbon footprint (CFP), which is the value calculated by converting greenhouse gases emitted throughout the entire process from raw material procurement to disposal, is reduced, and the burden on the global environment is small. Biomass-derived polyamides are described, for example, in Patent Document 2. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-171292 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-348057 Summary of the Invention [Problem to be solved by the invention]

[0006] The biomass-derived polyamide described in Patent Document 2 is limited to a polyamide made from pentamethylenediamine, and there is no description regarding biomass-derived polyamide 66 or a polyamide composition containing said polyamide 66.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polyamide composition with a reduced carbon footprint (CFP). [Means for solving the problem]

[0008] That is, the present invention includes the following aspects.

[0009] (1) (A) comprising a polyamide; the (A) polyamide contains a structural unit derived from (B) hexamethylenediamine, The polyamide composition, wherein the (B) hexamethylenediamine contains hexamethylenediamine produced from sugars using a microorganism.

[0010] (2) The polyamide composition according to (1), wherein the weight-average molecular weight of the polyamide (A) is 10,000 to 200,000.

[0011] (3) The polyamide composition according to (1) or (2), wherein the molecular weight distribution (Mw / Mn) of the polyamide (A) is 1.8 to 5.0.

[0012] (4) The polyamide composition according to any one of (1) to (3), wherein the (A) polyamide has a relative viscosity in sulfuric acid at 25° C. of 1.8 or more.

[0013] (5) The polyamide composition according to any one of (1) to (4), further comprising (C) an additional resin.

[0014] (6) The polyamide composition according to any one of (1) to (5), further comprising an additive (D).

[0015] (7) The polyamide composition according to any one of (1) to (6), further comprising (E) a flame retardant.

[0016] (8) The polyamide composition according to any one of (1) to (7), further comprising (F) a filler.

[0017] (9) The polyamide composition according to any one of (1) to (8), wherein the polyamide (A) is a polyamide obtained by solid-state polymerization. [Effects of the Invention]

[0018] According to the present invention, a polyamide composition having reduced CFP can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0020] In this specification, the term "polyamide" refers to a polymer having an amide group (-NHCO-) ​​in the main chain. In this specification, "biomass-derived" means derived from organic resources derived from living organisms.

[0021] <Polyamide composition> The polyamide composition of the present embodiment is (A) comprises a polyamide, the (A) polyamide contains a structural unit derived from (B) hexamethylenediamine, The (B) hexamethylenediamine is characterized by containing hexamethylenediamine produced from sugars using a microorganism.

[0022] The polyamide composition of the present embodiment has the above-described configuration, and therefore can keep the carbon footprint (CFP) low.

[0023] Hereinafter, the (A) polyamide to (G) filler may be referred to as component (A) to component (G), respectively.

[0024] Each component of the polyamide composition of the present embodiment will be described in detail below.

[0025] <(A) Polyamide> The (A) polyamide of this embodiment contains a structural unit derived from (B) hexamethylenediamine, and the (B) hexamethylenediamine (hereinafter sometimes referred to as "HMD") contains hexamethylenediamine produced from sugars using a microorganism. Examples of (A) polyamides include (a-1) polyamides obtained by condensing diamines and dicarboxylic acids (hereinafter, also referred to as "(a-1) polyamides"). Other examples include copolymers of (a-1) polyamides with (a-2) polyamides obtained by ring-opening polymerization of lactams (hereinafter, also referred to as "(a-2) polyamides") and / or (a-3) polyamides obtained by self-condensation of ω-aminocarboxylic acids (hereinafter, also referred to as "(a-3) polyamides"). (A) polyamides may be used alone or in combination of two or more.

[0026] (a-1) The diamine (monomer) used in the production of polyamide includes hexamethylenediamine, which is produced from sugars using microorganisms. Other diamines include, but are not limited to, linear aliphatic diamines, branched aliphatic diamines, alicyclic diamines, and aromatic diamines. Examples of linear aliphatic diamines include, but are not limited to, hexamethylenediamine and pentamethylenediamine other than hexamethylenediamine, which are produced from sugars using microorganisms. Examples of branched aliphatic diamines include, but are not limited to, 2-methylpentanediamine and 2-ethylhexamethylenediamine. Examples of alicyclic diamines include, but are not limited to, cyclohexanediamine, cyclopentanediamine, and cyclooctanediamine. Examples of aromatic diamines include, but are not limited to, p-phenylenediamine and m-phenylenediamine.

[0027] (a-1) As the dicarboxylic acid (monomer) used in the production of polyamide, petroleum-derived dicarboxylic acids and biomass-derived dicarboxylic acids can be used alone or in combination. Examples of dicarboxylic acids include, but are not limited to, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and aromatic dicarboxylic acids. Examples of the aliphatic dicarboxylic acid include, but are not limited to, adipic acid, pimelic acid, and sebacic acid. The alicyclic dicarboxylic acid is not limited to the following, but examples thereof include cyclohexanedicarboxylic acid. Examples of aromatic dicarboxylic acids include, but are not limited to, phthalic acid and isophthalic acid. The diamines and dicarboxylic acids as the monomers may be condensed either alone or in combination of two or more.

[0028] (a-2) Examples of lactams used in the production of polyamides include, but are not limited to, pyrrolidone, caprolactam, undecalactam, and dodecalactam. Furthermore, the lactams may each be obtained by condensing two or more kinds of monomers in combination.

[0029] (a-3) The ω-aminocarboxylic acid used in the production of polyamide is not limited to the following, but examples thereof include ω-amino fatty acids, which are ring-opened compounds of the above lactams with water. Furthermore, the above ω-aminocarboxylic acids may each be obtained by condensing two or more kinds of monomers in combination.

[0030] Specific examples of the (A) polyamide contained in the polyamide composition include polyamides that contain structural units derived from (B) hexamethylenediamine, such as polyamide 66 (polyhexamethylene adipamide), polyamide 610 (polyhexamethylene sebacamide), polyamide 612 (polyhexamethylene dodecamide), polyamide 6T (polyhexamethylene terephthalamide), and polyamide 6I (polyhexamethylene isophthalamide), and in which the (B) hexamethylenediamine is produced from sugars using a microorganism, and copolymer polyamides that contain these as structural components. Further examples include copolymer polyamides containing these and polyamide 4 (poly-α-pyrrolidone), polyamide 6 (polycaproamide), polyamide 11 (polyundecane amide), polyamide 12 (polydodecanamide), polyamide 46 (polytetramethylene adipamide), polyamide 56 (polypentamethylene adipamide), and polyamide 9T (polynonamethylene terephthalamide) as constituent components. Among these, the polyamide is preferably polyamide 66, polyamide 610, polyamide 612, polyamide 6I, polyamide 66 / 6, or polyamide 66 / 6I.

[0031] [(A) Polyamide content] The amount of polyamide (A) in the polyamide composition can be, for example, 10.0 mass% or more and 100.0 mass% or less, for example, 10.0 mass% or more and 99.8 mass% or less, for example, 20.0 mass% or more and 90.0 mass% or less, or for example, 30.0 mass% or more and 80.0 mass% or less, relative to the total mass of polyamide.

[0032] [(A) Method for producing polyamide] In producing (A) polyamide, the amount of dicarboxylic acid added and the amount of diamine containing (B) hexamethylenediamine added are preferably approximately the same molar amount. Taking into consideration the amount of diamine that escapes to the outside of the reaction system during the polymerization reaction, the molar amount of all diamines relative to the molar amount of all dicarboxylic acids is preferably 0.9 to 1.2, more preferably 0.95 to 1.1, and even more preferably 0.98 to 1.05.

[0033] The method for producing (A) polyamide preferably further comprises a step of increasing the degree of polymerization of (A) polyamide, and may optionally comprise a step of capping the ends of the resulting polymer with an end-capping agent. (A) The method for producing a polyamide preferably includes producing hexamethylenediamine from sugars using microorganisms before polymerizing a diamine and a dicarboxylic acid.

[0034] Specific methods for producing (A) polyamide include various methods such as those exemplified in the following 1) to 4). 1) A method in which an aqueous solution of a salt of dicarboxylic acid and (B) a diamine containing hexamethylenediamine, or a mixture of dicarboxylic acid and (B) a diamine containing hexamethylenediamine, or an aqueous suspension of these, is heated and polymerized while maintaining the molten state (hereinafter, this may be referred to as "thermal melt polymerization method"). 2) A method of increasing the degree of polymerization of (A) polyamide obtained by the hot melt polymerization method while maintaining it in a solid state at a temperature below the melting point (hereinafter sometimes referred to as "hot melt polymerization / solid state polymerization method"). 3) A method of polymerizing a salt of a diamine containing dicarboxylic acid (B) hexamethylenediamine, or a mixture of a dicarboxylic acid (B) and a diamine containing hexamethylenediamine while maintaining the salt in a solid state (hereinafter, this may be referred to as a "solid-state polymerization method"). 4) A method of polymerization using a dicarboxylic acid halide component and (B) a diamine component containing hexamethylenediamine (hereinafter, sometimes referred to as a "solution method"). Among these, a specific method for producing (A) polyamide is preferably a production method including a thermal melt polymerization method. When producing (A) polyamide by a thermal melt polymerization method, it is preferable to maintain the molten state until the polymerization is completed. Examples of the method for maintaining the molten state include a method for producing (A) polyamide under polymerization conditions suitable for its composition. Examples of the polymerization conditions include the following conditions. First, in the thermal melt polymerization method, the polymerization pressure is set to 14 kg / cm. 2 More than 25kg / cm 2 Heating is continued while controlling the pressure in the vessel to atmospheric pressure (gauge pressure is 0 kg / cm 2 ), the pressure is reduced over 30 minutes or more until the temperature reaches a desired level, thereby obtaining polyamide (A) having the desired composition.

[0035] In the method for producing (A) polyamide, the polymerization form is not particularly limited, and may be a batch system or a continuous system. The polymerization apparatus used for producing (A) polyamide is not particularly limited, and known apparatuses can be used, such as autoclave-type reactors, tumbler-type reactors, and extruder-type reactors such as kneaders.

[0036] Hereinafter, as a method for producing (A) polyamide, a method for producing (Aa) polyamide 66 by a batch-type hot melt polymerization method will be specifically shown, but the method for producing (Aa) polyamide 66 is not limited to this. First, an aqueous solution containing approximately 40% by mass or more and 60% by mass or less of the raw materials for (Aa) polyamide 66 (adipic acid, (B) hexamethylenediamine) is concentrated to approximately 65% ​​by mass or more and 90% by mass or less in a concentration tank operated at a temperature of 110°C or more and 180°C or less and a pressure of approximately 0.035 MPa or more and 0.6 MPa or less (gauge pressure) to obtain a concentrated solution. Next, the obtained concentrated solution is transferred to an autoclave, and heating is continued until the pressure in the autoclave reaches about 1.2 MPa or more and 2.2 MPa or less (gauge pressure). Thereafter, in the autoclave, the pressure is maintained at approximately 1.2 MPa to 2.2 MPa (gauge pressure) while removing at least one of the water and gas components, and when the temperature reaches approximately 220°C to 260°C, the pressure is reduced to atmospheric pressure (gauge pressure: 0 MPa). After the pressure inside the autoclave is reduced to atmospheric pressure, the pressure can be reduced as needed to effectively remove the by-produced water. The autoclave is then pressurized with an inert gas such as nitrogen, and the polyamide melt is extruded from the autoclave as a strand. The extruded strand is cooled and cut to obtain pellets of (A) polyamide 66.

[0037] [(A) Polyamide polymer end] The polymer terminals of (A) polyamide are not particularly limited, but can be classified and defined as follows: 1) amino terminus, 2) carboxy terminus, 3) terminus with a capping agent, and 4) other terminus. 1) The amino terminal is a polymer terminal having an amino group (-NH2 group) and is derived from the diamine such as the raw material (B) hexamethylenediamine unit. 2) The carboxyl end is a polymer end having a carboxyl group (-COOH group) and is derived from the raw material carboxylic acid such as adipic acid. 3) The term "terminals formed by a capping agent" refers to terminals formed when a capping agent is added during polymerization. Examples of the capping agent include the above-mentioned terminal capping agents. 4) Other terminals are polymer terminals that are not classified into the above 1) to 3). Specific examples of other terminals include terminals generated by deammoniating an amino terminal, terminals generated by decarboxylating a carboxy terminal, etc.

[0038] [(A) Characteristics of polyamide] ((A) Molecular weight of polyamide) The weight average molecular weight (Mw) can be used as an index of the molecular weight of polyamide. The weight average molecular weight (Mw) of polyamide can be, for example, 10,000 or more and 200,000 or less, for example, 15,000 or more and 100,000 or less, for example, 20,000 or more and 90,000 or less, or for example, 25,000 or more and 85,000 or less. The weight average molecular weight (Mw) can be measured using gel permeation chromatography (GPC) under the following measurement conditions. -Measurement conditions- Measuring device: Tosoh Corporation, HLC-8020 Solvent: Hexafluoroisopropanol solvent Standard sample: PMMA (polymethyl methacrylate) standard sample (Polymer Laboratory) GPC columns: TSK-GEL GMHHR-M and G1000HHRGPC

[0039] ((A) Molecular weight distribution of polyamide) (A) The molecular weight distribution (Mw / Mn) of polyamide is indicated by the weight average molecular weight (Mw) / number average molecular weight (Mn). The Mw / Mn of the (A) polyamide can be 1.8 or more and 5.0 or less, for example, 1.8 or more and 4.0 or less, for example, 1.9 or more and 3.0 or less.

[0040] Examples of methods for controlling the Mw / Mn of (A) polyamide within the above range include a method of adding a known polycondensation catalyst such as phosphoric acid or sodium hypophosphite as an additive during the hot melt polymerization of (A) polyamide 66, and a method of controlling polymerization conditions such as heating conditions and reduced pressure conditions. The Mw / Mn of the (A) polyamide can be calculated using the weight average molecular weight Mw and number average molecular weight Mn obtained by GPC under the following measurement conditions. -Measurement conditions- Measuring device: Tosoh Corporation, HLC-8020 Solvent: Hexafluoroisopropanol solvent Standard sample: PMMA (polymethyl methacrylate) standard sample (Polymer Laboratory) GPC columns: TSK-GEL GMHHR-M and G1000HHRGPC

[0041] ((A) Relative viscosity of polyamide in sulfuric acid) The (A) polyamide preferably has a relative viscosity in sulfuric acid at 25°C of 1.8 or more, more preferably 2.0 or more, more preferably 2.1 or more, even more preferably 2.3 or more, and particularly preferably 3.2 or more. On the other hand, the relative viscosity in sulfuric acid of the (A) polyamide is preferably 4.5 or less, more preferably 4.4 or less, and even more preferably 4.3 or less. When the (A) polyamide has a relative viscosity in sulfuric acid of the above-mentioned lower limit or more, a molded article with more excellent mechanical properties tends to be obtained. On the other hand, when the (A) polyamide has a relative viscosity in sulfuric acid of the above-mentioned upper limit or less, a molded article with more excellent fluidity and processability tends to be obtained. (A) The relative viscosity of polyamide in sulfuric acid can be measured by a method in accordance with JIS-K6920.

[0042] <(B) Hexamethylenediamine> The polyamide (A) contained in the polyamide composition of the present embodiment is obtained, for example, by polycondensation of a dicarboxylic acid and a diamine (B) such as hexamethylenediamine, as described above. (B) Hexamethylenediamine includes hexamethylenediamine produced from sugars using microorganisms. The sugars are not limited as long as they can be utilized by microorganisms, but are preferably cellulose, glucose, fructose, or sucrose, and more preferably glucose, fructose, or sucrose. The microorganisms are not limited as long as they are not toxic to hexamethylenediamine, but are preferably Escherichia, Bacillus, Corynebacterium, Arthrobacter, Brevibacterium, Clostridium, Zymomonas, Pseudomonas, or Burkholderia. The recombinant microorganism is selected from the genera Saccharomyces, Streptomyces, Rhodococcus, Synechocystis, Alkalihalobacillus, Saccharomyces, Schizosaccharomyces, Yarrowia, Candida, Pichia, and Aspergillus. More preferably, the recombinant microorganism is Escherichia coli, which belongs to the genus Escherichia.

[0043] <Proportion of component (B) produced from sugars using microorganisms> As described above, (B) hexamethylenediamine in this embodiment includes hexamethylenediamine produced from sugars using microorganisms. Of the (B) hexamethylenediamine constituting the (A) polyamide, the proportion of hexamethylenediamine produced from sugars using microorganisms is not particularly limited, but is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more. By setting the ratio of hexamethylenediamine produced from sugars using microorganisms among the hexamethylenediamine (B) constituting the polyamide (A) to the above-mentioned lower limit or more, the CFP of the polyamide composition can be further reduced. The proportion of component (B) produced from sugars using microorganisms can be calculated, for example, according to the method described in ASTM6866, by burning a sample and calculating the concentration of radioactive carbon contained in the sample.

[0044] <(C) Further Resins> The polyamide composition of the present embodiment may contain an additional resin (C). The (C) additional resin is not particularly limited, but examples thereof include polyamide resin, polyester resin, polyacetal resin, polycarbonate resin, polyacrylic resin, polyphenylene ether resin (including modified polyphenylene ether obtained by blending or graft polymerizing polyphenylene ether with other resins), polyarylate resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyketone resin, polyphenylene ether ketone resin, polyimide resin, polyamideimide resin, polyetherimide resin, polyurethane resin, polyolefin resin (e.g., α-olefin (co)polymer), and various ionomers. When a polyamide resin is used as the (C) additional resin, a polyamide different from the (A) polyamide is used.

[0045] <(D) Additives> The polyamide composition of the present embodiment may contain an additive (D). Note that in the present invention, the additive (D) does not include a flame retardant (E) and a filler (F). (D) Additives are not particularly limited, but examples thereof include heat stabilizers, lubricants, catalysts, colorants (dyes, pigments), flow modifiers, molecular weight regulators, antioxidants, compatibilizers, oligomers, polymers, etc.

[0046] The heat stabilizer may be any that inhibits thermal degradation of the material, prevents discoloration due to heat, and improves heat aging resistance and weather resistance, and includes, but is not limited to, copper-based stabilizers such as copper compounds such as copper acetate and copper iodide, phenol-based stabilizers such as hindered phenol compounds, phosphite-based stabilizers, hindered amine-based stabilizers, triazine-based stabilizers, sulfur-based stabilizers, etc. Other examples include the antioxidants mentioned above, such as alkylphenols, alkylene bisphenols, and alkylphenol thioethers, and ultraviolet absorbers such as salicylic acid esters, benzotriazole, and hydroxybenzophenone.

[0047] When a heat stabilizer is added to the polyamide composition of this embodiment, the content of the heat stabilizer is preferably 0.005 to 10 parts by mass per 100 parts by mass of (A) polyamide. By setting the content of the heat stabilizer to 0.005 parts by mass or more, the effect of improving thermal stability can be sufficiently obtained. Furthermore, by setting the content to 10 parts by mass or less, good manufacturability can be obtained in the extrusion process.

[0048] The polyamide composition of this embodiment may contain a lubricant. The content of the lubricant in the polyamide composition of this embodiment is 0.01 to 2.0 parts by mass, preferably 0.05 to 1.0 part by mass, and more preferably 0.08 to 0.8 parts by mass, relative to 100 parts by mass of the (A) polyamide.

[0049] The polyamide composition of the present embodiment may contain a colorant. By containing a colorant, it is possible to color a molded article.

[0050] Examples of colorants include, but are not limited to, dyes such as nigrosine, pigments such as titanium oxide and carbon black, metal particles such as aluminum, colored aluminum, nickel, tin, copper, gold, silver, platinum, iron oxide, stainless steel, and titanium, and metallic pigments such as mica pearl pigments, colored graphite, colored glass fiber, and colored glass flakes. These colorants can be used alone or in combination of two or more.

[0051] In the polyamide composition of this embodiment, the content of the colorant is preferably 0.01 parts by mass or more and 0.5 parts by mass or less, more preferably 0.05 parts by mass or more and 0.25 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.2 parts by mass or less, relative to 100 parts by mass of the (A) polyamide.

[0052] <(E) Flame retardant> The polyamide composition of the present embodiment may contain a flame retardant (E). Examples of the flame retardant include, but are not limited to, halogen-containing flame retardants, phosphorus-based flame retardants, and melamine cyanurate. A combination of two or more flame retardants may be used, or a flame retardant aid may be used.

[0053] In the polyamide composition of this embodiment, the content of the flame retardant is preferably 1 part by mass or more and 50 parts by mass or less, more preferably 3 parts by mass or more and 45 parts by mass or less, and even more preferably 5 parts by mass or more and 35 parts by mass or less, per 100 parts by mass of the (A) polyamide.

[0054] <(F) Filler> The polyamide composition of the present embodiment may contain a filler (F). By containing the filler (F), the polyamide composition of the present embodiment can further improve mechanical properties such as strength and rigidity when formed into a molded article.

[0055] The (F) filler is not particularly limited, and examples thereof include glass fiber, carbon fiber, calcium silicate fiber, potassium titanate fiber, aluminum borate fiber, glass flake, calcium carbonate, talc, kaolin, mica, hydrotalcite, zinc carbonate, calcium hydrogen phosphate, wollastonite, zeolite, boehmite, magnesium oxide, calcium silicate, sodium aluminosilicate, magnesium silicate, ketjen black, acetylene black, furnace black, carbon nanotubes, graphite, brass, copper, silver, aluminum, nickel, iron, calcium fluoride, montmorillonite, swellable fluoromica, apatite, milled fiber, etc. These (F) fillers may be used alone or in combination of two or more. Among these, the (F) filler is preferably glass fiber, carbon fiber, glass flake, talc, kaolin, mica, calcium hydrogen phosphate, wollastonite, carbon nanotubes, graphite, calcium fluoride, montmorillonite, swellable fluoromica, or apatite, from the viewpoint of rigidity, strength, and the like. Furthermore, the (F) filler is more preferably one or more selected from the group consisting of glass fiber, calcium carbonate, talc, mica, wollastonite, and milled fiber, further preferably glass fiber or carbon fiber, and particularly preferably glass fiber.

[0056] In the polyamide composition of this embodiment, the content of the (F) filler is preferably 0 parts by mass or more and 150 parts by mass or less, more preferably 10 parts by mass or more and 140 parts by mass or less, even more preferably 20 parts by mass or more and 135 parts by mass or less, particularly preferably 25 parts by mass or more and 130 parts by mass or less, and most preferably 30 parts by mass or more and 100 parts by mass or less, relative to 100 parts by mass of the (A) polyamide. When the content of the (F) filler is equal to or greater than the above lower limit, the mechanical properties such as strength and rigidity of the molded article tend to be improved. On the other hand, when the content of the (F) filler is equal to or less than the above upper limit, the molded article tends to have better surface appearance.

[0057] <Other additives> The polyamide composition may contain other additives commonly used in polyamides, provided that the purpose of this embodiment is not impaired. Examples of other additives include fibrillating agents, fluorescent bleaching agents, plasticizers, UV absorbers, antistatic agents, reinforcing agents, spreading agents, nucleating agents, rubbers, toughening agents, and other polymers. The content of other additives in the polyamide composition of this embodiment can be appropriately determined by those skilled in the art depending on the purpose.

[0058] <Method of producing polyamide composition> In the method for producing the polyamide composition, the method for adding each component is not particularly limited as long as it is a method of mixing (A) with, as needed, (C) to (F) and other additives described above.

[0059] Examples of methods for mixing the constituent materials include a method in which the materials are mixed using a Henschel mixer or the like, and then fed into a melt kneader and kneaded therein; and a method in which component (A) and components (C) to (F) are melted in a single-screw or twin-screw extruder from a top feeder, and component (F) filler and other additives are added as needed from a side feeder.

[0060] The components constituting the polyamide composition may be supplied to the melt kneader by supplying all of the components at once to the same supply port, or by supplying component (A) and, if necessary, components (C) to (F) from different supply ports.

[0061] The melt-kneading temperature is preferably about 250°C or higher and 375°C or lower in terms of resin temperature.

[0062] The melt-kneading time is preferably about 0.5 minutes or more and 5 minutes or less.

[0063] The melt-kneading device is not particularly limited, and known devices such as melt-kneaders such as a single-screw or twin-screw extruder, a Banbury mixer, or a mixing roll can be used.

[0064] The melt-kneading device is not particularly limited, and known devices such as melt-kneaders such as a single-screw or twin-screw extruder, a Banbury mixer, or a mixing roll can be used.

[0065] <Solid-state polymerization> The polyamide composition of the present embodiment is preferably solid-state polymerized. The solid-state polymerization can be carried out using a commonly used apparatus. That is, it can be carried out batchwise in a cone-type tumbler or continuously in a fluidized bed drying oven. The polyamide pellets of this embodiment are heated to a temperature below the melting point of the polyamide, and an inert gas such as nitrogen is passed through or the mixture is kept under reduced pressure to carry out solid-state polymerization and achieve a high degree of polymerization.

[0066] When (A) is mixed with, as needed, (C) to (F) and other additives described above and then subjected to solid-state polymerization to produce a polyamide composition, it is preferable to compound the components by melt kneading before carrying out solid-state polymerization.

[0067] <Usage> Molded articles obtained from the polyamide composition of the present embodiment are suitable for use as material parts for various applications, such as automobiles, machinery and industrial applications, electrical and electronic applications, industrial materials, construction materials, daily necessities and household goods, etc. Among these, they are particularly suitable for use as automobile parts because of their excellent heat aging resistance and electrical properties. [Example]

[0068] The present invention will be described in detail below with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

[0069] Each of the components of the compositions used in the present examples and comparative examples will be explained below (HMD stands for hexamethylenediamine). <Components> [(A) Polyamide] A-1: Biomass-derived ratio of polyamide 66 HMD 100% by mass A-2: Biomass-derived ratio of polyamide 66 HMD 80% by mass A-3: Biomass-derived ratio of polyamide 66 HMD 50% by mass A-4: Polyamide 610 HMD biomass-derived ratio 100% by mass A-5: Polyamide 612 HMD biomass-derived ratio 100% by mass A-6: Biomass-derived ratio of polyamide 66 HMD 20% by mass A-7: Solid-state polymerization product of polyamide 66 HMD with a biomass-derived ratio of 100% by mass

[0070] [(C) Further Resin] C-1: Polyphenylene ether modified with maleic anhydride (m-PPE) C-2: Ethylene-ethyl hydrogen maleate random copolymer (content of ethyl hydrogen maleate units relative to the mass of all structural units of the copolymer: 8% by mass) C-3: Biomass-derived ratio of polyamide 66 HMD 0% by mass C-4: Polyamide 6I Biomass-derived ratio of HMD 0% by mass C-5: Biomass-derived ratio of polyamide 6I / 6T HMD 0% by mass C-6: Polyamide 4T / 6T HMD biomass-derived ratio 0% by mass C-7: Polyamide 66 / 6I Biomass-derived ratio of HMD 0% by mass

[0071] [(D) Additives] D-1: Maleic anhydride grafted ethylene-butene copolymer (Mitsui Chemicals, Tafmer MD715) D-2: Ethylene-butene copolymer (Mitsui Chemicals, Inc., Tafmer™ DF605) D-3: Polyethylene-polystyrene graft copolymer (NOF Corporation, MODIPER-A1100) D-4: Polyolefin-polyamide polymer (Arkema, APOLHYA LP91) D-5: Polyethyleneimine (BASF, Lupasol FG) D-6: Antioxidant (BASF, Irganox 1098) D-7: Nigrosine dye (Orient Chemical Co., Ltd., TH807) D-8: Carbon black (primary particle size 27 nm) D-9: Adipic acid (Wako Pure Chemical Industries, Ltd., adipic acid) D-10: Calcium stearate (manufactured by Nippon Oil & Fats Co., Ltd., calcium stearate) D-11: Sodium aluminate (Wako Pure Chemical Industries, Ltd., sodium aluminate) D-12: Mixture of copper iodide and potassium iodide (both copper iodide and potassium iodide are manufactured by Wako Pure Chemical Industries, Ltd.) 1 part by mass of copper iodide is mixed with 10 parts by mass of potassium iodide. D-13: Nigrosine (Orient Chemical Co., Ltd., Nubian Black TN-870) D-14: Copper iodide (Wako Pure Chemical Industries, Ltd., copper iodide) D-15: Potassium iodide (Wako Pure Chemical Industries, Ltd., potassium iodide) D-16: Zinc sulfide (SACHTLEBEN, Sactris HD) D-17: Polyoxymethylene monolaurate (Kao Corporation, Emanone) D-18: Laser-transmitting colorant (Orient Chemical Industry Co., Ltd., eBIND LTW-8071H)

[0072] [(E) Flame retardant] E-1: Brominated polystyrene (ALBEMARLE CORPORATION, SAYTEX HP-3010G) E-2: Melamine cyanurate (Nissan Chemical, MC-4500) E-3: Aluminum phosphinate (Clariant, Exolit OP1230) E-4 Antimony trioxide (Daiichi F.R. Co., Ltd., Antimony trioxide)

[0073] [(F) Filler] F-1: Glass fiber (Nippon Electric Glass Co., Ltd., ECS 03T-275H) F-2: Glass fiber (Nippon Electric Glass Co., Ltd., ECS 03-T297) F-3: Glass fiber (average minor axis 7 μm, average major axis 28 μm) F-4: Wollastonite (NYCO, 400WC) F-5: Carbon fiber (Toho Tenax, HTC413) F-6: Talc (average particle size 19.4 μm) F-7: Glass fiber roving (manufactured by Chongqing International Composite Materials Co., Ltd., ER4301H)

[0074] [(A-1) Synthesis of Polyamide 66] The polymerization reaction of polyamide was carried out by the "hot melt polymerization method" as follows. First, 1500 g of an equimolar salt of adipic acid and (B) hexamethylenediamine, synthesized using the method described in JP 2022-171292 A, was dissolved in 1500 g of distilled water to prepare a 50% by mass equimolar homogeneous aqueous solution of the raw material monomers. This aqueous solution was charged into an autoclave with an internal volume of 5.4 L and purged with nitrogen. Next, the solution was concentrated by gradually removing water vapor to a solution concentration of 70% by mass while stirring at a temperature of 110°C to 150°C. The internal temperature was then raised to 220°C. At this time, the autoclave was pressurized to 1.8 MPa. The reaction was continued for 1 hour while gradually removing water vapor to maintain the pressure at 1.8 MPa until the internal temperature reached 245°C. The pressure was then reduced over 1 hour. The autoclave was then maintained at a reduced pressure of 650 torr (86.66 kPa) for 10 minutes using a vacuum device. The final internal temperature of the polymerization was 265°C. Next, the mixture was pressurized with nitrogen and formed into strands from the lower spinneret (nozzle), cooled with water, cut, and discharged in pellet form. The pellets were dried at 100°C in a nitrogen atmosphere for 12 hours to obtain (A-1) polyamide 66. The resulting (A-1) polyamide 66 had a weight average molecular weight of 40,000 and a molecular weight distribution (Mw / Mn) of 2.0.

[0075] [Synthesis of (A-2), (A-3), (A-6), and (C-3) Polyamide 66] Using the same procedure as for the synthesis of (A-1) polyamide 66, (B) polyamide 66 (A-2), (A-3), (A-6), and (C-3) were synthesized using the same ratio of biomass-derived hexamethylenediamine as described above, with the remainder being hexamethylenediamine derived from fossil resources.

[0076] [(A-4) Synthesis of Polyamide 610] (A-4) Polyamide 610 was synthesized using the same procedure as in the synthesis of (A-1) Polyamide 66, except that sebacic acid was used instead of adipic acid. The resulting (A-4) Polyamide 610 had a weight-average molecular weight of 24,000 and a molecular weight distribution (Mw / Mn) of 2.0.

[0077] [(A-5) Synthesis of Polyamide 612] (A-5) Polyamide 612 was synthesized using the same procedure as in the synthesis of (A-1) Polyamide 66, except that dodecanedioic acid was used instead of adipic acid. The resulting (A-5) Polyamide 612 had a weight-average molecular weight of 24,000 and a molecular weight distribution (Mw / Mn) of 2.0.

[0078] [(A-7) Polyamide 66 solid-state polymer] Polyamide 66 obtained by the same procedure as in the synthesis of (A-1) polyamide 66 was placed in an evaporator-type solid-state polymerization apparatus and subjected to solid-state polymerization for 6 hours at 230°C under a nitrogen gas flow. The resulting (A-7) polyamide 66 had a weight-average molecular weight of 48,000 and a molecular weight distribution (Mw / Mn) of 2.2.

[0079] <Production of Polyamide Composition> [Examples 1 to 30 and Comparative Example 1] Each polyamide composition was produced by the following method using the above (A) polyamide, (C) additional resin, (D) additive, (E) flame retardant, and (F) filler in the types and proportions shown in Tables 1 and 2 below. A twin-screw extruder (ZSK-26MC, manufactured by Coperion) was used as the polyamide composition production device. The twin-screw extruder had an upstream feed port in the first barrel from the upstream side of the extruder, a downstream first feed port in the sixth barrel, and a downstream second feed port in the ninth barrel. In addition, in the twin-screw extruder, the temperature from the upstream feed port to the die was set to the melting point Tm of each polyamide + 20°C, the screw rotation speed was set to 250 rpm, and the output rate was set to 25 kg / h.

[0080] In a specific production method using the above production apparatus, (A) polyamide, (C) additional resin, (D) additive, and (E) flame retardant were dry-blended in the types and proportions shown in Tables 1 and 2, and then fed into the upstream feed port of a twin-screw extruder. If a (F) filler was included, the (F) filler was fed into the first downstream feed port of the twin-screw extruder. The molten mixture extruded from the die head was cooled in the form of strands and pelletized to obtain pellets of each polyamide composition. The resulting pellets of the polyamide composition were dried in a nitrogen stream to reduce the moisture content in the polyamide composition to 500 ppm by mass or less.

[0081] [Calculating carbon footprint (CFP)] Carbon footprint (CFP) was calculated according to the GHG Protocol "Product Standard." The smaller the CFP value, the better the product, as it has a smaller environmental impact.

[0082] [Table 1]

[0083] [Table 2]

[0084] Tables 1 and 2 show that the polyamide composition of the present invention suppresses CFP. [Industrial Applicability]

[0085] According to the present invention, a polyamide composition having reduced CFP can be provided.

Claims

1. (A) a polyamide; the (A) polyamide contains (B) a structural unit derived from hexamethylenediamine, The polyamide composition, wherein the (B) hexamethylenediamine contains hexamethylenediamine produced from sugars using a microorganism.

2. 2. The polyamide composition according to claim 1, wherein the weight average molecular weight of the polyamide (A) is 10,000 to 200,000.

3. 2. The polyamide composition according to claim 1, wherein the molecular weight distribution (Mw / Mn) of the polyamide (A) is 1.8 to 5.

0.

4. 2. The polyamide composition according to claim 1, wherein the polyamide (A) has a relative viscosity in sulfuric acid at 25°C of 1.8 or more.

5. The polyamide composition according to claim 1, further comprising (C) an additional resin.

6. The polyamide composition according to claim 1, further comprising (D) an additive.

7. The polyamide composition according to claim 1, further comprising (E) a flame retardant.

8. The polyamide composition of claim 1 , further comprising (F) a filler.

9. 2. The polyamide composition according to claim 1, wherein the polyamide (A) is a polyamide obtained by solid-state polymerization.

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