Thermoplastic polyurea and method for producing same, thermoplastic polyurea composition, and molded body

Abstract

Provided is a thermoplastic polyurea that has a number average molecular weight of from more than 5,000 to 50,000, and the number average molecular weight and the amine value satisfy formula (1). Formula (1): 2.0≤(number average molecular weight×amine value [μmol / g] / 106≤4.0

Description

Thermoplastic polyurea, its manufacturing method, thermoplastic polyurea composition, and molded article

[0001] The present invention relates to a thermoplastic polyurea, a method for producing the same, a thermoplastic polyurea composition, and a molded article.

[0002] Polyurea has excellent heat resistance, mechanical strength (mechanical properties), and chemical resistance, and is used in injection-molded products, fibers, coatings, etc. Conventional polyureas are produced by polymerization of urea and formaldehyde or polymerization of diisocyanate and diamine, but the polyureas obtained by conventional methods are polymers that are difficult to melt-process, even if they are thermosetting or thermoplastic. Therefore, there is a demand for the development of polyureas that are easily melt-processable (have moldability).

[0003] To solve the above problems, polymerization using urea and diamine has been proposed. For example, as the diamine component, two or more linear alkylenediamines with different carbon numbers (see, for example, Patent Document 1), a primary diamine having at least one alkyl group with no more than 3 carbon atoms on any carbon atom of a linear saturated hydrocarbon group with a specific carbon number (see, for example, Patent Document 2), and a mixed system of a primary diamine having at least one alkyl group with no more than 10 carbon atoms on any carbon atom of a linear saturated aliphatic hydrocarbon group with a specific carbon number and a linear alkylenediamine with a specific carbon number (see, for example, Patent Document 3) have been disclosed. The techniques described in Patent Documents 1 to 3 above can produce thermoplastic polyureas with certain mechanical properties and certain moldability. Furthermore, Patent Document 4 discloses the preparation of a uniform, non-crosslinked, high-molecular-weight alkyldiamine-urea condensate (polyurea) without the use of conventional solvents by a process of reacting a diamine with urea in the presence of an excess of diamine. However, in recent years, there has been an increasing demand for both mechanical properties (specifically, improved elongation at break) and moldability (specifically, improved viscosity stability when melted). A thermoplastic polyurea that combines high levels of mechanical properties and moldability has not yet been obtained, and there is room for improvement.

[0004] Japanese Patent Application Laid-Open No. 36-2847 Japanese Patent Application Laid-Open No. 36-22150 Japanese Patent Application Laid-Open No. 36-20249 U.S. Patent No. 3,390,137

[0005] An object of the present invention is to provide a thermoplastic polyurea that combines high levels of mechanical properties and moldability, a method for producing the same, a thermoplastic polyurea composition containing the thermoplastic polyurea, and a molded article containing the thermoplastic polyurea composition.

[0006] As a result of extensive research, the present inventors have found that when a thermoplastic polyurea having a specific number average molecular weight satisfies formula (1), a thermoplastic polyurea having both high levels of mechanical properties and molding processability can be obtained, and have completed the present invention.

[0007] That is, the present invention provides the following items [1] to

[10] . [1] A thermoplastic polyurea having a number average molecular weight of more than 5,000 and not more than 50,000, wherein the number average molecular weight and the amine value satisfy the following formula (1): 2.0≦(number average molecular weight×amine value [μmol / g]) / 10. ６≦4.0 [2] The thermoplastic polyurea according to [1] above, wherein the number average molecular weight is 7,000 to 40,000. [3] The thermoplastic polyurea according to [1] or [2] above, wherein the amine value is 150 μmol / g or more. [4] The thermoplastic polyurea according to any one of [1] to [3] above, comprising a diamine-derived structural unit and a urea-derived structural unit. [5] The thermoplastic polyurea according to [4] above, wherein the ratio of the aliphatic diamine-derived structural units to the total diamine-derived structural units is 50 mol% or more. [6] The thermoplastic polyurea according to [4] or [5] above, wherein the ratio of the aliphatic diamine-derived structural units to the total diamine-derived structural units is 85 mol% or more. [7] The thermoplastic polyurea according to any one of [1] to [6] above, wherein the change in solution viscosity when kneaded for 5 minutes at a temperature 30°C higher than the melting point of the thermoplastic polyurea is 15% or less. [8] A thermoplastic polyurea composition comprising the thermoplastic polyurea according to any one of [1] to [7] above. [9] A molded article comprising the thermoplastic polyurea composition according to [8] above.

[10] A method for producing the thermoplastic polyurea according to any one of [1] to [7] above, comprising melt-kneading the urea and the diamine to prepare a molten mixture so that the molar ratio of the diamine to the urea is 1.20 to 1.60, adding additional urea to the prepared molten mixture, and polymerizing the urea and the diamine.

[0008] According to the present invention, it is possible to provide a thermoplastic polyurea that combines high levels of mechanical properties and moldability, a method for producing the same, a thermoplastic polyurea composition containing the thermoplastic polyurea, and a molded article containing the thermoplastic polyurea composition.

[0009] The following describes an example of an embodiment of the present invention. However, the embodiment described below is merely an example for embodying the technical concept of the present invention, and the present invention is not limited to the following description. In this specification, preferred embodiments are shown, but a combination of two or more of the individual preferred embodiments is also a preferred embodiment. For matters shown as numerical ranges, when there are several numerical ranges, the lower limit and upper limit can be selectively combined to form a preferred embodiment. In this specification, when a numerical range is described as "XX to YY," it means "XX or more and YY or less." In this specification, "polymer" means thermoplastic polyurea, and "structural unit" means "a unit constituting a polymer."

[0010] [Thermoplastic Polyurea] The thermoplastic polyurea of ​​the present invention has a number average molecular weight of more than 5,000 and not more than 50,000, and the number average molecular weight and amine value satisfy the following formula (1), preferably the following formula (1-1), more preferably the following formula (1-2), and particularly preferably the following formula (1-3): Formula (1): 2.0≦(number average molecular weight×amine value [μmol / g]) / 10 ６ ≦4.0 Formula (1-1): 2.0≦(number average molecular weight×amine value [μmol / g]) / 10 ６ ≦3.5 Formula (1-2): 2.0≦(number average molecular weight×amine value [μmol / g]) / 10 ６ ≦3.2 Formula (1-3): 2.0≦(number average molecular weight×amine value [μmol / g]) / 10 ６ ≦2.9

[0011] The thermoplastic polyurea of ​​the present invention can achieve both high levels of mechanical properties and molding processability when the number average molecular weight and amine value satisfy formula (1). On the other hand, when the number average molecular weight and amine value do not satisfy formula (1), either the mechanical properties or the molding processability is impaired.

[0012] The mechanism by which the effects of the present invention are exhibited is presumed to be as follows. Thermoplastic polyureas generally exhibit poor viscosity stability in a molten state, such as during melt molding. This is due to thickening caused by a crosslinking reaction between isocyanate groups generated at the thermoplastic polyurea terminals and urea bonds in the thermoplastic polyurea main chain, and the thickening becomes more pronounced as the molecular weight increases. In the present invention, when the thermoplastic polyurea satisfies formula (1), amine groups, which have significantly higher reactivity with isocyanates than urea bonds, are present at a high concentration per molecule, thereby suppressing the crosslinking reaction. In addition, when the thermoplastic polyurea satisfies formula (1), the amount of urea terminal groups in the thermoplastic polyurea is reduced, thereby reducing the isocyanate group concentration. As a result, it is possible to improve viscosity stability even in high-molecular-weight thermoplastic polyureas, thereby achieving both mechanical properties and moldability.

[0013] The thermoplastic polyurea of ​​the present invention satisfies formula (1), so that the change in solution viscosity before and after melt-kneading, as measured and calculated by the method described below, is 15% or less. That is, the thermoplastic polyurea of ​​the present invention satisfies formula (1), so that it has high molecular weight stability before and after melt-molding and high quality stability. The change in solution viscosity before and after melt-kneading is not particularly limited, but from the viewpoint of molding processability, it is preferably 15% or less, more preferably 12% or less, and particularly preferably 10% or less. When the change in solution viscosity before and after melt-kneading is 15% or less, viscosity stability during melt-molding is improved, and quality defects in molded products can be prevented. The change in solution viscosity can be measured by the method used in the examples described below.

[0014] The thermoplastic polyurea of ​​the present invention has a urea bond (—NH—C(═O)—NH—). The thermoplastic polyurea may also contain bonds other than urea bonds, such as a urethane bond (—NH—C(═O)—O—) or an amide bond (—NH—C(═O)—), as long as the effects of the present invention are not impaired.

[0015] The carbonyl group (—C(═O)—) in the urea bond of the thermoplastic polyurea of ​​the present invention is not particularly limited and may be derived from any of urea, isocyanate, carbon dioxide, carbonate, and phosgene, but is preferably derived from urea from the viewpoints of productivity, raw material toxicity, and availability. Here, the term “urea-derived” does not necessarily mean derived from urea, but also includes derived from urea derivatives such as methylene diurea and ethylene diurea.

[0016] The monomer units constituting the urea bond (i.e., the monomer units constituting the thermoplastic polyurea) are not particularly limited, and examples thereof include urea, isocyanate, carbon dioxide, carbonate, phosgene, diamine, and derivatives thereof. These may be used alone or in combination of two or more. Among these, from the viewpoints of moldability, productivity, and availability, a combination of diamine and urea, a combination of diamine and isocyanate, and a combination of diamine and carbon dioxide are preferred, and a combination of diamine and urea is more preferred.

[0017] The total amount of diamine-derived structural units (also referred to as "diamine units") and urea-derived structural units (also referred to as "urea units") in the total amount (100 mol %) of monomer units constituting the thermoplastic polyurea is preferably 80 mol % or more, more preferably 90 mol % or more, and particularly preferably 100 mol %.

[0018] <Diamine> The diamine constituting the diamine-derived structural unit (also referred to as "diamine unit") in the thermoplastic polyurea is not particularly limited, and examples thereof include aliphatic diamines, aromatic diamines, alicyclic diamines, ether diamines, etc. These may be used alone or in combination of two or more. The diamine may include urea (H ２ NC(=O)-NH ２ ) are not included. By selecting the type of diamine, the melting point, mechanical properties, chemical resistance, etc. of the thermoplastic polyurea can be controlled. Among these, aliphatic diamines are preferred from the viewpoint of achieving a good balance between moldability, mechanical properties, and chemical resistance.

[0019] (Aliphatic diamine) The aliphatic diamine means a diamine containing only an aliphatic hydrocarbon group without a cyclic structure, and does not include aromatic diamines, alicyclic diamines, or ether diamines, which will be described later. The aliphatic diamine may be a diamine containing only a saturated hydrocarbon group, or a diamine containing an unsaturated hydrocarbon group, but is preferably a diamine containing no unsaturated hydrocarbon group. The aliphatic diamine constituting the diamine unit is not particularly limited, and examples thereof include (i) 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,13-tridecanediamine, 1,14-tetradecanediamine, 1,15-pentadecanediamine, 1,16-hexadecanediamine, 1,17-heptadecanediamine, and 1,18-octadecanediamine. (ii) branched aliphatic diamines such as 2-methyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 2-methyl-1,9-nonanediamine, 2-methyl-1,10-decanediamine, 2-methyl-1,11-undecanediamine, 2-methyl-1,12-dodecanediamine, 1,3-dimethyl-1,8-octanediamine, 1,4-dimethyl-1,8-octanediamine, 2,4-dimethyl-1,8-octanediamine, 2,2,4-trimethyl-1,8-octanediamine, and 2,4,4-trimethyl-1,8-octanediamine. These may be used alone or in combination of two or more. Among these, from the viewpoint of achieving both mechanical properties and moldability, aliphatic diamines having 3 to 18 carbon atoms are preferred, aliphatic diamines having 5 to 15 carbon atoms are more preferred, aliphatic diamines having 7 to 12 carbon atoms are even more preferred, and aliphatic diamines having 9 carbon atoms are particularly preferred.

[0020] One or more types of linear aliphatic diamines and one or more types of branched aliphatic diamines may be used in combination. The content of linear aliphatic diamines relative to 100 mol% of aliphatic diamines is not particularly limited, but from the viewpoint of achieving both moldability, mechanical properties, and chemical resistance, it is preferably 50 mol% or more, more preferably 65 mol% or more, and particularly preferably 80 mol% or more. The combination of linear aliphatic diamines and branched aliphatic diamines is not particularly limited, but examples thereof include: (i) one of 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, and 1,12-dodecanediamine and 2-methyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, 2-methyl-1,9-nonanediamine, 2-methyl-1,10-decanediamine, and 2-methyl-1,12-dodecanediamine; (ii) a combination of one of 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine with one of 2-methyl-1,7-heptanediamine, 2-methyl-1,8-octanediamine, and 2-methyl-1,9-nonanediamine is more preferred, and (iii) a combination of 1,9-nonanediamine and 2-methyl-1,8-octanediamine is particularly preferred.

[0021] (Aromatic diamine) Aromatic diamine refers to a diamine having an aromatic ring such as a benzene ring or a naphthalene ring in its structure. The aromatic diamine is not particularly limited, and examples thereof include phenylenediamine, diaminodiphenyl ether, xylylenediamine, biphenylenediamine, dichlorobenzidine, dimethylbenzidine, diaminodiphenylmethane, and naphthalenediamine. These may be used alone or in combination of two or more. Among these, xylylenediamine is preferred from the viewpoint of availability, and metaxylenediamine is more preferred.

[0022] (Alicyclic diamine) The alicyclic diamine refers to a diamine having an alicyclic structure such as cyclopentane or cyclohexane in its structure. The alicyclic diamine is not particularly limited, and examples thereof include 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminopropyl)piperazine, and 2,5-bisaminomethylfuran. These may be used alone or in combination of two or more.

[0023] (Polyetherdiamine) Polyetherdiamine refers to a diamine containing an ether bond in its structure and not corresponding to the above-mentioned aliphatic diamine, aromatic diamine, or alicyclic diamine. There are no particular limitations on the polyetherdiamine, and examples thereof include polyethylene glycol (PEG), polypropylene glycol (PPG), polytrimethylene ether glycol (PO3G), poly(oxybutylene) glycol, polytetramethylene ether glycol (PTMG), poly(3-alkyltetrahydrofuran such as poly(3-methyltetrahydrofuran) (poly(3MeTHF)), polypentamethylene ether glycol, polyhexamethylene ether glycol, polyoctamethylene ether glycol, and the like, in which amino groups have been introduced at two terminals; and copolymers of the above-mentioned glycols in which amino groups have been introduced at two terminals. These may be used alone or in combination of two or more types.

[0024] In the thermoplastic polyurea of ​​the present invention, two or more diamines may be used in combination. The proportion of aliphatic diamine-derived structural units relative to the total diamine-derived structural units is not particularly limited, but from the viewpoint of achieving a good balance between moldability, mechanical properties, heat resistance, and chemical resistance, it is preferably 50 to 100 mol%, more preferably 70 to 100 mol%, and particularly preferably 85 to 100 mol%. The total proportion of aromatic diamine-derived structural units, alicyclic diamine-derived structural units, and ether diamine-derived structural units relative to the total diamine-derived structural units is not particularly limited, but from the viewpoint of achieving a good balance between moldability, mechanical properties, heat resistance, and chemical resistance, it is preferably 50 mol% or less, more preferably 30 mol% or less, and particularly preferably 15 mol% or less. When two or more diamines are used in combination, the arrangement order of the diamine units is not particularly limited and may be random, block, alternating, or the like.

[0025] The melting point of the thermoplastic polyurea is not particularly limited, but from the viewpoint of achieving both moldability and heat resistance, it is preferably 120 to 280° C., more preferably 140 to 260° C., even more preferably 160 to 240° C., and particularly preferably 170 to 220° C. The melting point of the thermoplastic polyurea can be measured by the method used in the examples described below.

[0026] The number average molecular weight (Mn) of the thermoplastic polyurethane is not particularly limited as long as it is more than 5,000 and not more than 50,000, but from the viewpoint of achieving both mechanical properties and moldability, it is preferably 7,000 to 40,000, more preferably 8,000 to 30,000, even more preferably 11,000 to 25,000, still more preferably 11,000 to 20,000, and particularly preferably 11,000 to 15,000. The number average molecular weight of the thermoplastic polyurethane can be measured by the method used in the examples described below.

[0027] The weight average molecular weight (Mw) of the thermoplastic polyurea is not particularly limited, but from the viewpoint of achieving both mechanical properties and moldability, it is preferably 7,000 to 100,000, more preferably 10,000 to 70,000, even more preferably 12,000 to 50,000, and particularly preferably 13,000 to 30,000. The weight average molecular weight of the thermoplastic polyurea can be measured by the method used in the examples described below.

[0028] The molecular weight distribution (Mw / Mn) of the thermoplastic polyurea is not particularly limited, but from the viewpoint of achieving both ease of production (ease of controlling the molecular weight distribution) and moldability, it is preferably 1.1 to 10.0, more preferably 1.3 to 5.0, and particularly preferably 1.6 to 3.0. The molecular weight distribution (Mw / Mn) of the thermoplastic polyurea can be measured by the method used in the examples described below.

[0029] The amine value of a thermoplastic polyurea can be adjusted by the terminal amine group content, and the number of terminals correlates with the number-average molecular weight. That is, a thermoplastic polyurea with a small number-average molecular weight exhibits a high amine value, while a thermoplastic polyurea with a large number-average molecular weight exhibits a low amine value. Furthermore, even with similar molecular weights, the amine value of a thermoplastic polyurea can be adjusted by adjusting the raw material charge ratio. That is, a thermoplastic polyurea with a high amine value can be obtained by adjusting the molar ratio of diamine to urea so that the diamine is in excess. The amine value of the thermoplastic polyurea is not particularly limited, but from the viewpoints of mechanical properties and moldability, it is preferably 150 μmol / g or more, more preferably 150 to 500 μmol / g, even more preferably 160 to 400 μmol / g, and particularly preferably 170 to 350 μmol / g. An amine value above the lower limit can improve viscosity stability during melt molding, while an amine value below the upper limit can prevent a low number-average molecular weight and insufficient mechanical properties. The amine value (amine group content) of the thermoplastic polyurea can be measured by the method described in the examples.

[0030] <Method for Producing Thermoplastic Polyurea> The thermoplastic polyurea of ​​the present invention can be produced by any method without particular limitation. For example, the polyurea can be obtained by a polycondensation reaction in which a diamine and a urea are reacted by heating, preferably in an excess amount of diamine, preferably in an inert gas atmosphere, with or without dissolution in a solvent such as water, phenol, or m-cresol, and then the reaction is completed while distilling off the solvent, if present.

[0031] Regarding the temperature of the polycondensation reaction, the reaction mixture is first heated at a relatively low temperature of 80 to 130°C to produce a low-degree condensate, temporarily halting the generation of ammonia, and then the temperature is gradually raised. At 140 to 190°C, the generation of ammonia becomes active again. The temperature is controlled at this time, and any solvent present is distilled off, and the temperature is raised again. After the deammonia reaction by heating is completed, the reaction mixture is heated and continued at a temperature of 200 to 280°C under reduced pressure, allowing the polycondensation reaction to proceed smoothly and resulting in a linear copolymer.

[0032] In the polycondensation reaction, particularly when no solvent is added, it is desirable to suppress solidification due to excessive growth during the temperature rise process. In the deammoniation reaction at 140 to 190°C, the melting point of the low-degree condensation product increases as the growth proceeds.

[0033] If the melting point of the low condensation product is equal to or higher than the reaction temperature, the solidification of the reaction system progresses and the system becomes unable to be stirred. Therefore, unlike other polycondensation reaction products such as polyamides and polyesters, the polycondensation reaction of thermoplastic polyurea, in which ammonia gas is a by-product distillate, has a large reaction equilibrium constant, and it can be said that it is particularly important to suppress excessive growth of the low condensation product.

[0034] The method for controlling the polycondensation reaction is not particularly limited, and examples thereof include known methods such as controlling the ratio of raw material monomers, suppressing the distillation of by-products, and using low-reactivity monomers such as carbon dioxide. These may be used alone or in combination of two or more. Among these, the method of controlling the ratio of raw material monomers is preferred because suppressing the distillation of by-products and using low-reactivity monomers require large-scale pressure-resistant equipment or catalysts.

[0035] The molar ratio (diamine / urea) of the charged monomers is not particularly limited, but from the viewpoint of the growth-inhibiting effect and the quality stability in the polymerizing step described below, it is preferably 1.20 to 1.60, more preferably 1.30 to 1.60, and particularly preferably 1.30 to 1.40. When the molar ratio (diamine / urea) of the charged monomers is equal to or greater than the lower limit, the growth-inhibiting effect can be improved, and when it is equal to or less than the upper limit, the quality stability in the polymerizing step described below can be improved. When the molar ratio (diamine / urea) of the charged monomers is 1.20 to 1.60, it is possible to suppress excessive growth of low-degree condensates while simultaneously achieving quality stability in the polymerizing step described below. That is, the molar ratio of charged monomers (diamine / urea) is set to 1.20 to 1.60, and the mixture is heated at a relatively low temperature of 80 to 130°C to produce a low-degree condensate and temporarily halt the generation of ammonia. After that, the mixture is heated to 140 to 190°C, and the deammoniating reaction by heating is completed. After that, the mixture is heated to 200 to 280°C, whereby smooth polymerization can be achieved without solidifying the reaction system.

[0036] (Addition of Urea: Increasing Molecular Weight After Heating) When the molar ratio (diamine / urea) of the charged monomers is 1.20 to 1.60, the resulting resin has a low molecular weight and insufficient mechanical properties, and therefore requires further molecular weight increase at a temperature of 200 to 280°C. The method for increasing molecular weight is not particularly limited, and examples include additional addition of raw materials, addition of a chain extender, distillation of excess monomer under reduced pressure, and solid-phase polymerization of the resulting resin. These methods may be used alone or in combination of two or more. Among these, from the viewpoints of production yield and process simplification, productivity, raw material toxicity, and availability, the methods of additional addition of raw materials and addition of a chain extender are preferred, and addition of urea is more preferred.

[0037] <Method of adding urea> The method of adding urea is not particularly limited, and urea may be added as a solution dissolved in a solvent inert to the polycondensation reaction, or as a solid. Among these, the method of adding urea as a solid is preferred from the viewpoints of process simplification and energy efficiency.

[0038] <Addition Rate of Urea> The addition rate of the urea solution or solid urea is not particularly limited, and a predetermined amount of urea solution or solid urea may be added all at once, or may be added in portions or successively.

[0039] <Timing of Urea Addition> The timing of urea addition is not particularly limited, and urea may be added during the deammoniation reaction at 140 to 190°C or during the polymerizing reaction at 200 to 280°C. However, from the viewpoint of more reliably suppressing excessive growth, it is preferable to add urea during the polymerizing reaction at 200 to 280°C.

[0040] [Thermoplastic Polyurea Composition] The thermoplastic polyurea composition of the present invention contains the thermoplastic polyurea of ​​the present invention, and may further contain, as necessary, other components such as secondary raw materials for the polycondensation reaction (additives to be added to the polycondensation reaction) and additives to be added during molding of the thermoplastic polyurea composition.

[0041] <Secondary raw materials for polycondensation reaction (additives added to polycondensation reaction)> The secondary raw materials for the polycondensation reaction (additives added to the polycondensation reaction) are not particularly limited, and examples thereof include antioxidants, antistatic agents, flame retardants, flame retardant assistants, heat stabilizers, etc. These may be used alone or in combination of two or more.

[0042] <Additives added during molding of thermoplastic polyurea composition> Additives may be added during molding of the thermoplastic polyurea composition. The additives are not particularly limited, and examples thereof include glass fiber, carbon fiber, antioxidant, antistatic agent, flame retardant, flame retardant assistant, heat stabilizer, plasticizer, etc. These may be used alone or in combination of two or more.

[0043] [Molded Article] The molded article of the present invention contains the thermoplastic polyurea composition of the present invention. The thermoplastic polyurea composition of the present invention can be processed into various molded articles such as films described below by known molding methods such as injection molding, extrusion molding, T-die molding, inflation molding, and hot pressing.

[0044] The breaking elongation of the molded article of the present invention is preferably 5% or more, more preferably 6 to 60%, and particularly preferably 7 to 50%, from the viewpoint of mechanical properties.

[0045] The uses of the molded article of the present invention are not particularly limited, and examples thereof include electric and electronic parts, automobile parts, industrial parts, household products, medical parts, fibers, films, sheets, tubes, hoses, hollow molded parts, foam molded articles, and other molded articles of any shape.

[0046] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples, "%" and "parts" represent "% by mass" and "parts by mass", respectively, unless otherwise specified. The measurement methods and evaluation methods employed in the following examples and comparative examples are shown below.

[0047] [Number Average Molecular Weight (Mn) and Weight Average Molecular Weight (Mw)] The number average molecular weight (Mn) and weight average molecular weight (Mw) of the thermoplastic polyurea are the number average molecular weight (Mn) and weight average molecular weight (Mw) converted into polymethyl methacrylate (manufactured by Resonac Corporation) measured using gel permeation chromatography (GPC) under the following measurement conditions. <Measurement Conditions> Measurement device: HLC-8420GPC Columns: 1 TSKgel Guard Column SUPER H-H manufactured by Tosoh Corporation 2 TSKgel SUPER HM-H manufactured by Tosoh Corporation 1 TSKgel SUPER H-RC manufactured by Tosoh Corporation Solvent: hexafluoroisopropanol containing 12 mM sodium trifluoroacetate Flow rate: 0.4 mL / min Measurement temperature: 40°C

[0048] [Amine Value] 0.2 g of a thermoplastic polyurea sample was dissolved in 30 mL of phenol, and 3 mL of methanol was added to prepare a sample solution. Titration was carried out using 0.01 or 0.1 N aqueous HCl solution with thymol blue as an indicator. The point at which the solution turned pale pink was set as the endpoint, and the terminal amino group content (amine value) ([NH ２], unit: μmol / g) was measured. Equation (2): Amine value [μmol / g] = Titration amount [mL] × Normal number [mol / L] ÷ Weight [g] × 1000 The reagents used for measuring the amine value are as follows: Phenol: Grade 1 manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Methanol: Special grade reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Thymol blue: Kanto Chemical Co., Ltd. HCl aqueous solution: Volumetric analysis grade manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0049] [Melting point (°C)] The melting point (°C) of the obtained thermoplastic polyurea was measured by a differential scanning calorimeter according to the method described in JIS K7121:2012. Specifically, under a nitrogen flow of 50 mL / min, the temperature was raised from 25°C to 240°C at a heating rate of 10°C / min, and then held at 240°C for 5 minutes, then cooled to 25°C at 10°C / min, and then held at 25°C for 5 minutes, and then heated to 240°C at 10°C / min. The temperature of the endothermic peak on the highest temperature side was taken as the melting point (°C). However, if a clear endothermic peak was not observed by the above method, specifically in Example 2 and Comparative Example 3, under a nitrogen flow of 50 mL / min, the temperature was raised from 25°C to 240°C at a heating rate of 10°C / min. The temperature of the endothermic peak on the highest temperature side was taken as the melting point (°C). If no endothermic peak was observed in either case, it was determined that there was no melting point.

[0050] [Materials Used] The materials used in the Examples and Comparative Examples are as follows: Urea: manufactured by Tokyo Chemical Industry Co., Ltd. 1,6-Hexanediamine: manufactured by Tokyo Chemical Industry Co., Ltd. 1,10-Decanediamine: manufactured by Tokyo Chemical Industry Co., Ltd. 1,12-Dodecanediamine: manufactured by Tokyo Chemical Industry Co., Ltd. Metaxylylenediamine: manufactured by Tokyo Chemical Industry Co., Ltd.

[0051] Example 1 Polymer Production A 200 mL flask equipped with a device capable of distilling off generated liquids and gases was charged with urea, 1,9-nonanediamine, and 2-methyl-1,8-octanediamine in a ratio of (urea / 1,9-nonanediamine / 2-methyl-1,8-octanediamine) = (0.24 mol / 0.27 mol / 0.04 mol) (molar ratio 43.5 / 48.0 / 8.5). Under a nitrogen flow at 50 mL / min, the temperature was raised from 25°C to 130°C and heated for 1 hour, then further raised to 160°C and heated for 1 hour. After further raising the temperature to 240°C, an additional 0.06 mol (molar ratio 11.3) of urea was added, and the mixture was heated for 8 hours, yielding a colorless, transparent thermoplastic polyurea. The thermoplastic polyurea thus obtained had a number average molecular weight of 12,000, a weight average molecular weight of 21,400, a molecular weight distribution of 1.8, and an amine value of 172 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 2.1 and the melting point was 210° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0052] <Solution Viscosity Measurement> 0.1 g of a thermoplastic polyurea sample was weighed out, and 20 mL of m-cresol was added thereto. The mixture was heated at 100°C for 1 hour to dissolve the sample. The solution viscosity of the obtained solution was measured at 25.0°C according to the method described in JIS K7367-1:2002 using a thermostatic water bath BK300 manufactured by Yamato Scientific Co., Ltd. and an Ubbelohde viscometer (viscometer constant 0.1) manufactured by Shibata Scientific Co., Ltd. The measurement was carried out at least twice, and the solution viscosity was calculated from the average value and formula (3). Formula (3): Solution viscosity [dL / g] = (t - t ０ ) / (t ０ × c) t [sec]: titration time of thermoplastic polyurea sample t ０ [sec]: titration time of thermoplastic polyurea sample c [g / dL]: sample concentration of thermoplastic polyurea solution The reagents used for measuring the solution viscosity are as follows: m-cresol: manufactured by Tokyo Chemical Industry Co., Ltd.

[0053] <Evaluation of Solution Viscosity Change (Viscosity Stability)> (i) Solution viscosity (η １), and (ii) the solution viscosity (η ２ ) (i.e., the solution viscosity (η ２ The viscosity change of the solution was calculated by the following formula (4): Solution viscosity change [%] = (η ２ -η １ ) / η １ ×100 η １ [dL / g]: Solution viscosity η of thermoplastic polyurea before melt kneading ２ [dL / g]: Solution viscosity of thermoplastic polyurea after melt kneading

[0054] <Measurement of Breaking Elongation (Evaluation of Tensile Properties)> The obtained thermoplastic polyurea was used in a small kneading machine ("MC15-HT" manufactured by XPLORE INSTRUMENTS) to prepare small test pieces Type 1BA at a stirring speed of 50 rpm, a kneading temperature of the melting point + 30°C, and a mold temperature of the melting point - 60°C. These were then crystallized in a 110°C thermostatic bath for 6 hours to obtain dumbbell test pieces. For polyureas for which no melting point was observed, the kneading temperature was set to the maximum temperature during polymerization. The resulting dumbbell test pieces were measured for breaking elongation at 23°C using an "Autograph AG2000B" manufactured by Shimadzu Corporation. Specifically, the chuck distance was 50 mm and the test speed was 5 mm / min.

[0055] Example 2 Urea, 1,9-nonanediamine, and 2-methyl-1,8-octanediamine were charged into a flask equipped with a device capable of distilling off generated liquids and gases, so that (urea / 1,9-nonanediamine / 2-methyl-1,8-octanediamine) = (0.24 mol / 0.16 mol / 0.16 mol) (molar ratio 43.5 / 28.3 / 28.3). Under a nitrogen flow at 50 mL / min, the temperature was raised from 25°C to 130°C and heated for 1 hour, then further raised to 160°C and heated for 1 hour. After further raising the temperature to 240°C, an additional 0.06 mol (molar ratio 10.9) of urea was added and heated for 8 hours, yielding a colorless, transparent thermoplastic polyurethane. The thermoplastic polyurea obtained had a number average molecular weight of 9,000, a weight average molecular weight of 15,200, a molecular weight distribution of 1.7, and an amine value of 230 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 2.1 and the melting point was 175° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0056] Example 3 Urea, 1,6-hexanediamine, and 1,10-decanediamine were charged into a flask equipped with a device capable of distilling off generated liquid and gas, so that (urea / 1,6-hexanediamine / 1,10-decanediamine) = (0.24 mol / 0.03 mol / 0.29 mol) (molar ratio 43.5 / 4.9 / 51.6). Under a nitrogen flow at 50 mL / min, the temperature was raised from 25°C to 130°C and heated for 1 hour, then further raised to 160°C and heated for 1 hour. After further raising the temperature to 240°C, an additional 0.06 mol (molar ratio 10.6) of urea was added and heated for 8 hours, yielding a colorless, transparent thermoplastic polyurea. The resulting thermoplastic polyurea had a number average molecular weight of 9,100, a weight average molecular weight of 15,900, a molecular weight distribution of 1.7, and an amine value of 261 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 2.4 and the melting point was 218° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0057] Example 4 Urea and 1,12-dodecanediamine were charged into a flask equipped with a device capable of distilling off the generated liquid and gas, so that (urea / 1,12-dodecanediamine) = (0.24 mol / 0.31 mol) (molar ratio 43.5 / 56.5). Under a nitrogen flow at 50 mL / min, the temperature was raised from 25°C to 130°C and heated for 1 hour, then further raised to 160°C and heated for 1 hour. After further raising the temperature to 240°C, 0.06 mol (molar ratio 10.4) of urea was added and heated for 8 hours, yielding a colorless and transparent thermoplastic polyurea. The resulting thermoplastic polyurea had a number average molecular weight of 8,400, a weight average molecular weight of 13,600, a molecular weight distribution of 1.6, and an amine value of 324 μmol / g, calculated as "number average molecular weight × amine value / 10" ６ The viscosity index was 2.7 and the melting point was 214° C. The thermoplastic polyurea obtained was evaluated for solution viscosity change (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0058] Example 5 Urea, 1,10-decanediamine, and meta-xylylenediamine were charged into a flask equipped with a device capable of distilling off the generated liquid and gas, so that (urea / 1,10-decanediamine / meta-xylylenediamine) = (0.24 mol / 0.27 mol / 0.04 mol) (molar ratio 43.5 / 48.0 / 8.5). Under a nitrogen flow at 50 mL / min, the temperature was raised from 25°C to 130°C and heated for 1 hour, then further raised to 160°C and heated for 1 hour. After further raising the temperature to 240°C, an additional 0.06 mol (molar ratio 10.9) of urea was added and heated for 8 hours, yielding a colorless and transparent thermoplastic polyurea. The resulting thermoplastic polyurea had a number average molecular weight of 10,500, a weight average molecular weight of 18,000, a molecular weight distribution of 1.7, and an amine value of 245 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 2.6 and the melting point was 214° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0059] Example 6 Urea, 1,6-hexanediamine, and 1,8-octanediamine were charged into a flask equipped with a device capable of distilling off the generated liquid and gas, so that (urea / 1,6-hexanediamine / 1,8-octanediamine) = (0.48 mol / 0.31 mol / 0.31 mol) (molar ratio 43.5 / 28.3 / 28.3). Under a nitrogen flow at 50 mL / min, the temperature was raised from 25°C to 130°C and heated for 1 hour, then further raised to 160°C and heated for 1 hour. After further raising the temperature to 240°C, an additional 0.12 mol (molar ratio 10.9) of urea was added and heated for 8 hours, yielding a colorless, transparent thermoplastic polyurethane. The thermoplastic polyurea thus obtained had a number average molecular weight of 11,400, a weight average molecular weight of 21,200, a molecular weight distribution of 1.9, and an amine value of 177 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 2.0 and the melting point was 210° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0060] Comparative Example 1 Urea (manufactured by Tokyo Chemical Industry Co., Ltd.), 1,9-nonanediamine, and 2-methyl-1,8-octanediamine were charged into a flask equipped with a device capable of distilling off generated liquids and gases, so that (urea / 1,9-nonanediamine / 2-methyl-1,8-octanediamine) = (0.31 mol / 0.34 mol / 0.06 mol) (molar ratio 43.5 / 48.0 / 8.5). Under a nitrogen flow at 50 mL / min, the temperature was raised from 25°C to 130°C and heated for 1 hour, then further raised to 160°C and heated for 1 hour. After further raising the temperature to 240°C, an additional 0.09 mol (molar ratio 13.0) of urea was added and heated for 2 hours, yielding a colorless and transparent thermoplastic polyurethane. The thermoplastic polyurea thus obtained had a number average molecular weight of 6,500, a weight average molecular weight of 11,300, a molecular weight distribution of 1.7, and an amine value of 100 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 0.7 and the melting point was 210° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0061] Comparative Example 2 Thermoplastic polyurethanes were produced and dumbbell test pieces were prepared in the same manner as in Example 1, except that, instead of adding 0.06 mol (molar ratio 11.3) of urea after heating to 240°C, 0.04 mol (molar ratio 7.6) of urea was added after heating to 240°C. The thermoplastic polyurethanes obtained had a number average molecular weight of 5,000, a weight average molecular weight of 7,100, a molecular weight distribution of 1.4, and an amine value of 540 μmol / g, calculated as "number average molecular weight × amine value / 10" ６ The viscosity index was 2.7 and the melting point was 207° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0062] (Comparative Example 3) Thermoplastic polyurethanes were produced and dumbbell test pieces were prepared in the same manner as in Comparative Example 1, except that the monomer charge ratio in the thermoplastic polyurethane production of Comparative Example 1 was changed to (urea / 1,9-nonanediamine / 2-methyl-1,8-octanediamine) = (0.24 mol / 0.16 mol / 0.16 mol) (molar ratio 43.5 / 28.3 / 28.3), instead of (urea / 1,9-nonanediamine / 2-methyl-1,8-octanediamine) = (0.31 mol / 0.34 mol / 0.06 mol) (molar ratio 43.5 / 48.0 / 8.5). The resulting thermoplastic polyurethane had a number average molecular weight of 6,100, a weight average molecular weight of 10,200, a molecular weight distribution of 1.7, and an amine value of 109 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 0.7 and the melting point was 175° C. The thermoplastic polyurea obtained was evaluated for solution viscosity change (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0063] (Comparative Example 4) Thermoplastic polyurethanes were produced and dumbbell test pieces were prepared in the same manner as in Comparative Example 1, except that the monomer charge ratio in the thermoplastic polyurethane production of Comparative Example 1 was changed to (urea / 1,6-hexanediamine / 1,10-decanediamine) = (0.24 mol / 0.03 mol / 0.29 mol) (molar ratio 43.5 / 4.9 / 51.6), instead of (urea / 1,9-nonanediamine / 2-methyl-1,8-octanediamine) = (0.31 mol / 0.34 mol / 0.06 mol) (molar ratio 43.5 / 48.0 / 8.5). The resulting thermoplastic polyurethane had a number average molecular weight of 6,800, a weight average molecular weight of 12,900, a molecular weight distribution of 1.9, and an amine value of 77 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 0.5 and the melting point was 220° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0064] (Comparative Example 5) Thermoplastic polyurethanes were produced and dumbbell test pieces were prepared in the same manner as in Comparative Example 1, except that the monomer charging ratio in the thermoplastic polyurethane production of Comparative Example 1 was changed to (urea / 1,9-nonanediamine / 2-methyl-1,8-octanediamine) = (0.31 mol / 0.34 mol / 0.06 mol) (molar ratio 43.5 / 48.0 / 8.5), but the monomer charging ratio was changed to (urea / 1,12-dodecanediamine) = (0.24 mol / 0.31 mol) (molar ratio 43.5 / 56.5). The resulting thermoplastic polyurethane had a number average molecular weight of 8,300, a weight average molecular weight of 14,800, a molecular weight distribution of 1.8, and an amine value of 104 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity index was 0.9 and the melting point was 210° C. The thermoplastic polyurea obtained was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0065] Comparative Example 6: Urea, 2-methyl-1,8-octanediamine, and 1,10-decanediamine were charged into a flask equipped with a device capable of distilling off the generated liquid and gas, so that (urea / 2-methyl-1,8-octanediamine / 1,10-decanediamine) = (0.24 mol / 0.20 mol / 0.05 mol) (molar ratio 49.5 / 40.6 / 9.9). 0.002 mol of caproic acid amide was then added. Under a nitrogen flow at 50 mL / min, the temperature was raised from 25°C to 130°C and heated for 1 hour, then further raised to 160°C and heated for 1 hour. After further raising the temperature to 240°C, it was confirmed that the amount of ammonia generated had decreased, and the mixture was heated under a reduced pressure of 100 Pa for 2 hours to obtain a colorless, transparent thermoplastic polyurea. The thermoplastic polyurea thus obtained had a number average molecular weight of 19,300, a weight average molecular weight of 58,700, a molecular weight distribution of 3.0, and an amine value of 70 μmol / g, calculated as "number average molecular weight × amine value / 10 ６ The viscosity of the resulting thermoplastic polyurea was evaluated for change in solution viscosity (viscosity stability) and elongation at break (tensile properties). The results are shown in Table 1.

[0066] In Table 1, "Not measurable*" for Comparative Example 2 means that the sample broke when attached to the test jig.

[0067] From Table 1, it can be seen that the thermoplastic polyurethane has a number average molecular weight of more than 5,000 and not more than 50,000, and the number average molecular weight and the amine value satisfy formula (1), thereby enabling both mechanical properties (improved elongation at break) and moldability (suppression of change in melt viscosity) to be achieved at a high level.

[0068] Comparison of Examples 1 to 6 with Comparative Examples 1 and 3 to 6 reveals that the thermoplastic polyurea of ​​the present invention has improved viscosity stability when melted.

[0069] Comparison of Examples 1 to 6 with Comparative Examples 1, 3 to 6 shows that the viscosity stability of a thermoplastic polyurea having an amine value of 150 μmol / g or more is improved regardless of the diamine unit (A-1) and the diamine unit (A-2).

[0070] Comparison between Example 1 and Comparative Example 2 shows that good tensile properties are achieved by setting the number average molecular weight to more than 5000 g / mol.

[0071] According to the present invention, there are provided a thermoplastic polyurea and a method for producing the same, a thermoplastic polyurea composition containing the thermoplastic polyurea, and a molded article containing the thermoplastic polyurea composition, which exhibit both high levels of mechanical properties and moldability. The thermoplastic polyurea of ​​the present invention can be used, for example, in various substrates for electronic components, housings for electronic components, caging for electronic components, coverlays, wire coatings, laminate films, cover films for displays, tubes for home appliances, fuel pipes, chemical tubes, face shields, industrial hydraulic belts, airless tires, tire inner liners, seal members, diaphragms, wire cables, sliding gears, bearing retainers, hair dryers, bobbin cases, eyeglass lenses, eyeglass frames, filter bowls, mixer faucets, medical catheters, wearable devices, etc.

Claims

1. A thermoplastic polyurea having a number average molecular weight of more than 5,000 and not more than 50,000, wherein the number average molecular weight and the amine value satisfy the following formula (1): 2.0≦(number average molecular weight×amine value [μmol / g]) / 10. ６ ≦4.0 2. The thermoplastic polyurea of ​​claim 1, wherein the number average molecular weight is 7,000 to 40,000.

3. The thermoplastic polyurea according to claim 1 or 2, wherein the amine value is 150 μmol / g or more.

4. The thermoplastic polyurea according to claim 1 or 2, which comprises structural units derived from diamine and structural units derived from urea.

5. The thermoplastic polyurea according to claim 4, wherein the ratio of the structural units derived from the aliphatic diamine to the total structural units derived from the diamine is 50 mol % or more.

6. The thermoplastic polyurea according to claim 4, wherein the ratio of the structural units derived from aliphatic diamine to the total structural units derived from diamine is 85 mol % or more.

7. The thermoplastic polyurea according to claim 1 or 2, wherein the change in solution viscosity when kneaded for 5 minutes at a temperature 30°C higher than the melting point of the thermoplastic polyurea is 15% or less.

8. A thermoplastic polyurea composition comprising the thermoplastic polyurea according to claim 1 or 2.

9. A molded article comprising the thermoplastic polyurea composition according to claim 8.

10. A method for producing the thermoplastic polyurea according to claim 1 or 2, comprising melt-kneading the urea and the diamine to prepare a molten mixture so that the molar ratio of the diamine to the urea is 1.20 to 1.60, adding additional urea to the prepared molten mixture, and polymerizing the urea and the diamine.

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