Polybutylene terephthalate resin composition, method of preparing same, and molded article including same

Abstract

The present invention relates to a polybutylene terephthalate resin composition, a method for preparing the polybutylene terephthalate resin composition, and a molded article comprising the polybutylene terephthalate resin composition. The present invention has the effects of: providing a polybutylene terephthalate resin composition suitable for use in electrical and electronic products or automobile parts due to excellent mechanical properties, processability, flame retardancy and elongation despite containing a high content of polybutylene terephthalate; a method for preparing the polybutylene terephthalate resin composition; and a molded article comprising the polybutylene terephthalate resin composition.

Description

Technical Field

[0001] [Cross - Reference to Related Applications]

[0002] This application claims the priority of Korean Patent Application No. 10 - 2023 - 0132314, filed with the Korean Intellectual Property Office on October 05, 2023, and Korean Patent Application No. 10 - 2024 - 0116556, filed with the Korean Intellectual Property Office on August 29, 2024, based on the priority of the above - mentioned patent, the respective disclosures of which are incorporated herein by reference.

[0003] The present invention relates to a polybutylene terephthalate resin composition, a method for preparing the polybutylene terephthalate resin composition, and a molded article including the polybutylene terephthalate resin composition. More specifically, it relates to: a polybutylene terephthalate resin composition that can be used for electrical and electronic products or automotive parts due to excellent mechanical properties, processability, flame retardancy, and elongation, despite containing a high content of polybutylene terephthalate; a method for preparing the polybutylene terephthalate resin composition; and a molded article including the polybutylene terephthalate resin composition. Background Art

[0004] Recently, many studies have been conducted on resinifying electrical and electronic products or automotive parts. In particular, polybutylene terephthalate (PBT) has received attention as a material for metal - replacement parts in terms of economic efficiency and physical properties.

[0005] Polybutylene terephthalate (PBT) is a crystalline polymer having advantages such as high heat resistance and short manufacturing time. However, PBT has poor compatibility with other resins or reinforcing agents such as glass fiber, and thus cannot exhibit additional properties such as flame retardancy and elongation.

[0006] In particular, even when exposed to harsh external environments, electrical and electronic products or automotive parts must provide elongation, processability, impact stability, flame retardancy, and elongation, but it is difficult to meet these requirements with non - reinforced polybutylene terephthalate (PBT).

[0007] [Related Technical Literature]

[0008] [Patent Literature]

[0009] European Patent Application Publication No. 4101883 Summary of the Invention

[0010] Technical Problem

[0011] Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide: a polybutylene terephthalate resin composition which can be used for electrical and electronic products or automotive parts due to excellent mechanical properties, processability, flame retardancy and elongation rate despite containing a high content of polybutylene terephthalate; a method for preparing the polybutylene terephthalate resin composition; and a molded article including the polybutylene terephthalate resin composition.

[0012] The above and other objects can be achieved by the present invention described below.

[0013] Technical Solution

[0014] I) According to one aspect of the present invention, there is provided a polybutylene terephthalate resin composition comprising 100 parts by weight of polybutylene terephthalate; 1 to 30 parts by weight of an organometallic salt hypophosphite flame retardant; 1 to 30 parts by weight of a phosphate ester flame retardant; and 1 to 30 parts by weight of a polyester elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer,

[0015] wherein, when the content of the organometallic salt hypophosphite flame retardant is a, the content of the phosphate ester flame retardant is b, and the content of the polyester elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer is c, a > b > c is satisfied;

[0016] the weight ratio (a:b) of the organometallic salt hypophosphite flame retardant to the phosphate ester flame retardant is 7:2 to 7:4; and

[0017] the weight ratio (b:c) of the phosphate ester flame retardant to the polyester elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer is 4:3 to 8:3.

[0018] II) According to I), the polybutylene terephthalate may include polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 1.1 and less than or equal to 1.5 and polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 0.8 and less than or equal to 1.1 in a weight ratio of 1:0 to 1:1.

[0019] III) According to I) or II), the organometallic salt hypophosphite flame retardant may have a structure represented by the following Chemical Formula 1.

[0020] [Chemical Formula 1]

[0021]

[0022] Among them, R1 and R2 are each an alkyl or aryl group having 1 to 6 carbon atoms, M includes one or more selected from Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and protonated nitrogen bases, and n is from 1 to 4.

[0023] IV) According to I) to III), as a specific example, the organometallic salt hypophosphite flame retardant may have a structure represented by the following Chemical Formula 1-1.

[0024] [Chemical Formula 1-1]

[0025]

[0026] V) According to I) to IV), the phosphate ester flame retardant may have a structure represented by the following Chemical Formula 2.

[0027] [Chemical Formula 2]

[0028]

[0029] Among them, R3, R4, and R5 are each independently hydrogen or a C1-C4 alkyl group, X is a C6-C20 aryl group or a C6-C20 arylene group substituted with a C1-C4 alkyl group, and n is an integer from 0 to 4.

[0030] VI) According to I) to V), the phosphate ester flame retardant may be resorcinol bis(2,6-dimethylphenyl) phosphate.

[0031] VII) According to I) to VI), the polyester elastomer may be a compound composed of terephthalate as an aromatic dicarboxylic acid, 1,4-butanediol as an aliphatic diol, and polyoxytetramethylene glycol as an aliphatic polyether compound.

[0032] VIII) According to I) to VII), the ethylene-(meth)acrylic acid glycidyl ester copolymer may be a polyethylene-based copolymer obtained by polymerizing (meth)acrylic acid glycidyl ester.

[0033] IX) According to I) to VIII), the ethylene-(meth)acrylic acid glycidyl ester copolymer may be obtained by copolymerizing an olefin monomer and a monomer containing an epoxy group.

[0034] X) According to I) to IX), the ethylene-(meth)acrylic acid glycidyl ester copolymer may be obtained by polymerizing ethylene, (meth)acrylic acid glycidyl ester, and vinyl acetate.

[0035] XI) According to another aspect of the present invention, there is provided a polybutylene terephthalate resin composition, based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, comprising 30% to 85% by weight of polybutylene terephthalate having an intrinsic viscosity (I.V.) greater than 1.1 and not exceeding 1.5, 0 to 40% by weight of polybutylene terephthalate having an intrinsic viscosity (I.V.) greater than 0.8 and not exceeding 1.1, 10% to 20% by weight of the organometallic salt hypophosphite flame retardant, 1% to 10% by weight of the phosphate ester flame retardant, and 1% to 5% by weight of the polyester elastomer or the ethylene-(meth)acrylic acid glycidyl ester copolymer.

[0036] XII) According to XI), the additives may include one or more selected from heat stabilizers, flame retardants, flame retardant aids, activators, processing aids, plasticizers, coupling agents, light stabilizers, mold release agents, dispersants, anti-dripping agents, weather stabilizers, antioxidants, compatibilizers, pigments, dyes, antistatic agents, wear-resistant agents, fillers, and antibacterial agents.

[0037] XIII) According to XI) to XII), the polybutylene terephthalate resin composition may be a non-reinforced material.

[0038] XIV) According to XI) to XIII), the polybutylene terephthalate resin composition may be a material for components in automotive electrical / electronic devices.

[0039] XV) According to XI) to XIV), the polybutylene terephthalate resin composition may have an elongation at break of more than 22% measured at a rate of 50 mm / min according to ISO527.

[0040] XVI) According to XI) to XV), the polybutylene terephthalate resin composition may have a cantilever beam impact strength of more than 4.7 kJ / m 2 measured using a 4-mm thick specimen according to ISO180 (23°C, notched).

[0041] XVII) According to XI) to XVI), the polybutylene terephthalate resin composition may have a flame retardancy of V0 or higher measured according to the UL94 method for a specimen with a size of 0.8 mm.

[0042] XVIII) According to yet another aspect of the present invention, there is provided a method for preparing a polybutylene terephthalate resin composition, the method comprising: based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, adding 30% to 85% by weight of polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 1.1 and not exceeding 1.5, 0 to 40% by weight of polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 0.8 and not exceeding 1.1, 10% to 20% by weight of the organometallic salt hypophosphite flame retardant, 1% to 10% by weight of the phosphate ester flame retardant, and 1% to 5% by weight of the polyester elastomer or the ethylene-(meth)acrylic acid glycidyl ester copolymer into an extruder, and performing melt kneading and extrusion,

[0043] wherein, when the content of the organometallic salt hypophosphite flame retardant is a, the content of the phosphate ester flame retardant is b, and the content of the polyester elastomer or the ethylene-(meth)acrylic acid glycidyl ester copolymer is c, a > b > c is satisfied;

[0044] the weight ratio (a:b) of the organometallic salt hypophosphite flame retardant to the phosphate ester flame retardant is 7:2 to 7:4; and

[0045] the weight ratio (b:c) of the phosphate ester flame retardant to the polyester elastomer or the ethylene-(meth)acrylic acid glycidyl ester copolymer is 4:3 to 8:3.

[0046] XIX) According to yet another aspect of the present invention, there is provided a molded article comprising the above polybutylene terephthalate resin composition.

[0047] XX) According to XIX), the molded article may be an automotive part or an electrical and electronic part.

[0048] XXI) According to XIX) or XX), the molded article may be a part of an automotive electrical / electronic device.

[0049] XXII) According to XIX) to XXI), the part of the automotive electrical / electronic device may include a connector part or a sensor part.

[0050] XXIII) According to XIX) to XXII), the connector part may include a connector for a TV.

[0051] Beneficial effects

[0052] According to the present invention, the present invention has the following effects: providing a polybutylene terephthalate resin composition which, although containing a high content of polybutylene terephthalate, has excellent mechanical properties, processability, flame retardancy, and elongation at break.

[0053] Therefore, the polybutylene terephthalate resin composition according to the present invention can be used as a material for automotive electrical / electronic devices, which include connectors, sensors, and parking brake systems that require the physical properties of the polybutylene terephthalate resin composition. Detailed Description

[0054] Hereinafter, the polybutylene terephthalate resin composition of the present invention, a method for preparing the polybutylene terephthalate resin composition, and a molded article including the polybutylene terephthalate resin composition will be described in detail.

[0055] In the present specification, a polymer containing a certain compound means a polymer prepared by polymerizing the compound, and the units in the polymer are derived from the compound. In the present specification, a polymer containing a compound means a polymer obtained by polymerizing the compound, and the units in the polymerized polymer are derived from the compound.

[0056] In the present specification, the composition ratio of a (co)polymer may refer to the content of the units constituting the (co)polymer, or may refer to the content of the units introduced during the polymerization of the (co)polymer.

[0057] In the present specification, unless otherwise defined, "content" refers to weight, and "%" refers to weight %.

[0058] The present inventors confirmed that when containing a high content of polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 1.1 and 1.5 or less, and a predetermined content of an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, and a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, the mechanical properties, processability, flame retardancy, and elongation at break are excellent. Based on these results, the present inventors conducted further research to complete the present invention.

[0059] For example, the polybutylene terephthalate resin composition of the present invention comprises 100 parts by weight of polybutylene terephthalate; 1 to 30 parts by weight of an organometallic salt hypophosphite flame retardant; 1 to 30 parts by weight of a phosphate ester flame retardant; and 1 to 30 parts by weight of a polyester elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer, and does not contain reinforcing fibers and polyethylene terephthalate. In this case, although a high content of polybutylene terephthalate is included, the mechanical properties, processability, flame retardancy, and elongation can be excellent, and a balance of physical properties can be achieved.

[0060] Hereinafter, each component constituting the polybutylene terephthalate resin composition of the present invention will be described in detail as follows.

[0061] Polybutylene terephthalate

[0062] The polybutylene terephthalate used in the present invention can be a non-reinforced material.

[0063] As a specific example, the polybutylene terephthalate can include polybutylene terephthalate (first polybutylene terephthalate) having an intrinsic viscosity (I.V) greater than 1.1 and 1.5 or less and polybutylene terephthalate (second polybutylene terephthalate) having an intrinsic viscosity (I.V) greater than 0.8 and 1.1 or less in a weight ratio of 1:0 to 1:1. Within this range, the mechanical strength and elongation can be excellent.

[0064] First polybutylene terephthalate

[0065] In the present invention, the first polybutylene terephthalate can be polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 1.1 and 1.5 or less.

[0066] For example, there is no particular limitation on the first polybutylene terephthalate as long as it follows the definition of the present invention. For example, the first polybutylene terephthalate can be polybutylene terephthalate that has not undergone a molding process such as injection after polymerizing the monomers constituting the polybutylene terephthalate, or an equivalent available polybutylene terephthalate.

[0067] For example, the first polybutylene terephthalate can be referred to as the first (original) polybutylene terephthalate, new polybutylene terephthalate, fresh polybutylene terephthalate, or non-regenerated polybutylene terephthalate.

[0068] For example, the first polybutylene terephthalate of the present invention may have an intrinsic viscosity (I.V.) greater than 1.1 and 1.5 or less, preferably 1.15 to 1.5, more preferably 1.15 to 1.3. In this case, the elongation at break and the melt flow index can be optimized.

[0069] In the present disclosure, unless otherwise specified, when measuring the intrinsic viscosity, a sample solution with a concentration of 0.05 g / ml is prepared by completely dissolving the sample in dichloromethane as the solvent, and then filtered using a filter to obtain a filtrate. Then, using the obtained filtrate, the intrinsic viscosity is measured at 20 °C using an Ubbelohde viscometer.

[0070] For example, the first polybutylene terephthalate may have a polydispersity index of 2.75 or less, preferably 2.6 or less, more preferably 2.5 or less, still more preferably 2.0 to 2.5. Within this range, the physical property balance between the elongation at break and the melt flow index can be satisfied.

[0071] In the present invention, the polydispersity index refers to the molecular weight distribution, which is a value calculated by dividing the weight-average molecular weight by the number-average molecular weight. A high polydispersity index means a large standard deviation of the molecular weight distribution, which means there are more molecules greater than or less than the weight-average molecular weight.

[0072] In the present invention, unless otherwise defined, the weight-average molecular weight and the number-average molecular weight can be measured using gel permeation chromatography (GPC, Waters Breeze). As a specific example, the weight-average molecular weight and the number-average molecular weight can be measured by gel permeation chromatography (GPC, Waters Breeze) using tetrahydrofuran (THF) as the eluent. In this case, the weight-average molecular weight and the number-average molecular weight obtained as relative values of a polystyrene (PS) standard sample. As a specific measurement example, the weight-average molecular weight and the number-average molecular weight can be measured under the following conditions: solvent: THF, column temperature: 40 °C, flow rate: 0.3 ml / min, sample concentration: 20 mg / ml, injection volume: 5 μl, column model: 1×PLgel 10μm MiniMix-B (250×4.6 mm) + 1×PLgel 10μm MiniMix-B (250×4.6 mm) + 1×PLgel 10μm MiniMix-B Guard (50×4.6 mm), equipment name: Agilent 1200 series system, refractive index detector: Agilent G1362 RID, RI temperature: 35 °C, data processing: Agilent ChemStation S / W, test method (Mn, Mw and PDI): OECD TG 118.

[0073] For example, the first polybutylene terephthalate may have a weight-average molecular weight of 28,000 g / mol or more, preferably 29,000 g / mol or more, more preferably 30,000 g / mol or more, and still more preferably 30,000 g / mol to 37,000 g / mol. Within this range, the balance between mechanical properties and physical properties can be excellent.

[0074] There is no particular limitation on the polybutylene terephthalate (PBT), and it can be manufactured and used by methods known in the art, or commercially available materials can be used.

[0075] For example, based on a total of 100% by weight of polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 1.1 and 1.5 or less, a metal salt of hypophosphorous acid, a non-halogenated phosphate flame retardant, a polyester elastomer, or an ethylene-(meth)acrylic acid glycidyl ester copolymer and additives, the polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 1.1 and 1.5 or less can be included in an amount of 30% to 85% by weight, and as a specific example, 30% to 80% by weight, preferably 35% to 80% by weight. In this case, the physical property balance between elongation at break and melt flow index can be satisfied.

[0076] For example, in polybutylene terephthalate resins, the first polybutylene terephthalate can be included in an amount of 25% to 75% by weight, preferably 25% to 70% by weight, more preferably 30% to 70% by weight. Within this range, the impact resistance and heat resistance can be excellent.

[0077] For example, the first polybutylene terephthalate may be a resin obtained by polymerizing an aromatic diol compound and a carbonate precursor.

[0078] For example, the aromatic diol compound may include one or more selected from bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfoxide, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl)ketone, 1,1-bis(4-hydroxyphenyl)ethane, 2,2-bis(4-hydroxyphenyl)propane (bisphenol A; BPA), 2,2-bis(4-hydroxyphenyl)butane, 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z; BPZ), 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane, 2,2-bis(4-hydroxy-3,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-bromophenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, and α,ω-bis[3-(o-hydroxyphenyl)propyl]polydimethylsiloxane, preferably bisphenol A.

[0079] For example, the carbonate precursor may include one or more selected from dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, diphenyl carbonate, dimethylxylene carbonate (dithoryl carbonate), bis(chlorophenyl) carbonate, m-tolyl carbonate, dinaphthyl carbonate, bis(diphenyl) carbonate, phosgene, triphosgene, diphosgene, carbonyl bromide, and bis(haloformate). In terms of manufacturing efficiency and physical properties, triphosgene, phosgene, or a mixture thereof is preferably used.

[0080] As a specific example, the polybutylene terephthalate obtained by polymerizing the aromatic diol compound and the carbonate precursor includes a repeating unit represented by the following Chemical Formula 3.

[0081] [Chemical Formula 3]

[0082]

[0083] In Chemical Formula 3, R′1 to R′4 are each independently hydrogen, C 1-10 alkyl, C 1-10 alkoxy, or halogen; Z′ is an unsubstituted or C 1-6 alkyl- or C 6-20 aryl-substituted C 1-10 alkylene, an unsubstituted or C 1-10 alkyl-substituted C 3-15 cycloalkylene, O, S, SO, SO2, or CO.

[0084] Preferably, in Chemical Formula 3, R′1 to R′4 are each independently hydrogen or C 1-3alkyl, and Z′ is an unsubstituted or methyl- or phenyl-substituted C 1-6 alkylene group.

[0085] Second polybutylene terephthalate

[0086] In the present invention, the second polybutylene terephthalate may have an intrinsic viscosity (I.V.) greater than 0.8 and 1.1 or less, preferably 0.85 to 1.1, more preferably 0.9 to 1.1. In this case, the balance of physical properties between the elongation at break and the melt flow index can be satisfied.

[0087] For example, the second polybutylene terephthalate may have a polydispersity index greater than 2.75, preferably 2.8 or more, more preferably 2.8 to 3. Within this range, the balance of mechanical properties and physical properties can be excellent.

[0088] For example, the second polybutylene terephthalate may have a weight average molecular weight of 20,000 g / mol or more and less than 28,000 g / mol, preferably 22,000 g / mol to 27,000 g / mol, more preferably 23,000 g / mol to 27,000 g / mol. Within this range, the balance of mechanical properties and physical properties can be excellent.

[0089] It is known that the second polybutylene terephthalate has lower properties in all aspects such as impact resistance, heat resistance, and elongation at break compared to the first polybutylene terephthalate, and thus is used in a small amount of less than 25% by weight in the polybutylene terephthalate resin composition. However, the polybutylene terephthalate resin composition according to the present invention exhibits excellent mechanical properties, processability, flame retardancy, and elongation at break even though it contains more than 20% by weight, preferably 23% by weight or more, of the second polybutylene terephthalate.

[0090] The monomers forming the second polybutylene terephthalate can preferably be selected within the same range as that of the first polybutylene terephthalate.

[0091] For example, the second polybutylene terephthalate can be a commercially available product as long as the product meets the definition of the present invention.

[0092] Organometallic salt hypophosphite flame retardant

[0093] An organometallic salt hypophosphite flame retardant is added to improve the flame retardancy of the resin composition, and the organometallic salt hypophosphite flame retardant may have a structure represented by the following Chemical Formula 1.

[0094] [Chemical Formula 1]

[0095]

[0096] In Chemical Formula 1, R1 and R2 are each an alkyl group or an aryl group having 1 to 6 carbon atoms, M includes one or more selected from Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K, and protonated nitrogen bases, and n is from 1 to 4.

[0097] As a specific example, the organometallic salt hypophosphite flame retardant may have a structure represented by the following Chemical Formula 1-1.

[0098] [Chemical Formula 1-1]

[0099]

[0100] For example, based on all components including the first polybutylene terephthalate, the second polybutylene terephthalate, the organometallic salt hypophosphite flame retardant, the phosphate ester flame retardant, the polyester elastomer, or the ethylene-(meth)acrylic acid glycidyl ester copolymer and the additive that make up the polybutylene terephthalate resin composition in a total of 100% by weight, the organometallic salt hypophosphite flame retardant may be included in an amount of 10% to 20% by weight, as a preferred example, 13% to 20% by weight, and as a more preferred example, 13% to 18% by weight. When the content exceeds this range, the elongation at break and the flame retardancy may decrease, and unevenness may occur on the surface of the injection product manufactured using the polybutylene terephthalate resin composition containing the organometallic salt hypophosphite flame retardant, resulting in deterioration of the appearance quality.

[0101] Phosphate ester flame retardant

[0102] A phosphate ester flame retardant is added to improve the flame retardancy of the resin composition by the above-mentioned first additive, and the phosphate ester flame retardant may have a structure represented by the following Chemical Formula 2.

[0103] [Chemical Formula 2]

[0104]

[0105] In Chemical Formula 2, R3, R4, and R5 are the same or different and are hydrogen or a C1-C4 alkyl group, X is a C6-C20 aryl group or a C6-C20 aryl group substituted with a C1-C4 alkyl group, and n is an integer from 0 to 4.

[0106] X may preferably be derived from diols such as resorcinol, hydroquinone, or bisphenol A.

[0107] When n is 0, it may include triphenyl phosphate, tricresyl phosphate, tris(xylenyl) phosphate, tris(2,6-dimethylphenyl) phosphate, tris(2,4,6-trimethylphenyl) phosphate, tris(2,4-di-tert-butylphenyl) phosphate, and tris(2,6-di-tert-butylphenyl) phosphate.

[0108] When n is 1, it may include resorcinol bis(diphenyl) phosphate, resorcinol bis(2,6-dimethylphenyl) phosphate, resorcinol bis(2,4-di-tert-butylphenyl) phosphate, hydroquinone bis(2,6-dimethylphenyl) phosphate, and hydroquinone bis(2,4-di-tert-butylphenyl) phosphate.

[0109] The phosphate flame retardants can be used alone or in a mixture.

[0110] Preferably, the phosphate flame retardant can be resorcinol bis(2,6-dimethylphenyl) phosphate.

[0111] The weight ratio of the organometallic salt hypophosphite flame retardant to the phosphate flame retardant can be 1:0.2 to 1:0.9, or 1:0.2 to 1:0.6. In this case, a synergistic effect of flame retardancy can be provided without affecting other properties.

[0112] For example, based on all components including the first polybutylene terephthalate, the second polybutylene terephthalate, the organometallic salt hypophosphite flame retardant, the phosphate flame retardant, the polyester elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer, and the additive that make up the polybutylene terephthalate resin composition in a total of 100% by weight, the phosphate flame retardant can be included in an amount of 1% to 10% by weight, as a preferred example, 2% to 10% by weight, and as a more preferred example, 3% to 9% by weight. When the content exceeds this range, the elongation at break and flame retardancy may decrease, and unevenness may occur on the surface of the injection product made of the polybutylene terephthalate resin composition containing the phosphate flame retardant, resulting in deterioration of the appearance quality.

[0113] Polyester elastomer

[0114] One of the polyester elastomers of the present invention and the following ethylene-(meth)acrylic acid glycidyl ester copolymer can be selected and used for impact enhancement of the resin composition.

[0115] The polyester elastomer can include units derived from aromatic dicarboxylic acids or their ester-forming derivatives, units derived from aliphatic diols, and units derived from polyalkylene oxides.

[0116] Units derived from aromatic dicarboxylic acids may include one or more selected from terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.

[0117] Ester-forming derivatives of aromatic dicarboxylic acids may be units from one or more selected from dimethyl terephthalate, dimethyl isophthalate, dimethyl 2,6-naphthalenedicarboxylate, and dimethyl 1,4-cyclohexanedicarboxylate, preferably units from dimethyl terephthalate.

[0118] Based on the total weight of the polyester elastomer, units derived from aromatic dicarboxylic acids or units from their ester-forming derivatives may be included in an amount of 25% to 65% by weight or 30% to 60% by weight, preferably 30% to 60% by weight.

[0119] Units derived from aliphatic diols may have a weight-average molecular weight of 300 g / mol or less and may be units from aliphatic diols.

[0120] Units derived from aliphatic diols may be units from one or more selected from ethylene glycol, propylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol, preferably units from 1,4-butanediol.

[0121] Based on the total weight of the polyester elastomer, units derived from aliphatic diols may be included in an amount of 20% to 45% by weight or 25% to 40% by weight, preferably 25% to 40% by weight.

[0122] Units derived from polyalkylene oxides are aliphatic polyethers, which may act as soft segments in the polyester elastomer.

[0123] Units derived from polyalkylene oxides may be units from one or more selected from polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, copolymers of ethylene oxide and propylene oxide, ethylene oxide addition polymers of polypropylene glycol, and copolymers of ethylene oxide and tetrahydrofuran, preferably units from polytetramethylene glycol or ethylene oxide addition polymers of polypropylene glycol.

[0124] Polytetramethylene glycol may have a number-average molecular weight of 600 g / mol to 3,000 g / mol, 1,000 g / mol to 2,500 g / mol, or 1,800 g / mol to 2,200 g / mol, preferably 1,800 g / mol to 2,200 g / mol.

[0125] The ethylene oxide adduct polymer of polypropylene glycol can be polypropylene glycol having ends capped with ethylene oxide and can have a weight-average molecular weight of 2,000 g / mol to 3,000 g / mol.

[0126] Based on the total weight of the thermoplastic polyester elastomer, the units derived from polyalkylene oxide can be included in an amount of 10% by weight to 50% by weight or 15% by weight to 45% by weight. Within this range, the flexibility, heat resistance, and compatibility of the polyester elastomer can be further improved.

[0127] In addition, the polyester elastomer can have a weight-average molecular weight of 2,000 g / mol to 3,000 g / mol.

[0128] The polyester elastomer can have a Shore D hardness of 35D to 55D or 40D to 50D. Within this range, the extrusion processing and molding of the polybutylene terephthalate resin composition can be facilitated, and the chemical resistance can be improved.

[0129] When measured for 10 minutes at a temperature of 230 °C under a load of 2.16 kg according to ASTM D1238, the polyester elastomer can have a melt index of 0.1 g / min to 10 g / min or 1 g / min to 10 g / min. Within this range, the extrusion processing and molding of the polybutylene terephthalate resin composition can be facilitated, and the chemical resistance can be improved.

[0130] In addition, the polyester elastomer can be prepared by a method including the following steps: a step of preparing a polyester elastomer precursor by melt-polymerizing an aromatic dicarboxylic acid or its ester-forming derivative, an aliphatic diol, and a polyalkylene oxide; and a step of preparing the polyester elastomer by solid-phase polymerization of the polyester elastomer precursor.

[0131] Hereinafter, each step of the method for preparing the polyester elastomer will be described in detail.

[0132] Step of preparing the polyester elastomer precursor

[0133] First, an aromatic dicarboxylic acid or its ester-forming derivative, an aliphatic diol, and a polyalkylene oxide are prepared as starting materials.

[0134] Based on the total weight of the starting materials, the aromatic dicarboxylic acid or its ester-forming derivative can be added in an amount of 25% by weight to 65% by weight or 30% by weight to 60%, preferably 30% by weight to 60%. Within this range, the reaction equilibrium is excellent, and thus melt polymerization can proceed smoothly.

[0135] Specific examples of the aromatic dicarboxylic acid or its ester-forming derivative are as described above.

[0136] Based on the total weight of the starting materials, the aliphatic diol can be added in an amount of 20% to 45% by weight, or 25% to 40% by weight. Within this range, the reaction equilibrium is excellent, and thus the melt polymerization can proceed smoothly.

[0137] Specific examples of the aliphatic diol are as described above.

[0138] Based on the total weight of the starting materials, the polyalkylene oxide can be added in an amount of 10% to 50% by weight or 15% to 45% by weight, preferably 15% to 45% by weight. Within this range, the flexibility, heat resistance, and compatibility of the polyester-based elastomer can be further improved.

[0139] Specific examples of the polyalkylene oxide are as described above.

[0140] Next, first, a catalyst is added to the starting materials, and after raising the temperature to 140°C to 215°C, the melt polymerization is started.

[0141] The catalyst can be tetrabutyl titanate.

[0142] When the melt polymerization is started, a transesterification reaction can occur between the starting materials, thereby producing oligomers, preferably bis(4-hydroxybutyl) terephthalate (BHBT) oligomers.

[0143] The transesterification reaction can be carried out for 1 hour to 3 hours or 1 hour 30 minutes to 2 hours 30 minutes.

[0144] Next, after adding the catalyst to the oligomers for the second time, the temperature is raised to 215°C to 245°C, and then the polycondensation reaction can be carried out while reducing the pressure from 760 Torr to 0.3 Torr. The polyester-based elastomer precursor can be produced by the polycondensation reaction.

[0145] The polycondensation reaction can be carried out for 1 hour to 3 hours or 1 hour 30 minutes to 2 hours 30 minutes.

[0146] When measuring the weight for 10 minutes at a temperature of 230°C under a load of 2.16 kg according to ASTM D1238, the polyester-based elastomer precursor can have a melt index of 15 g / min to 25 g / min or 18 g / min to 22 g / min.

[0147] Next, the polyester-based elastomer precursor can be extruded in a strand shape under nitrogen pressure and pelletized to obtain the polyester-based elastomer precursor in pellet form.

[0148] In addition, during the melt polymerization, a branching agent can be further added to increase the melt viscosity and melt strength of the polyester-based elastomer.

[0149] The branching agent may include one or more selected from glycerol, pentaerythritol, trimellitic anhydride, trimellitic acid, trimethylolpropane, and neopentyl glycol, preferably trimellitic anhydride.

[0150] Based on 100 parts by weight of the starting materials, the branching agent may be included in an amount of 0.05% to 0.1% by weight. Within this range, the melt viscosity and degree of polymerization of the polyester elastomer are appropriate, so that the melt polymerization reaction can be easily controlled, and the polyester elastomer precursor can be easily discharged to the outside of the reactor.

[0151] Steps for preparing the polyester elastomer

[0152] Next, the polyester elastomer precursor may be solid-phase polymerized to produce the polyester elastomer.

[0153] The solid-phase polymerization may be carried out by introducing the polyester elastomer precursor into a solid-phase polymerization reactor, and then gradually reducing the pressure from 140 °C to 200 °C under an inert atmosphere over 10 hours to 24 hours to a high vacuum.

[0154] The solid-phase polymerization reactor may be a container vacuum dryer connected to a rotatable high-vacuum pump, and the inert atmosphere may be a nitrogen atmosphere.

[0155] In addition, the polyester elastomer may be a commercially available material, preferably KEYFLEX BT 1040D from LG Chemical (DSC melting point: 198 °C, Shore D hardness: 40).

[0156] For example, based on a total of 100% by weight of all components including the first polybutylene terephthalate, the second polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives that make up the polybutylene terephthalate resin composition, the polyester elastomer may be included in an amount of 1% to 10% by weight, as a preferred example, 2% to 10% by weight, and as a more preferred example, 3% to 9% by weight. Within this range, the impact resistance can be significantly improved without deteriorating the inherent mechanical properties of the resin.

[0157] Ethylene-(meth)acrylic acid glycidyl ester copolymer

[0158] The ethylene-(meth)acrylic acid glycidyl ester copolymer of the present invention can be used for impact enhancement of the resin composition.

[0159] The ethylene-(meth)acrylic acid glycidyl ester copolymer may be a polyethylene-based copolymer obtained by polymerizing (meth)acrylic acid glycidyl ester.

[0160] Based on all components constituting 100% by weight of the ethylene-(meth)acrylic acid glycidyl ester copolymer, (meth)acrylic acid glycidyl ester can be included in an amount of 3% by weight or more, 3% to 10% by weight, or 3% to 7% by weight. In this case, impact enhancement and elongation at break can be sufficiently increased.

[0161] The ethylene-(meth)acrylic acid glycidyl ester copolymer includes a compound represented by the following Chemical Formula 4. In this case, the impact resistance can be excellent.

[0162] [Chemical Formula 4]

[0163]

[0164] As shown in Chemical Formula 4, the ethylene-(meth)acrylic acid glycidyl ester copolymer can be obtained by copolymerizing an olefin monomer and a monomer containing an epoxy group.

[0165] For example, ethylene can be used as the olefin monomer. When necessary, an olefin having 3 to 19 carbon atoms, such as propylene, isopropylene, butene, isobutene, octene, or a combination thereof, can be used.

[0166] As the monomer containing an epoxy group, (meth)acrylic acid glycidyl ester or the like can be used. Based on the total weight of all components constituting the corresponding copolymer, the (meth)acrylic acid glycidyl ester monomer can be used in an amount of 0.01% by weight or more, 5% by weight or more, 5% to 40% by weight, 5% to 30% by weight, or 10% to 25% by weight.

[0167] Preferably, the glycidyl group-modified olefin rubber polymer can be a compound represented by Chemical Formula 4 and a polyethylene-based copolymer grafted with (meth)acrylic acid glycidyl ester. In this case, the impact strength can be excellent.

[0168] As a more preferred example, the glycidyl group-modified olefin rubber polymer can be a copolymer obtained by polymerizing ethylene, (meth)acrylic acid glycidyl ester, and vinyl acetate. In this case, the impact strength can be excellent.

[0169] For example, based on all components including a first polybutylene terephthalate, a second polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives that make up the polybutylene terephthalate resin composition in a total of 100% by weight, the glycidyl-modified olefin rubber polymer can be included in an amount of 1% to 10% by weight, as a preferred example, 2% to 10% by weight, and as a more preferred example, 3% to 9% by weight. Within this range, the impact resistance can be significantly improved without degrading the inherent mechanical properties of the resin.

[0170] Polybutylene terephthalate resin composition

[0171] The polybutylene terephthalate resin composition is preferably a polybutylene terephthalate resin composition for injection molding. Since the polybutylene terephthalate resin composition has excellent flame retardancy and elongation, phase separation does not occur during injection molding, and thus products with a thin thickness or a complex structure can be manufactured.

[0172] For example, when the content of the organometallic salt hypophosphite flame retardant is a, the content of the phosphate ester flame retardant is b, and the content of the polyester elastomer or the ethylene-(meth)acrylic acid glycidyl ester copolymer is c, the polybutylene terephthalate resin composition of the present invention can satisfy a > b > c. In this case, the mechanical strength, processability, flame retardancy, and elongation can be significantly improved by affecting the compatibility, dispersibility, and processability.

[0173] The weight ratio (a:b) of the organometallic salt hypophosphite flame retardant to the phosphate ester flame retardant can be 7:2 to 7:4. In this case, the mechanical strength, processability, flame retardancy, and elongation can be significantly improved by affecting the compatibility, dispersibility, and processability.

[0174] The weight ratio (b:c) of the phosphate ester flame retardant to the polyester elastomer or the ethylene-(meth)acrylic acid glycidyl ester copolymer can be 4:3 to 8:3. In this case, the mechanical strength, processability, flame retardancy, and elongation can be significantly improved by affecting the compatibility, dispersibility, and processability.

[0175] For example, for this purpose, within the range that does not impair the performance of each component, the polybutylene terephthalate resin composition of the present invention may include one or more selected from heat stabilizers, flame retardants, flame retardant aids, activators, processing aids, plasticizers, coupling agents, light stabilizers, mold release agents, dispersants, anti-dripping agents, weather resistance stabilizers, antioxidants, compatibilizers, pigments, dyes, antistatic agents, wear-resistant agents, fillers, and antibacterial agents, preferably one or more selected from antioxidants, colorants, activators, mold release agents, heat stabilizers, and plasticizers. In this case, both the impact strength and the processing performance can be excellent without reducing the mechanical properties.

[0176] Based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, the additives may be included in an amount of 7% by weight or less, as specific examples, 0.1% by weight to 5% by weight, preferably 0.1% by weight to 3% by weight, more preferably 0.2% by weight to 0.8% by weight.

[0177] For example, the antioxidant may be a known antioxidant blended in the polybutylene terephthalate resin composition.

[0178] The antioxidants include phosphorus antioxidants and phenolic antioxidants.

[0179] The hindered phenolic antioxidants may include pentaerythritol - tetra[3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)propionate], thiodiethylene - bis[3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl)propionate].

[0180] The phosphorus antioxidants may include bis(2,6 - di - tert - butyl - 4 - methylphenyl)pentaerythritol diphosphite or bis(2,4 - dicumylphenyl)pentaerythritol diphosphite.

[0181] According to the present invention, it may be desirable to use a combination of two different types of the above - mentioned antioxidants. Specifically, the heat resistance can be further improved by using a mixture of a hindered phenolic antioxidant and a phosphorus antioxidant.

[0182] For example, the weight ratio of the hindered phenolic antioxidant to the phosphorus antioxidant may be 1:0.1 to 1:1, preferably 1:0.4 to 1:1, more preferably 1:0.6 to 1:1. When mixed in the above weight ratio, the heat resistance can be further improved without deteriorating the performance of the resin composition.

[0183] Based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, the antioxidant can be included in an amount of 0.01% to 5% by weight, preferably 0.01% to 3% by weight. Within this range, the heat resistance can be excellent.

[0184] For example, the anti-dripping agent can be a known anti-dripping agent blended in the polybutylene terephthalate resin composition.

[0185] As a specific example, when using at least one of tetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, and ethylene / tetrafluoroethylene copolymer, it is preferred because the flame retardant quality can be improved through the anti-dripping effect.

[0186] In one embodiment of the present invention, the anti-dripping agent can be a commercially available product.

[0187] Based on a total of 100% by weight of the lubricant, antioxidant, and anti-dripping agent, the anti-dripping agent can be included in an amount of 0.01% to 5%, 0.1% to 3%, 0.1% to 2%, 0.1% to 1%, or 0.2% to 0.8% by weight in one or more of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer. When the content of the anti-dripping agent exceeds the above range, molding problems may occur in the molded article manufactured using the polyester resin composition containing the anti-dripping agent, resulting in quality deterioration. Below the above range, the anti-dripping effect may not be fully exerted.

[0188] For example, based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, the colorant can be included in an amount of 0.01% to 5% by weight, preferably 0.01% to 3% by weight. Within this range, the processability can be excellent.

[0189] For example, the colorant masterbatch can be a carbon colorant masterbatch. In this case, there is an effect of improving the dispersibility without causing layer separation of the composition.

[0190] For example, the lubricant can be pentaerythritol tetrastearate. In this case, the wettability of the composition of the present invention can be improved, and at the same time, the heat resistance and processability can be excellent.

[0191] For example, based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, the lubricant can be included in an amount of 0.01% to 3% by weight, preferably 0.01% to 2% by weight. Within this range, the wettability of the polybutylene terephthalate composition can be improved, and the mechanical properties can be excellent.

[0192] For example, the heat stabilizer may include one or more selected from tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite (TBPP), 2,4,6-tri-tert-butylphenyl-2-butyl-2-ethyl-1,3-propanediol phosphite, diisodecyl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphate (PEP24), bis(2,4-dicumylphenyl) pentaerythritol diphosphate, and tetra(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4'-diyl diphosphonate.

[0193] For example, based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, the heat stabilizer can be included in an amount of 0.01% to 2% by weight, preferably 0.01% to 1% by weight. Within this range, the heat resistance can be excellent.

[0194] In the present invention, as the mold release agent, the mold release agent used in the related art can be used within the range that does not affect the impact strength, processability, flame retardancy, and high molding shrinkage rate.

[0195] For example, based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, the mold release agent can be included in an amount of 0.01% to 5% by weight, preferably 0.01% to 3% by weight. Within this range, the mold release property can be excellent.

[0196] In the present invention, as the plasticizer, the plasticizer used in the related art can be used within the range that does not affect the impact strength, processability, flame retardancy, and high molding shrinkage rate.

[0197] For example, based on a total of 100% by weight of polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer, and additives, the plasticizer can be included in an amount of 0.01% to 5% by weight, preferably 0.01% to 3% by weight. Within this range, the flame retardancy can be excellent.

[0198] The polybutylene terephthalate resin composition of the present invention can have an elongation at break of more than 22% or 22% to 50% measured at a rate of 50 mm / min according to ISO 527. Within this range, the elongation at break can be excellent and the durability can be improved.

[0199] The polybutylene terephthalate resin composition of the present invention can have a Charpy impact strength (23 °C, notched) of 4.7 kJ / m 2 or more or 4.8 kJ / m 2 to 5.1 kJ / m 2 measured using a 4 mm thick specimen according to ISO 180. Within this range, the balance of physical properties can be improved.

[0200] The polybutylene terephthalate resin composition of the present invention can have a flame retardancy of V0 or more measured for a specimen with a size of 0.8 mm according to the UL94 method.

[0201] The polybutylene terephthalate resin composition of the present invention can have a melt flow rate of 9.2 g / 10 min or more or 9.2 g / 10 min to 30 g / 10 min measured according to ISO1133.

[0202] Hereinafter, a method for preparing the polybutylene terephthalate resin composition of the present invention will be described in detail.

[0203] Method for preparing polybutylene terephthalate resin composition

[0204] When describing the method for preparing the polybutylene terephthalate resin composition of the present invention, all the contents of the above polybutylene terephthalate resin composition are included.

[0205] The method for preparing the polybutylene terephthalate resin composition of the present invention includes the steps of adding polybutylene terephthalate having an intrinsic viscosity (I.V) greater than 1.1 and 1.5 or less, a metal salt of diethylphosphinic acid, resorcinol phosphate, and a polyester-based elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer to an extruder, and performing melt kneading and extrusion. In this case, by satisfying the physical property balance, excellent mechanical strength, processability, flame retardancy, and elongation can be provided for electrical and electronic products or automotive parts having a thin thickness or a complex structure, and injection molding characteristics can be achieved.

[0206] The method for preparing the polybutylene terephthalate resin composition may include the above additives.

[0207] In the method for preparing the polybutylene terephthalate resin composition, kneading and extrusion may be performed by a single-screw extruder, a twin-screw extruder, or a Banbury mixer, preferably by a twin-screw extruder. In this case, the composition can be uniformly dispersed and the compatibility can be excellent.

[0208] For example, the step of preparing pellets using an extrusion kneader may be performed at a barrel temperature of 210°C to 290°C, 230°C to 270°C, or 240°C to 260°C. In this case, the processing capacity per unit time can be appropriate, melt kneading can be sufficiently performed, and thermal decomposition of the resin components can be prevented.

[0209] For example, the step of preparing pellets using an extrusion kneader may be performed at a screw rotation speed of 100 rpm / min to 300 rpm / min, as a specific example, 150 rpm / min to 300 rpm / min, and as a preferred example, 200 rpm / min to 300 rpm / min. In this case, the processing capacity per unit time can be appropriate, the processing efficiency can be improved, and over-cutting can be prevented.

[0210] The polybutylene terephthalate resin composition pellets can be used as they are or after dehumidification and drying with hot air.

[0211] For example, dehumidification drying may be performed in a hot air dryer at a temperature range of 80°C to 100°C for more than 3 hours.

[0212] For example, the pellets can be made into injection molded products using an injection molding machine at an injection barrel temperature of 210°C to 300°C, 220°C to 290°C, or 240°C to 270°C.

[0213] For example, the extruder may have more than 6 kneading blocks, preferably more than 7 kneading blocks, more preferably more than 8 kneading blocks. As a preferred example, there are 8 to 15 kneading blocks, and as a more preferred example, there are 9 to 12 kneading blocks. In this case, arranging the kneading blocks in the order of forward kneading blocks, neutral kneading blocks, and reverse kneading blocks with respect to the resin flow direction can be effective. Depending on the combination method, continuous or separate block combinations can be used. In this case, the dispersibility of the components and the compatibility of the composition are further improved, thereby providing a high-quality mixture.

[0214] There is no particular limitation on the type of extruder, but considering uniform mixing and dispersion, ease of processing, and economy, it may be desirable to use a twin-screw extruder with two screws.

[0215] The extruder consists of a feeder for supplying materials into the barrel, a screw for transporting and mixing the materials supplied into the barrel, and a die for extruding the mixed materials. The screw consists of multiple screw elements to provide various functions.

[0216] One or more feeders can be provided. Optionally, two or more feeders can be provided. For example, a main feeder and an optional auxiliary feeder can be provided. Optionally, two or more auxiliary feeders can be provided.

[0217] For example, all components except the polyester-based elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer can be fed into the main inlet, and the polyester-based elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer can be fed into the auxiliary inlet 1.

[0218] As another example, all components except the polyester-based elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer and the flame retardant can be fed into the main inlet, the polyester-based elastomer or ethylene-(meth)acrylic acid glycidyl ester copolymer can be fed into the auxiliary inlet, and the flame retardant can be fed into the auxiliary inlet 2.

[0219] Hereinafter, molded articles including the polybutylene terephthalate resin composition of the present invention are described. When describing the molded articles of the present invention, all the contents including the above polybutylene terephthalate resin composition are included.

[0220] Molded article

[0221] The molded articles of the present invention may include the polybutylene terephthalate resin composition. That is, the molded articles of the present invention can be manufactured by extrusion molding or injection molding the above polybutylene terephthalate resin composition according to the methods used in the art.

[0222] For example, a molded article can be obtained by kneading and extruding a polybutylene terephthalate resin composition. Kneading and extrusion can be carried out using a conventional extruder, and as a preferred example, a single-screw extruder or a twin-screw extruder.

[0223] For example, the molded article can be an injection-molded electrical and electronic product or an automotive interior component. In this case, by the polybutylene terephthalate resin composition of the present invention, a high-quality molded article can be provided by satisfying all of the heat resistance, processability, electrical properties, flame retardancy, and high injection-molding characteristics required by the market.

[0224] The molded article can be manufactured by extrusion molding the above polybutylene terephthalate resin composition. For example, a demolding extrusion molded article, a sheet formed by extrusion molding, or a film formed by extrusion molding can be manufactured by molding the polybutylene terephthalate resin composition. Various extrusion molding methods include cold runner methods, hot runner methods, injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection of supercritical fluids), insert molding, in-mold coating molding, insulated mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high-speed injection molding.

[0225] Therefore, the polybutylene terephthalate resin composition according to the present invention can be applied to various automotive electrical / electronic device material fields that particularly require its physical properties, including connectors, sensors, and parking brake systems.

[0226] In describing the polybutylene terephthalate resin composition of the present invention, the method for preparing the polybutylene terephthalate resin composition, and the molded article including the polybutylene terephthalate resin composition, it should be noted that other conditions or equipment not specifically described in this specification can be appropriately selected within the range generally practiced in the art, without particular limitation.

[0227] Hereinafter, the present invention will be described in more detail with reference to the following preferred embodiments. However, these embodiments are provided for illustrative purposes only and should not be construed as limiting the scope and concept of the present invention. In addition, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the concept and scope of the present invention, and such changes and modifications are also within the scope of the appended claims.

[0228] [Examples]

[0229] Examples 1 to 5 and Comparative Examples 1 to 10

[0230] The raw materials used in the examples and comparative examples are as follows.

[0231] (A) Polybutylene terephthalate

[0232] (A-1) Intrinsic viscosity (IV) 1.2, Jangchun Co., Product name: PBT 1100-211S

[0233] (A-2) Intrinsic viscosity (IV) 1.0, Tunhe Co., Product name: TH6098A

[0234] (A-3) Intrinsic viscosity (IV) 0.8, Tunhe Co., Product name: TH6082A

[0235] (B) Organometallic salt hypophosphite flame retardant: Clariant Co., OP 1240 (material represented by Chemical formula 1-1 below)

[0236] [Chemical formula 1-1]

[0237]

[0238] (C) Phosphate ester flame retardant: Resorcinol bis(2,6-dimethylphenyl) phosphate (PX200, Japan dieHachi Co.), Phosphorus content: 8.7 wt%

[0239] (D-1) Polyester elastomer: Keyflex BT1040D (LG Chemical Co.) with a hardness of 40D, composed of terephthalate as an aromatic dicarboxylic acid, 1,4-butanediol as an aliphatic diol, and polyoxytetramethylene glycol as an aliphatic polyether compound

[0240] (D-2) Ethylene-(meth)acrylic acid glycidyl ester copolymer: DuPont Co., Product name: Elvaloy PTW (GMA content: 5 wt%)

[0241] (D-3) Melamine cyanurate

[0242] (D-4) Melamine polyphosphate

[0243] (E) Additives

[0244] E-1) Lubricant: Lione Chemtec Co., LC102N (PE type)

[0245] E-2) Antioxidant: Songnox 6260

[0246] E-3) Anti-dripping agent: Teflon JF-4A

[0247] Mix the raw materials of the polybutylene terephthalate resin composition described in Table 1 and Table 2 below, and then prepare a polybutylene terephthalate resin composition with a uniform dispersion in the form of pellets by extrusion. Then, heat the pellets, inject them into a mold, and then cool them to prepare specimens through an injection molding process.

[0248] Specifically, mix each component shown in Table 1 and Table 2 below in a mixer, and then use a twin-screw extruder ( L / D: 42, SM Platek equipment) to feed it into the main inlet at a feeding rate of 50 kg / h at 250 rpm and extrude to obtain pellets of the polybutylene terephthalate resin composition. At this time, feed the glass fiber through the auxiliary inlet and use nine mixing blocks of the extruder.

[0249] Dry the pellets in a convection oven at 120 °C for more than 4 hours, and then inject them using an injection molding machine (ENGEL, 80 tons) at an injection temperature of 250 °C, a mold temperature of 60 °C, and an injection speed of 30 mm / s to prepare specimens.

[0250] [Table 1]

[0251] Classification Example 1 Example 2 Example 3 Example 4 Example 5 A-1 73.3 75.3 77.7 51.4 51.4 A-2 - - - 25.9 25.9 B 14 14 14 14 14 C 8 6 4 4 4 D-1 3 3 3 3 - D-2 - - - - 3

[0252] In Table 1, based on 100% by weight, add each raw material to A-1 to D-2 in units of weight percentage, with a total of 0.8% by weight of lubricant (E-1), 0.4% by weight of antioxidant (E-2), and 0.5% by weight of anti-dripping agent (E-3).

[0253] [Table 2]

[0254]

[0255] In Table 2, based on 100% by weight, add each raw material to A-1 to D-4 in units of weight percentage, with a total of 0.8% by weight of lubricant (E-1), 0.4% by weight of antioxidant (E-2), and 0.5% by weight of anti-dripping agent (E-3). In Comparative Example 10, based on 100% by weight, add each raw material to A-1 to D-4, with a total of 0.8% by weight of lubricant (E-1) and 0.4% by weight of antioxidant (E-2).

[0256] Test Example 1: Evaluation of the physical properties of molded specimens

[0257] Evaluate the properties of the molded specimens manufactured in Examples 1 to 5 and Comparative Examples 1 to 10. The evaluation criteria are as follows.

[0258] - Tensile strength (MPa): Measure the tensile strength at a rate of 50 mm / min according to ISO 527.

[0259] - Elongation at break (%): Measure the elongation at break at a rate of 50 mm / min according to ISO 527.

[0260] - Flexural strength (MPa): Measure the flexural strength at a rate of 2 mm / min according to ISO 178.

[0261] - Impact strength (IZOD): Measure the impact strength of a 4-mm thick specimen according to ISO 180 (notched, 23 °C).

[0262] - Flame retardancy: Measure the flame retardancy of a 0.8-mm specimen size according to UL94.

[0263] The results measured by the evaluation criteria are shown in Tables 3 and 4 below.

[0264] [Table 3]

[0265] Classification Example 1 Example 2 Example 3 Example 4 Example 5 Tensile strength (MPa) 33 37 39 38 39 Elongation (%) 42.5 26.7 29.4 27.5 25.7 Flexural strength (MPa) 53 64 64 67 65 <![CDATA[Impact strength (kJ / m 2 )]]> 4.8 5.1 5.1 5.1 4.8 Flame retardancy V0 V0 V0 V0 V0

[0266] [Table 4]

[0267]

[0268] As shown in Tables 3 and 4, since the polybutylene terephthalate resin compositions of Examples 1 to 5 according to the present invention contain polybutylene terephthalate, an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, and a polyester elastomer or an ethylene-(meth)acrylic acid glycidyl ester copolymer in a predetermined mixing ratio, mechanical strength, processability, and flame retardancy are maintained or improved, and the elongation at break is significantly increased, thereby providing product reliability as a component of automotive electrical / electronic equipment. On the other hand, in Comparative Example 1 in which the phosphate ester flame retardant is not included and melamine cyanurate is used, the elongation at break and impact strength are significantly reduced compared to Example 1, making it difficult to provide product reliability as a component of automotive electrical / electronic equipment.

[0269] Furthermore, in Comparative Examples 2 and 3 in which the phosphate ester flame retardant is not included and melamine polyphosphate is used, the elongation at break and impact strength are significantly reduced compared to Example 1, making it difficult to provide product reliability as a component of automotive electrical / electronic equipment.

[0270] Furthermore, in Comparative Example 4 in which neither the polyester elastomer nor the ethylene-(meth)acrylic acid glycidyl ester copolymer is included, the elongation at break and impact strength are significantly reduced compared to Example 1, and the processability is poor, making it difficult to provide product reliability as a component of automotive electrical / electronic equipment.

[0271] In addition, in Comparative Example 5 where the intrinsic viscosity of the un-reinforced polybutylene terephthalate is insufficient, compared with Example 1, the processability is excellent, but the elongation at break is reduced. Therefore, Comparative Example 5 is not suitable as a component.

[0272] In addition, in Comparative Example 6 where an excessive amount of an organometallic salt hypophosphite flame retardant is used, compared with Example 1, the elongation at break and impact strength are significantly reduced, showing poor results.

[0273] In addition, in Comparative Example 7 where the organometallic salt hypophosphite flame retardant is used in a small amount, compared with Example 1, the flame retardancy is reduced, showing poor results for application to components.

[0274] In addition, in Comparative Example 8 where an excessive amount of a phosphate ester flame retardant is used, compared with Example 1, the tensile strength and flexural strength are reduced, and the processability is poor.

[0275] In addition, in Comparative Example 9 where the phosphate ester flame retardant is used in a small amount, compared with Example 1, the elongation at break is reduced, making it difficult to provide product reliability.

[0276] In addition, in Comparative Example 10 where no anti-dripping agent is included, compared with Example 3, the flame retardancy is poor.

[0277] That is, the polybutylene terephthalate resin composition according to one embodiment of the present invention contains an organometallic salt hypophosphite flame retardant, a phosphate ester flame retardant, a polyester elastomer, or an ethylene-(methyl)acrylic acid glycidyl ester copolymer while containing a high content of polybutylene terephthalate. Therefore, the mechanical properties, processability, flame retardancy, and elongation at break of the molded article manufactured using the polybutylene terephthalate resin composition are improved, and thus the molded article can be applied to components of automotive electrical / electronic devices.

Claims

1. A polybutylene terephthalate resin composition, comprising 100 parts by weight of polybutylene terephthalate; 1 to 30 parts by weight of an organic metal salt-based phosphinate flame retardant; 1 to 30 parts by weight of a phosphate ester flame retardant; and 1 to 30 parts by weight of a polyester elastomer or ethylene-(meth)acrylate glycidyl copolymer, in, When the content of the organic metal salt phosphinate flame retardant is a, the content of the phosphate flame retardant is b, and the content of the polyester elastomer or ethylene-(meth)acrylate glycidyl ester copolymer is c, a>b>c is satisfied; The weight ratio (a:b) of the organic metal salt phosphinate flame retardant to the phosphate flame retardant is 7:2 to 7:4; and The weight ratio (b:c) of the phosphate flame retardant to the polyester elastomer or ethylene-glycidyl (meth)acrylate copolymer is 4:3 to 8:

3.

2. The polybutylene terephthalate resin composition according to claim 1, wherein The polybutylene terephthalate includes polybutylene terephthalate having an intrinsic viscosity (IV) greater than 1.1 and less than 1.5 and polybutylene terephthalate having an intrinsic viscosity (IV) greater than 0.8 and less than 1.1 at a weight ratio of 1:0 to 1:

1.

3. The polybutylene terephthalate resin composition according to claim 1, wherein The organic metal salt-based phosphinate flame retardant has a structure represented by the following Chemical Formula 1: [Chemical formula 1] wherein R1 and R2 are each an alkyl or aryl group having 1 to 6 carbon atoms, M comprises one or more selected from Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, K and a protonated nitrogen base, and n is 1 to 4.

4. The polybutylene terephthalate resin composition according to claim 1, wherein The phosphate-based flame retardant has a structure represented by the following Chemical Formula 2: [Chemical formula 2] Wherein, R3, R4 and R5 are each independently hydrogen or a C1-C4 alkyl group, X is a C6-C20 aryl group or a C6-C20 arylene group substituted by a C1-C4 alkyl group, and n is an integer from 0 to 4.

5. The polybutylene terephthalate resin composition according to claim 1, wherein The polyester-based elastomer is a compound composed of terephthalate as an aromatic dicarboxylic acid, 1,4-butanediol as an aliphatic diol, and polyoxytetramethylene glycol as an aliphatic polyether compound.

6. The polybutylene terephthalate resin composition according to claim 1, wherein The ethylene-glycidyl (meth)acrylate copolymer is obtained by copolymerizing an olefin monomer and a monomer including an epoxy group.

7. A polybutylene terephthalate resin composition, based on a total of 100 wt% of polybutylene terephthalate, an organic metal salt-based phosphinate flame retardant, a phosphate ester flame retardant, a polyester elastomer or an ethylene-(meth)acrylate glycidyl copolymer and an additive, comprising: 30 to 85% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) greater than 1.1 and less than 1.5, 0 to 40% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) greater than 0.8 and less than 1.1, 10 to 20% by weight of an organic metal salt phosphinate flame retardant, 1 to 10 wt% of a phosphate flame retardant, and 1 to 5 wt% of a polyester elastomer or ethylene-glycidyl (meth)acrylate copolymer.

8. The polybutylene terephthalate resin composition according to claim 7, wherein The additives include one or more selected from heat stabilizers, flame retardants, flame retardant aids, activators, processing aids, plasticizers, coupling agents, light stabilizers, release agents, dispersants, anti-drip agents, weather stabilizers, antioxidants, compatibilizers, pigments, dyes, antistatic agents, wear resistant agents, fillers and antibacterial agents.

9. The polybutylene terephthalate resin composition according to claim 1 or 7, wherein The polybutylene terephthalate resin composition is a material used in parts of automotive electric / electronic equipment.

10. The polybutylene terephthalate resin composition according to claim 1, wherein The polybutylene terephthalate resin composition has an elongation of 22% or more measured at a rate of 50 mm / min according to ISO 527, 4.7 kJ / m measured according to ISO 180 using a 4 mm thick specimen 2 Izod impact strength (23°C, notched) and Flame retardancy of V0 or higher measured on a specimen having a size of 0.8 mm according to the UL94 method.

11. A method for preparing a polybutylene terephthalate resin composition, comprising: Based on 100 wt% in total of polybutylene terephthalate, organic metal salt-based phosphinate flame retardant, phosphate-based flame retardant, polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer and additives, 30 wt% to 85 wt% of polybutylene terephthalate having an intrinsic viscosity (IV) of greater than 1.1 and less than 1.5, 0 to 40 wt% of polybutylene terephthalate having an intrinsic viscosity (IV) of greater than 0.8 and less than 1.1, 10 wt% to 20 wt% of the organic metal salt-based phosphinate flame retardant, 1 wt% to 10 wt% of the phosphate-based flame retardant and 1 wt% to 5 wt% of the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer are added to an extruder, and melt-kneading and extrusion are performed, Wherein, when the content of the organic metal salt phosphinate flame retardant is a, the content of the phosphate flame retardant is b, and the content of the polyester elastomer or ethylene-(meth)acrylate glycidyl ester copolymer is c, a>b>c is satisfied; The weight ratio (a:b) of the organic metal salt phosphinate flame retardant to the phosphate flame retardant is 7:2 to 7:4; and The weight ratio (b:c) of the phosphate flame retardant to the polyester elastomer or ethylene-glycidyl (meth)acrylate copolymer is 4:3 to 8:

3. 12 . A molded article comprising the polybutylene terephthalate resin composition according to claim 1 .

13. The molded article according to claim 12, wherein The molded article is a component for automotive electric / electronic equipment.

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