Polybutylene terephthalate resin composition, its method of production and molded article containing same

Abstract

The present invention relates to a polybutylene terephthalate resin composition, a method for producing the same, and a molded article containing the same. Despite containing a high content of polybutylene terephthalate, the polybutylene terephthalate resin composition has excellent mechanical properties, processability, and flame retardancy as well as excellent elongation, making it advantageous for use in electrical and electronic products or automobile parts. Therefore, the present invention has the effect of providing a method for producing the same and a molded article containing the same.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0132314 filed on October 5, 2023, and Korean Patent Application No. 10-2024-0116556, refiled on August 29, 2024 based thereon, and all contents disclosed in the documents of said Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a polybutylene terephthalate resin composition, a method for producing the same, and a molded article containing the same. More specifically, the present invention relates to a polybutylene terephthalate resin composition that is useful for applications in electrical and electronic products or automobile parts because it has excellent mechanical properties, processability, flame retardancy, and elongation despite containing a high content of polybutylene terephthalate, a method for producing the same, and a molded article containing the same. [Background technology]

[0003] In recent years, many studies have been conducted to resinify electrical and electronic products and automotive parts. In particular, polybutylene terephthalate (PBT) has attracted attention as a material for replacing metal parts from the standpoints of economy and physical properties.

[0004] Polybutylene terephthalate (PBT) is a crystalline polymer and has advantages such as high heat resistance and a short manufacturing time. However, it has a problem in that it is unable to exhibit additional physical properties such as flame retardancy and elongation due to its poor compatibility with other resins and reinforcing agents such as glass fiber.

[0005] In particular, electrical and electronic products and automotive parts must have elongation as well as processability, impact stability, and flame retardancy even when exposed to harsh external environments, but these requirements are currently difficult to meet with unreinforced polybutylene terephthalate (PBT). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent Publication No. 4101883 Summary of the Invention [Problem to be solved by the invention]

[0007] In order to solve the above-mentioned problems of the prior art, the present invention aims to provide a polybutylene terephthalate resin composition that has excellent mechanical properties, processability, flame retardancy, and elongation, despite containing a high content of polybutylene terephthalate, and is therefore advantageous for use in electrical and electronic products or automotive parts, a method for producing the same, and a molded article containing the same.

[0008] The above and other objects of the present invention can all be achieved by the present invention described below. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a flame retardant composition comprising: I) 100 parts by weight of polybutylene terephthalate; 1 to 30 parts by weight of an organometallic salt-based phosphinate flame retardant; 1 to 30 parts by weight of a phosphate-based flame retardant; and 1 to 30 parts by weight of a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer; When the content of the organometallic salt-based phosphinate flame retardant is defined as a, the content of the phosphate-based flame retardant is defined as b, and the content of the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer is defined as c, the relationship a>b>c is satisfied; The organometallic salt-based phosphinate flame retardant and the phosphate-based flame retardant are in a weight ratio (a:b) of 7:2 to 7:4, The polybutylene terephthalate resin composition is characterized in that the phosphate-based flame retardant and the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer are contained in a weight ratio (b:c) of 4:3 to 8:3.

[0010] II) In I), the polybutylene terephthalate may contain a polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5 and a polybutylene terephthalate having an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1 in a weight ratio of 1:0 to 1:1.

[0011] III) In the above I) or II), the organometallic salt-based phosphinate flame retardant may have a structure represented by the following chemical formula 1:

[0012] [ka]

[0013] (The R1 and R2 are each an alkyl group or an aryl group having 1 to 6 carbon atoms, M is one or more selected from the group consisting of 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.)

[0014] IV) In the above I) to III), the organometallic salt-based phosphinate flame retardant may specifically have a structure represented by the following chemical formula 1-1.

[0015] [ka]

[0016] V) In the above I) to IV), the phosphate-based flame retardant may have a structure represented by the following chemical formula 2:

[0017] [ka]

[0018] (In the above Chemical Formula 2, 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 of 0 to 4.)

[0019] VI) In the above I) to V), the phosphate-based flame retardant may be resorcinol bis(2,6-dimethylphenyl)phosphate.

[0020] VII) In the above I) to VI), the polyester elastomer may be a compound consisting of terephthalate as the aromatic dicarboxylic acid, 1,4-butanediol as the aliphatic diol, and polyoxytetramethylene glycol as the aliphatic polyether compound.

[0021] VIII) In the above I) to VII), the ethylene-glycidyl (meth)acrylate copolymer may be a polyethylene copolymer in which glycidyl (meth)acrylate is polymerized.

[0022] IX) In the above I) to VIII), the ethylene-glycidyl (meth)acrylate copolymer may be one in which an olefin-based monomer and a monomer containing an epoxy group are copolymerized.

[0023] X) In the above I) to IX), the ethylene-glycidyl (meth)acrylate copolymer may be one obtained by polymerizing ethylene, glycidyl (meth)acrylate, and vinyl acetate.

[0024] The present invention also provides XI) a polybutylene terephthalate resin composition, characterized in that the polybutylene terephthalate resin composition contains 30 to 85% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5, and 0 to 40% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1, relative to a total of 100% by weight of polybutylene terephthalate; an organometallic salt phosphinate flame retardant; a phosphate flame retardant; a polyester elastomer or an ethylene-glycidyl (meth)acrylate copolymer; and additives, the organometallic salt phosphinate flame retardant being contained in an amount of 10 to 20% by weight, the phosphate flame retardant being contained in an amount of 1 to 10% by weight, and the polyester elastomer or the ethylene-glycidyl (meth)acrylate copolymer being contained in an amount of 1 to 5% by weight.

[0025] XII) In the above XI), the additive may be at least one selected from the group consisting of a heat stabilizer, a flame retardant, a flame retardant aid, a lubricant, a processing aid, a plasticizer, a coupling agent, a light stabilizer, a release agent, a dispersant, an anti-dripping agent, a weather stabilizer, an antioxidant, a compatibilizer, a pigment, a dye, an antistatic agent, an anti-wear agent, a filler, and an antibacterial agent.

[0026] XIII) In the above XI) to XII), the polybutylene terephthalate resin composition may be a non-reinforced material.

[0027] XIV) In the above XI) to XIII), the polybutylene terephthalate resin composition may be a material used for electrical components.

[0028] XV) In the above XI) to XIV), the polybutylene terephthalate resin composition may have an elongation of 22% or more when measured in accordance with ISO 527 at 50 mm / min.

[0029] XVI) In the above XI) to XV), the polybutylene terephthalate resin composition has an Izod impact strength (23°C, Notched) of 4.7 kJ / m, measured on a 4 mm thick test piece in accordance with ISO 180. 2It may be more than that.

[0030] XVII) In the above XI) to XVI), the polybutylene terephthalate resin composition may have a flame retardancy of V0 or higher as measured on a standard 0.8 mm test piece in accordance with UL94 method.

[0031] The present invention also provides a method for producing a flame retardant composition comprising: XVIII) a flame retardant composition including 30 to 85% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5, and 0 to 40% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1, based on a total of 100% by weight of polybutylene terephthalate; an organometallic salt-based phosphinate flame retardant; a phosphate-based flame retardant; a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer; and additives; the flame retardant composition including 10 to 20% by weight of the organometallic salt-based phosphinate flame retardant, 1 to 10% by weight of the phosphate-based flame retardant, and 1 to 5% by weight of the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer; and the flame retardant composition including 10 to 20% by weight of the organometallic salt-based phosphinate flame retardant, 1 to 10% by weight of the phosphate-based flame retardant, and 1 to 5% by weight of the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer; the flame retardant composition including 30 to 85% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5, and the flame retardant composition including 0 to 40% by weight of the polybutylene terephthalate having an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1, the flame retardant composition including 10 to 20% by weight of the organometallic salt-based phosphinate flame retardant, 1 to 10% by weight of the phosphate-based flame When the content of the organometallic salt-based phosphinate flame retardant is defined as a, the content of the phosphate-based flame retardant is defined as b, and the content of the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer is defined as c, the relationship a>b>c is satisfied; The organometallic salt-based phosphinate flame retardant and the phosphate-based flame retardant are in a weight ratio (a:b) of 7:2 to 7:4, The present invention provides a method for producing a polybutylene terephthalate resin composition, wherein the phosphate-based flame retardant and the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer are contained in a weight ratio (b:c) of 4:3 to 8:3.

[0032] The present invention also provides XIX) a molded article comprising the polybutylene terephthalate resin composition described above.

[0033] XX) In the above XIX), the molded article may be an automobile part or an electric / electronic part.

[0034] XXI) In the above XIX) or XX), the molded article may be an electrical component.

[0035] XXII) In the above XIX) to XXI), the electrical component may be a connector, a sensor component, or the like.

[0036] XXIII) In any of the above XIX) to XXII), the connector part may be a TV connector or the like. [Effects of the Invention]

[0037] According to the present invention, there is an effect of providing a polybutylene terephthalate resin composition which has excellent mechanical properties, processability, flame retardancy and elongation despite containing a high content of polybutylene terephthalate.

[0038] Therefore, the polybutylene terephthalate resin composition according to the present invention can be applied to various electrical material fields, including connectors, sensors, and parking brake systems, which particularly require these physical properties. DETAILED DESCRIPTION OF THE INVENTION

[0039] The polybutylene terephthalate resin composition of the present invention, its production method, and molded articles containing the same will be described in detail below.

[0040] In this description, unless otherwise defined, the meaning of "comprise" can be defined as "produced by polymerization containing," "polymerized containing," or "contains as a unit derived from." In this description, a polymer comprising a certain compound means a polymer polymerized containing that compound, and the units in the polymerized polymer are derived from that compound.

[0041] In this description, the composition ratio of a (co)polymer may refer to the content of units constituting the (co)polymer, or may refer to the content of units added during polymerization of the (co)polymer.

[0042] In this description, "content" means weight unless otherwise defined, and "%" means weight % unless otherwise defined.

[0043] The present inventors have confirmed that when a high content of polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5 is contained, and an organometallic salt-based phosphinate flame retardant, a phosphate-based flame retardant, and a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer are contained in specific amounts, the mechanical properties, processability, flame retardancy, and elongation are particularly excellent. Based on this, the present inventors have conducted further research and have completed the present invention.

[0044] The polybutylene terephthalate resin composition described herein, for example, comprises 100 parts by weight of polybutylene terephthalate; 1 to 30 parts by weight of an organometallic salt-based phosphinate flame retardant; 1 to 30 parts by weight of a phosphate-based flame retardant; and 1 to 30 parts by weight of a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer; and is characterized by not containing any reinforcing fibers or polyethylene terephthalate. In this case, despite containing a high content of polybutylene terephthalate, the composition has excellent mechanical properties, processability, flame retardancy, and elongation, and thus provides a balance of physical properties.

[0045] Each component constituting the polybutylene terephthalate resin composition of the present invention will be described in detail below.

[0046] Polybutylene Terephthalate The polybutylene terephthalate used in the present invention may be a non-reinforced material.

[0047] Specifically, the polybutylene terephthalate may contain a polybutylene terephthalate (first polybutylene terephthalate) having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5, and a polybutylene terephthalate (second polybutylene terephthalate) having an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1, in a weight ratio of 1:0 to 1:1. Within this range, there is an advantage that both mechanical strength and elongation are excellent.

[0048] 1st Polybutylene Terephthalate In this description, the first polybutylene terephthalate may be a polybutylene terephthalate having an intrinsic viscosity (IV) of greater than 1.1 and less than or equal to 1.5.

[0049] The first polybutylene terephthalate is not particularly limited as long as it complies with the definition of the present invention. For example, it may be polybutylene terephthalate that has not been subjected to molding processes such as injection molding after being produced by polymerizing monomers that constitute polybutylene terephthalate, or a corresponding available polybutylene terephthalate.

[0050] The first polybutylene terephthalate may be referred to as, for example, virgin polybutylene terephthalate, nascent polybutylene terephthalate, fresh polybutylene terephthalate, or unrecycled polybutylene terephthalate.

[0051] For example, the first polybutylene terephthalate described herein can optimize the elongation and flow index by having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5, preferably 1.15 to 1.5, and more preferably 1.15 to 1.3.

[0052] Unless otherwise specified, the intrinsic viscosity is a value measured by completely dissolving a sample to be measured in a methylene chloride solvent at a concentration of 0.05 g / ml, filtering the filtrate through a filter, and measuring the filtrate at 20°C using an Ubbelohde viscometer.

[0053] 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, and even more preferably 2.0 to 2.5. Within this range, an excellent balance of physical properties between elongation and flow index can be achieved.

[0054] In this description, the polydispersity index refers to the distribution of molecular weights, and is calculated by dividing the weight average molecular weight by the number average molecular weight. A high polydispersity index means that the standard deviation of the molecular weight distribution is large, and that there are more molecular weights that are larger or smaller than the weight average molecular weight.

[0055] In this description, unless otherwise specified, the weight average molecular weight and number average molecular weight can be measured using GPC (Gel Permeation Chromatography, water breeze). Specifically, they can be measured as relative values ​​to a standard PS (standard polystyrene) sample through GPC using THF (tetrahydrofuran) as an eluent. In this specific measurement example, the solvent is THF, the column temperature is 40°C, the flow rate is 0.3 ml / min, the sample concentration is 20 mg / ml, the injection volume is 5 μL, the column model is 1×PLgel 10 μm MiniMix-B (250 × 4.6 mm) + 1×PLgel 10 μm MiniMix-B (250 × 4.6 mm) + 1×PLgel 10 μm MiniMix-B Guard (50 × 4.6 mm), the measuring equipment is an Agilent 1200 series system, the refractive index detector is an Agilent G1362 RID, the RI temperature is 35°C, the data is processed by Agilent ChemStation S / W, and the test method (Mn, Mw, and PDI) can be measured under the conditions of OECD TG 118.

[0056] The first polybutylene terephthalate may have a weight average molecular weight of, for example, 28,000 g / mol or more, preferably 29,000 g / mol or more, more preferably 30,000 g / mol or more, and even more preferably 30,000 to 37,000 g / mol. Within this range, the first polybutylene terephthalate has the effect of exhibiting excellent mechanical properties and a good balance of physical properties.

[0057] The polybutylene terephthalate (PBT) is not particularly limited, and may be produced by a method known in the art or may be a commercially available material.

[0058] The polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5 may be contained in an amount of, for example, 30 to 85 wt%, specifically 30 to 80 wt%, and preferably 35 to 80 wt%, based on a total of 100 wt% of the polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5, the metal salt of phosphinic acid, the non-halogen phosphate flame retardant, the polyester elastomer or the ethylene-glycidyl (meth)acrylate copolymer, and the additives. In this case, an excellent balance of physical properties between elongation and flow index can be achieved.

[0059] For example, the first polybutylene terephthalate may be present in the polybutylene terephthalate resin at 25 to 75% by weight, preferably 25 to 70% by weight, and more preferably 30 to 70% by weight, and within this range, there is an advantage in that the impact resistance and heat resistance are excellent.

[0060] For example, the first polybutylene terephthalate may be a resin polymerized containing an aromatic diol compound and a carbonate precursor.

[0061] Examples of the aromatic diol compound include 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, and the like. The hydroxyphenyl ester may be one or more selected from the group consisting of bisphenol A, 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-(ο-hydroxyphenyl)propyl]polydimethylsiloxane, and preferably bisphenol A.

[0062] The carbonate precursor may be, for example, at least one selected from the group consisting of dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl)carbonate, m-cresyl carbonate, dinaphthyl carbonate, bis(diphenyl)carbonate, carbonyl chloride (phosgene), triphosgene, diphosgene, carbonyl bromide, and bishaloformates. From the viewpoints of production efficiency and physical properties, it is preferable to use triphosgene, phosgene, or a mixture thereof.

[0063] As a specific example, polybutylene terephthalate formed by polymerization of the aromatic diol compound and the carbonate precursor includes a repeating unit represented by the following chemical formula 3:

[0064] [ka]

[0065] In the above formula 3, R'1 to R'4 are each independently hydrogen, C 1-10 Alkyl group, C 1-10 an alkoxy group, or a halogen; Z' is unsubstituted or C 1-6 Alkyl group or C 6-20 C substituted with aryl groups 1-10 Alkylene groups, unsubstituted or C 1-10 Alkyl-substituted C 3-15 A cycloalkylene group, O, S, SO, SO2, or CO.

[0066] Preferably, in the above Chemical Formula 3, R'1 to R'4 are each independently hydrogen or C 1-3 alkyl group, Z' is unsubstituted or substituted with a methyl group or a phenyl group. 1-6 It may also be an alkylene group.

[0067] Secondary Polybutylene Terephthalate In this description, the second polybutylene terephthalate has an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1, preferably 0.85 to 1.1, and more preferably 0.9 to 1.1, to achieve an excellent balance of physical properties between elongation and flow index.

[0068] The second polybutylene terephthalate may have a polydispersity index of, for example, more than 2.75, preferably 2.8 or more, more preferably 2.8 to 3. Within this range, the second polybutylene terephthalate has the effect of being excellent in mechanical properties and balance of physical properties.

[0069] The second polybutylene terephthalate may have a weight average molecular weight of, for example, 20,000 g / mol or more and less than 28,000 g / mol, preferably 22,000 to 27,000 g / mol, and more preferably 23,000 to 27,000 g / mol. Within this range, the second polybutylene terephthalate has the effect of providing excellent mechanical properties and a good balance of physical properties.

[0070] The second polybutylene terephthalate has lower physical properties, such as impact resistance, heat resistance, and elongation, than the first polybutylene terephthalate, and has traditionally been used in small amounts of less than 25% by weight in polybutylene terephthalate resin compositions. However, the polybutylene terephthalate resin composition of the present invention contains the second polybutylene terephthalate in an excess of 20% by weight or more, preferably 23% by weight or more, in the polybutylene terephthalate-based resin, yet still exhibits excellent mechanical properties, processability, flame retardancy, and elongation.

[0071] The monomers constituting the second polybutylene terephthalate may preferably be selected within the same range as those mentioned for the first polybutylene terephthalate.

[0072] As the second polybutylene terephthalate, for example, a commercially available product may be used as long as it complies with the definition of the present invention.

[0073] Organometallic Phosphinate Flame Retardants The organometallic salt-based phosphinate flame retardant is added to enhance the flame retardancy of the resin composition, and can be represented by the structure of Chemical Formula 1 below.

[0074] [ka]

[0075] (The R1 and R2 are each an alkyl group or an aryl group having 1 to 6 carbon atoms, M is one or more selected from the group consisting of 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.)

[0076] The organometallic salt-based phosphinate flame retardant may have a structure represented by the following chemical formula 1-1, as a specific example.

[0077] [ka]

[0078] The organometallic salt phosphinate flame retardant may be present in an amount of, for example, 10 to 20 wt %, preferably 13 to 20 wt %, and more preferably 13 to 18 wt %, based on a total of 100 wt % of all components constituting the polybutylene terephthalate resin composition (first polybutylene terephthalate, second polybutylene terephthalate, organometallic salt phosphinate flame retardant, phosphate flame retardant, polyester elastomer or ethylene-glycidyl (meth)acrylate copolymer, and additives). Outside these ranges, the elongation and flame retardancy may be reduced, and molded articles manufactured using the polybutylene terephthalate resin composition may suffer from surface unevenness of the injected article, impairing the appearance quality.

[0079] Phosphate-based flame retardants The phosphate-based flame retardant is added to enhance the flame retardancy of the resin composition and can be represented by the structure of Chemical Formula 2 below.

[0080] [ka] (In the above 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 of 0 to 4.)

[0081] X may preferably be derived from resorcinol, hydroquinol or a dialcohol of bisphenol A.

[0082] When n is 0, examples include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tri(2,6-dimethylphenyl)phosphate, tri(2,4,6-trimethylphenyl)phosphate, tri(2,4-di-tert-butylphenyl)phosphate, and tri(2,6-di-tert-butylphenyl)phosphate.

[0083] When n is 1, examples include resorcinol bis(diphenyl)phosphate, resorcinol bis(2,6-dimethylphenyl)phosphate, resorcinol bis(2,4-di-tert-butylphenyl)phosphate, hydroquinol bis(2,6-dimethylphenyl)phosphate, and hydroquinol bis(2,4-di-tert-butylphenyl)phosphate.

[0084] The phosphate flame retardants may be applied alone or may be used in mixtures.

[0085] Preferably, the phosphate flame retardant may be resorcinol bis(2,6-dimethylphenyl) phosphate.

[0086] The organometallic salt-based phosphinate flame retardant and the phosphate-based flame retardant are used in a weight ratio of 1:0.2 to 1:0.9 or 1:0.2 to 1:0.6, which can provide a synergistic effect of flame retardancy without affecting other physical properties.

[0087] The phosphate-based flame retardant may be present in an amount of, for example, 1 to 10 wt %, preferably 2 to 10 wt %, and more preferably 3 to 9 wt %, based on a total of 100 wt % of all components constituting the polybutylene terephthalate resin composition (first polybutylene terephthalate, second polybutylene terephthalate, organometallic salt-based phosphinate flame retardant, phosphate-based flame retardant, polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer, and additives). Outside these ranges, the elongation and flame retardancy may be reduced, and molded articles manufactured using the polybutylene terephthalate resin composition containing the phosphate-based flame retardant may suffer from surface unevenness in the injected article, resulting in impaired appearance quality.

[0088] Polyester elastomer The polyester elastomer of the present invention can be used to reinforce the impact of a resin composition by selecting it from the ethylene-glycidyl (meth)acrylate copolymer described below.

[0089] The polyester elastomer may contain units derived from an aromatic dicarboxylic acid or an ester-forming derivative thereof, units derived from an aliphatic diol, and units derived from a polyalkylene oxide.

[0090] The aromatic dicarboxylic acid-derived unit may be one or more selected from the group consisting of terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid.

[0091] The unit derived from an ester-forming derivative of an aromatic dicarboxylic acid may be a unit derived from one or more selected from the group consisting of dimethyl terephthalate, dimethyl isophthalate, 2,6-dimethylnaphthalenedicarboxylate, and dimethyl 1,4-cyclohexanedicarboxylate, and among these, a unit derived from dimethyl terephthalate is preferred.

[0092] The units derived from the aromatic dicarboxylic acid or its ester-forming derivative may be contained in an amount of 25 to 65% by weight, or 30 to 60% by weight, based on the total weight of the polyester elastomer, and among these, 30 to 60% by weight is preferred.

[0093] The unit derived from an aliphatic diol has a weight average molecular weight of 300 g / mol or less and may be a unit derived from an aliphatic diol.

[0094] The unit derived from an aliphatic diol may be a unit derived from one or more selected from the group consisting of ethylene glycol, propylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexanedimethanol, and among these, a unit derived from 1,4-butanediol is preferred.

[0095] The aliphatic diol-derived units may be contained in an amount of 20 to 45% by weight, or 25 to 40% by weight, based on the total weight of the polyester-based elastomer, and among these, 25 to 40% by weight is preferred.

[0096] The polyalkylene oxide-derived unit is an aliphatic polyether and can act as a soft segment in the polyester elastomer.

[0097] The polyalkylene oxide-derived unit may be a unit derived from one or more selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, a copolymer of ethylene oxide and propylene oxide, an ethylene oxide addition polymer of polypropylene glycol, and a copolymer of ethylene oxide and tetrahydrofuran, and among these, a unit derived from polytetramethylene glycol or an ethylene oxide addition polymer of polypropylene glycol is preferred.

[0098] The polytetramethylene glycol may have a number average molecular weight of 600 to 3,000 g / mol, 1,000 to 2,500 g / mol, or 1,800 to 2,200 g / mol, and among these, 1,800 to 2,200 g / mol is preferred.

[0099] The ethylene oxide addition polymer of polypropylene glycol may be polypropylene glycol whose terminals are capped with ethylene oxide, and may have a weight average molecular weight of 2,000 to 3,000 g / mol.

[0100] The polyalkylene oxide-derived units may be contained in an amount of 10 to 50 wt % or 15 to 45 wt % based on the total weight of the thermoplastic polyester-based elastomer. When the above range is satisfied, the flexibility, heat resistance, and compatibility of the polyester-based elastomer may be improved.

[0101] On the other hand, the polyester elastomer may have a weight average molecular weight of 2,000 to 3,000 g / mol.

[0102] The polyester-based elastomer may have a Shore D hardness of 35 to 55D, or 40 to 50D. When the Shore D hardness satisfies the above range, the polybutylene terephthalate resin composition can be easily extruded and molded, and its chemical resistance can be improved.

[0103] The polyester elastomer may have a melt index of 0.1 to 10 g / min, or 1 to 10 g / min, when its weight is measured at a temperature of 230°C under a load of 2.16 kg for 10 minutes in accordance with ASTM D 1238. When the melt index satisfies the above range, the polybutylene terephthalate resin composition can be easily extruded and molded, and its chemical resistance can be improved.

[0104] Meanwhile, the polyester-based elastomer can be produced by a production method including the steps of: (c) melt-polymerizing an aromatic dicarboxylic acid or an ester-forming derivative thereof, an aliphatic diol, and a polyalkylene oxide to produce a polyester-based elastomer precursor; and (d) solid-state polymerizing the polyester-based elastomer precursor to produce a polyester-based elastomer.

[0105] Each step of the method for producing the polyester elastomer will now be described in detail.

[0106] (C) Step of Producing a Polyester-Based Elastomer Precursor First, an aromatic dicarboxylic acid or an ester-forming derivative thereof, an aliphatic diol, and a polyalkylene oxide can be prepared as starting materials.

[0107] The aromatic dicarboxylic acid or its ester-forming derivative may be added in an amount of 25 to 65 wt % or 30 to 60 wt % based on the total weight of the starting materials, with 30 to 60 wt % being preferred. When the above range is satisfied, the reaction balance is excellent, and melt polymerization can be carried out smoothly.

[0108] Specific examples of the aromatic dicarboxylic acid or its ester-forming derivative are as described above.

[0109] The aliphatic diol may be added in an amount of 20 to 45 wt %, or 25 to 40 wt %, based on the total weight of the starting materials. When the above ranges are satisfied, the reaction balance is excellent, and melt polymerization can be carried out smoothly.

[0110] Specific examples of the aliphatic diol are as described above.

[0111] The polyalkylene oxide may be added in an amount of 10 to 50 wt % or 15 to 45 wt % based on the total weight of the starting materials, and is preferably added in an amount of 15 to 45 wt %. When the amount is within the above range, the flexibility, heat resistance, and compatibility of the polyester elastomer may be improved.

[0112] Specific examples of the polyalkylene oxide are as described above.

[0113] Next, a catalyst is initially added to the starting materials, and the temperature is raised to 140 to 215° C., after which melt polymerization can be initiated.

[0114] The catalyst may be titanium butoxide.

[0115] Once the melt polymerization is initiated, a transesterification reaction can occur between the starting materials, thereby producing oligomers, preferably bis(4-hydroxybutyl) terephthalate (BHBT) oligomers.

[0116] The transesterification reaction may be carried out for 1 to 3 hours, or 1 hour 30 minutes to 2 hours 30 minutes.

[0117] Then, a catalyst is added to the oligomer for the second time, and the temperature is increased to 215 to 245°C. Then, the pressure is reduced from 760 torr to 0.3 torr, and a condensation polymerization reaction is carried out, whereby a polyester elastomer precursor is produced through the condensation polymerization reaction.

[0118] The polycondensation reaction may be carried out for 1 to 3 hours, or 1 hour 30 minutes to 2 hours 30 minutes.

[0119] The polyester elastomer precursor may have a melt index of 15 to 25 g / min, or 18 to 22 g / min, when its weight is measured at a temperature of 230° C. under a load of 2.16 kg for 10 minutes in accordance with ASTM D1238.

[0120] Next, the polyester elastomer precursor is extruded in the form of strands under nitrogen pressure and pelletized to produce pelletized polyester elastomer precursor.

[0121] Meanwhile, during the melt polymerization, a branching agent may be further added to improve the melt viscosity and melt tension of the polyester elastomer.

[0122] The branching agent may be one or more selected from the group consisting of glycerol, pentaerythritol, trimellitic anhydride, trimellitic acid, trimethylolpropane, and neopentyl glycol, among which trimellitic anhydride is preferred.

[0123] The branching agent may be included in an amount of 0.05 to 0.1 wt % based on 100 parts by weight of the starting material. When the above range is satisfied, the melt viscosity and degree of polymerization of the polyester-based elastomer are appropriate, which makes it easy to control the melt polymerization reaction and to discharge the polyester-based elastomer precursor out of the reactor.

[0124] (D) Polyester elastomer manufacturing steps Next, the polyester elastomer precursor can be subjected to solid-state polymerization to produce a polyester elastomer.

[0125] The solid-state polymerization may be carried out by charging the polyester elastomer precursor into a solid-state polymerization reactor, and then performing the solid-state polymerization in an inert atmosphere at 140 to 200° C. for 10 to 24 hours while gradually reducing the pressure to a high vacuum.

[0126] The solid-state polymerization reactor may be a vessel vacuum dryer connected to a rotatable high vacuum pump, and the inert atmosphere may be a nitrogen atmosphere.

[0127] Meanwhile, the polyester elastomer may be a commercially available material, and preferably, KEYFLEX BT 1040D (DSC melting point: 198° C., hardness: Shore D40) manufactured by LG Chemicals may be used.

[0128] The polyester elastomer may be present in an amount of, for example, 1 to 10 wt %, preferably 2 to 10 wt %, and more preferably 3 to 9 wt %, based on a total of 100 wt % of all components constituting the polybutylene terephthalate resin composition (first polybutylene terephthalate, second polybutylene terephthalate, organometallic salt-based phosphinate flame retardant, phosphate-based flame retardant, polyester elastomer or ethylene-glycidyl (meth)acrylate copolymer, and additives). Within this range, there is an advantage that impact resistance is significantly improved without deteriorating the inherent mechanical properties and compatibility of the resin.

[0129] Ethylene-glycidyl (meth)acrylate copolymer The ethylene-glycidyl (meth)acrylate copolymer described herein can be used to improve the impact resistance of resin compositions.

[0130] The ethylene-glycidyl (meth)acrylate copolymer may be a polyethylene-based copolymer in which glycidyl (meth)acrylate is polymerized.

[0131] The glycidyl (meth)acrylate may be contained in an amount of 3% by weight or more, 3 to 10% by weight, or 3 to 7% by weight based on 100% by weight of all components constituting the ethylene-glycidyl (meth)acrylate copolymer, and in this case, the effects of impact reinforcement and increased elongation can be sufficiently provided.

[0132] The ethylene-glycidyl (meth)acrylate copolymer contains a compound represented by the following chemical formula 4, and in this case, has the advantage of excellent impact resistance.

[0133] [ka]

[0134] The ethylene-glycidyl (meth)acrylate copolymer may be a copolymer of an olefin-based monomer and a monomer containing an epoxy group as represented by Chemical Formula 4 above.

[0135] The olefin monomer may be ethylene, and if necessary, an alkylene having 3 to 19 carbon atoms, such as propylene, isopropylene, butylene, isobutylene, octene, or a combination thereof.

[0136] The epoxy group-containing monomer may be glycidyl (meth)acrylate, etc. The glycidyl (meth)acrylate comonomer may be used in an amount of 0.01 wt % or more, 5 wt % or more, 5 to 40 wt %, 5 to 30 wt %, or 10 to 25 wt % based on the total weight of all components constituting the copolymer.

[0137] Preferably, the glycidyl-modified olefin-based rubber polymer may be a polyethylene-based copolymer grafted with the compound represented by the chemical formula 4 and glycidyl (meth)acrylate, and in this case, it has the effect of having excellent impact strength.

[0138] As a more preferred example, the glycidyl-modified olefin rubber polymer may be a copolymer containing ethylene, glycidyl (meth)acrylate, and vinyl acetate, which has the effect of providing excellent impact strength.

[0139] The glycidyl-modified olefin-based rubber polymer may be present in an amount of, for example, 1 to 10 wt %, preferably 2 to 10 wt %, and more preferably 3 to 9 wt %, based on a total of 100 wt % of all components constituting the polybutylene terephthalate resin composition (first polybutylene terephthalate, second polybutylene terephthalate, organometallic salt-based phosphinate flame retardant, phosphate-based flame retardant, polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer, and additives). Within this range, there is an advantage that impact resistance is significantly improved without deteriorating the inherent mechanical properties and compatibility of the resin.

[0140] Polybutylene terephthalate resin composition The polybutylene terephthalate resin composition may preferably be a polybutylene terephthalate resin composition for injection molding, which has excellent flame retardancy and elongation, and therefore has the advantage that phase separation does not occur and products with thin thicknesses or complex structures can be produced during injection molding.

[0141] For example, the polybutylene terephthalate resin composition described herein may satisfy the relationship a>b>c, where a is the content of the organometallic salt-based phosphinate flame retardant, b is the content of the phosphate-based flame retardant, and c is the content of the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer. In this case, compatibility, dispersibility, processability, etc. may be affected, resulting in significant improvements in mechanical strength, processability, flame retardancy, and elongation.

[0142] The organometallic salt-based phosphinate flame retardant and the phosphate-based flame retardant may be in a weight ratio (a:b) of 7:2 to 7:4, which may affect compatibility, dispersibility, processability, etc., thereby significantly improving mechanical strength, processability, flame retardancy, and elongation.

[0143] The phosphate-based flame retardant and the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer may be in a weight ratio (b:c) of 4:3 to 8:3, which affects compatibility, dispersibility, processability, etc., and can result in significant improvements in mechanical strength, processability, flame retardancy, and elongation.

[0144] For example, the polybutylene terephthalate resin composition described herein may contain, depending on the purpose, one or more selected from the group consisting of heat stabilizers, flame retardants, flame retardant aids, lubricants, processing aids, plasticizers, coupling agents, light stabilizers, mold release agents, dispersants, anti-dripping agents, weathering stabilizers, antioxidants, compatibilizers, pigments, dyes, antistatic agents, anti-wear agents, fillers, and antibacterial agents, within ranges that do not impair the physical properties of the respective components. Preferably, the polybutylene terephthalate resin composition may contain one or more selected from the group consisting of antioxidants, colorants, lubricants, mold release agents, heat stabilizers, and plasticizers. In this case, there is an advantage that the mechanical properties are not impaired and that both impact strength and processability are excellent.

[0145] The additives are contained in an amount of 7% by weight or less, specifically 0.1 to 5% by weight, preferably 0.1 to 3% by weight, and more preferably 0.2 to 0.8% by weight, based on a total of 100% by weight of the polybutylene terephthalate, the organometallic salt-based phosphinate flame retardant, the phosphate-based flame retardant, the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer, and the additives.

[0146] As the antioxidant, for example, a known antioxidant that is blended in a polybutylene terephthalate resin composition can be used.

[0147] Examples of the antioxidant include phosphorus-based antioxidants and phenol-based antioxidants.

[0148] Examples of the hindered phenol-based antioxidant include pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] and thiodiethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate].

[0149] Examples of the phosphorus-based antioxidant include bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite and bis(2,4-dicumylphenyl)pentaerythritol diphosphite.

[0150] According to this description, it is preferable to use a mixture of two different types of the above-mentioned antioxidants. Specifically, by using a mixture of a hindered phenol-based antioxidant and a phosphorus-based antioxidant, the heat resistance can be further improved.

[0151] The hindered phenol-based antioxidant and the phosphorus-based antioxidant can be mixed and used, for example, in a weight ratio of 1:0.1 to 1:1, preferably in a weight ratio of 1:0.4 to 1:1, and more preferably in a weight ratio of 1:0.6 to 1:1. When mixed in the above-mentioned ratio, the heat resistance of the resin composition can be further improved without deteriorating the physical properties.

[0152] The antioxidant may be contained in an amount of 0.01 to 5% by weight, preferably 0.01 to 3% by weight, based on a total of 100% by weight of the polybutylene terephthalate, the organometallic salt-based phosphinate flame retardant, the phosphate-based flame retardant, the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer, and the additives. Within this range, the composition has the effect of providing excellent heat resistance.

[0153] As the anti-dripping agent, for example, a known anti-dripping agent that is blended into a polybutylene terephthalate resin composition can be used.

[0154] Specifically, when one or more of tetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, and ethylene / tetrafluoroethylene copolymer are used, it is preferable because the flame retardant quality can be improved through the drip prevention effect.

[0155] In one embodiment of the present invention, the anti-dripping agent may be a commercially available product.

[0156] The anti-dripping agent may be included in an amount of 0.01 to 5 wt%, 0.1 to 3 wt%, 0.1 to 2 wt%, 0.1 to 1 wt%, or 0.2 to 0.8 wt%, based on a total of 100 wt% of one or more of polybutylene terephthalate, organometallic salt-based phosphinate flame retardants, phosphate-based flame retardants, polyester-based elastomers, and ethylene-glycidyl (meth)acrylate copolymers, lubricants, antioxidants, and anti-dripping agents. If the content of the anti-dripping agent is too high outside of this range, molded articles produced using the polybutylene terephthalate resin composition containing the anti-dripping agent may suffer from reduced moldability and reduced quality. If the content is below this range, the anti-dripping effect may not be sufficient.

[0157] The colorant may be contained in an amount of, for example, 0.01 to 5% by weight, preferably 0.01 to 3% by weight, based on a total of 100% by weight of the polybutylene terephthalate; the organometallic salt-based phosphinate flame retardant; the phosphate-based flame retardant; the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer; and the additives, and excellent processability is achieved within the above range.

[0158] The colorant masterbatch may be, for example, a carbon colorant masterbatch, in which case there is an effect that layer separation of the composition does not occur and dispersibility is improved.

[0159] The lubricant may be, for example, pentaerythritol tetrastearate, which improves the wettability of the composition of the present invention and also provides excellent heat resistance, processability, and the like.

[0160] The lubricant may be contained in an amount of, for example, 0.01 to 3% by weight, preferably 0.01 to 2% by weight, based on a total of 100% by weight of polybutylene terephthalate; organometallic salt-based phosphinate flame retardant; phosphate-based flame retardant; polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer; and additives. Within this range, the lubricant has the effect of improving the wettability of the polybutylene terephthalate composition while also providing excellent mechanical properties.

[0161] Examples of the heat stabilizer include tris(nonylphenyl)phosphite, tris(2,4-di-t-butylphenyl)phosphite (TBPP), 2,4,6-tri-tert-butylphenyl-2-butyl-2-ethyl-1,3-propanediol phosphite, diisodecyl pentaerythritol diphosphite, and distearyl pentaerythritol diphosphite. diphosphite), bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite (PEP24), bis(2,4-dicumylphenyl)pentaerythritol diphosphite, and tetrakis(2,4-di-t-butylphenyl)[1,1-biphenyl]-4,4'-diyl bisphosphonate.

[0162] The heat stabilizer may be contained in an amount of, for example, 0.01 to 2% by weight, preferably 0.01 to 1% by weight, based on a total of 100% by weight of polybutylene terephthalate; organometallic salt-based phosphinate flame retardant; phosphate-based flame retardant; polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer; and additives, and excellent heat resistance is achieved within this range.

[0163] In the present description, the mold release agent may be of a type used in the related technical field, as long as it does not affect the impact strength, processability, flame retardancy, and high mold shrinkage.

[0164] The release agent may be contained in an amount of, for example, 0.01 to 5% by weight, preferably 0.01 to 3% by weight, based on a total of 100% by weight of polybutylene terephthalate; organometallic salt-based phosphinate flame retardant; phosphate-based flame retardant; polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer; and additives, and within the above range, the release agent has excellent release properties.

[0165] In the present description, the plasticizer may be of a type used in the related technical field, within the limits that do not affect the impact strength, processability, flame retardancy, and high molding shrinkage.

[0166] The plasticizer may be contained in an amount of, for example, 0.01 to 5% by weight, preferably 0.01 to 3% by weight, based on a total of 100% by weight of the polybutylene terephthalate; the organometallic salt-based phosphinate flame retardant; the phosphate-based flame retardant; the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer; and the additives, and excellent flame retardancy is achieved within the above range.

[0167] The polybutylene terephthalate resin composition described herein may have an elongation of 22% or more, or 22 to 50%, as measured at 50 mm / min in accordance with ISO 527. Within this range, the composition has the effect of exhibiting excellent elongation and improved durability.

[0168] The polybutylene terephthalate resin composition described herein has an Izod impact strength (23°C, Notched) of 4.7 kJ / m2 measured on a 4 mm thick test piece in accordance with ISO 180. 2 or above, or 4.8 to 5.1 kJ / m 2 Within this range, the balance of physical properties is improved.

[0169] The polybutylene terephthalate resin composition of the present invention can have a flame retardancy of V0 or higher as measured on a 0.8 mm standard test piece in accordance with UL94.

[0170] The polybutylene terephthalate resin composition of the present invention may have a fluidity measured in accordance with ISO 1133 of 9.2 g / 10 min or more, or from 9.2 to 30 g / 10 min.

[0171] The method for producing the polybutylene terephthalate resin composition of the present invention will be described below.

[0172] Method for producing polybutylene terephthalate resin composition In describing the method for producing the polybutylene terephthalate resin composition of the present invention, all of the above-mentioned details of the polybutylene terephthalate resin composition are included.

[0173] The method for producing a polybutylene terephthalate resin composition described herein is characterized by comprising the steps of feeding polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5, a metal salt of diethylphosphinic acid, a resorcinol phosphate ester, and a polyester elastomer or an ethylene-glycidyl (meth)acrylate copolymer into an extruder, melt-kneading, and extruding the mixture. In this case, by satisfying a balance of physical properties, the composition provides excellent mechanical strength, processability, flame retardancy, and elongation to electrical and electronic products or automotive parts having thin thicknesses or complex structures, while also achieving excellent injection molding properties.

[0174] The method for producing the polybutylene terephthalate resin composition may include the additives described above.

[0175] In the method for producing the polybutylene terephthalate resin composition, the kneading and extrusion may be performed using a single-screw extruder, a twin-screw extruder, or a Banbury mixer, and is preferably performed using a twin-screw extruder, which has the effect of uniformly dispersing the composition and providing excellent compatibility.

[0176] The step of producing pellets using the extrusion kneader may be carried out, for example, at a barrel temperature within a range of 210 to 290°C, 230 to 270°C, or 240 to 260°C. In this case, the processing amount per unit time is appropriate, sufficient melt-kneading is possible, and problems such as thermal decomposition of the resin component are not caused.

[0177] The step of producing pellets using the extrusion kneader may be carried out under conditions where the screw rotation speed is, for example, 100 to 300 rpm / min, specifically 150 to 300 rpm / min, and preferably 200 to 300 rpm / min. In this case, the throughput per unit time is appropriate, resulting in excellent process efficiency and the effect of suppressing excessive breakage.

[0178] The polybutylene terephthalate resin composition pellets may be used as they are, or may be used after being dehumidified and dried under hot air.

[0179] The dehumidifying and drying can be carried out, for example, in a hot air dryer at a temperature range of 80 to 100° C. for 3 hours or more.

[0180] For example, the pellets can be produced as an injection-molded product using an injection machine at an injection barrel temperature of 210 to 300°C, 220 to 290°C, or 240 to 270°C.

[0181] The extruder may have, for example, 6 or more, preferably 7 or more, more preferably 8 or more, preferably 8 to 15, and more preferably 9 to 12 kneading blocks. In this case, it may be effective to use a combination of kneading blocks in the forward direction, perpendicular direction, and reverse direction relative to the resin flow direction, and a combination of continuous or separated blocks may be used depending on the mixing method. In this case, the dispersibility of the components and the compatibility of the composition are further improved, and a kneaded product of higher quality can be provided.

[0182] The type of the extruder is not particularly limited, but in consideration of uniform mixing and dispersion, ease of processing, and economy, it is preferable to use a twin-screw extruder having two screws.

[0183] The extruder is composed of a feeder for supplying materials into a barrel, a screw for transporting and kneading the materials supplied into the barrel, and a die for extruding the kneaded materials, and the screw is composed of multiple screw elements to provide various functions.

[0184] The number of the raw material supplier may be one or more, and two or more may be provided selectively as needed. For example, a main inlet and a selective auxiliary inlet may be provided, and two or more auxiliary inlets may be provided as needed.

[0185] For example, all components except for the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer can be fed into the main inlet, and the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer can be fed into the auxiliary inlet 1.

[0186] As another example, all components except for the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer and the flame retardant may be fed into the main feeding port, the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer may be fed into the auxiliary feeding port, and the flame retardant may be fed into the auxiliary feeding port 2.

[0187] A molded article containing the polybutylene terephthalate resin composition of the present invention will be described below. In describing the molded article of the present invention, all of the above-mentioned polybutylene terephthalate resin compositions are included.

[0188] Molded product The molded article of the present invention may comprise the polybutylene terephthalate resin composition. That is, the molded article of the present invention may be produced by extrusion molding or injection molding the polybutylene terephthalate resin composition using a method commonly used in the art without limitation.

[0189] For example, the molded article may be formed by kneading and extruding the polybutylene terephthalate resin composition. The kneading and extrusion may be performed using a conventional extruder, and preferred examples include a single-screw extruder and a twin-screw extruder.

[0190] The molded article may be, for example, an electric or electronic product or an automobile interior material that can be injection-molded. In this case, the polybutylene terephthalate resin composition described herein has the advantage of satisfying all of the heat resistance, processability, electrical properties, flame retardancy, and high injection molding properties required in the market, making it possible to provide a high-quality molded article.

[0191] The molded article can be produced by subjecting the polybutylene terephthalate resin composition described above to various extrusion moldings, for example, by molding the composition into various shapes such as profile extrusion molded articles, extrusion-molded sheets, films, etc. Examples of the various extrusion moldings include cold runner and hot runner molding methods, as well as injection molding methods such as injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection of supercritical fluids), insert molding, in-mold coating molding, heat-insulating mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high speed injection molding.

[0192] Therefore, the polybutylene terephthalate resin composition according to the present invention can be applied to various electrical material fields, including connectors, sensors, and parking brake systems, which particularly require these physical properties.

[0193] In describing the polybutylene terephthalate resin composition, its production method, and molded articles described herein, it is clearly stated that other conditions, equipment, etc. not explicitly described can be appropriately selected within the range commonly used in the art and are not particularly limited.

[0194] Preferred examples are presented below to aid in understanding the present invention. However, the following examples are merely illustrative of the present invention, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope of the scope and technical idea of ​​the present invention. Naturally, such changes and modifications also fall within the scope of the appended claims.

[0195] [Example] Examples 1 to 5 and Comparative Examples 1 to 10 The raw materials used in the examples and comparative examples are as follows. (A) Polybutylene terephthalate (A-1) Intrinsic viscosity (IV) 1.2, Changchun product name PBT 1100-211S (A-2) Intrinsic viscosity (IV) 1.0, Tunhe product name TH6098A (A-3) Intrinsic viscosity (IV) 0.8, Tunhe product name TH6082A

[0196] (B) Organometallic salt-based phosphinate flame retardant: Clariant, Exolit® OP 1240 (a substance represented by the following chemical formula 1-1)

[0197] [ka]

[0198] (C) Phosphate-based flame retardant: resorcinol bis(2,6-dimethylphenyl)phosphate (PX200, Daihachi Chemical Industry Co., Ltd., Japan), content 8.7 wt%

[0199] (D-1) Polyester elastomer: Keyflex BT 1040D (LG Chem Co., Ltd.) with a hardness of 40D, consisting of terephthalate as an aromatic dicarboxylic acid, 1,4-butanediol as an aliphatic diol, and polyoxytetramethylene glycol as an aliphatic polyether compound. (D-2) Ethylene-glycidyl (meth)acrylate copolymer: DuPont product name Elvaloy PTW (GMA content: 5% by weight) (D-3) Melamine cyanurate (D-4) Melamine polyphosphate

[0200] (E) Additives E-1) Lubricant: Lione Chemtec's LC102N (PE type) E-2) Antioxidant: Songnox 6260 E-3) Anti-drip agent: Teflon JF-4A

[0201] The raw materials of the polybutylene terephthalate resin composition shown in Tables 1 and 2 below were mixed and extruded to prepare a polybutylene terephthalate resin composition having a uniform dispersion in the form of pellets. The pellets were then heated and injected into a mold, followed by cooling in an injection process to prepare test specimens.

[0202] Specifically, the components shown in Tables 1 and 2 below were mixed in a mixer, and then extruded at 250 rpm into a main inlet at a feed rate of 50 kg / h using a twin-screw extruder (φ40, L / D: 42, equipped with SM Platek) set at 250°C to produce pellets of a polybutylene terephthalate resin composition. Glass fiber was fed into an auxiliary inlet, and the extruder had nine mixing blocks.

[0203] The pellets were dried in a convection oven at 120°C for at least 4 hours, and then injected into an injection molding machine (ENGEL, 80 ton) at an injection temperature of 250°C, a mold temperature of 60°C, and an injection speed of 30 mm / sec to prepare test specimens.

[0204] [Table 1]

[0205] [Table 2]

[0206] Test Example 1: Evaluation of the physical properties of molded product test pieces The physical properties of the molded test pieces produced in Examples 1 to 5 and Comparative Examples 1 to 10 were evaluated according to the following evaluation criteria. Tensile strength (MPa): measured according to ISO 527 at 50 mm / min. Elongation (%): measured according to ISO 527 at 50 mm / min. Flexural strength (MPa): measured according to ISO 178 at 2 mm / min. Impact strength (IZOD): measured on 4 mm thick test specimens in accordance with ISO 180 (Notched, 23° C.). - Flame retardancy: Measured in accordance with UL94 using a 0.8mm test piece.

[0207] The results measured according to the above evaluation criteria are shown in Tables 3 and 4 below.

[0208] [Table 3]

[0209] [Table 4]

[0210] Referring to Tables 3 and 4, the polybutylene terephthalate resin compositions of Examples 1 to 5 according to the present invention contain polybutylene terephthalate, an organometallic salt-based phosphinate flame retardant, a phosphate-based flame retardant, and a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer in a predetermined blending ratio, thereby maintaining or improving mechanical strength, processability, and flame retardancy, while also significantly improving elongation, thereby providing product reliability as an electrical component. In contrast, Comparative Example 1, which did not contain a phosphate-based flame retardant and used melamine cyanurate, showed significantly reduced elongation and impact strength compared to Example 1, and was therefore unable to provide product reliability as an electrical component.

[0211] In addition, it was confirmed that Comparative Examples 2 and 3, which did not contain a phosphate-based flame retardant but used melamine polyphosphate, had significantly lower elongation and impact strength than Example 1, and therefore could not provide product reliability as an electrical component.

[0212] On the other hand, it was confirmed that Comparative Example 4, which did not contain either a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer, had significantly lower elongation and impact strength than Example 1, and also had poor processability, and therefore could not provide product reliability as an electrical component.

[0213] In addition, it was confirmed that Comparative Example 5, in which the intrinsic viscosity of the unreinforced polybutylene terephthalate was inappropriate, had excellent processability compared to Example 1, but had a reduced elongation rate, resulting in a defective part.

[0214] In addition, Comparative Example 6, in which an organometallic salt-based phosphinate flame retardant was used in an excess amount outside the appropriate range, showed significantly lower elongation and impact strength than Example 1, and poor results were confirmed.

[0215] In addition, it was confirmed that Comparative Example 7, in which an organometallic salt-based phosphinate flame retardant was used in a small amount outside the appropriate range, had reduced flame retardancy compared to Example 1, and was therefore unsuitable for application to parts.

[0216] In addition, in Comparative Example 8, in which the phosphate-based flame retardant was used in an excess amount outside the appropriate range, it was confirmed that the tensile strength and flexural strength were reduced and the processability was also poor compared to Example 1.

[0217] In addition, it was confirmed that Comparative Example 9, in which a small amount of phosphate-based flame retardant was used outside the appropriate range, had a lower elongation rate than Example 1, and was unable to provide product reliability.

[0218] Furthermore, it was confirmed that Comparative Example 10, which did not contain an anti-dripping agent, had poor flame retardancy compared to Example 3.

[0219] That is, the polybutylene terephthalate resin composition according to one embodiment of the present invention contains a high content of polybutylene terephthalate and also contains an organometallic salt-based phosphinate flame retardant, a phosphate-based flame retardant, and a component selected from a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer. As a result, molded articles manufactured from the composition have improved mechanical properties, processability, flame retardancy, and elongation, making the composition suitable for use in electrical components, etc.

Claims

1. The flame retardant composition comprises 100 parts by weight of polybutylene terephthalate, 1 to 30 parts by weight of an organometallic salt-based phosphinate flame retardant, 1 to 30 parts by weight of a phosphate-based flame retardant, and 1 to 30 parts by weight of a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer, wherein a>b>c is satisfied, where a is the content of the organometallic salt-based phosphinate flame retardant, b is the content of the phosphate-based flame retardant, and c is the content of the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer; The organometallic salt-based phosphinate flame retardant and the phosphate-based flame retardant are in a weight ratio (a:b) of 7:2 to 7:4; The polybutylene terephthalate resin composition is characterized in that the phosphate-based flame retardant and the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer are contained in a weight ratio (b:c) of 4:3 to 8:

3.

2. The polybutylene terephthalate resin composition according to claim 1, characterized in that the polybutylene terephthalate contains a polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5 and a polybutylene terephthalate having an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1 in a weight ratio of 1:0 to 1:

1.

3. The polybutylene terephthalate resin composition according to claim 1, wherein the organometallic salt-based phosphinate flame retardant has a structure represented by the following Chemical Formula 1: 【Chemistry 10】 (The above R 1 and R 2 are each an alkyl group or an aryl group having 1 to 6 carbon atoms, M is one or more selected from the group consisting of 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: 【Chemistry 11】 (In the above-mentioned Chemical Formula 2, R 3 , R 4 and R 5 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 of 0 to 4.

5. The polybutylene terephthalate resin composition according to claim 1, wherein the polyester-based elastomer is a compound consisting 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-based monomer and a monomer containing an epoxy group.

7. Polybutylene terephthalate; organometallic salt-based phosphinate flame retardant; phosphate-based flame retardant; polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer; and additives, in a total of 100% by weight, Contains 30 to 85% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5, Contains 0 to 40% by weight of polybutylene terephthalate having an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1, The organometallic salt-based phosphinate flame retardant is contained in an amount of 10 to 20 wt %; The phosphate-based flame retardant is contained in an amount of 1 to 10 wt %; The polybutylene terephthalate resin composition contains the polyester elastomer or the ethylene-glycidyl (meth)acrylate copolymer in an amount of 1 to 5% by weight.

8. 8. The polybutylene terephthalate resin composition according to claim 7, wherein the additive is at least one selected from the group consisting of a heat stabilizer, a flame retardant, a flame retardant auxiliary, a lubricant, a processing aid, a plasticizer, a coupling agent, a light stabilizer, a release agent, a dispersant, an anti-dripping agent, a weathering stabilizer, an antioxidant, a compatibilizer, a pigment, a dye, an antistatic agent, an anti-wear agent, a filler, and an antibacterial agent.

9. 10. The polybutylene terephthalate resin composition according to claim 1 or 7, wherein the polybutylene terephthalate resin composition is used as a material for electrical components.

10. The polybutylene terephthalate resin composition has an elongation of 22% or more as measured in accordance with ISO 527 at 50 mm / min, Izod impact strength (23°C, Notched) measured on a 4 mm thick test piece in accordance with ISO 180 is 4.7 kJ / m 2 That's all, 2. The polybutylene terephthalate resin composition according to claim 1, wherein the flame retardancy measured on a 0.8 mm test piece in accordance with UL94 method is V0 or higher.

11. a step of feeding polybutylene terephthalate; an organometallic salt phosphinate flame retardant; a phosphate-based flame retardant; a polyester-based elastomer or an ethylene-glycidyl (meth)acrylate copolymer; and additives, the polybutylene terephthalate having an intrinsic viscosity (IV) of more than 1.1 and not more than 1.5 in an amount of 30 to 85% by weight, the polybutylene terephthalate having an intrinsic viscosity (IV) of more than 0.8 and not more than 1.1 in an amount of 0 to 40% by weight, the organometallic salt phosphinate flame retardant being contained in an amount of 10 to 20% by weight, the phosphate-based flame retardant being contained in an amount of 1 to 10% by weight, and the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer being contained in an amount of 1 to 5% by weight, into an extruder, and melt-kneading and extruding the mixture; wherein a>b>c is satisfied, where a is the content of the organometallic salt-based phosphinate flame retardant, b is the content of the phosphate-based flame retardant, and c is the content of the polyester-based elastomer or ethylene-glycidyl (meth)acrylate copolymer; The organometallic salt-based phosphinate flame retardant and the phosphate-based flame retardant are in a weight ratio (a:b) of 7:2 to 7:4; The phosphate-based flame retardant and the polyester-based elastomer or the ethylene-glycidyl (meth)acrylate copolymer are contained in a weight ratio (b:c) of 4:3 to 8:

3.

12. A molded article comprising the polybutylene terephthalate resin composition according to any one of claims 1 to 10.

13. The molded product according to claim 12, wherein the molded product is an electrical component.

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