Flame-retardant polybutylene terephthalate resin composition and resin molded product

Abstract

The flame-retardant polybutylene terephthalate resin composition comprises, relative to 100 parts by mass of (A) PBT resin, 0 to 100 parts by mass of (B) a fibrous inorganic compound, 25 to 50 parts by mass of (C) at least one selected from the group consisting of a predetermined phosphinate, a predetermined diphosphinate and polymers thereof, 4 to 15 parts by mass of (D) a salt of a triazine compound and cyanuric acid or isocyanuric acid, 5 to 15 parts by mass of (E) a thermoplastic polyester elastomer, 0.5 to 3 parts by mass of (F) a polycarbodiimide compound, and 0 to 3 parts by mass of (G) a fluororesin.

Description

Technical Field

[0001] The present invention relates to a flame retardant polybutylene terephthalate resin composition and a resin molded product. Background Art

[0002] Polybutylene terephthalate resin (hereinafter also referred to as "PBT resin") has excellent mechanical properties, electrical properties, heat resistance, weather resistance, water resistance, and chemical resistance, and is widely used as an engineering plastic in various applications such as automotive parts and electrical / electronic parts. On the other hand, as the application field expands, the performance required is becoming increasingly advanced. For example, in automotive parts, it is expected to improve flame retardancy, tracking resistance, hydrolysis resistance, etc.

[0003] In order to improve the tracking resistance of PBT resin, a PBT resin composition in which a phosphorus-based flame retardant and a nitrogen-containing compound are combined and blended has been proposed (see Patent Document 1).

[0004] Furthermore, since phosphorus-based flame retardants generally reduce hydrolysis resistance, resin compositions have been proposed that improve hydrolysis resistance by adding epoxy compounds or carbodiimides (see Patent Documents 2 to 3).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2011 / 148796

[0008] Patent Document 2: Japanese Patent Application Publication No. 2019-44037

[0009] Patent Document 3: Japanese Patent Application Publication No. 2009-215347 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] However, the hydrolysis resistance of the resin composition described in Patent Document 2 cannot be said to be sufficient, the flame retardancy (V-0) such as UL94 of the resin composition described in Patent Document 3 is insufficient, and the resin composition described in the examples is difficult to mold when used for injection molding due to its high viscosity.

[0012] That is, conventional PBT resin compositions cannot fully satisfy flame retardancy, tracking resistance, hydrolysis resistance, and low melt viscosity, and further improvement is desired.

[0013] The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a flame-retardant polybutylene terephthalate resin composition having excellent flame retardancy, tracking resistance, and hydrolysis resistance and low melt viscosity, and a resin molded product obtained by molding the composition.

[0014] Solutions for solving problems

[0015] One aspect of the present invention for solving the above-mentioned problems is as follows.

[0016] (1) A flame-retardant polybutylene terephthalate resin composition, which comprises, based on 100 parts by mass of (A) polybutylene terephthalate resin, 0 to 100 parts by mass of (B) a fibrous inorganic compound, 25 to 50 parts by mass of (C) at least one selected from the group consisting of a phosphinate represented by the following general formula (1), a polymer thereof, and a diphosphinate represented by the following general formula (2) and a polymer thereof, 4 to 15 parts by mass of (D) a salt of a triazine compound and cyanuric acid or isocyanuric acid, 5 to 15 parts by mass of (E) a thermoplastic polyester elastomer, 0.5 to 3 parts by mass of (F) a polycarbodiimide compound, and 0 to 3 parts by mass of (G) a fluororesin.

[0017]

[0018] [In the general formula (1) and the general formula (2), R 1 , R 2 , R 3 and R 4 Each independently represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, and R 5 represents an alkylene group, an alicyclic divalent group or an aromatic divalent group. 1 and R 2 They may bond to each other to form a ring with adjacent phosphorus atoms. a m+ represents a metal having a valence of m, where m is an integer of 2 to 4. b n+ It represents a metal with a valence number n, where n is an integer from 2 to 4.]

[0019] (2) The flame-retardant polybutylene terephthalate resin composition according to (1), wherein the cumulative particle size (D95) measured according to JIS8825 of the phosphinate (C) represented by the following general formula (1), its polymer, and the diphosphinate represented by the general formula (2) or its polymer is 10 μm or more.

[0020] (3) The flame-retardant polybutylene terephthalate resin composition according to (1) or (2), wherein the (F) polycarbodiimide compound is an aromatic polycarbodiimide.

[0021] (4) The flame-retardant polybutylene terephthalate resin composition according to any one of (1) to (3), wherein the content of the component (C) is 5: 含量(parts by mass), the content of the above-mentioned (D) component is referred to as D 含量 (parts by mass), the content of the component (B) is referred to as B 含量 (parts by mass), the content of the above-mentioned (G) component is referred to as G 含量 (parts by mass), the content of the above-mentioned (E) component is referred to as E 含量 (parts by mass), the density of the component (E) is referred to as E 密度 (g / cm 3 ), the following formula 1 is satisfied.

[0022]

[0023] (5) A resin molded article obtained by molding the flame-retardant polybutylene terephthalate resin composition according to any one of (1) to (4) above.

[0024] Effects of the Invention

[0025] According to the present invention, there can be provided a flame-retardant polybutylene terephthalate resin composition having excellent flame retardancy, tracking resistance, and hydrolysis resistance and low melt viscosity, and a resin molded product obtained by molding the composition. DETAILED DESCRIPTION

[0026] <Polybutylene terephthalate resin composition>

[0027] The flame-retardant polybutylene terephthalate resin composition (hereinafter, also simply referred to as "PBT resin composition") of the present embodiment is characterized in that it contains, relative to 100 parts by mass of (A) polybutylene terephthalate resin: 0 to 100 parts by mass of (B) a fibrous inorganic compound, 25 to 50 parts by mass of (C) at least one selected from the group consisting of a phosphinate represented by the general formula (1), a polymer thereof, and a diphosphinate represented by the general formula (2) and a polymer thereof, 4 to 15 parts by mass of (D) a salt of a triazine compound and cyanuric acid or isocyanuric acid, 5 to 15 parts by mass of (E) a thermoplastic polyester elastomer, 0.5 to 3 parts by mass of (F) a polycarbodiimide compound, and 0 to 3 parts by mass of (G) a fluororesin.

[0028] The PBT resin composition of the present embodiment comprises a predetermined amount of (B) a fibrous inorganic compound, (C) at least one selected from the group consisting of a phosphinate represented by the general formula (1), a polymer thereof, a diphosphinate represented by the general formula (2), and a polymer thereof (hereinafter also referred to as “(C) diphosphinate, etc.”), (D) a salt of a triazine compound and cyanuric acid or isocyanuric acid, (E) a thermoplastic polyester elastomer, (F) a polycarbodiimide compound, and (G) a fluororesin (wherein the components (B) and (G) are arbitrary components) relative to 100 parts by mass of the PBT resin (A), thereby achieving excellent flame retardancy, tracking resistance, and hydrolysis resistance, and having a low melt viscosity.

[0029] Hereinafter, each component will be described in detail. In addition, in this specification, "(A) PBT resin" may be referred to as (A) component, and the same applies to each component (B) to (G).

[0030] [(A) Polybutylene terephthalate resin (PBT resin)]

[0031] PBT resin is a resin obtained by polycondensing a dicarboxylic acid component containing at least terephthalic acid or its ester-forming derivative (C1-6 alkyl ester, acyl halide, etc.) and a diol component containing at least alkylene glycol (1,4-butanediol) having 4 carbon atoms or its ester-forming derivative (acetylated product, etc.). PBT resin is not limited to homopolybutylene terephthalate, and may be a copolymer containing 60 mol% or more (particularly 75 mol% or more and 95 mol% or less) of butylene terephthalate units.

[0032] The amount of terminal carboxyl groups in the PBT resin is not particularly limited as long as the effect of the PBT resin composition of the present embodiment is not impaired. The amount of terminal carboxyl groups in the PBT resin is preferably 30 meq / kg or less, and more preferably 25 meq / kg or less.

[0033] The intrinsic viscosity (IV) of the PBT resin is preferably 0.69 to 1.00 dL / g. When a PBT resin having an intrinsic viscosity within this range is used, the resulting resin composition has particularly excellent mechanical properties and fluidity. On the contrary, when the intrinsic viscosity is less than 0.69 dL / g, excellent mechanical properties and hydrolysis resistance cannot be obtained, and when it exceeds 1.00 dL / g, excellent fluidity may not be obtained.

[0034] In addition, for a PBT resin having an intrinsic viscosity within the above range, the intrinsic viscosity can be adjusted by mixing PBT resins having different intrinsic viscosities. For example, a PBT resin having an intrinsic viscosity of 0.9 dL / g and a PBT resin having an intrinsic viscosity of 0.7 dL / g can be mixed to prepare a PBT resin having an intrinsic viscosity of 0.8 dL / g. The intrinsic viscosity (IV) of a PBT resin can be measured, for example, in o-chlorophenol at a temperature of 35°C.

[0035] In the PBT resin, as dicarboxylic acid components (comonomer components) other than terephthalic acid and its ester-forming derivatives, for example, there can be mentioned C8-14 aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, 2,6-naphthalene dicarboxylic acid, and 4,4'-dicarboxy diphenyl ether; C4-16 alkane dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, and sebacic acid; C5-10 cycloalkane dicarboxylic acids such as cyclohexane dicarboxylic acid; and ester-forming derivatives of these dicarboxylic acid components (C1-6 alkyl ester derivatives, acyl halides, etc.). These dicarboxylic acid components can be used alone or in combination of two or more.

[0036] Among these dicarboxylic acid components, more preferred are C8-12 aromatic dicarboxylic acids such as isophthalic acid and C6-12 alkane dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid.

[0037] In the PBT resin, as the diol component (comonomer component) other than 1,4-butanediol, for example, there can be mentioned C2-10 alkylene glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,6-hexanediol, neopentyl glycol, and 1,3-octanediol; polyoxyalkylene glycols such as diethylene glycol, triethylene glycol, and dipropylene glycol; alicyclic diols such as cyclohexanedimethanol and hydrogenated bisphenol A; aromatic diols such as bisphenol A and 4,4'-dihydroxybiphenyl; C2-4 alkylene oxide adducts of bisphenol A such as 2 mol ethylene oxide adducts and 3 mol propylene oxide adducts of bisphenol A; or ester-forming derivatives (acetylated products, etc.) of these diols. These diol components can be used alone or in combination of two or more.

[0038] Among these diol components, more preferred are C2-6 alkylene glycols such as ethylene glycol and 1,3-propylene glycol, polyoxyalkylene glycols such as diethylene glycol, and alicyclic diols such as cyclohexanedimethanol.

[0039] As comonomer components that can be used other than dicarboxylic acid components and diol components, for example, aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and 4-carboxy-4'-hydroxybiphenyl; aliphatic hydroxycarboxylic acids such as glycolic acid and hydroxycaproic acid; C3-12 lactones such as propiolactone, butyrolactone, valerolactone, and caprolactone (ε-caprolactone, etc.); ester-forming derivatives of these comonomer components (C1-6 alkyl ester derivatives, acyl halides, acetylated products, etc.).

[0040] [(B) Fibrous Inorganic Compounds]

[0041] In the present embodiment, (B) fibrous inorganic compound is an arbitrary component used for the purpose of improving mechanical strength. As fibrous inorganic compound, glass fiber, carbon fiber, zinc oxide fiber, titanium oxide fiber, wollastonite, silica fiber, silica-alumina fiber, zirconium oxide fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber and other mineral-derived fibers, stainless steel fiber, aluminum fiber, titanium fiber, copper fiber, brass fiber and other metal fibers can be cited. Among them, glass fiber is preferred. They can be used alone or in combination of two or more.

[0042] When glass fibers are used, the type thereof is not particularly limited, and for example, A glass, C glass, D glass, E glass, etc. may be used. Among them, E glass (alkali-free glass) is preferably used.

[0043] In addition, the glass fiber is usually preferably used as chopped fibers (chopped glass fibers) obtained by cutting a plurality of these fibers into a bundle into a predetermined length. The cut length of the chopped glass fibers is not particularly limited, and may be, for example, about 1 to 10 mm.

[0044] Products requiring heat resistance and rigidity require fibrous inorganic compounds, and products requiring good appearance preferably contain less fibrous inorganic compounds. In this embodiment, 0 to 100 parts by mass of fibrous inorganic compounds are included relative to 100 parts by mass of PBT resin. If more than 100 parts by mass, the melt viscosity increases, the toughness decreases, and the appearance deteriorates. Preferably, 0 to 80 parts by mass of fibrous inorganic compounds are included, and more preferably 0 to 70 parts by mass.

[0045] [(C) Phosphinates, diphosphinates, and polymers thereof]

[0046] In the present embodiment, at least one selected from the group consisting of phosphinates represented by the following general formula (1) and polymers thereof, and diphosphinates represented by the following general formula (2) and polymers thereof is used for the purpose of improving flame retardancy and tracking resistance.

[0047]

[0048] [In the general formula (1) and the general formula (2), R 1 , R 2 , R 3 and R 4 Each independently represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, and R 5 represents an alkylene group, an alicyclic divalent group or an aromatic divalent group. 1 and R 2 They may bond to each other to form a ring with adjacent phosphorus atoms. a m+ represents a metal having a valence of m, where m is an integer of 2 to 4. b n+ It represents a metal with a valence number n, where n is an integer from 2 to 4.]

[0049] As R 1 ~R 4 As shown in the alkyl group, for example, a straight-chain or branched C1-6 alkyl group such as methyl, ethyl, isopropyl, n-butyl, tert-butyl, etc. can be cited. As a cycloalkyl group, for example, a C5-8 cycloalkyl group such as cyclohexyl, etc. can be cited. As an aryl group, a C6-10 aryl group such as phenyl, etc. can be cited. As an aralkyl group, a C6-10 aryl-C1-4 alkyl group such as benzyl, etc. can be cited. Among these groups, alkyl groups (preferably C1-4 alkyl groups, etc.) and aryl groups (phenyl groups, etc.) are generally preferred.

[0050] R 1 and R 2 The ring formed by bonding with the adjacent phosphorus atom is a heterocyclic ring having the phosphorus atom as a heteroatom constituting the ring (phosphorus atom-containing heterocyclic ring), and generally 4-20-membered heterocyclic rings are mentioned, and 5-16-membered heterocyclic rings are preferred. In addition, the phosphorus atom-containing heterocyclic ring may be a bicyclic ring. The phosphorus atom-containing heterocyclic ring may have a substituent.

[0051] As R 5As the alkylene group shown, for example, there can be mentioned a straight-chain or branched C1-10 alkylene group which may have a substituent such as a C6-10 aryl group, such as methylene, ethylene, phenylethylene, propylene, trimethylene, 1,4-butanediyl, 1,3-butanediyl, etc. As the alicyclic divalent group, for example, there can be mentioned a C5-8 alicyclic divalent group such as cyclohexylene, cyclohexylenedimethylene, etc. Examples of the aromatic divalent radical include C6-10 arylene radicals which may have a substituent such as a C1-4 alkyl group, such as phenylene and tolylene; C6-10 arylene di-C1-4 alkylene radicals which may have a C1-4 alkyl group such as a methyl group on the aromatic ring, such as xylylene; diaryl radicals which may have a C1-4 alkyl group such as a methyl group on the aromatic ring (for example, biphenylene; linear or branched C1-4 alkane-di-C6-10 arylene radicals such as methyl diphenylene; divalent radicals corresponding to C6-10 aryl ethers such as diphenyl ether; divalent radicals corresponding to di-C6-10 aryl ketones such as diphenyl ketone; divalent radicals corresponding to di-C6-10 aryl sulfide such as diphenyl sulfide, etc.). 5 Among these, an alkylene group (particularly a C1-6 alkylene group, etc.) is preferred.

[0052] As M a 、M b The metals shown in the above-mentioned examples include alkali metals (potassium, sodium, etc.), alkaline earth metals (magnesium, calcium, etc.), transition metals (iron, cobalt, nickel, copper, etc.), metals of Group 12 of the Periodic Table (zinc, etc.), metals of Group 13 of the Periodic Table (aluminum, etc.), etc. The aforementioned metal salt may contain one of these metals, or a combination of two or more thereof. Among the aforementioned metals, alkaline earth metals (magnesium, calcium, etc.) and metals of Group 13 of the Periodic Table (aluminum, etc.) are preferred.

[0053] The valence of the metal is particularly 1 to 4, preferably 2 to 4, and more preferably 2 or 3.

[0054] Specific examples of the phosphinic acid represented by the general formula (1) include dialkylphosphinic acid Ca salts (such as diC1-10 alkylphosphinic acid Ca salts) such as dimethylphosphinic acid Ca, methylethylphosphinic acid Ca, and diethylphosphinic acid Ca, arylphosphinic acid Ca salts (such as mono- or di-C6-10 arylphosphinic acid Ca salts) such as phenylphosphinic acid Ca and diphenylphosphinic acid Ca, alkylarylphosphinic acid Ca salts (such as C1-4 alkyl-C6-10 arylphosphinic acid Ca salts) such as methylphenylphosphinic acid Ca, alkylarylphosphinic acid Ca salts (such as C1-4 alkyl-C6-10 arylphosphinic acid Ca salts) such as 1-hydroxy-1H-phospholane-1-oxide Ca salt and 2-carboxy-1-hydroxy-1H-phospholane-1-oxide Ca salt, and Al salts and other metal salts corresponding to these Ca salts.

[0055] Specific examples of the diphosphinate represented by the general formula (2) include, for example, ethane-1,2-bis(phosphinic acid) Ca salts and other alkane bis(phosphinic acid) Ca salts [C1-10 alkane bis(phosphinic acid) Ca salts, etc.], ethane-1,2-bis(methylphosphinic acid) Ca salts and other alkane bis(alkylphosphinic acid) Ca salts [C1-10 alkane bis(C1-6 alkylphosphinic acid) Ca salts, etc.], Al salts corresponding to these Ca salts, and other metal salts.

[0056] Among the metal salts represented by the above formula (1) or (2), preferred phosphinic acids include dialkylphosphinic acid metal salts (Ca salts, Al salts, etc.), alkanebisphosphinic acid metal salts (Ca salts, Al salts, etc.), and the like.

[0057] In the present embodiment, the cumulative particle size (D95) (hereinafter also referred to as "D95 particle size") measured by the diphosphite (C) according to JIS8825 is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 200 μm or less. If the D95 particle size is less than 5 μm, the hydrolysis resistance is reduced. In addition, if the D95 particle size exceeds 500 μm, the gate of the mold is easily clogged, and the appearance of the molded product is deteriorated.

[0058] In the present embodiment, 25 to 50 parts by mass of (C) phosphinate or the like is contained relative to 100 parts by mass of the PBT resin. If it is less than 25 parts by mass, the flame retardancy becomes insufficient, and if it exceeds 50 parts by mass, it causes a decrease in mechanical properties and hydrolysis resistance. At least one selected from the group consisting of the phosphinate represented by the general formula (1), its polymer, and the diphosphinate represented by the general formula (2) and its polymer preferably contains 28 to 48 parts by mass, and more preferably contains 30 to 45 parts by mass.

[0059] [(D) Salt of triazine compound and cyanuric acid or isocyanuric acid]

[0060] The salt of a triazine compound and cyanuric acid or isocyanuric acid functions as a flame retardant aid. As the salt, a salt of a triazine compound represented by the following general formula (3) and cyanuric acid or isocyanuric acid is preferably exemplified.

[0061]

[0062] [In general formula (3), R 6 , R 7 are independently a hydrogen atom, an amino group, an aryl group, or an oxyalkyl group having 1 to 3 carbon atoms, and R 6 , R 7 Can be the same or different.

[0063] In the present embodiment, among the salts of the triazine compound represented by the general formula (3) and cyanuric acid or isocyanuric acid, melamine cyanurate is particularly preferably used.

[0064] The D95 particle size of the salt of the triazine compound and cyanuric acid or isocyanuric acid is preferably 100 μm or less, more preferably 0.1 to 80 μm, and even more preferably 1 to 60 μm. If the D95 particle size is 100 μm or more, the fluidity is reduced.

[0065] In this embodiment, the salt of the triazine compound and cyanuric acid or isocyanuric acid is contained in 4 to 15 parts by mass. If it is less than 4 parts by mass, the flame retardancy becomes insufficient, and if it exceeds 15 parts by mass, it becomes a major cause of the reduction in mechanical properties such as strength and toughness. It is preferred to contain 4 to 14 parts by mass of the salt of the triazine compound and cyanuric acid or isocyanuric acid, and more preferably 5 to 13 parts by mass.

[0066] [(E) Thermoplastic polyester elastomer]

[0067] Thermoplastic polyester elastomers are used for the purpose of improving the toughness of the resin composition. In addition, compared with common olefin-based elastomers, such as copolymers with polyethylene or polypropylene as hard segments and polypropylene rubber as soft segments, ethylene-vinyl acetate copolymers, etc., thermoplastic polyester elastomers have better flame retardancy. Thermoplastic polyester elastomers are generally block copolymers having a structure in which a hard polyester block (hard block or hard segment such as aromatic polyester) and a soft polyester block (soft block or soft segment) are bonded by an ester bond. Thermoplastic polyester elastomers can be divided into two types of polyether type and polyester type according to the type of soft block, and any type can be used in this embodiment.

[0068] The hard polyester constituting the hard block can be obtained by polycondensation of dicarboxylic acids and diols, or polycondensation of hydroxycarboxylic acids, similar to PBT resins. Generally, an aromatic polyester using at least an aromatic monomer component [aromatic diols and reactive derivatives thereof exemplified in the aforementioned PBT resin, aromatic dicarboxylic acids and terephthalic acid (including reactive derivatives of these aromatic dicarboxylic acids) exemplified in the aforementioned PBT resin, and / or aromatic hydroxycarboxylic acids (hydroxybenzoic acid, hydroxynaphthoic acid, 4-carboxy-4'hydroxy-biphenyl, and derivatives of these hydroxycarboxylic acids (alkyl, alkoxy or halogen substituted, etc.)] can be used. Aromatic monomer components can be used alone or in combination of two or more. Aromatic polyesters can be used in combination with copolymerizable monomers (copolymerizable monomers exemplified in the aforementioned PBT resin, and also containing 1,4-butanediol, terephthalic acid, etc.) as needed.

[0069] For the aromatic polyester, at least an aromatic monomer component may be used as a monomer component, for example, it may be a wholly aromatic polyester (a polyester of an aromatic dicarboxylic acid and an aromatic diol, a polyester of an aromatic hydroxycarboxylic acid, etc.), or it may be a polyester of an aromatic dicarboxylic acid and a non-aromatic diol (1,4-butanediol, an aliphatic diol listed in the PBT resin section, an alicyclic diol, etc.), a polyester of a non-aromatic dicarboxylic acid (an aliphatic dicarboxylic acid listed in the aforementioned PBT resin section, etc.) and an aromatic diol, a polyester of an aromatic hydroxycarboxylic acid and a non-aromatic hydroxycarboxylic acid (an aliphatic hydroxycarboxylic acid such as glycolic acid and hydroxycaproic acid), etc.

[0070] Among the hard polyesters, preferred are crystalline aromatic polyesters [e.g., polyaromatic dicarboxylic acid alkylene glycol esters (poly(ethylene terephthalate, poly(butylene terephthalate), polyethylene naphthalate, poly(butylene naphthalate) and other poly(aromatic dicarboxylic acid C2-4 alkylene glycol esters), modified poly(aromatic dicarboxylic acid C2-4 alkylene glycol esters) modified or copolymerized with 1 to 30 mol % (e.g., 3 to 25 mol %, preferably a ratio of about 5 to 20 mol %) of copolymer components (copolymerizable monomers such as isophthalic acid exemplified above), etc.], liquid crystal polyesters, particularly poly(butylene terephthalate), etc.

[0071] The soft polyester constituting the soft block of the polyester elastomer can be obtained by polycondensation of dicarboxylic acids and diols, polycondensation of hydroxycarboxylic acids and lactones, etc., similar to PBT resin. The soft polyester may be softer than the hard polyester constituting the hard block, and generally, polyesters using at least aliphatic monomer components [aliphatic diols (1,4-butanediol, aliphatic diols and reactive derivatives thereof listed in the above PBT resin section), aliphatic dicarboxylic acids (aliphatic dicarboxylic acids and reactive derivatives thereof listed in the above PBT resin section), aliphatic hydroxycarboxylic acids (glycolic acid, hydroxycaproic acid, etc.), lactones listed in the above PBT resin section, etc.] can be used. The aliphatic monomer component can be used in combination with a copolymerizable monomer (generally a non-aromatic monomer component, such as alicyclic diols, alicyclic dicarboxylic acids, and reactive derivatives thereof listed in the above PBT resin section, etc.) as required.

[0072] Among the soft polyesters, amorphous polyesters are preferred, such as aliphatic polyesters using aliphatic dicarboxylic acid and aliphatic diol, and polylactone (ring-opening polymer of the aforementioned lactone).

[0073] The soft segment of the polyether elastomer may have at least a polyether unit, and may be composed of a polyether [e.g., an aliphatic polyether having a polyoxyalkylene unit (polyoxyalkylene glycols exemplified in the above PBT resin, preferably poly-C2-6 alkylene glycols, etc.), polyesters using the polyethers, etc. Among the polyethers, poly-C2-4 alkylene glycols such as polyoxyethylene glycol, polyoxypropylene glycol, and polyoxytetramethylene glycol are preferred. Examples of polyesters using polyethers include polyesters of polyethers (polyoxyalkylene glycols, etc.) and dicarboxylic acids [usually non-aromatic dicarboxylic acids, such as aliphatic or alicyclic dicarboxylic acids exemplified in the above PBT resin, and reactive derivatives thereof, etc.].

[0074] Among these soft blocks, a soft polyester block having at least one unit selected from a polyether unit (aliphatic polyether unit, polyester unit using an aliphatic polyether) and an aliphatic polyester unit is preferred.

[0075] Specific examples of thermoplastic polyester elastomers include polyester-type (i.e., polyester-polyester-type) thermoplastic elastomers [e.g., block copolymers of hard segments composed of aromatic crystalline polyesters or liquid crystal polyesters (especially homopolymers having polybutylene terephthalate units, or copolymers obtained by copolymerizing copolymer components (ethylene glycol, isophthalic acid, etc.)) and soft segments composed of aliphatic polyesters (polyesters of C2-6 alkylene glycols such as polyethylene adipate and polybutylene adipate and C6-12 alkane dicarboxylic acids, etc.)], and polyether-type (i.e., polyester-polyether-type) thermoplastic elastomers [e.g., block copolymers of hard segments composed of aromatic crystalline polyesters or liquid crystal polyesters and soft segments composed of polyethers such as polyoxy C2-4 alkylene glycols such as polytetramethylene glycol (polyesters of polyoxyalkylene glycols and dicarboxylic acids, etc.)], etc.

[0076] Among the polyester elastomers, block copolymers of (e-1) a hard poly(arylene dicarboxylic acid alkylene glycol) block and (e-2) a soft polyester block composed of polycaprolactone, an aliphatic polyether having an oxy-C2-6 alkylene unit (poly(C2-6 alkylene glycol) etc.), or an aliphatic polyester are preferred. Thermoplastic polyester elastomers may be used alone or in combination of two or more.

[0077] In the thermoplastic elastomer, the mass ratio of the hard segment (or hard component) to the soft segment (or soft component) is usually 10 / 90 to 90 / 10, preferably 20 / 80 to 80 / 20, and more preferably about 30 / 70 to 70 / 30 (e.g. 40 / 60 to 60 / 40).

[0078] For thermoplastic polyester elastomers, in applications requiring flexibility, for example, the flexural modulus is 1000 MPa or less, preferably in the range of about 50 to 400 MPa (particularly 100 to 300 MPa). In such applications, if the flexural modulus is too small, there will be problems with workability during processing, and if it is too large, there is a concern that sufficient flexibility cannot be obtained.

[0079] The PBT resin composition of the present embodiment contains 5 to 15 parts by mass of a thermoplastic polyester elastomer. If it is less than 5 parts by mass, the effect of improving toughness is reduced, and if it exceeds 15 parts by mass, deformation due to reduced rigidity is likely to occur. The thermoplastic polyester elastomer is preferably contained in an amount of 6 to 13 parts by mass, and more preferably 8 to 12 parts by mass.

[0080] [(F) Polycarbodiimide compound]

[0081] In this embodiment, a polycarbodiimide compound is used for the purpose of improving hydrolysis resistance. The polycarbodiimide compound is a compound having at least two carbodiimide groups represented by (-N=C=N-) in the molecule, and can be synthesized by a generally known method. For example, an organic phosphorus compound or an organic metal compound can be used as a catalyst to synthesize various polyisocyanates (diisocyanates) at a temperature of about 70°C or above in a solvent-free or inactive solvent by an additional decarbonation condensation reaction. As a method for producing a polycarbodiimide compound, there are known methods described in the specification of U.S. Patent No. 2941956, Japanese Patent Publication No. 47-33279, J.Org.Chem.28,2069-2075 (1963), Chemical Review 1981.Vol.81.No.4.p619-621, etc.

[0082] Examples of organic diisocyanates used as synthetic raw materials in the production of polycarbodiimide compounds include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, or mixtures thereof. Specifically, examples include hexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, and methylcyclohexane diisocyanate.

[0083] In addition, in the case of polycarbodiimide compounds, the polymerization reaction can be stopped midway by cooling, etc., and controlled to an appropriate degree of polymerization. In this case, the terminal becomes an isocyanate. Furthermore, in order to control the appropriate degree of polymerization, there is also a method as follows: using a compound that reacts with the terminal isocyanate of an aliphatic polycarbodiimide compound such as a monoisocyanate, all or part of the remaining terminal isocyanate is capped. By controlling the degree of polymerization, the compatibility and storage stability of the polymer can be improved, which is preferred from the viewpoint of improving quality.

[0084] Examples of the monoisocyanate used to control the degree of polymerization by blocking the terminal of the polycarbodiimide compound include phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, and butyl isocyanate.

[0085] The preferred number average molecular weight of the polycarbodiimide compound used in this embodiment is 1000 to 30000, preferably 2000 to 20000, and more preferably 3000 to 15000. If the number average molecular weight is too small, there is a risk of poor heat resistance, while if it is too large, there is a risk of not being able to fully obtain the effect of improving hydrolysis resistance due to poor dispersion in the resin and reduced reactivity.

[0086] In addition, due to the high requirements for hydrolysis resistance and heat resistance, it is particularly preferred to use aromatic polycarbodiimides containing aromatic components in the molecular chain skeleton, for example, aromatic dicarbodiimide compounds such as p-phenylene-bis-o-tolylcarbodiimide, p-phenylene-bis-p-chlorophenylcarbodiimide, ethylene-bis-diphenylcarbodiimide, poly (4,4'-methylenebiscyclohexylcarbodiimide), poly (4,4'-diphenylmethanecarbodiimide) ), poly(3,3'-dimethyl-4,4'-diphenylmethanecarbodiimide), poly(naphthylenecarbodiimide), poly(p-phenylenecarbodiimide), poly(m-phenylenecarbodiimide), poly(tolylcarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(methyl-diisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide) and other aromatic polycarbodiimide compounds, etc.

[0087] Generally speaking, if a carbodiimide compound is contained in a thermoplastic aromatic polyester resin composition, gas or odor may be generated during melt kneading, molding, etc. However, when the compounding amount is 0.5 to 3.0% by mass, both better hydrolysis resistance and suppression of the generation of isocyanate gas derived from the carbodiimide compound can be achieved, and the deterioration of the working environment can be suppressed and better hydrolysis resistance can be achieved. The polycarbodiimide compound is preferably contained in an amount of 0.5 to 2.5 parts by mass, and more preferably 0.8 to 2.0 parts by mass.

[0088] [(G) Fluororesin]

[0089] In the present embodiment, the fluororesin is an arbitrary component used as an anti-drip agent. Suitable fluororesins include homopolymers or copolymers of fluorinated monomers such as tetrafluoroethylene, chlorotrifluoroethylene, vinylidene fluoride, hexafluoropropylene, and perfluoroalkyl vinyl ether, and copolymers of the aforementioned fluorinated monomers with copolymerizable monomers such as ethylene, propylene, and (meth)acrylate. These fluororesins can be used alone or in combination of two or more.

[0090] Examples of such fluororesins include homopolymers such as polytetrafluoroethylene, polychlorotrifluoroethylene, and polyvinylidene fluoride; and copolymers such as tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers, ethylene-tetrafluoroethylene copolymers, and ethylene-chlorotrifluoroethylene copolymers.

[0091] The amount of the fluororesin added is 0 to 3 parts by mass, preferably 0 to 2 parts by mass, and more preferably 0.3 to 1.0 parts by mass, based on 100 parts by mass of the (A) polybutylene terephthalate resin.

[0092] In this embodiment, the content of the component (C) is C 含量 (parts by mass), and the content of the component (D) is referred to as D 含量 (parts by mass), and the content of the component (B) is referred to as B 含量 (parts by mass), the content of the (G) component is G 含量 (parts by mass), and the content of the (E) component is referred to as E 含量 (parts by mass), the density of the component (E) is referred to as E 密度 (g / cm 3 ) preferably satisfies the following formula 1. Here, C 含量 (parts by mass), D 含量 (parts by mass), B 含量 (parts by mass), G 含量 (parts by mass), and E 含量 (Parts by mass) are all contents (parts by mass) relative to 100 parts by mass of component (A). The PBT resin composition of the present embodiment exhibits excellent flame retardancy by satisfying Formula 1. Formula 1 is a formula in which the content of component (E), which is a component that contributes to reducing flame retardancy, is subtracted from the total content of component (C), component (D), component (B), and component (G), which are components that contribute to improving flame retardancy, and the content ratio is set in consideration of the contribution of each component. It should be noted that the contribution of component (E) to the reduction of flame retardancy decreases in inverse proportion to the cube of its density, so the content of component (E) is divided by the cube of the density. The numerical range of Formula 1 is preferably 140 or more, and more preferably 140 to 300. If it is less than 140, the flame retardancy cannot be satisfied, and if it exceeds 300, it causes deterioration of the appearance of the molded product and reduction of physical properties.

[0093]

[0094] <Resin molded products>

[0095] The resin molded product of the present embodiment is formed by molding the above PBT resin composition. Therefore, the resin molded product of the present embodiment is excellent in flame retardancy, tracking resistance, and hydrolysis resistance, as is the PBT resin composition of the present embodiment. In addition, the PBT resin composition of the present embodiment has a low melt viscosity and is therefore easy to mold.

[0096] There is no particular limitation on the method for making a resin molded article using the PBT resin composition of the present embodiment, and a known method can be used. For example, the PBT resin composition of the present embodiment can be put into an extruder for melt kneading to form pellets, and the pellets can be put into an injection molding machine equipped with a predetermined mold to make a resin molded article by injection molding.

[0097] The resin molded product of this embodiment can be suitably used as a resin composition for molded products that are exposed to high temperature and high humidity environments for a long time in automobiles, trains, and aviation industries. The molded product formed by the resin composition can prevent the occurrence of deterioration due to hydrolysis even when used for a long time in a sufficiently high temperature and high humidity environment, and can be used for housings, connectors, etc. of components using high voltages due to excellent tracking resistance and flame retardancy.

[0098] Hereinafter, the present embodiment will be described in further detail by way of examples, but the present embodiment is not limited to the following examples.

[0099] [Example 1]

[0100] In each embodiment / comparative example, a twin-screw extruder was used to melt-knead and extrude the components (A) to (F) in the ratios (parts by mass) shown in Tables 1 to 4 under the following conditions to obtain pellets formed of a PBT resin composition: the raw material supply portion and the front end of the die were set to a barrel temperature of 260°C, a temperature between 200 and 260°C, a discharge rate of 15 kg / h, and a screw speed of 130 rpm. As a twin-screw extruder, a The details of the components shown in Tables 1 to 4 are as follows.

[0101] The particle sizes (D95 particle size) of the components (C) and (D) were measured using a laser diffraction / scattering particle size distribution analyzer ("LA920" manufactured by Horiba, Ltd.) using water as a dispersion medium.

[0102] (A) PBT resin

[0103] A1: Polybutylene terephthalate manufactured by Polyplastics Co., Ltd. (intrinsic viscosity: 0.80 (dL / g))

[0104] A2: Polybutylene terephthalate manufactured by Polyplastics Co., Ltd. (intrinsic viscosity: 0.79 (dL / g))

[0105] A3: Polybutylene terephthalate manufactured by Polyplastics Co., Ltd. (intrinsic viscosity: 0.73 (dL / g))

[0106] A4: Polybutylene terephthalate manufactured by Polyplastics Co., Ltd. (intrinsic viscosity: 0.69 (dL / g))

[0107] (B) Fibrous Inorganic Compounds

[0108] B1: Made by Nippon Electric Glass Co., Ltd., glass fiber ECS 03-T-187

[0109] (C) Phosphinates, etc.

[0110] C1: Clariant Japan, phosphorus-based flame retardant tri(diethylphosphinate)aluminum EXOLIT 1240, particle size: 75 μm

[0111] C2: Clariant Japan, phosphorus-based flame retardant tri(diethylphosphinate)aluminum EXOLIT OP940, particle size: 20 μm

[0112] C3: Clariant Japan, phosphorus-based flame retardant tri(diethylphosphinate)aluminum EXOLIT OP935, particle size 10 μm

[0113] C4: Clariant Japan, phosphorus-based flame retardant tri(diethylphosphinate)aluminum EXOLIT OP945, particle size 5μm

[0114] (D) Salt of triazine and cyanuric acid

[0115] D1: BASF Japan, melamine cyanurate MELAPUR MC50, particle size: 50 μm

[0116] D2: Made by BASF Japan, melamine cyanurate, particle size: 3 μm

[0117] D3: Made by BASF Japan, melamine cyanurate, particle size: 60 μm

[0118] (E) Thermoplastic polyester elastomer, comparative polymer

[0119] E1: Toyobo Co., Ltd., polyester elastomer PELPRENE GP400, density: 1.14 g / cm 3

[0120] E2: Mitsui Chemicals, Inc., alpha-olefin copolymer TAFMER MP0610, density: 0.87 g / cm 3

[0121] E3: UNIC ethylene ethyl acrylate copolymer NUC-6570, density: 0.93g / cm 3

[0122] E4: Dow Chemical, acrylic core-shell polymer PARALOID EXL-2311, density: 1.10 g / cm 3

[0123] E5: Sumitomo Chemical Co., Ltd., ethylene-glycidyl methacrylate copolymer IGETABOND E, density: 0.94 g / cm 3

[0124] (F) Polycarbodiimide compounds

[0125] F1: Made by LANXESS, carbodiimide STABAXOL P200

[0126] (G) Fluororesin

[0127] G1: POLYFLON MPA FA-500H, manufactured by Daikin Industries, Ltd.

[0128] (Other ingredients)

[0129] · Antioxidant: BASF Japan, IRGANOX 245

[0130] · Antioxidant: ADEKA Corporation, ADEKASTAB PEP-36 · Lubricant: Riken Vitamin Co., Ltd., B-74

[0131] [Table 1]

[0132]

[0133] [Table 2]

[0134]

[0135] [Table 3]

[0136]

[0137] [Table 4]

[0138]

[0139] [evaluate]

[0140] The following evaluations were performed using the obtained pellets of each Example / Comparative Example.

[0141] (1) Flammability

[0142] Based on the method of SUBJECT 94 (UL94) of UNDERWRITERS LABORATORIES, flame retardancy (V-0) was evaluated using 5 test pieces (thickness: 1.6 mm). Those that satisfied V-0 were rated as V-0, and those that did not satisfy V-0 were rated as unqualified. The evaluation results are shown in Tables 5 to 8.

[0143] (2) Tracking resistance

[0144] According to IEC60112 3rd edition, a 0.1 mass % ammonium chloride aqueous solution and a platinum electrode were used to measure the applied voltage (V: volt) at which tracking occurs on the test piece. The measurement results are shown in Tables 5 to 8. It should be noted that the maximum applied voltage is 600 V, and if the applied voltage is 600 V, it can be said that the tracking resistance is good.

[0145] (3) Tensile strength

[0146] The obtained pellets were used to measure tensile strength in accordance with ISO527-1, 2. The measurement results are shown in Tables 5 to 8. When the tensile strength is 50 MPa or more when not reinforced with the fibrous inorganic compound (B) and 90 MPa or more when reinforced with the fibrous inorganic compound (B), it can be said that the mechanical strength is good.

[0147] (4)Hydrolysis resistance

[0148] After exposure in a pressure cooker tester at 121°C and 100% RH for 50 hours, the tensile strength (MPa) was measured according to ISO527-1, 2, and the strength retention was calculated from the tensile strength before treatment. The calculated results are shown in Tables 5 to 8. If the strength retention is 70% or more, it can be said that the hydrolysis resistance is good.

[0149] (5) Melt viscosity

[0150] The obtained pellets were dried at 140°C for 3 hours and then precipitated using CAPILOGRAPH 1B (manufactured by Toyo Seiki Seisaku-sho, Ltd.) at a furnace temperature of 260°C, a capillary of φ1 mm×20 mmL, and a shear rate of 1000 sec. according to ISO11443. -1 The measurement results are shown in Tables 5 to 8. When the melt viscosity is 0.45 kPa·s or less, it can be said that the melt viscosity is low and the fluidity is good.

[0151] [Table 5]

[0152]

[0153] [Table 6]

[0154]

[0155] [Table 7]

[0156]

[0157] [Table 8]

[0158]

[0159] According to Tables 5 to 8, the evaluations of Examples 1 to 21 were all good. That is, the PBT resin compositions of Examples 1 to 19 exhibited excellent flame retardancy, tracking resistance, and hydrolysis resistance, and had low melt viscosity.

[0160] On the other hand, in Comparative Examples 1 to 22, good results could not be obtained in all the evaluations at the same time.

[0161] From the above, it is understood that unless the components (A) to (G) are blended in predetermined amounts, it is not possible to obtain good results in terms of flame retardancy, tracking resistance, hydrolysis resistance, and low melt viscosity.

[0162] In addition, the flame retardancy of Comparative Examples 6, 8, 9, 11, and 17 to 19 that do not satisfy Formula 1 is poor.

Claims

1. A flame-retardant polybutylene terephthalate resin composition, comprising, relative to 100 parts by mass of (A) polybutylene terephthalate resin: 0 to 100 parts by mass of (B) a fibrous inorganic compound, 25 to 50 parts by mass of (C) at least one selected from the group consisting of a phosphinate represented by the following general formula (1), a polymer thereof, a diphosphinate represented by the following general formula (2), and a polymer thereof, 4 to 15 parts by mass of (D) a salt of a triazine compound and cyanuric acid or isocyanuric acid, 5 to 15 parts by mass of (E) a thermoplastic polyester elastomer, 0.5 to 3 parts by mass of (F) a polycarbodiimide compound, and 0 to 3 parts by mass of (G) a fluororesin, In the general formula (1) and the general formula (2), R 1 , R 2 , R 3 and R 4 Each independently represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, and R 5 represents an alkylene group, an alicyclic divalent group or an aromatic divalent group, R 1 and R 2 optionally bonded to each other to form a ring with adjacent phosphorus atoms, M a m+ represents a metal with a valence of m, where m is an integer from 2 to 4, M b n+ represents a metal with a valence number n, where n is an integer from 2 to 4, The (A) polybutylene terephthalate resin has an intrinsic viscosity (IV) of 0.69 to 1.00 dL / g.

2. The flame-retardant polybutylene terephthalate resin composition according to claim 1, wherein The phosphinate represented by the general formula (1), a polymer thereof, and the diphosphinate represented by the general formula (2), or a polymer thereof, have a cumulative particle size D95 measured in accordance with JIS8825 of 10 μm or more.

3. The flame-retardant polybutylene terephthalate resin composition according to claim 1 or 2, wherein The (F) polycarbodiimide compound is an aromatic polycarbodiimide.

4. The flame-retardant polybutylene terephthalate resin composition according to claim 1 or 2, wherein The content of the component (C) is defined as C 含量 The content of the component (D) is D 含量 , the content of the (B) component is set to B 含量 The content of the component (G) is G 含量 , the content of the (E) component is set to E 含量 The density of the component (E) is E 密度 When the following formula 1 is satisfied, the C 含量 , D 含量 , B 含量 , G 含量 、E 含量 The unit is mass parts, the E 密度 The unit is g / cm 3 , 5 . A resin molded product obtained by molding the flame-retardant polybutylene terephthalate resin composition according to claim 1 .

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