Polyamide molding

Abstract

To provide a fire retardant polyamide molding excellent in blister resistance even if exposed to high temperature during a reflow process.SOLUTION: A polyamide molding having a thickness of more than 0.5 mm includes: a polyamide (A) having a melting point of 280°C or higher; a glass fiber (B1); and a halogen-based fire retardant (C). The content of the glass fiber (B1) is 45-120 pts.mass with respect to 100 pts.mass of the polyamide (A), the content of the halogen-based fire retardant (C) is 25-60 pts.mass with respect to 100 pts.mass of the polyamide (A), the glass fiber (B1) has an average fiber diameter of 12 μm or less, and an average irregular shape ratio in a section perpendicular to a longitudinal direction of less than 1.5.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Polyamide resin compositions are known as materials with excellent performance in terms of heat resistance, etc. A halogen-based flame retardant, for example, a bromine-based flame retardant, may be blended into the polyamide resin composition as a flame retardant (see Patent Documents 1 to 3). A polyamide resin composition with enhanced flame retardancy in this way is also called a flame-retardant polyamide resin composition. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-082228 A [Patent Document 2] International Publication No. 2020 / 040191 [Patent Document 3] JP 2013-056969 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, it is known that when a polyamide molded article made of a flame-retardant polyamide resin composition is exposed to high temperatures during a reflow process, blisters are generated in the polyamide molded article (see Patent Documents 1 and 3). It is believed that such blisters are caused by internal pressure generated by vaporization and expansion of moisture and gas contained in the molded article when the molded article is exposed to high temperatures. As a result of the inventors' investigation, it was found that blisters are likely to occur in polyamide molded articles that contain a halogen-based flame retardant in an amount necessary from the viewpoint of flame retardancy. It is also known that blisters are more likely to occur as the thickness of the polyamide molded article increases.

[0005] Therefore, even when a flame-retardant polyamide resin composition is used, that is, a flame-retardant polyamide molded article is required to have excellent blister resistance. The blister resistance can be evaluated, for example, by preparing a plurality of test pieces molded into a predetermined shape from the flame-retardant polyamide resin composition, subjecting the test pieces to a reflow test, and measuring the ratio of the number of test pieces on which blisters have occurred (blister occurrence rate).

[0006] Therefore, an object of the present invention is to provide a flame-retardant polyamide molding that has excellent blister resistance even when exposed to high temperatures during a reflow process. [Means for solving the problem]

[0007] As a result of intensive research aimed at solving the above problems, the present inventors have conceived the following invention and found that the problems can be solved. That is, the present invention is as follows.

[0008] [1] A polyamide molding having a thickness of more than 0.5 mm, comprising a polyamide (A) having a melting point of 280°C or higher, a glass fiber (B1), and a halogen-based flame retardant (C), the content of the glass fiber (B1) being 45 to 120 parts by mass per 100 parts by mass of the polyamide (A), the content of the halogen-based flame retardant (C) being 25 to 60 parts by mass per 100 parts by mass of the polyamide (A), and the glass fiber (B1) having an average fiber diameter of 12 μm or less and an average irregularity ratio in a cross section perpendicular to the longitudinal direction being less than 1.5. [2] The polyamide molded article according to [1], wherein the polyamide (A) is a semi-aromatic polyamide. [3] The polyamide molded body according to [2], wherein, in the semi-aromatic polyamide, more than 50 mol % of the dicarboxylic acid-derived structural units constituting the semi-aromatic polyamide are aromatic dicarboxylic acid-derived structural units, and more than 50 mol % of the diamine-derived structural units constituting the semi-aromatic polyamide are aliphatic diamine-derived structural units having 4 to 18 carbon atoms. [4] The polyamide molded article according to [3], wherein the aliphatic diamine is at least one selected from the group consisting of 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine. [5] The polyamide molded product according to any one of [1] to [4], further comprising a flame retardant auxiliary (D), the content of the flame retardant auxiliary (D) being 0.1 to 50 parts by mass per 100 parts by mass of the polyamide (A). [6] The polyamide molded article according to any one of [1] to [5], wherein the halogen-based flame retardant (C) is at least one of brominated polystyrene and polybrominated styrene. [7] The polyamide molded product according to any one of [1] to [6], wherein the glass fibers (B1) contain at least one surface treatment agent selected from the group consisting of coupling agents and sizing agents. [8] The polyamide molded article according to [7], wherein the sizing agent comprises at least one selected from the group consisting of urethane resin-based sizing agents, acrylic resin-based sizing agents, epoxy resin-based sizing agents, and acid anhydride group-containing resin-based sizing agents. [9] The polyamide molded article according to any one of [1] to [8], which is an injection molded article.

[10] The polyamide molded article according to any one of [1] to [9], which is a part of an SMT-compatible automotive connector. Effect of the Invention

[0009] According to the present invention, it is possible to provide a flame-retardant polyamide molding that has excellent blister resistance even when exposed to high temperatures during a reflow process. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing examples of the cross-sections of a typical glass fiber, where FIG. 1(a) shows an example in which the outer shape of the cross-section is cocoon-shaped, FIG. 1(b) shows an example in which the outer shape of the cross-section is elliptical, and FIG. 1(c) shows an example in which the outer shape of the cross-section is rectangular. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention (hereinafter, sometimes referred to as "the present embodiment") will be described based on one example. However, the embodiment shown below is an example for embodying the technical idea of ​​the present invention, and the present invention is not limited to the following description. In addition, in this specification, preferred embodiments are shown, but a combination of two or more of the individual preferred embodiments is also a preferred embodiment. When there are several numerical ranges for matters shown as numerical ranges, the lower limit and upper limit can be selectively combined to form a preferred embodiment. In this specification, when a numerical range is stated as "XX to YY", it means "not less than XX and not more than YY". Furthermore, in this specification, a "unit" (where "" indicates a monomer) means a "structural unit derived from", for example, a "dicarboxylic acid unit" means a "structural unit derived from a dicarboxylic acid", and a "diamine unit" means a "structural unit derived from a diamine".

[0012] <Polyamide molded body> First, the polyamide molded article according to the present embodiment will be described. The polyamide molded article is made of a polyamide resin composition. The polyamide molded article according to this embodiment is a polyamide molded article having a thickness of more than 0.5 mm. The polyamide molded product according to this embodiment contains polyamide (A) having a melting point of 280°C or higher, glass fiber (B1), and halogen-based flame retardant (C), the content of the glass fiber (B1) being 45 to 120 parts by mass per 100 parts by mass of the polyamide (A), the content of the halogen-based flame retardant (C) being 25 to 60 parts by mass per 100 parts by mass of the polyamide (A), and the glass fiber (B1) having an average fiber diameter of 12 μm or less and an average irregularity ratio in a cross section perpendicular to the longitudinal direction being less than 1.5. The polyamide molded article according to the present embodiment has excellent blister resistance even when exposed to high temperatures during the reflow process. The blister resistance can be evaluated, for example, by the method described in the Examples section below.

[0013] The polyamide molded body according to this embodiment may have any outer shape as long as it has at least one thickness exceeding 0.5 mm. The polyamide molded body having a thickness exceeding 0.5 mm means that at least one of the thicknesses of the polyamide molded body is greater than 0.5 mm. The thicknesses of the polyamide molded body include not only the thickness of the outer shape but also the thickness of the inner wall. When the polyamide molded body has multiple surfaces, one of the thicknesses of the polyamide molded body refers to the distance from one surface to the other surface facing each other.

[0014] Usually, the thicker the polyamide molded body, the harder it is for heat to be transmitted to the center of the polyamide molded body, and the longer the path for the moisture contained in the polyamide molded body to turn into water vapor and be released from the inside of the polyamide molded body to the outside. Therefore, the moisture contained in the polyamide molded body is less likely to evaporate during preheating in the reflow process, and more moisture remains inside the polyamide molded body at the peak temperature in the reflow process. Therefore, the thicker the polyamide molded body, the more likely it is that blisters will occur. However, the polyamide molded body according to this embodiment can be made less likely to cause blisters even if it is thick.

[0015] The polyamide molded article according to this embodiment has a thickness of preferably 0.75 mm or more, more preferably more than 1.0 mm, even more preferably 1.5 mm or more, and even more preferably 4.0 mm or more or 7.0 mm or more. Therefore, the polyamide molded article according to this embodiment is suitable for large parts and the like. In addition, the polyamide molded article according to this embodiment contains a polyamide resin having excellent heat resistance and also contains a halogen-based flame retardant having excellent flame retardancy, so that it is also suitable for applications exposed to high temperatures, such as vehicle applications.

[0016] When the thickness of the polyamide molded body according to this embodiment refers to the thickness of the outer shape, it has a thickness of preferably 0.75 mm or more, more preferably more than 1.0 mm, even more preferably 1.5 mm or more, still more preferably 4.0 mm or more, and even more preferably 7.0 mm or more.

[0017] When the thickness of the polyamide molded article according to the present embodiment refers to the thickness of the inner wall, the thickness is preferably 0.75 mm or more, more preferably more than 1.0 mm, even more preferably more than 1.5 mm, and even more preferably more than 2.0 mm. The thickness range is preferably more than 0.5 mm and 3.0 mm or less, and more preferably 0.75 mm or more and 2.0 mm or less.

[0018] As described above, since the polyamide molded article according to this embodiment is suitable for large parts and the like, the outer thickness may be, for example, 5 mm or more, or 7 mm or more.

[0019] In addition, the polyamide molded article according to this embodiment is less likely to develop blisters, and therefore is less likely to undergo partial material deterioration. Therefore, it tends to have excellent mechanical properties, particularly properties such as tensile breaking strength, bending strength, and tensile breaking strain. Since the polyamide molded article according to this embodiment has excellent properties such as tensile breaking strength, bending strength, and tensile breaking strain, it is also suitable for joining with different members (e.g., wiring, boards). Therefore, it is useful for connector applications.

[0020] <Method of manufacturing polyamide molded article> The method for producing the polyamide molded article according to this embodiment is not particularly limited, and the polyamide molded article can be produced by molding the polyamide resin composition using a known method. In addition, additives such as a chain extender may be added to the polyamide resin composition during molding. Furthermore, after molding, a treatment such as heat treatment or electron beam crosslinking may be performed. Examples of the method for producing the polyamide molded article include an extrusion molding method and an injection molding method. From the viewpoint of being able to produce molded articles of various shapes, the injection molding method is preferred. Therefore, the polyamide molded article according to this embodiment is preferably an injection molded article obtained by injection molding a polyamide resin composition described in detail later.

[0021] <Applications of polyamide moldings> The polyamide molded article according to this embodiment can be used as various molded articles of any shape and purpose, including electric parts, electronic parts, automobile parts, industrial parts, water faucet parts, fibers, films, sheets, household goods, leisure goods, and other items.

[0022] Examples of electrical and electronic components include connectors such as FPC connectors, BtoB connectors, card connectors, SMT connectors (coaxial connectors, etc.), memory card connectors, etc.; SMT relays; SMT bobbins; sockets such as memory sockets, CPU sockets, etc.; switches such as command switches, SMT switches, etc.; optical components such as optical fiber components, optical sensors, etc.; LED application components such as LED reflectors; and electronic boards such as solar cell boards, LED mounting boards, flexible printed wiring boards, and resin molded circuit boards.

[0023] Automotive parts include, for example, cooling parts such as thermostat housings, coolant control valve housings, thermal management module housings, radiator tanks, radiator hoses, water outlets, water inlets, water pump housings, and rear joints; intake and exhaust system parts such as intercooler tanks, intercooler cases, turbo duct pipes, EGR cooler cases, resonators, throttle bodies, intake manifolds, and tail pipes; fuel system parts such as fuel delivery pipes, gasoline tanks, quick connectors, canisters, pump modules, fuel piping, oil strainers, lock nuts, and seals; structural parts such as mount brackets, torque rods, and cylinder head covers; bearing retainers, gear tensioners, and head screws. These include drive system parts such as headlamp actuator gears, throttle valve gears, sliding door rollers, and clutch peripheral parts; brake system parts such as air brake tubes; automotive electrical parts such as wire harness connectors in the engine bay, motor parts, sensors, ABS bobbins, combination switches, and on-board switches; and interior and exterior parts such as sliding door dampers, door mirror stays, door mirror brackets, inner mirror stays, roof rails, engine mount brackets, air cleaner inlet pipes, door checkers, plastic chains, emblems, clips, breaker covers, cup holders, airbags, fenders, spoilers, radiator supports, radiator grilles, louvers, air scoops, hood bulges, back doors, and fuel sender modules.

[0024] Examples of industrial parts include gas pipes, oil field drilling pipes, hoses, anti-termite cables (communication cables, pass cables, etc.), paint parts of powder coated products (inner coatings of water pipes, etc.), undersea oil field pipes, pressure resistant hoses, hydraulic tubes, paint tubes, fuel pump housings and impellers, separators, supercharge ducts, butterfly valves, conveyor roller bearings, railway sleeper spring supports, outboard motor engine covers, generator engine covers, wind turbine blades, irrigation valves, large switches, and monofilaments (extruded yarns) for fishing nets, etc.

[0025] Examples of faucet parts include housings for parts that transport tap water, housings for parts that store tap water, housings for filter casings, faucets, housings for pipes, housings for bathroom faucets (hot and cold water switching valves, water volume switching valves, etc.), housings for sanitary parts, housings for kitchen faucets, housings for water heaters, valve parts (shut-off balls, slides, cylinders) and valve part housings, housings for toilet stop valves, housings inside shower heads, valve housings for water heaters, fittings for residential piping (underfloor piping, etc.), fittings for bathroom faucets, fittings for water piping, pipe joints, housings for water meters. Housings, water meter parts (bearings, propellers, pins) and water meters, gas meter housings, distributor housings, valve / pump housings for domestic appliances, steam-resistant parts for steam irons, inner containers of electric kettles, dishwasher parts (washing tubs, cleaning nozzles, baskets), pump housings, pump parts (e.g. turbine wheels, impellers), housings for water supply systems (hot water tanks, etc.), heating system housings, cooling system housings, water flow control valves, pressure reducing valves, relief valves, solenoid valves, three-way valves, thermo valves, water temperature sensors, water flow sensors, bathtub adapters, etc.

[0026] Examples of household products include valve / pump housings for tea and coffee makers; valve / pump housings for cooking appliances such as rice cookers and steamers; steam-resistant parts for cooking appliances such as rice cookers and steamers (such as rice cooker top lids); sliding parts (e.g. gears) for cooking appliances such as rice cookers and steamers; sliding parts for commercial cooking appliances (e.g. gears for gear pumps); steam-resistant parts for commercial cooking appliances (e.g. pipes for commercial rice cookers), etc.

[0027] Examples of leisure goods include inner soles of sports shoes, frames and grommets of rackets, heads and sleeves of golf clubs, reels and rods of fishing tackle, propellers of boats, suspensions, gears, saddles, bottle cages of bicycles, and the like.

[0028] The polyamide molded article according to this embodiment can be manufactured by injection molding, and therefore can be suitably used for electrical and electronic components that require the manufacture of a large number of components in a short time. Specifically, it can be suitably used for electrical and electronic components that include SMT processes, more specifically, for surface-mounted components such as SMT-compatible connectors, SMT relays, SMT bobbins, sockets, command switches, SMT switches, camera modules, power supply components, sensors, capacitor base plates, hard disk components, resistors, fuse holders, coil bobbins, and IC housings.

[0029] A particularly suitable example of the polyamide molded body according to this embodiment is a part of an SMT-compatible in-vehicle connector. The SMT-compatible in-vehicle connector generally includes a housing and a terminal made of a resin composition using a resin having a melting point of 260°C or higher. The SMT-compatible in-vehicle connector may include a seal ring, a gasket, a shell, and the like. In-vehicle connectors usually have larger outer dimensions than connectors for consumer electronic devices. Furthermore, since the thickness is large during the SMT process, they are more likely to be exposed to a higher temperature environment. Furthermore, since the moisture inside the molded body is not easily released during the preheating process of the SMT process, blisters are likely to occur. In addition, high flame retardancy is required. Furthermore, since the quality requirements for in-vehicle applications are strict, the occurrence of blisters is not permitted. Therefore, the polyamide molded body is required to have excellent blister resistance even when exposed to high temperatures during the SMT process. The polyamide molded body according to this embodiment can meet these requirements, and is therefore suitable for a part of an in-vehicle connector.

[0030] <Components of polyamide molding> Next, the components contained in the polyamide molded article according to this embodiment will be described.

[0031] As described above, the polyamide molding of this embodiment contains polyamide (A) having a melting point of 280°C or higher, glass fiber (B1), and halogen-based flame retardant (C), the content of the glass fiber (B1) is 45 to 120 parts by mass per 100 parts by mass of the polyamide (A), the content of the halogen-based flame retardant (C) is 25 to 60 parts by mass per 100 parts by mass of the polyamide (A), and the glass fiber (B1) has an average fiber diameter of 12 μm or less and an average irregularity ratio in a cross section perpendicular to the longitudinal direction of less than 1.5.

[0032] [Polyamide (A)] The polyamide molded product according to this embodiment contains a polyamide (A) having a melting point of 280° C. or higher. Examples of the polyamide (A) include condensation polymers of dicarboxylic acids and diamines, ring-opening polymers of cyclic lactams, and condensation polymers of aminocarboxylic acids.

[0033] Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, dimethylmalonic acid, 2,2-diethylsuccinic acid, 2,2-dimethylglutaric acid, 2-methyladipic acid, and trimethyladipic acid; 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cycloheptanedicarboxylic acid, and cyclohexanedicarboxylic acid; and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,4-phenylenedioxydiacetic acid, 1,3-phenylenedioxydiacetic acid, diphenic acid, diphenylmethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, and 4,4'-biphenyldicarboxylic acid. These dicarboxylic acids can be used alone or in combination of two or more. The polyamide (A) may further contain structural units derived from a polyvalent carboxylic acid having three or more valences, such as trimellitic acid, trimesic acid, or pyromellitic acid, to the extent that melt molding is possible, as long as the effects of the present invention are not impaired.

[0034] The diamines include aliphatic diamines, alicyclic diamines, aromatic diamines, etc. Examples of the aliphatic diamines include linear aliphatic diamines such as ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine; 1-butyl-1,2-ethanediamine, 1,1-dimethyl-1,4-butanediamine, and 1-ethyl-1,4-butanediamine; hexanediamine, 1,2-dimethyl-1,4-butanediamine, 1,3-dimethyl-1,4-butanediamine, 1,4-dimethyl-1,4-butanediamine, 2,3-dimethyl-1,4-butanediamine, 2-methyl-1,5-pentanediamine, 3-methyl-1,5-pentanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,4-dimethyl-1,6-hexanediamine, 3,3-dimethyl-1,6-hexanediamine, 2,2-dimethyl-1,6-hexanediamine, 2,2,4-trimethyl-1 ,6-Hexanediamine, 2,4,4-trimethyl-1,6-hexanediamine, 2-propyl-1,6-hexanediamine, 2,4-diethyl-1,6-hexanediamine, 2,2-dimethyl-1,7-heptanediamine, 2,3-dimethyl-1,7-heptanediamine, 2,4-dimethyl-1,7-heptanediamine, 2,5-dimethyl-1,7-heptanediamine, 2-ethyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 3-methyl-1,8-octanediamine, 4-methyl Examples of the branched chain aliphatic diamines include 1,8-octanediamine, 1,3-dimethyl-1,8-octanediamine, 1,4-dimethyl-1,8-octanediamine, 2,4-dimethyl-1,8-octanediamine, 3,4-dimethyl-1,8-octanediamine, 4,5-dimethyl-1,8-octanediamine, 2,2-dimethyl-1,8-octanediamine, 3,3-dimethyl-1,8-octanediamine, 4,4-dimethyl-1,8-octanediamine, and 5-methyl-1,9-nonanediamine. The diamine is preferably an aliphatic diamine.

[0035] Examples of the alicyclic diamine include cyclohexane diamine, methylcyclohexane diamine, isophorone diamine, norbornane dimethylamine, and tricyclodecane dimethylamine. Examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 4,4'-diaminodiphenyl ether. These diamines can be used alone or in combination of two or more. The polyamide (A) may further contain structural units derived from a polyvalent amine having three or more valences, such as bis(hexamethylene)triamine, to the extent that melt molding is possible, provided that the effects of the present invention are not impaired.

[0036] Examples of the cyclic lactams include acetolactam, propiolactam, butyrolactam, valerolactam, caprolactam, enantholactam, caprylolactam, pelargolactam, caprinolactam, and laurolactam. Examples of the aminocarboxylic acid include aminopropionic acid, aminobutyric acid, aminovaleric acid, aminocaproic acid, aminoenanthic acid, aminocaprylic acid, aminopelargonic acid, aminocapric acid, and aminolauric acid.

[0037] The polyamide (A) is preferably an aliphatic polyamide, a wholly aromatic polyamide, or a semi-aromatic polyamide, which is prepared by appropriately combining monomers such as the above-mentioned dicarboxylic acids, diamines, cyclic lactams, aminocarboxylic acids, trivalent or higher polyvalent carboxylic acids, and trivalent or higher polyvalent amines so that the melting point is 280°C or higher. In the present invention, the term "wholly aromatic polyamide" refers to a polyamide in which more than 50 mol % of the dicarboxylic acid units constituting the polyamide are aromatic dicarboxylic acid units and more than 50 mol % of the diamine units constituting the polyamide are aromatic diamine units. In the present invention, the term "semi-aromatic polyamide" refers to a polyamide in which more than 50 mol % of the dicarboxylic acid units constituting the polyamide are aromatic dicarboxylic acid units and more than 50 mol % of the diamine units constituting the polyamide are aliphatic diamine units, or a polyamide in which more than 50 mol % of the dicarboxylic acid units constituting the polyamide are aliphatic dicarboxylic acid units and more than 50 mol % of the diamine units constituting the polyamide are aromatic diamine units. Among these, from the viewpoint of obtaining a polyamide molded article having excellent blister resistance even when exposed to high temperatures during a reflow process, at least one selected from the group consisting of aliphatic polyamides and semi-aromatic polyamides is preferred, and semi-aromatic polyamides are more preferred. A more preferred example is a semi-aromatic polyamide in which more than 50 mol % of the dicarboxylic acid-derived constitutional units constituting the semi-aromatic polyamide are aromatic dicarboxylic acid-derived constitutional units, and more than 50 mol % of the diamine-derived constitutional units constituting the semi-aromatic polyamide are aliphatic diamine-derived constitutional units having 4 to 18 carbon atoms.

[0038] Examples of the aliphatic polyamide include a ring-opening polymer of the cyclic lactam, a condensation polymer of the aminocarboxylic acid, or a condensation polymer of the aliphatic dicarboxylic acid and the aliphatic diamine. Among these, from the viewpoint of obtaining a polyamide molded body having excellent blister resistance even when exposed to high temperatures during a reflow process, a condensation polymer of the aliphatic dicarboxylic acid and the aliphatic diamine is preferred, and from the viewpoint of ease of production, polyamide 46 is more preferred.

[0039] From the viewpoint of obtaining a polyamide molded body having excellent blister resistance even when exposed to high temperatures during the reflow process, the semi-aromatic polyamide is preferably one in which more than 50 mol % of the dicarboxylic acid units constituting the semi-aromatic polyamide are aromatic dicarboxylic acid units and more than 50 mol % of the diamine units constituting the semi-aromatic polyamide are aliphatic diamine units.

[0040] Examples of the aromatic dicarboxylic acid constituting the semi-aromatic polyamide include the aromatic dicarboxylic acids mentioned above. Suitable examples of such aromatic dicarboxylic acids are dicarboxylic acids in which the aromatic group has 6 to 10 carbon atoms. Among them, phthalic acid, isophthalic acid, and terephthalic acid are preferred, isophthalic acid and terephthalic acid are more preferred, and terephthalic acid is even more preferred. Thus, such aromatic dicarboxylic acids are dicarboxylic acids in which the aromatic group has 6 carbon atoms (i.e., a phenylene group). From the viewpoint of heat resistance, the content of aromatic dicarboxylic acid units in all dicarboxylic acid units constituting the semi-aromatic polyamide is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and even more preferably 90 mol% or more, and 100 mol% or less. The semi-aromatic polyamide may contain other dicarboxylic acid units other than the aromatic dicarboxylic acid units. Examples of such other dicarboxylic acids include the above-mentioned aliphatic dicarboxylic acids and alicyclic dicarboxylic acids. The content of other dicarboxylic acid units in the total dicarboxylic acid units constituting the semi-aromatic polyamide is preferably 40 mol% or less, more preferably 30 mol% or less, even more preferably 20 mol% or less, and even more preferably 10 mol% or less.

[0041] Examples of the aliphatic diamine constituting the semi-aromatic polyamide include the aliphatic diamines described above. From the viewpoint of excellent physical properties such as heat resistance and low water absorption, the carbon number of the aliphatic diamine is preferably 4 or more, more preferably 6 or more, and even more preferably 8 or more, and is preferably 18 or less, more preferably 12 or less. Therefore, such an aliphatic diamine is preferably an aliphatic diamine having 4 to 18 carbon atoms.

[0042] As the aliphatic diamine, from the viewpoint of excellent physical properties such as heat resistance and low water absorption, at least one selected from the group consisting of 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine is preferable, at least one selected from the group consisting of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is more preferable, and a combination of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is even more preferable.

[0043] The content of aliphatic diamine units in all diamine units constituting the semi-aromatic polyamide is preferably 60 mol % or more, more preferably 70 mol % or more, even more preferably 80 mol % or more, and even more preferably 90 mol % or more, and 100 mol % or less.

[0044] The semi-aromatic polyamide may contain other diamine units other than the aliphatic diamine units. Examples of such other diamines include the above-mentioned aromatic diamines and alicyclic diamines. The content of the other diamine units in the total diamine units constituting the semi-aromatic polyamide is preferably 40 mol% or less, more preferably 30 mol% or less, even more preferably 20 mol% or less, and even more preferably 10 mol% or less.

[0045] When 1,9-nonanediamine and 2-methyl-1,8-octanediamine are used in combination as the aliphatic diamine, from the viewpoint of heat resistance, the molar ratio of 1,9-nonanediamine to 2-methyl-1,8-octanediamine (1,9-nonanediamine / 2-methyl-1,8-octanediamine) is preferably in the range of 95 / 5 to 40 / 60, more preferably in the range of 90 / 10 to 50 / 50, and even more preferably in the range of 90 / 10 to 60 / 40.

[0046] The semi-aromatic polyamide may contain structural units derived from cyclic lactams and / or aminocarboxylic acids. Examples of such structural units include structural units derived from cyclic lactams such as caprolactam and laurolactam; and aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid. The total content of cyclic lactam units and aminocarboxylic acid units in the semi-aromatic polyamide is preferably 40 mol% or less, more preferably 20 mol% or less, based on 100 mol% of the total of dicarboxylic acid units and diamine units constituting the semi-aromatic polyamide.

[0047] Specific examples of the semi-aromatic polyamide include polytetramethylene terephthalamide (polyamide 4T), polyhexamethylene terephthalamide (polyamide 6T), polynonamethylene terephthalamide (polyamide 9T), polydecamethylene terephthalamide (polyamide 10T), polyhexamethylene isophthalamide (polyamide 6I), a copolymer of polyamide 6I and polyamide 6T (polyamide 6I / 6T), and a copolymer of polyamide 6T and polyundecane amide (polyamide 11) (polyamide 6T / 11). Among them, at least one selected from the group consisting of polyamide 4T, polyamide 6T, polyamide 9T, and polyamide 10T is preferred, at least one selected from the group consisting of polyamide 9T and polyamide 10T is more preferred, and polyamide 9T is even more preferred.

[0048] The polyamide (A) preferably has 10% or more of the terminal groups of its molecular chain capped with a terminal capping agent, and more preferably has a terminal capping rate of 20% or more. As the end-capping agent, a monofunctional compound having reactivity with the amino group or carboxy group at the polyamide end can be used, and from the viewpoints of reactivity and stability of the blocked end, a monocarboxylic acid or a monoamine is preferred, and from the viewpoints of ease of handling, a monocarboxylic acid is more preferred. In addition, monoisocyanates, monoacid halides, monoesters, monoalcohols, etc. can also be used as the end-capping agent.

[0049] As the monocarboxylic acid used as the terminal blocking agent, those having reactivity with amino groups can be used, and examples thereof include aliphatic monocarboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid, and isobutyric acid; alicyclic monocarboxylic acids such as cyclohexane carboxylic acid; aromatic monocarboxylic acids such as benzoic acid, toluic acid, α-naphthalene carboxylic acid, β-naphthalene carboxylic acid, methylnaphthalene carboxylic acid, and phenyl acetic acid; and any mixtures thereof. Among these, from the viewpoints of reactivity, stability of blocked terminals, cost, and the like, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, and benzoic acid are preferred.

[0050] The monoamine used as the terminal blocking agent may be one having reactivity with a carboxy group, and examples of such monoamines include aliphatic monoamines such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine, and dibutylamine; alicyclic monoamines such as cyclohexylamine and dicyclohexylamine; aromatic monoamines such as aniline, toluidine, diphenylamine, and naphthylamine; and any mixtures thereof. Among these, butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine, and aniline are preferred from the viewpoints of reactivity, boiling point, stability of blocked terminals, and cost.

[0051] The terminal capping rate of polyamide (A) is calculated by measuring the number of carboxyl terminals, amino terminals, and terminal groups capped with a terminal capping agent present in polyamide (A) and then calculating the terminal capping rate according to the following formula (1). From the viewpoints of accuracy and simplicity, the number of each terminal group is calculated as follows: 1 It is preferable to determine it from the integral value of the characteristic signal corresponding to each terminal group by 1 H-NMR. End sealing rate (%)=[(TS) / T]×100 (1) [In the formula, T represents the total number of terminal groups in the molecular chain of polyamide (A) (which is usually equal to twice the number of polyamide molecules), and S represents the total number of carboxyl and amino terminals remaining uncapped.]

[0052] The polyamide (A) can be produced by any method known as a method for producing crystalline polyamides, such as a solution polymerization method or an interfacial polymerization method using dicarboxylic acid and diamine in the form of acid chloride as raw materials, a melt polymerization method, a solid-state polymerization method, or a melt extrusion polymerization method using dicarboxylic acid and diamine as raw materials.

[0053] The polyamide (A) can be produced, for example, by first adding diamine, dicarboxylic acid, and if necessary, a catalyst and an end-capping agent all at once to produce a nylon salt, then heating and polymerizing the prepolymer at a temperature of 200 to 250°C, and further solid-phase polymerizing the prepolymer, or polymerizing the prepolymer using a melt extruder. When the final stage of the polymerization is carried out by solid-phase polymerization, it is preferable to carry out the polymerization under reduced pressure or in an inert gas flow. If the polymerization temperature is within the range of 200 to 280°C, the polymerization rate is high, productivity is excellent, and coloring and gelation can be effectively suppressed. When the final stage of the polymerization is carried out using a melt extruder, the polymerization temperature is preferably 370°C or less, and when polymerization is carried out under such conditions, polyamide (A) with little decomposition and little deterioration can be obtained.

[0054] Examples of catalysts that can be used in producing polyamide (A) include phosphoric acid, phosphorous acid, hypophosphorous acid, and salts or esters thereof. Examples of the above salts or esters include salts of phosphoric acid, phosphorous acid, or hypophosphorous acid with metals such as potassium, sodium, magnesium, vanadium, calcium, zinc, cobalt, manganese, tin, tungsten, germanium, titanium, and antimony; ammonium salts of phosphoric acid, phosphorous acid, or hypophosphorous acid; ethyl esters, isopropyl esters, butyl esters, hexyl esters, isodecyl esters, octadecyl esters, decyl esters, stearyl esters, and phenyl esters of phosphoric acid, phosphorous acid, or hypophosphorous acid. Among these, sodium hypophosphite monohydrate or phosphorous acid is preferred.

[0055] The polyamide (A) has an intrinsic viscosity [η] of preferably 0.60 to 1.2 dl / g, more preferably 0.65 to 1.1 dl / g, measured at 30° C. using concentrated sulfuric acid as a solvent. If a polyamide (A) having an intrinsic viscosity [η] of 0.60 dl / g or more is used, the mechanical properties of the resulting molded article become good. If a polyamide (A) having an intrinsic viscosity [η] of 1.2 dl / g or less is used, the moldability is further improved. The intrinsic viscosity [η] of the polyamide (A) is measured by the method described in the Examples.

[0056] The melting point of the polyamide (A) is 280° C. or higher, preferably 290° C. or higher, and more preferably 300° C. or higher, from the viewpoint of heat resistance and the like, in which the effects of the present invention are more significantly exhibited. From the viewpoint of suppressing the thermal decomposition of the polyamide during melt molding, the melting point is preferably 350° C. or lower, more preferably 340° C. or lower, and even more preferably 330° C. or lower. The melting point of the polyamide (A) can be measured by the method described in the Examples section below.

[0057] [Glass fiber (B1)] The polyamide molded product according to this embodiment contains glass fiber (B1). The glass fiber (B1) has an average fiber diameter of 12 μm or less and an average irregularity ratio in a cross section perpendicular to the longitudinal direction of less than 1.5. The glass fiber (B1) may be used alone or in combination of two or more kinds. The polyamide molded product can have excellent mechanical strength by containing the glass fiber (B1).

[0058] The glass fiber (B1) not only increases the mechanical strength of the polyamide molded article, but also contributes to providing a polyamide molded article that has excellent blister resistance even when exposed to high temperatures during the reflow process. Although the mechanism is not clear, it is thought that the glass fiber (B1) makes it difficult to inhibit the evaporation of water vapor from the polyamide molded article during preheating in the reflow process.

[0059] The average fiber diameter of the glass fiber (B1) is preferably 11 μm or less, more preferably 10.5 μm or less, and even more preferably 10 μm or less, from the viewpoint of obtaining a polyamide molded article having better blister resistance and / or mechanical strength. The average fiber diameter of the glass fiber (B1) is preferably smaller from the viewpoint of obtaining a polyamide molded article having better blister resistance, and may be, for example, 9 μm or less, 8 μm or less, or 7.5 μm or less. The lower limit of the average fiber diameter of the glass fiber (B1) is not limited as long as it is available, but may be, for example, 0.5 μm or more, 1 μm or more, or 2 μm or more.

[0060] Measurement of the average fiber diameter of glass fibers (B1) The average fiber diameter of the glass fibers (B1) is determined by observing the glass fibers (B1) with an electron microscope, obtaining a cross-sectional image, and analyzing this image. In the obtained image, the major axis of each of 400 glass fibers (B1) is measured, and this major axis is regarded as each fiber diameter. The major axis here is the same as the major axis used in calculating the irregularity ratio described later. The average value of the fiber diameters of the 400 fibers is regarded as the average fiber diameter of the glass fibers (B1). The average fiber diameter of the glass fibers (B1) in the polyamide molding can be determined by dissolving the polyamide molding in an organic solvent, extracting the glass fibers (B1), and performing the same method as above. The average fiber diameter of the glass fibers (B2) other than the glass fibers (B1) can also be determined by the same method.

[0061] FIG. 1 is a diagram showing a typical example of a cross section of a general glass fiber, in which FIG. 1(a) shows an example in which the cross section has a cocoon-shaped outer shape, FIG. 1(b) shows an example in which the cross section has an ellipse-shaped outer shape, and FIG. 1(c) shows an example in which the cross section has a rectangular outer shape. The irregularity ratio in the cross section of the glass fiber (B1) is expressed by the ratio of the major axis to the minor axis (i.e., D1 / D2) when the major axis in the cross section is D1 and the minor axis in the cross section is D2. However, the major axis and the minor axis are orthogonal to each other. Note that when the cross section of the glass fiber (B1) has an irregular shape, for example, a cocoon-shaped (see FIG. 1(a)), an ellipse (see FIG. 1(b)), a semicircle, a rectangle (see FIG. 1(c)), a polygon, a star, or other noncircular cross section, it is possible to specify the minor axis D2 and the major axis D1 as shown in FIG. 1. The lower limit of the irregularity ratio is 1.0 (long diameter D1 = short diameter D2). Usually, the irregularity ratio is expressed as the average value of the irregularity ratios of a large number of glass fibers (B1). The irregularity ratio of a cross section of glass fibers (B2) other than the glass fiber (B1) can be calculated by the same method.

[0062] From the viewpoint of obtaining a polyamide molded article having superior blister resistance, the average deformation ratio in the cross section of the glass fiber (B1) is preferably 1.4 or less, more preferably 1.3 or less, even more preferably 1.2 or less or less than 1.2, and still more preferably 1.1 or less or 1.05 or less.

[0063] Measurement of average irregularity ratio of glass fiber (B1) The irregularity ratio of the glass fiber (B1) is obtained by observing the glass fiber (B1) with an electron microscope, obtaining a cross-sectional image, and analyzing this image. In the obtained image, the long and short diameters of 400 glass fibers (B1) are specified as shown in Figure 1. The irregularity ratio is obtained by calculating the ratio (long diameter / short diameter) from the specified long and short diameters. The average irregularity ratio of the 400 fibers is taken as the average irregularity ratio of the glass fiber (B1). In the case of a polyamide molded body, the polyamide molded body is dissolved in an organic solvent to extract the glass fiber (B1), and the average irregularity ratio of the glass fiber (B1) can be measured in the same manner as above. The average irregularity ratio of glass fibers (B2) other than the glass fiber (B1) can also be obtained in the same manner.

[0064] The average fiber length of the glass fibers (B1) is not limited. For example, the average fiber length of the glass fibers (B1) is within the range of 1 to 10 mm, within the range of 1 to 7 mm, or within the range of 2 to 4 mm.

[0065] (Surface treatment agent) The glass fiber (B1) may contain at least one surface treatment agent selected from the group consisting of a coupling agent and a sizing agent. For example, the glass fiber (B1) may contain a sizing agent. The glass fiber (B1) may also contain a coupling agent and a sizing agent. The glass fiber (B1) preferably contains a surface treatment agent on its surface. The amount of the surface treatment agent attached is usually 0.01 mass% or more based on the total mass of the glass fiber (B1) (i.e., the total amount of the glass fiber (B1) and the surface treatment agent).

[0066] Examples of the coupling agent include a silane coupling agent and a titanium coupling agent. Examples of the silane coupling agent include γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-aminopropyltriethoxysilane.

[0067] Examples of the bundling agent include urethane resin-based bundling agents, acrylic resin-based bundling agents, epoxy resin-based bundling agents, and acid anhydride group-containing resin-based bundling agents. However, when the urethane resin-based bundling agent, the acrylic resin-based bundling agent, and the epoxy resin-based bundling agent contain an acid anhydride group, they are considered to belong to the acid anhydride group-containing resin-based bundling agent. The acid anhydride group-containing resin-based bundling agent is composed of a resin containing at least an acid anhydride group, and is preferably composed of a copolymer containing an acid anhydride group. From the viewpoint of obtaining a polyamide molded body having better blister resistance and a polyamide molded body having better mechanical strength, it is preferable that the bundling agent contains at least one selected from the group consisting of an epoxy resin-based bundling agent and an acid anhydride group-containing resin-based bundling agent. From the viewpoint of obtaining a polyamide molded body having even better blister resistance, it is preferable that the bundling agent contains an epoxy resin-based bundling agent. From the viewpoint of obtaining a polyamide molded body having even better mechanical strength, it is preferable that the bundling agent contains a urethane resin-based bundling agent. It is believed that selection of an appropriate surface treatment agent for the glass fiber (B1) contributes to imparting to the polyamide molding a strength capable of withstanding the internal pressure of water vapor even under the peak temperature conditions of the reflow process.

[0068] As described above, the content of the glass fiber (B1) is 45 to 120 parts by mass relative to 100 parts by mass of the polyamide (A). When the content of the glass fiber (B1) is 45 parts by mass or more relative to 100 parts by mass of the polyamide (A), the mechanical strength of the obtained molded article can be increased. From this viewpoint, the lower limit of the content of the glass fiber (B1) may be 50 parts by mass or more, 55 parts by mass or more, 60 parts by mass or more, or 65 parts by mass or more. Furthermore, when the content of the glass fiber (B1) is 120 parts by mass or less relative to 100 parts by mass of the polyamide (A), the performance (e.g., excellent blister resistance) of the obtained molded article can be maintained. From this viewpoint, the upper limit of the content of the glass fiber (B1) may be 110 parts by mass or less, 100 parts by mass or less, 95 parts by mass or less, or 90 parts by mass or less.

[0069] The method for producing the glass fiber (B1) is not limited. The glass fiber (B1) may be a commercially available product or a custom-made product. For example, the glass fiber (B1) may be produced by obtaining glass fiber having an average irregularity ratio of less than 1.5, so that the average fiber diameter is 12 μm or less.

[0070] The polyamide molded product used in this embodiment may contain glass fiber (B2) other than the above glass fiber (B1). The glass fiber (B1) and the glass fiber (B2) may be collectively referred to as glass fiber (B). When the polyamide molded product contains the glass fiber (B1) and the glass fiber (B2), the content (parts by mass) of the glass fiber (B1) in the polyamide molded product is preferably greater than the content (parts by mass) of the glass fiber (B2), and the content of the glass fiber (B1) is more preferably 2 times or more, even more preferably 5 times or more, and even more preferably 10 times or more, of the content of the glass fiber (B2).

[0071] [Halogen-based flame retardants (C)] The polyamide molded product according to this embodiment contains a halogen-based flame retardant (C). By containing the halogen-based flame retardant (C), the flame retardancy is improved.

[0072] The halogen-based flame retardant (C) is not particularly limited, and a compound known as a flame retardant containing a halogen element can be used, such as a bromine-based flame retardant (C1) or a chlorine-based flame retardant (C2), and the bromine-based flame retardant (C1) is preferred. These may be used alone or in combination of two or more.

[0073] (Brominated flame retardants (C1)) Examples of the brominated flame retardant (C1) include hexabromocyclododecane, decabromodiphenyl oxide, octabromodiphenyl oxide, tetrabromobisphenol A, bis(tribromophenoxy)ethane, bis(pentabromophenoxy)ethane, tetrabromobisphenol A epoxy resin, tetrabromobisphenol A carbonate, ethylene(bistetrabromophthalic)imide, ethylenebispentabromodiphenyl, tris(tribromophenoxy)triazine, bis(dibromopropyl)tetrabromobisphenol A, bis(dibromopropyl)tetrabromobisphenol B, and the like. Nol S, brominated polyphenylene ether (including poly(di)bromophenylene ether, etc.), brominated polystyrene (including polydibromostyrene, polytribromostyrene, crosslinked brominated polystyrene, etc.; may be modified brominated polystyrene with an epoxy acrylate or the like added thereto), brominated crosslinked aromatic polymer, brominated epoxy resin, brominated phenoxy resin, brominated styrene-maleic anhydride polymer, tetrabromobisphenol S, tris(tribromoneopentyl)phosphate, polybromotrimethylphenylindane, tris(dibromopropyl)-isocyanurate, etc.

[0074] As the brominated flame retardant (C1), from the viewpoint of reducing the amount of corrosive gas generated during melt processing such as extrusion or molding, and obtaining molded articles excellent in flame retardancy and mechanical properties of electric or electronic parts, brominated polyphenylene ether and brominated polystyrene are preferred, and brominated polystyrene is more preferred.

[0075] Brominated polystyrene can be produced, for example, by a method in which a styrene monomer is polymerized to produce polystyrene, and then the benzene ring of the polystyrene is brominated, or by a method in which a brominated styrene monomer (bromostyrene, dibromostyrene, tribromostyrene, etc.) is polymerized.

[0076] The bromine content in the brominated polystyrene is preferably 55-75% by mass, more preferably 55-70% by mass. By making the bromine content 55% by mass or more, the amount of bromine required for flame retardancy can be satisfied with a small amount of brominated polystyrene, and the deterioration of mechanical properties can be suppressed, and a polyamide molded product having excellent mechanical properties and heat resistance can be obtained. In addition, by making the bromine content 75% by mass or less, thermal decomposition is unlikely to occur during melt processing such as extrusion and molding, gas generation can be suppressed, and a polyamide molded product having excellent heat discoloration resistance can be obtained.

[0077] (Chlorinated flame retardants (C2)) Examples of the chlorine-based flame retardant (C2) include chlorinated paraffin, chlorinated polyethylene, dodecachloropentacyclooctadeca-7,15-diene ("Dechlorane Plus 25" manufactured by Occidental Chemical Co.), and HET anhydride.

[0078] The content of the halogen-based flame retardant (C) is 25 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the polyamide (A). The content can be changed as long as the desired flame retardancy is satisfied, and is preferably 30 parts by mass or more and 60 parts by mass or less, more preferably 35 parts by mass or more and 60 parts by mass or less. By making the content of the halogen-based flame retardant (C) 30 parts by mass or more, a polyamide molded product having excellent flame retardancy can be obtained. In addition, by making the content of the halogen-based flame retardant (C) 60 parts by mass or less, a resin composition having excellent flowability can be obtained, and a polyamide molded product having excellent mechanical properties can be obtained. When using a plurality of halogen-based flame retardants (C), the total amount of them may be within the above range.

[0079] [Flame retardant synergist (D)] The polyamide molded article according to this embodiment may further contain a flame retardant auxiliary (D). By using the flame retardant auxiliary (D) in combination with the halogen-based flame retardant (C), the polyamide molded article can exhibit even more excellent flame retardancy.

[0080] Examples of the flame retardant assistant (D) include antimony compounds such as antimony oxides, such as diantimony trioxide, diantimony tetraoxide, and diantimony pentaoxide, and antimonates, such as sodium antimonate; melamine compounds, such as melamine orthophosphate, melamine pyrophosphate, melamine borate, and melamine polyphosphate; tin oxides, such as tin monoxide and tin dioxide; iron oxides, such as ferric oxide and gamma-iron oxide; aluminum oxide, silicon oxide (silica), titanium oxide, zirconium oxide, manganese oxide, molybdenum oxide, Metal oxides such as cobalt oxide, bismuth oxide, chromium oxide, tin oxide, nickel oxide, copper oxide, and tungsten oxide; metal hydroxides such as aluminum hydroxide; metal powders such as aluminum, iron, titanium, manganese, zinc, molybdenum, cobalt, bismuth, chromium, tin, antimony, nickel, copper, and tungsten; metal carbonates such as zinc carbonate, magnesium carbonate, and barium carbonate; metal borates such as zinc borate and calcium borate; zinc stannates such as zinc tin trioxide; and silicones. However, those corresponding to glass fiber (B1) and glass fiber (B2) are excluded. These may be used alone or in combination of two or more.

[0081] Among the above, at least one selected from the group consisting of antimony compounds, melamine compounds, metal oxides, metal hydroxides, metal borates, and zinc stannate is preferred, and at least one selected from the group consisting of diantimony trioxide, diantimony tetroxide, diantimony pentaoxide, sodium antimonate, melamine orthophosphate, melamine pyrophosphate, melamine borate, melamine polyphosphate, aluminum oxide, aluminum hydroxide, zinc borate, and zinc tin trioxide is more preferred.

[0082] The flame retardant auxiliary (D) is preferably in the form of powder and is contained in the polyamide molded article according to this embodiment. The upper limit of the average particle size is preferably 30 μm, more preferably 15 μm, further preferably 10 μm, and particularly preferably 7 μm. On the other hand, the lower limit of the average particle size of the flame retardant auxiliary (D) is preferably 0.01 μm. When the average particle size is 0.01 to 30 μm, the flame retardancy of the resulting polyamide molded article is improved. In this specification, the term "average particle size" refers to the volume average particle size, and can be calculated from the particle size at which the cumulative volume is 50% (50% particle size D50) in the particle size distribution measured using a laser diffraction particle size distribution analyzer.

[0083] When the polyamide molded article according to the present embodiment contains a flame retardant auxiliary (D), the content of the flame retardant auxiliary (D) is preferably 0.1 to 50 parts by mass, more preferably 1 to 25 parts by mass, further preferably 2 to 20 parts by mass, and even more preferably 3 to 15 parts by mass, based on 100 parts by mass of the polyamide (A), thereby making it possible to significantly achieve the above-mentioned effects.

[0084] [Other ingredients (E)] The polyamide molded article according to this embodiment may contain other components (E) as required in addition to the above-mentioned polyamide (A), glass fiber (B1), and halogen-based flame retardant (C), as well as the flame retardant auxiliary (D) used as required.

[0085] Examples of other components (E) include stabilizers such as copper compounds; antioxidants such as hindered phenol antioxidants, hindered amine antioxidants, phosphorus antioxidants, and thio antioxidants (component (E1) used in the examples); colorants (component (E4) used in the examples); ultraviolet absorbers; light stabilizers; antistatic agents; heat stabilizers; crystal nucleating agents; plasticizers; lubricants; release agents (component (E3) used in the examples); slip agents; dispersants; oxygen absorbers; hydrogen sulfide adsorbents; crystallization retarders; impact modifiers such as α-olefin copolymers and rubber; and anti-drip agents such as fluororesins (component (E2) used in the examples).

[0086] The content of the other component (E) is not particularly limited as long as it does not impair the effects of the present invention, but is preferably 0.02 parts by mass or more and 200 parts by mass or less, more preferably 0.03 parts by mass or more and 100 parts by mass or less, even more preferably 0.05 to 50 parts by mass, and even more preferably 0.1 to 20 parts by mass, relative to 100 parts by mass of polyamide (A).

[0087] In the total amount of the polyamide molded body according to this embodiment, the total content of the polyamide (A), the glass fiber (B1) and the halogen-based flame retardant (C) is preferably 40 mass% or more, more preferably 50 mass% or more, even more preferably 60 mass% or more, and still more preferably 70 mass% or more.

[0088] The polyamide molded article according to this embodiment contains the polyamide (A), glass fiber (B1), and halogen-based flame retardant (C) in predetermined amounts, and thus has the effects of having excellent flame retardancy while maintaining the excellent physical properties of the polyamide (A), and of having excellent blister resistance even when exposed to high temperatures during the reflow process.

[0089] (Polyamide resin composition) The polyamide molded article according to this embodiment is a product obtained by molding a polyamide resin composition. That is, the components and contents contained in the polyamide molded article are the same as the components and contents (charged amounts) contained in the polyamide resin composition. Therefore, in the present invention, the material of the above-mentioned polyamide molded article is described as the material of the polyamide resin composition used when producing the polyamide molded article of the present invention.

[0090] (Method of producing polyamide resin composition) The method for producing the polyamide resin composition is not particularly limited, and a method capable of uniformly mixing the polyamide (A), the glass fiber (B1), the halogen-based flame retardant (C), and the flame retardant auxiliary (D) and other additives used as necessary can be preferably adopted. The mixing is usually preferably performed by melt-kneading using a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or the like. The melt-kneading conditions are not particularly limited, and examples thereof include a method of melt-kneading for about 1 to 30 minutes at a temperature range about 10 to 50°C higher than the melting point of the polyamide. EXAMPLES

[0091] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these.

[0092] The evaluations in the examples and comparative examples were carried out according to the methods described below.

[0093] <1. Evaluation of blister resistance> Using an injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. (clamping force: 18 tons, screw diameter: φ18 mm), the polyamide resin compositions prepared in the Examples and Comparative Examples were injection molded at a cylinder temperature 14°C higher than the melting point of the polyamide, component (A), and a mold temperature of 140°C to produce a plurality of sheet-like molded bodies A having a length of 30 mm, a width of 10 mm, and a thickness of 1 mm as polyamide molded bodies.

[0094] The obtained test pieces were left to stand for 168 hours under conditions of a temperature of 85°C and a relative humidity of 85%. After that, a reflow test was performed on the test pieces using a reflow device (Tamura Corporation, TNP25-538EM). In the reflow test, the temperature was raised from 25°C to 150°C over 60 seconds, then raised to 180°C over 90 seconds, and then raised to the peak temperature over another 60 seconds and held at the peak temperature for 20 seconds. The peak temperature was set to 260°C.

[0095] After the reflow test, the appearance of each test piece was visually observed. If even a small protrusion (bulge) was found in one place on the surface of the test piece, it was determined that the test piece had a blister.

[0096] The blister incidence rate was calculated from the observation results of 100 test pieces. Specifically, the blister incidence rate was calculated as the ratio (percentage) of the number of test pieces in which a blister occurred at least in one place among the 100 test pieces.

[0097] The blister resistance was evaluated using the following five-level index. Evaluation results of "A" and "B" are at a level that is acceptable for practical use. A: Blister occurrence rate is between 0% and 10% B: Blister occurrence rate is 10% or more but less than 25% C: Blister occurrence rate is 25% or more but less than 50% D: Blister occurrence rate is 50% or more but less than 75% E: Blister occurrence rate is 75% or more and 100% or less

[0098] <2. Evaluation of mechanical properties 1> First, a test piece with a thickness of 4 mm was prepared as shown below. Next, the mechanical properties such as tensile properties and bending properties were evaluated using this test piece.

[0099] [2-1. Preparation of molded bodies B and C] Using an injection molding machine (clamping force: 100 tons, screw diameter: φ32 mm) manufactured by Sumitomo Heavy Industries, Ltd., the polyamide resin compositions prepared in the examples and comparative examples were molded using a T-runner mold under conditions of a cylinder temperature 14°C higher than the melting point of the polyamide of component (A) and a mold temperature of 140°C to produce multipurpose test specimen type A1 (dumbbell-shaped test specimen described in JIS K7139:2009: thickness 4 mm, total length 170 mm, parallel part length 80 mm, central parallel part width 10 mm) (hereinafter also referred to as "molded body B"). Also, a molded product (hereinafter, also referred to as "molded product C") was molded which had the same shape as molded product B, but had a weld in the center of the parallel part in the direction perpendicular to the longitudinal direction of the parallel part.

[0100] [2-2. Tensile properties: tensile breaking strength and tensile breaking strain] Using the molded body B prepared in 2-1 above, the tensile breaking strength (MPa) and tensile breaking strain (%) were measured using a universal material testing machine (Instron) at a test speed of 1 mm / min and a gripper distance of 115 mm in accordance with ISO527-1 (2nd edition, 2012).

[0101] [2-3. Tensile properties: Weld tensile breaking strength] Using the molded body C prepared in 2-1 above, the weld tensile breaking strength (MPa) was measured using a universal material testing machine (Instron) at a test speed of 1 mm / min and a gripping distance of 115 mm in accordance with ISO527-1 (2nd edition, 2012).

[0102] [2-4. Flexural properties: flexural strength and flexural modulus] The flexural strength (MPa) and flexural modulus (GPa) of the molded body B prepared in 2-1 above were measured using a universal testing machine (Instron) at a test speed of 2 mm / min and a support distance of 64 mm in accordance with ISO178 (2012, 2nd edition).

[0103] <3. Evaluation of mechanical properties 2> A test piece with a thickness of 1 mm was prepared, and the mechanical properties were then evaluated from the viewpoint of bending properties using this test piece.

[0104] [3-1. Flexural properties: flexural strength, flexural modulus and weld flexural strength] Using an injection molding machine manufactured by Sumitomo Heavy Industries, Ltd. (clamping force: 18 tons, screw diameter: φ18 mm), the polyamide resin compositions prepared in the examples and comparative examples were injection molded under conditions of a cylinder temperature 14°C higher than the melting point of the polyamide of component (A) and a mold temperature of 140°C to produce a sheet-like molded product D having a length of 30 mm, a width of 10 mm and a thickness of 1 mm, and a molded product E having the same shape as molded product D but with a weld perpendicular to the longitudinal direction of the parallel portion. The flexural strength (MPa) and flexural modulus (GPa) of the obtained molded body D were measured using a precision universal material testing machine AG-2000B (manufactured by Shimadzu Corporation) under conditions of a test speed of 1 mm / min and a support distance of 16 mm. Furthermore, the weld bending strength (MPa) of the obtained molded body E was measured using a precision universal material testing machine AG-2000B (manufactured by Shimadzu Corporation) under conditions of a test speed of 1 mm / min and a support distance of 16 mm.

[0105] <4. Flame retardancy evaluation> Flame retardancy was evaluated according to the UL-94 standard. Using an injection molding machine (clamping force: 80 tons, screw diameter: φ26 mm) manufactured by Nissei Plastic Industrial Co., Ltd., the polyamide resin compositions prepared in the Examples and Comparative Examples were molded under conditions of a cylinder temperature 14°C higher than the melting point of the polyamide of component (A) and a mold temperature of 140°C, to obtain a molded body F having a thickness of 0.75 mm, a width of 13 mm and a length of 125 mm.

[0106] Next, the upper end of the obtained molded product F was clamped to fix the molded product E vertically, and a specified blue flame of 20±1 mm in height was applied to the lower end for 10 seconds and then released, and the burning time (first time) of molded product F was measured. Immediately after the fire was extinguished, the flame was applied to the lower end again and released, and the burning time (second time) of molded product F was measured. The same measurement was repeated for five pieces, obtaining a total of ten pieces of data, five pieces of data for the first burning time and five pieces of data for the second burning time. The sum of the ten pieces of data was designated T, and the maximum value of the ten pieces of data was designated M, and the data was evaluated according to the following evaluation criteria. The presence or absence of dripping during application of flame was also visually confirmed.

[0107] [Evaluation Criteria] V-0: T was 50 seconds or less and M was 10 seconds or less, the flame did not reach the clamp, and the flaming molten material did not ignite cotton 12 inches below when it fell. V-1: T was 250 seconds or less and M was 30 seconds or less, the flame did not rise to the clamp, and the flaming molten material did not ignite cotton 12 inches below when it fell. V-2: T was less than 250 seconds and M was less than 30 seconds, the flame did not rise to the clamp, and the flaming molten material fell and ignited cotton 12 inches below. X: None of the UL94 evaluation criteria are met.

[0108] <Examples 1 to 4 and Comparative Examples 1 and 2> A polyamide resin composition containing at least a polyamide (A), a glass fiber (B1) or a glass fiber (B2), and a halogen-based flame retardant (C) was prepared.

[0109] Specifically, a polyamide resin composition was prepared according to the formulation shown in Table 1. For this purpose, components other than glass fiber (B1) or glass fiber (B2) were fed from the most upstream hopper of a twin-screw extruder ("MEGA 32L" manufactured by STEER Engineering: screw φ31.6 mm, L / D=52, rotation speed 150 rpm, discharge rate 10 kg / h), and glass fiber (B1) or glass fiber (B2) was fed from a side feeder and melt-kneaded at 320°C. The melt-kneaded polyamide resin composition was extruded in the form of a strand, cooled, and then cut to obtain pellets of the polyamide resin composition. Using the obtained pellets, molded bodies of predetermined shapes were produced according to the above-mentioned method, and various physical properties were evaluated. The results are shown in Table 1.

[0110] The components shown in Table 1 are as follows. [Polyamide (A)] Polyamide 1 obtained in Production Example 1 <Production Example 1: Production of Polyamide (A-1)> 7882.0g of terephthalic acid, 7742.9g of a diamine mixture of 1,9-nonanediamine:2-methyl-1,8-octanediamine = 85:15 (molar ratio), 280.8g of benzoic acid as an end-capping agent, 16.0g of sodium hypophosphite monohydrate, and 4L of distilled water were placed in an autoclave with an internal volume of 40L. Then, nitrogen replacement was performed. The internal temperature was raised to 200°C over 2 hours. At this time, the autoclave was pressurized to 2MPa. Thereafter, the internal temperature was kept at 215°C, and the water vapor was gradually removed to maintain the pressure at 2MPa while reacting for 2 hours. Next, the pressure was reduced to 1.2MPa over 30 minutes to obtain a prepolymer. This prepolymer was crushed to a size of 6mm or less and dried at 120°C under reduced pressure for 12 hours. This was solid-phase polymerized for 10 hours at a temperature of 230°C and a pressure of 13.3Pa to obtain polyamide (A-1). The polyamide (A-1) had a melting point of 306° C. and an intrinsic viscosity [η] of 0.93 dl / g. The melting point and intrinsic viscosity were measured as follows.

[0111] Melting point The melting point of the polyamide of component (A) was determined as the peak temperature (°C) of the melting peak that appeared when the temperature was raised from 30°C to 340°C at a rate of 10°C / min in a nitrogen atmosphere using a differential scanning calorimeter "DSC7020" manufactured by Hitachi High-Tech Science Corp. When there were multiple melting peaks, the peak temperature of the melting peak on the highest temperature side was determined as the melting point.

[0112] ·Intrinsic viscosity [η] Concentrated sulfuric acid solutions of polyamide (A) were prepared as sample solutions, using concentrated sulfuric acid (concentration: 98% by mass) as a solvent, so that the solution concentrations c were 0.05, 0.1, 0.2, and 0.4 g / dl, respectively. Then, in a thermostatic bath at 30°C, the flow time t0 (seconds) of the solvent and the flow time t1 (seconds) of the sample solutions of each concentration were measured using an Ubellohde viscometer. The inherent viscosity (ηinh) was calculated using the following formula, and the value obtained by extrapolating the inherent viscosity (ηinh) to a concentration of 0 was taken as the intrinsic viscosity [η] of polyamide (A). ηinh(dl / g)=[ln(t1 / t0)] / c [In the formula, t0 represents the flow time (seconds) of the solvent, t1 represents the flow time (seconds) of the sample solution, and c represents the solution concentration (g / dl).]

[0113] [Glass fiber (B1)] Glass fiber (B1-1): Glass fiber chopped strands containing a urethane-based bundling agent on the surface (length: 3 mm, average fiber diameter: 10 μm, average irregularity ratio: 1.0 (cross-sectional shape: round)) Glass fiber (B1-2): Glass fiber chopped strands containing a urethane-based bundling agent on the surface (length: 3 mm, average fiber diameter: 7 μm, average irregularity ratio: 1.0 (cross-sectional shape: round)) Glass fiber (B1-3): Chopped strand glass fiber containing an acid anhydride group-containing resin-based bundling agent (length: 3 mm, average fiber diameter: 10 μm, average irregularity ratio: 1.0 (cross-sectional shape: round), diameter: 10 μm) Glass fiber (B1-4): Glass fiber chopped strands containing an epoxy resin-based bundling agent on the surface (length: 3 mm, average fiber diameter: 10 μm, average irregularity ratio: 1.0 (cross-sectional shape: round)) [Glass fiber (B2)] Glass fiber (B2-1): Glass fiber chopped strands containing a urethane-based bundling agent on the surface (length: 3 mm, average fiber diameter: 13 μm, average irregularity ratio: 1.0 (cross-sectional shape: round)) Glass fiber (B2-2): Glass fiber chopped strands containing a urethane-based bundling agent on the surface (length: 3 mm, short diameter: 7 μm, long diameter: 28 μm, irregularity ratio: 4.0 (cross-sectional shape: flat))

[0114] Measurement of the average fiber diameter of glass fibers (B1) The average fiber diameter of the glass fibers (B1) was determined by observing the glass fibers (B1) with an electron microscope, obtaining a cross-sectional image, and analyzing this image. In the obtained image, the major axis of each of 400 glass fibers (B1) was measured, and this major axis was regarded as the diameter of each fiber. The average value of the fiber diameters of the 400 fibers was regarded as the average fiber diameter of the glass fibers (B1). The average fiber diameter of the glass fibers (B2) was also determined by the same method.

[0115] Measurement of average irregularity ratio of glass fiber (B1) The irregularity ratio of glass fiber (B1) was determined by observing glass fiber (B1) with an electron microscope, obtaining a cross-sectional image, and analyzing this image. In the obtained image, the long and short diameters of 400 glass fibers (B1) were identified as shown in Figure 1. The irregularity ratio was determined by calculating the ratio (long diameter / short diameter) from the identified long and short diameters. The average irregularity ratio of the 400 fibers was taken as the average irregularity ratio of glass fiber (B1). The average irregularity ratio of glass fiber (B2) was also determined using the same method.

[0116] [Halogenated flame retardants (C)] Brominated flame retardant: LANXESS Solutions Japan Ltd., product name "Firemaster CP-44HF" (glycidyl methacrylate modified polybrominated styrene)

[0117] [Flame retardant synergist (D)] Flame retardant assistant: Nippon Light Metals Co., Ltd., product name "Flamtard S" (zinc stannate)

[0118] [Other ingredients (E)] Component (E1) (antioxidant): Sumitomo Chemical Co., Ltd., trade name "Sumilizer GA-80" (3,9-bis{1,1-dimethyl-2-[β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl}-2,4,8,10-tetraoxaspiro[5.5]undecane) (E2) Component (anti-drip agent): Mitsui DuPont Fluorochemicals Co., Ltd., product name "640-J" (polytetrafluoroethylene powder) (E3) Component (release agent): Mitsui Chemicals, Inc., product name "Hiwax 200P" (polyolefin wax) (E4) Component (colorant): Carbon black: Mitsubishi Chemical Corporation, product name "#980B"

[0119] [Table 1]

[0120] Comparing Examples 1 to 4 with Comparative Examples 1 and 2 in Table 1, it was found that the polyamide molded body having a thickness of 1 mm and made of the polyamide resin composition prepared in the Examples had excellent flame retardancy and excellent blister resistance even when exposed to high temperatures during the reflow process.

[0121] In addition, in Table 1, when Examples 1 to 4 are compared with Comparative Examples 1 and 2, it is found that the polyamide molded article having a thickness of 4 mm and made of the polyamide resin composition prepared in the Examples is excellent in mechanical properties, particularly tensile break strength, flexural strength, and tensile break strain. In addition, in Table 1, when Examples 1 to 4 are compared with Comparative Examples 1 and 2, it is found that the polyamide molded article having a thickness of 1 mm and made of the polyamide resin composition prepared in the Examples is comparable in other properties, such as flame retardancy and mechanical properties. [Industrial Applicability]

[0122] As described above, the polyamide molded article of the present invention has excellent flame retardancy and excellent blister resistance even when exposed to high temperatures during a reflow process. In particular, the polyamide molded article of the present invention is useful for various molded articles that require high reliability of electrical connection.

Claims

1. A polyamide molding having a thickness of more than 0.5 mm, The polyamide molded body, The present invention comprises a polyamide (A) having a melting point of 280°C or higher, a glass fiber (B1), and a halogen-based flame retardant (C), the content of the glass fiber (B1) is 45 to 120 parts by mass per 100 parts by mass of the polyamide (A), the content of the halogen-based flame retardant (C) is 25 to 60 parts by mass per 100 parts by mass of the polyamide (A), The glass fiber (B1) is The average fiber diameter is 12 μm or less, and The average deformation ratio in a cross section perpendicular to the longitudinal direction is less than 1.5; Polyamide molding.

2. 2. The polyamide molded article according to claim 1, wherein the polyamide (A) is a semi-aromatic polyamide.

3. The polyamide molding according to claim 2, wherein in the semi-aromatic polyamide, more than 50 mol% of the structural units derived from dicarboxylic acids constituting the semi-aromatic polyamide are structural units derived from aromatic dicarboxylic acids, and more than 50 mol% of the structural units derived from diamines constituting the semi-aromatic polyamide are structural units derived from aliphatic diamines having 4 to 18 carbon atoms.

4. 4. The polyamide molded article according to claim 3, wherein the aliphatic diamine is at least one selected from the group consisting of 1,4-butanediamine, 1,6-hexanediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, and 1,10-decanediamine.

5. The polyamide molded product further contains a flame retardant auxiliary (D), The polyamide molded article according to any one of claims 1 to 4, wherein the content of the flame retardant auxiliary (D) is 0.1 to 50 parts by mass per 100 parts by mass of the polyamide (A).

6. The polyamide molded article according to any one of claims 1 to 4, wherein the halogen-based flame retardant (C) is at least one of brominated polystyrene and polybrominated styrene.

7. The polyamide molded article according to any one of claims 1 to 4, wherein the glass fibers (B1) contain at least one surface treatment agent selected from the group consisting of coupling agents and sizing agents.

8. 8. The polyamide molded article according to claim 7, wherein the sizing agent comprises at least one selected from the group consisting of urethane resin-based sizing agents, acrylic resin-based sizing agents, epoxy resin-based sizing agents, and acid anhydride group-containing resin-based sizing agents.

9. The polyamide molded article according to any one of claims 1 to 4, which is an injection molded article.

10. The polyamide molded article according to any one of claims 1 to 4, which is a part of an SMT-compatible automotive connector.

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