Polyurea and producing method thereof

Abstract

To provide a polyurea capable of producing without using a large scale reactor, less in gel generation and having a high molecular weight and color tone and a producing method thereof.SOLUTION: There are provided a polyurea which is a reaction product made from a diamine compound and carbon dioxide as raw materials, a b value of pellets made from the reaction product being 5.0 or less; a method for producing the polyurea by reacting a diamine compound with carbon dioxide in the presence of a condensing agent; a method for producing the polyurea in which an amount of the condensing agent used is less than 1 mole per 1 mole of the diamine compound; a method for producing the polyurea in which the condensing agent is a carbodiimide compound; and a method for producing the polyurea by reacting a diamine compound with carbon dioxide at a pressure of less than 5.0 MPa.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to polyureas and methods for their production. [Background technology]

[0002] Polyureas are widely used in injection molded products, adhesives, etc. because of their excellent heat resistance, mechanical strength, and chemical resistance.

[0003] A typical method for producing polyurea is to polymerize a diamine compound and a diisocyanate as raw materials. Known methods for producing polyurea include melt polymerization and low-temperature solid-phase polymerization. However, such methods have the problem that the diisocyanate has high polymerizability, which causes branching in the polymer chain, resulting in the formation of gel and making it difficult to obtain a high molecular weight.

[0004] A method that does not use diisocyanate as a raw material can be considered as a method for avoiding the branching problem. As such a production method, Patent Document 1 discloses a method for producing polyurea by polymerizing a diamine compound and carbon dioxide under a pressure condition of 5 to 10 MPa. However, the production method of Patent Document 1 requires the use of a large-scale reaction vessel because carbon dioxide is introduced at 5 to 10 MPa for polymerization. In addition, the reaction time is long, so the color tone is insufficient and improvement of the color tone is required. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-107095 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made to solve the above problems, and has an object to provide a polyurea that can be produced without using a large-scale reaction vessel, does not produce gel, and has a high molecular weight and a good color tone, and a method for producing the same. [Means for solving the problem]

[0007] Means for Solving the Problems The present inventors have conducted intensive research to solve the above problems, and as a result have found that the above object can be achieved by producing a diamine compound by reacting a diamine compound with carbon dioxide in the presence of a condensing agent, thereby completing the present invention.

[0008] That is, the gist of the present invention is as follows. <1> A polyurea which is a reaction product of a diamine compound and carbon dioxide as raw materials, and the b value of pellets made from the polyurea is 5.0 or less. <2> A diamine compound is reacted with carbon dioxide in the presence of a condensing agent. <1> A method for producing the polyurea described in claim 1. <3> The amount of the condensing agent used is less than 1.0 mole per mole of the diamine compound. <2> A method for producing the polyurea described in claim 1. <4> The condensing agent is a carbodiimide compound. <2> or <3> A method for producing the polyurea described in claim 1. <5> React diamine compounds with carbon dioxide at a pressure of less than 5.0 MPa <2> ~ <4> A method for producing the polyurea according to any one of claims 1 to 4. Effect of the Invention

[0009] According to the present invention, it is possible to provide a polyurea which can be produced without using a large-scale reaction vessel, is free from gel generation, and has a high molecular weight and a good color tone. According to the production method of the present invention, a polyurea having a high molecular weight and a good color tone can be polymerized with good productivity under a low pressure of less than 5.0 MPa, where the concentration of carbon dioxide is sufficiently low. Furthermore, since the polymerization can be performed under a low pressure, no large-scale equipment is required. Furthermore, since carbon dioxide is used as a raw material, it is expected to have the effect of suppressing the greenhouse effect. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The polyurea of ​​the present invention is a reaction product of a diamine compound and carbon dioxide as raw materials. For example, the polyurea of ​​the present invention contains a diamine compound and carbon dioxide as monomer components.

[0011] The diamine compound includes an aliphatic diamine, an alicyclic diamine, and an aromatic diamine.

[0012] The aliphatic diamine is an organic compound having two amino groups in one molecule and having neither an aromatic ring nor an alicyclic ring. The aliphatic diamine is preferably an aliphatic primary diamine from the viewpoint of suppressing the generation of gel. The number of carbon atoms of the aliphatic diamine is not particularly limited, but is preferably 2 to 50, more preferably 4 to 36, even more preferably 4 to 18, and particularly preferably 4 to 12. Examples of the aliphatic diamine include 1,4-butanediamine, 1,5-pentanediamine, 1,5-diamino-2-methylpentane, 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, and dimer diamine. Dimer diamine is a cyclic or acyclic dimer acid, which is a dimer of unsaturated fatty acid such as oleic acid, in which all carboxyl groups are replaced with primary amino groups (see JP-A-9-12712). Here, dimer acid mainly includes a dibasic acid having 36 carbon atoms obtained by dimerizing unsaturated fatty acid such as oleic acid, linoleic acid, or linolenic acid, and includes a monomer acid having 18 carbon atoms, a trimer acid having 54 carbon atoms, and a polymerized fatty acid having 20 to 90 carbon atoms depending on the degree of purification. The dimer acid includes a double bond, and the degree of unsaturation may be reduced by, for example, a hydrogenation reaction. Commercially available dimer diamines include, for example, "VERSAMINE 551" manufactured by BASF Japan, "VERSAMINE 552" manufactured by BASF Japan (hydrogenated product of VERSAMINE 551), "PRIAMINE 1075" manufactured by Croda Japan, and "PRIAMINE 1074" manufactured by Croda Japan.

[0013] Alicyclic diamines are organic compounds that have two amino groups and one or more (particularly one) alicyclic rings in one molecule, but do not have an aromatic ring. The number of carbon atoms in alicyclic diamines is not particularly limited, and may be, for example, 6 to 50, preferably 6 to 30, and more preferably 6 to 12. Examples of alicyclic diamines include cyclohexanediamine, cyclopentanediamine, bisaminomethylcyclohexane, bisaminomethylcyclopentane, bisaminomethylnorbornene, and bis-(4,4'-aminocyclohexyl)methane.

[0014] An aromatic diamine is an organic compound having two amino groups and one or more (particularly one) aromatic ring in one molecule, but no alicyclic ring. The number of carbon atoms in the aromatic diamine is not particularly limited, and may be, for example, 6 to 50, preferably 6 to 30, and more preferably 6 to 12. Examples of aromatic diamines include metaxylylenediamine and paraxylylenediamine.

[0015] From the viewpoint of further increasing the molecular weight, it is preferable that at least one diamine compound is an aliphatic diamine having 4 to 36 carbon atoms (particularly, an aliphatic primary diamine). A primary diamine is a diamine in which both of the two amino groups are "NH 2 " is a compound represented by the formula: ". Among the diamine compounds, aliphatic diamine compounds having 4 to 12 carbon atoms are preferred, and from the viewpoint of raw material procurement, 1,4-butanediamine, 1,5-pentanediamine, 1,5-diamino-2-methylpentane, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, and 1,12-dodecanediamine are more preferred. The diamine compound may contain polyoxyalkylene diamine or polyorganosiloxane diamine, and examples of the diamine compound include triethylene glycol diamine, polyoxypropylene diamine, and polydimethylsiloxane diamine. By selecting the type of diamine compound, the melting point, flexibility, water absorption, and the like of the polyurea can be controlled. The diamine compound may be used alone or in combination of two or more kinds.

[0016] Examples of carbon dioxide include gas obtained by separating and refining carbon dioxide contained in factory exhaust gases from the steel and oil manufacturing industries, combustion gases from garbage incineration, air, etc., and commercially available refined gases. Among these, gas obtained by separating and refining carbon dioxide contained in factory exhaust gases, combustion gases, air, etc. is preferable in terms of reducing greenhouse gases. In terms of ease of availability, commercially available refined gases are preferable.

[0017] The purity of carbon dioxide is preferably 90% or more, more preferably 95% or more, and even more preferably 99% or more. By making the purity of carbon dioxide 90% or more, carbon dioxide and a diamine compound can be efficiently polymerized under low pressure.

[0018] In the present invention, polycondensation is carried out in the presence of a condensing agent. The condensing agent may be a carbodiimide compound. A carbodiimide compound is a compound having a carbodiimide group represented by (-N=C=N-) in the molecule. Examples of carbodiimide compounds include N,N'-diisopropylcarbodiimide (DIC), N,N'-dicyclohexylcarbodiimide (DCC), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, bis(2-methylphenyl)carbodiimide, bis(2-isopropylphenyl)carbodiimide, bis(2-chlorophenyl)carbodiimide, bis(2-nitrophenyl)carbodiimide, bis(2,6-diethylphenyl)carbodiimide, bis(2,6-diisopropylphenyl)carbodiimide, and 1,3-di-p-toluylcarbodiimide. Among these, DCC is preferred from the viewpoint of increasing the molecular weight of the polyurea.

[0019] In the production method of the present invention, a polyurea having a higher molecular weight can be obtained with good productivity by reacting a diamine compound with carbon dioxide in the presence of a condensing agent. For example, a polyurea having a higher molecular weight can be obtained with good productivity by reacting a diamine compound with carbon dioxide at a specific low pressure in the presence of a specific carbodiimide compound. In the absence of a condensing agent, the reaction between carbon dioxide and a diamine compound does not proceed sufficiently under low pressure (e.g., atmospheric pressure), and polyurea cannot be obtained.

[0020] The process by which the molecular chain grows varies depending on the condensing agent used. For example, when a carbodiimide compound is used as the condensing agent, it is presumed that the diamine compound reacts with carbon dioxide according to the following formulas (1) to (4) to grow the molecular chain. In detail, first, the diamine compound reacts with carbon dioxide to generate a carbamic acid compound (formula (1)). Then, the carbamic acid compound reacts with the condensing agent to generate O-acylisourea (formula (2)). Next, the O-acylisourea reacts with another diamine compound to generate polyurea and a urea derivative (formula (3)). Next, the urea derivative reacts with yet another diamine compound to generate polyurea and an amine compound (formula (4)). It is presumed that the molecular chain grows by repeating formulas (3) and (4).

[0021] [ka] (R 1 is a hydrocarbon with 2 to 50 carbon atoms, R 2 , R 3 each independently represents a monovalent aliphatic group, a monovalent alicyclic group, or an aromatic group.

[0022] Usually, when a condensation reaction is carried out using a condensing agent such as DCC, the amount of the condensing agent must be 1 mole or more per mole of the raw material, and the condensing agent such as DCC must be purified because it is converted to a urea derivative such as 1,3-dicyclohexylurea. On the other hand, in the present invention, as shown in formula (4), the urea derivative is consumed by an exchange reaction with a diamine compound and contributes to the growth of molecular chains, so the amount of the condensing agent used may be 1 mole or less per mole of the raw material.

[0023] Specifically, the amount of the condensing agent used is preferably less than 1.0 mol, more preferably 0.4 to 0.6 mol, even more preferably 0.45 to 0.55 mol, sufficiently preferably 0.48 to 0.52, and most preferably 0.49 to 0.51 mol, per mol of the diamine compound. By using an amount of 0.5 mol or more per mol of the diamine compound, a polyurea having a high molecular weight and in which some or all of the terminal amino groups are blocked can be obtained.

[0024] The method of reacting the diamine compound with carbon dioxide includes a method of introducing carbon dioxide after putting the diamine compound into a reaction vessel, and a method of filling the reaction vessel with carbon dioxide and adding the diamine compound thereto. The former method is preferred from the viewpoint of reducing the volatilization of the diamine compound and the clogging of the piping. In either method (the former and latter methods), the diamine compound eventually absorbs carbon dioxide.

[0025] Carbon dioxide can be introduced into the reaction vessel using a device such as a pump, a compressor, a blower, etc. These devices may be used alone or in combination of two or more kinds.

[0026] Methods for making the diamine compound absorb carbon dioxide include exposing the diamine compound to a carbon dioxide gas flow and bubbling the diamine compound with carbon dioxide, the latter being preferred from the viewpoint of absorption efficiency. In this case, the reaction vessel may be heated so that the diamine compound can easily absorb carbon dioxide. Carbon dioxide can be used as a raw material by distributing and / or circulating it.

[0027] In the production method of the present invention, a terminal blocking agent may be used as necessary. Examples of the terminal blocking agent include monoamines such as hexylamine, octylamine, cyclohexylamine, and aniline, and monocarboxylic acids such as acetic acid, lauric acid, and benzoic acid. These may be used alone or in combination of two or more. The amount of the terminal blocking agent is not particularly limited, but from the viewpoint of increasing the molecular weight, it is preferably 5 mol % or less, more preferably 2 mol % or less, and even more preferably 0 mol % relative to the diamine compound.

[0028] In the production method of the present invention, a metal catalyst may be used as necessary. The metal catalyst may be, for example, in the form of a so-called organometallic compound, or in the form of a metal oxide, a metal hydroxide, a metal sulfate, or a metal halide. Examples of the organometallic compound include alkylated compounds, alkoxylated compounds, monohydroxymonocarboxylic acid complexed compounds, organic acid esterified compounds, halides, and composite compounds thereof.

[0029] Examples of the alkyl group constituting the alkylated product include linear or branched alkyl groups (particularly linear alkyl groups) having 3 to 20 carbon atoms (particularly 3 to 12 carbon atoms). Examples of the alkyl group include an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, and an n-pentyl group. Examples of the alkoxy group constituting the alkoxylated product include linear or branched alkoxy groups (particularly linear alkoxy groups) having 3 to 12 carbon atoms (particularly 3 to 5 carbon atoms). Examples of the alkoxy group include an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, a sec-butyloxy group, an isobutyloxy group, a tert-butyloxy group, and an n-pentyloxy group. Examples of the monohydroxymonocarboxylic acid constituting the monohydroxymonocarboxylic acid complex include monohydroxymonocarboxylic acids having 2 to 6 carbon atoms (particularly 2 to 4 carbon atoms). Examples of the monohydroxymonocarboxylic acid include glycolic acid, lactic acid, 2-hydroxybutyric acid, and 2-hydroxy-2-methylpropanoic acid. Examples of the organic acid constituting the organic acid ester include monocarboxylic acid compounds having 1 to 10 carbon atoms (particularly 1 to 5 carbon atoms). Examples of the monocarboxylic acid compounds include formic acid, acetic acid, propionic acid, butyric acid, 2-methylpropanoic acid, and valeric acid. Examples of halogen atoms constituting the halide include a fluorine atom, a chlorine atom, and a bromine atom.

[0030] In the production method of the present invention, it is preferable to use, among metal catalysts, a compound containing one or more (particularly one) metal elements selected from the group consisting of zinc, aluminum, tin, titanium, zirconium and cerium as the catalyst. Examples of compounds containing zinc element include zinc alkyls, zinc dialkyls, zinc chloride, zinc bromide, zinc sulfate, zinc oxide, and zinc acetate. An example of a compound containing an aluminum element is aluminum sec-butoxide. Examples of compounds containing tin element include monoalkyltin oxides such as monobutyltin oxide; dialkyltin oxides such as dibutyltin oxide and dioctyltin oxide; tetraalkyltins such as tetrabutyltin; tin esters such as dibutyltin dilaurate, monobutyltin tris(2-ethylhexanoate) and tin octanoate; and dialkyltin oxide hydroxides such as butyltin oxide hydroxide. Examples of compounds containing titanium element include tetraalkyl titanates such as tetra-n-butyl titanate, tetra-n-propyl titanate, and tetraisopropyl titanate; titanocene dichloride; titanocene bis(trifluoromethanesulfonate); and titanium chelate compounds such as dihydroxybis(ammonium lactate)titanium. Examples of compounds containing zirconium element include tetraalkyloxyzirconiums such as tetra-n-butoxyzirconium and tetra-n-propoxyzirconium; zirconium tetraacetylacetonate; zirconium octylate; zirconium oxide; zirconium chloride; ammonium zirconium carbonate; zirconium oxyacetate; zirconium hydroxide acetate; and zirconocene dichloride. An example of a compound containing cerium element is cerium oxide. The metal catalyst may be used alone or in combination of two or more kinds.

[0031] The content of the metal catalyst is not particularly limited, and is, for example, 5 mol % or less relative to the diamine compound, and from the viewpoint of further increasing the molecular weight, is preferably 2 mol % or less, more preferably 1 mol % or less, and even more preferably 0 mol %.

[0032] In the production method of the present invention, in addition to the above metal catalyst, phosphoric acid, phosphorous acid, hypophosphorous acid, or their ester derivatives, amides or anhydrides may be used in combination as the catalyst. Examples of ester derivatives include phenyl esters and alkyl esters. Examples of amides include phosphoramidites. Examples of anhydrides include pyrophosphoric acid and metaphosphoric acid. Other examples of catalysts include tertiary amines such as triethylamine, pyridine, and 4-dimethylaminopyridine; phosphorus chlorides such as phosphorus trichloride; phosphite derivatives such as triarylphosphite; phosphine derivatives such as triarylphosphine and triarylphosphine dihalides; and arylboronic acids such as 3,5-bistrifluorophenylboronic acid. Catalysts other than metal catalysts may be used alone or in combination of two or more.

[0033] The content of the catalyst other than the metal catalyst is not particularly limited, and is, for example, 5 mol % or less relative to the diamine compound, and from the viewpoint of further increasing the molecular weight, is preferably 2 mol % or less, more preferably 1 mol % or less, and even more preferably 0 mol %.

[0034] In the production method of the present invention, a dehydrating agent may be used as necessary. Examples of the dehydrating agent include calcium chloride, calcium oxide, aluminum oxide, magnesium oxide, potassium carbonate, calcium sulfate, magnesium sulfate, sodium sulfate, molecular sieve (zeolite), and silica gel. When a dehydrating agent is used, it is preferable to remove the dehydrating agent by a filtration step or the like after the reaction is completed.

[0035] In the present invention, the polymerization pressure can be less than 5.0 MPa, and from the viewpoint of cost reduction by simplifying the production method or production equipment, it is preferable to set it to less than 3.0 MPa, more preferably less than 2.0 MPa, even more preferably 1.0 MPa or less, sufficiently preferably 0.5 MPa or less, and most preferably 0.2 MPa or less. If the polymerization pressure is 5.0 MPa or more, it is not preferable because it is necessary to use a large-scale reaction vessel. In addition, if the polymerization pressure is 5.0 MPa or more, when a reaction vessel made of a stainless steel material such as SUS316 or SUS304 is used, corrosion by carbon dioxide becomes significant, and the reaction vessel and the polymerized product are colored, which is not preferable. If the inner surface of the reaction vessel is processed with a material such as Hastelloy or Inconel, corrosion can be suppressed, but the cost of the equipment increases significantly, which is not preferable. On the other hand, by setting the polymerization pressure to less than 5.0 MPa, the pressure resistance performance required for the reaction vessel decreases, so that it is easy to increase the size of the production equipment and the cost of the equipment also decreases. The polymerization pressure can be atmospheric pressure (for example, 0.1 MPa), which leads to a significant cost reduction by simplifying the production method or production equipment. The atmospheric pressure may be from 0.05 to 0.15 MPa, particularly from 0.08 to 0.12 MPa.

[0036] From the viewpoint of increasing the molecular weight, the carbon dioxide partial pressure in the polymerization pressure is preferably less than 5.0 MPa, more preferably 0.1 MPa or more and less than 5.0 MPa, even more preferably 0.1 MPa or more and less than 3 MPa, sufficiently preferably 0.1 MPa or more and less than 2.0 MPa, and most preferably 0.1 MPa or more and less than 1 MPa. By setting the carbon dioxide partial pressure to 0.1 MPa or more and less than 5.0 MPa, the reaction rate of the polycondensation reaction between the diamine compound and carbon dioxide in the presence of the condensing agent can be improved, and polyurea can be obtained with good productivity.

[0037] As a method for controlling the polymerization pressure, a method of controlling the pressure by sealing the reaction vessel and using carbon dioxide, or a method of controlling the pressure by using a back pressure valve while flowing carbon dioxide are preferred. The former method is preferred in that it can reduce the volatilization of the diamine compound and the clogging of the piping, and the latter method is preferred in that it can always distill off the amine compound produced during the reaction.

[0038] When carbon dioxide is circulated, it is usually circulated through the reaction solution at a flow rate of 0.05 mol% / min or more and less than 2.50 mol% / min. From the viewpoint of increasing the molecular weight, the flow rate is preferably 0.10 mol% / min or more and less than 2.00 mol% / min, more preferably 0.20 mol% / min or more and less than 1.50 mol% / min, even more preferably 0.20 mol% / min or more and less than 1.00 mol% / min, and most preferably 0.60 mol% / min or more and less than 1.00 mol% / min.

[0039] When the reaction vessel is sealed and the polymerization pressure is controlled to a pressure higher than atmospheric pressure using carbon dioxide, the pressure may be released at regular intervals and then repressurized with carbon dioxide in order to discharge the amine compound produced by the reaction from the reaction vessel as necessary. The intervals for releasing the pressure are not particularly limited, and from the viewpoints of improving the workability of the pressure release and pressurization operations, the productivity of the polyurea, and further increasing the molecular weight, the intervals are preferably 5 minutes / time to 120 minutes / time, more preferably 10 minutes / time to 90 minutes / time, and even more preferably 15 minutes / time to 45 minutes / time.

[0040] The ultimate pressure during pressure release is not particularly limited, but from the viewpoint of further increasing the molecular weight and discharging the amine compound, it is preferably less than 0.5 MPa, more preferably less than 0.3 MPa, and even more preferably 0.1 MPa or less.

[0041] In the production method of the present invention, the polyurea obtained by either the method of controlling the reaction by sealing the reaction vessel and using carbon dioxide or the method of circulating carbon dioxide may be used to continue the reaction under an inert gas atmosphere and / or under reduced pressure. From the viewpoint of further increasing the molecular weight, it is preferable to continue the reaction under reduced pressure. In this way, the generated amine compound is removed from the polyurea, the reaction of generating the polyurea progresses, and a polyurea with a higher molecular weight can be obtained.

[0042] The polymerization temperature is not particularly limited, and is preferably 120 to 290° C., more preferably 140 to 280° C., further preferably 160 to 280° C., sufficiently preferably 200 to 280° C., and most preferably 220 to 260° C. By setting the polymerization temperature at 120 to 290° C., it is possible to improve the reaction rate of the polycondensation reaction between the diamine compound and carbon dioxide in the presence of a condensing agent without promoting thermal decomposition of the polyurea, and to obtain the polyurea with good productivity.

[0043] The production method of the present invention can be applied to either a melt polymerization method or a solid-phase polymerization method depending on the melting point of the diamine compound and the polymerization temperature. From the viewpoint of further increasing the molecular weight, the melt polymerization method is preferred.

[0044] In the production method of the present invention, a specific solvent may be added to the reaction system in order to suppress accumulation of scattered matter generated inside the reaction vessel. The reflux of the solvent in the reaction vessel has the effect of washing away scattered matter adhering to the inside of the reaction vessel. Examples of the solvent include ether-based solvents such as triglyme; hydrocarbon-based solvents such as dodecane, decahydronaphthalene, and tetrahydronaphthalene; and aromatic solvents such as Solvesso 150 and Solvesso 200. Among them, tetrahydronaphthalene is preferable from the viewpoint of safety such as flammability. The solvent may be used alone or as a mixture of two or more kinds. Usually, accumulation of scattered matter inside the reaction vessel can be suppressed by using the solvent in an amount of 1 to 20% by mass relative to the diamine compound. The amount of the solvent used is preferably 2 to 15% by mass, more preferably 3 to 12% by mass, and even more preferably 4 to 10% by mass relative to the diamine compound from the viewpoint of more effective inhibition of accumulation of scattered matter and more rapid rise in the internal temperature of the reaction vessel. The solvent can be removed from the polyurea by reducing the pressure in the reaction vessel system after the reaction to less than 100 Pa and stirring for a certain period of time.

[0045] By using the manufacturing method of the present invention, the number average molecular weight of the polyurea can be 4000 or more. If the number average molecular weight is 4000 or more, molding processing is easy. From the viewpoint of increasing the molecular weight, the number average molecular weight of the polyurea of ​​the present invention is preferably 7000 or more, more preferably 8500 or more, even more preferably 9500 or more, sufficiently preferably 12000 or more, and most preferably 15000 or more. The upper limit of the number average molecular weight of the polyurea is not particularly limited, and the number average molecular weight of the polyurea is usually 100000 or less, particularly 50000 or less.

[0046] In this specification, the number average molecular weight of polyurea is a value measured by gel permeation chromatography (GPC).

[0047] When the polyurea of ​​the present invention is crystalline, it usually has a melting point of 300° C. or less. From the viewpoint of suppressing thermal degradation during melt processing, the melting point of the polyurea of ​​the present invention is preferably 280° C. or less, more preferably 260° C. or less, and further preferably 250° C. or less. The lower limit of the melting point of the polyurea is not particularly limited, and the polyurea may be amorphous and does not exhibit a melting point.

[0048] In this specification, the melting point of the polyurea is the peak temperature measured by a differential scanning calorimeter.

[0049] The b value of the polyurea pellets of the present invention must be 5.0 or less, preferably 4.0 or less, more preferably 3.0 or less, and even more preferably 2.5 or less. The lower limit of the b value of the polyurea is not particularly limited, but is usually -2.0 or more, and preferably 0 or more.

[0050] In this specification, the b value of polyurea is the b value in the Hunter Lab color space measured by filling a pellet measurement cell with pellets and measuring with a spectrophotometer. The size of the pellets used is preferably 2 to 5 mm in diameter and 3 to 6 mm in length.

[0051] The polyurea of ​​the present invention may contain additives such as antioxidants, antistatic agents, flame retardants, flame retardant auxiliaries, heat stabilizers, fibrous reinforcing materials, fillers, and pigments. Examples of fibrous reinforcing materials include glass fibers, carbon fibers, and cellulose nanofibers. Examples of fillers include talc, swellable clay minerals, silica, alumina, glass beads, graphite, fillers, and cellulose nanocrystals. Examples of pigments include titanium oxide and carbon black. These may be added during polymerization, molding, film formation, or spinning.

[0052] The content of the additive is not particularly limited, and is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less, based on the polyurea.

[0053] Polyureas can be processed into various molded articles by known molding methods such as injection molding, extrusion molding, and blow molding.

[0054] Moreover, the polyurea can be processed into a film, sheet, or fiber by a known film-forming method or spinning method.

[0055] These molded articles, films, fibers, etc. can be used for various applications such as industrial materials such as electric / electronic parts, automobile parts, and office machine parts, industrial materials, and household goods. EXAMPLES

[0056] 1.Measurement method (1) Identification of polyurea Infrared spectroscopy (potassium bromide method) showed a peak at 1618 cm -1 (CO stretch) and 1575cm -1 The absorption spectrum of (NH stretching) was confirmed and judged according to the following criteria. ○: Both absorption spectra were observed. ×: Any absorption spectrum was not observed.

[0057] (2) Presence or absence of gel Polyurea was mixed with trifluoroacetic acid to a solution concentration of 40% by mass. If there were no impurities after mixing, it was marked with "○" indicating that no gel had been generated, and if there were unnecessary substances, it was marked with "×" indicating that gel had been generated.

[0058] (3) Number average molecular weight Using a gel permeation chromatography (GPC) apparatus HLC-8420GPC manufactured by Tosoh Corporation, sample preparation and GPC measurement were carried out under the following conditions to determine the number average molecular weight. <Sample preparation> 8 mg of polyurea was dissolved in 5 mL of hexafluoroisopropanol containing 10 mM sodium trifluoroacetate, and then filtered through a disk filter. <Condition> Column: Tosoh TSKgel SuperHM-M Eluent: 10 mM sodium trifluoroacetate in hexafluoroisopropanol Flow rate: 0.4mL / min Temperature: 40℃ Standard sample: Polymethyl methacrylate Easi Vial PM (registered trademark) manufactured by Agilent Technologies

[0059] (4) Melting point 10 mg of the obtained polyurea resin was weighed out and measured as a sample using a differential scanning calorimeter (input compensation type DSC8000) manufactured by PerkinElmer Co., Ltd. in accordance with JIS K 7121. The measurement conditions were as follows: the temperature was raised from 20°C to 280°C at a heating rate of 20°C / min, held at 280°C for 5 minutes, cooled to 20°C at a heating rate of 150°C / min, held at 20°C for 5 minutes, and then the melting point was calculated from the measurement results when the temperature was raised from 20°C to 280°C at a heating rate of 20°C / min.

[0060] (5) b value Using a Nippon Denshoku Industries Co., Ltd. SE-6000 spectrophotometer, the b value of pellets filled in a pellet measurement cell (diameter 35 mm x height 15 mm) was measured using a C light source, 2°C field of view, and reflection method.

[0061] Example 1 150 parts by mass of 1,10-decanediamine as a diamine compound was placed in a reaction vessel equipped with a fractionator, and after heating and dissolving at 120°C, 89.8 parts by mass (50 mol% based on the total diamine compounds) of N,N'-dicyclohexylcarbodiimide was added as a condensation agent. The reaction temperature was then raised to 240°C, and the mixture was stirred for 8 hours under atmospheric pressure (0.1 MPa) while circulating carbon dioxide (purity 99.5%) at a flow rate of 0.94 mol% / min based on the total diamine compounds in the reaction solution, to obtain a polyurea.

[0062] Example 2 150 parts by mass of 1,10-decanediamine as a diamine compound was placed in a reaction vessel equipped with a fractionator, and after heating and dissolving at 120°C, 89.8 parts by mass (50 mol% based on the total diamine compounds) of N,N'-dicyclohexylcarbodiimide was added as a condensation agent. The reaction temperature was then raised to 240°C, and the mixture was stirred for 8 hours under atmospheric pressure (0.1 MPa) while flowing carbon dioxide (purity 99.5%) at a flow rate of 0.94 mol% / min based on the total diamine compounds into the reaction solution, and then stirred for another 2 hours under reduced pressure to obtain a polyurea.

[0063] Example 3 150 parts by mass of 1,10-decanediamine and 15 parts by mass of tetrahydronaphthalene were placed in a reaction vessel equipped with a fractionator and dissolved by heating at 120°C, and then 89.8 parts by mass of N,N'-dicyclohexylcarbodiimide (50 mol% based on the total diamine compounds) were added as a condensation agent. The reaction temperature was then raised to 240°C, and the mixture was stirred for 8 hours under atmospheric pressure (0.1 MPa) while flowing carbon dioxide (purity 99.5%) at a flow rate of 0.94 mol% / min based on the total diamine compounds into the reaction solution, and then stirred for another 2 hours under reduced pressure to obtain a polyurea.

[0064] Example 4 150 parts by mass of 1,10-decanediamine as a diamine compound and 0.44 parts by mass of hexylamine as an end-blocking agent were placed in a reaction vessel equipped with a fractionator, and after heating and dissolving at 120°C, 89.8 parts by mass of N,N'-dicyclohexylcarbodiimide as a condensation agent (50 mol% based on the total diamine compounds) was added. Next, the reaction temperature was raised to 240°C, and the mixture was stirred for 8 hours under atmospheric pressure (0.1 MPa) while flowing carbon dioxide (purity 99.5%) into the reaction solution at a flow rate of 0.94 mol% / min based on the total diamine compounds, to obtain a polyurea.

[0065] Example 5 150 parts by mass of 1,10-decanediamine as a diamine compound and 89.8 parts by mass of N,N'-dicyclohexylcarbodiimide as a condensation agent were placed in a 500 mL capacity SUS316 reaction vessel, the air in the reaction vessel was replaced with nitrogen three times, and then heated and dissolved at 120°C. Next, the reaction vessel was replaced with carbon dioxide (purity 99.5%) three times, sealed, the internal temperature was raised to 240°C, and carbon dioxide was introduced into the reaction vessel so that the pressure became 0.98 MPa. While maintaining the pressure of the reaction vessel at 0.98 MPa, the mixture was stirred for 8 hours to obtain a polyurea.

[0066] Example 6 150 parts by mass of 1,10-decanediamine as a diamine compound and 89.8 parts by mass of N,N'-dicyclohexylcarbodiimide as a condensation agent were placed in a SUS316 reaction vessel with an internal volume of 500 mL, and the air in the reaction vessel was replaced with nitrogen three times, and then heated and dissolved at 120 ° C. Then, the reaction vessel was replaced with carbon dioxide (purity 99.5%) three times, sealed, the internal temperature was raised to 240 ° C, and carbon dioxide was flowed into the reaction vessel so that the pressure became 0.98 MPa. Stirring was performed for 8 hours while maintaining the pressure of the reaction vessel at 0.98 MPa. Then, the pressure of the reaction vessel was lowered to atmospheric pressure (0.1 MPa), and stirring was performed for another 2 hours under reduced pressure to obtain polyurea.

[0067] Example 7 150 parts by mass of 1,10-decanediamine as a diamine compound and 54.9 parts by mass of N,N'-diisopropylcarbodiimide as a condensing agent were placed in a SUS316 reaction vessel with an internal volume of 500 mL, and the air in the reaction vessel was replaced with nitrogen three times, and then heated and dissolved at 120 ° C. Then, the reaction vessel was replaced with carbon dioxide (purity 99.5%) three times, and then sealed, the internal temperature was raised to 240 ° C, and carbon dioxide was introduced into the reaction vessel so that the pressure became 0.98 MPa. Stirring was performed for 8 hours while maintaining the pressure of the reaction vessel at 0.98 MPa. Then, the pressure of the reaction vessel was lowered to atmospheric pressure (0.1 MPa), and stirring was performed for another 2 hours under reduced pressure to obtain polyurea.

[0068] Comparative Examples 1 and 4 The same procedures as in Examples 1 and 4 were carried out except that the condensation agent and production conditions were changed as shown in Table 1. The resulting product was subjected to infrared spectroscopy using the potassium bromide method, and the spectrum was almost the same as that of the raw material decanediamine, and no peaks specific to polyurea were observed.

[0069] Comparative Examples 2 and 3 Polyureas were obtained in the same manner as in Examples 5 and 6, except that the condensation agent and production conditions were changed as shown in Table 1.

[0070] Reference example 1 The experiment was carried out based on Patent Document 1 (JP Patent Publication No. 2012-107095) (particularly Example 8 thereof). The details were as follows. 550 parts by mass of 1,10-decanediamine as a diamine compound and 1.62 parts by mass of hexylamine as an end-capping agent were placed in a SUS316 reaction vessel with an internal volume of 4 L. Next, the air in the reaction vessel was replaced with carbon dioxide three times, then the vessel was sealed, heated to an internal temperature of 200°C, and carbon dioxide (100% purity) was introduced into the reaction vessel so that the pressure was 5 MPa. The pressure in the reaction vessel was then maintained at 5 MPa and polymerization was carried out with stirring for 24 hours, and finally the pressure in the reaction vessel was reduced to 0.1 MPa, stirring was stopped, and the vessel was left to stand overnight.

[0071] Table 1 shows the property values ​​of the polyureas obtained in the Examples and Reference Examples, as well as the results of the Comparative Examples.

[0072] [Table 1]

[0073] The abbreviations in Table 1 are as follows. DDA: 1,10-decanediamine; HAN: hexylamine; CO 2 :carbon dioxide; DCC: N,N'-dicyclohexylcarbodiimide DIC: N,N'-diisopropylcarbodiimide

[0074] In Examples 1 to 7, the diamine compound was reacted with carbon dioxide in the presence of a condensing agent, and therefore polymerization was possible at atmospheric pressure (0.1 MPa) and at low pressure (0.98 MPa) in a closed environment, respectively. Moreover, no large-scale equipment was required, no gel was formed, and polyurea with a number average molecular weight of 4000 or more and a b value of 5.0 or less could be obtained.

[0075] In Examples 2 to 3 and 6 to 7, the reaction was carried out under reduced pressure in the latter stage of the reaction, and therefore polyureas having higher molecular weights than those in Example 1 and Example 5 could be obtained, respectively.

[0076] In Comparative Examples 1 to 4, since a condensing agent was not added, the reaction between carbon dioxide and the diamine compound was not sufficient, and a polyurea could not be obtained, or a polyurea with a sufficiently high molecular weight could not be obtained.

[0077] By comparing Example 4, Comparative Example 4, and Reference Example 1, it is found that even if the feed composition gives a polyurea at 5.0 MPa, if the reaction is carried out at atmospheric pressure (0.1 MPa) without a condensing agent, a polyurea cannot be obtained. However, it is found that if the reaction is carried out at atmospheric pressure (0.1 MPa) in the presence of a condensing agent, a polyurea can be obtained. By comparing Examples 5 and 6 with Comparative Examples 2 and 3, respectively, it is found that when the reaction is carried out in the presence of a condensing agent, the reactivity is improved and a polyurea with a higher molecular weight and good color tone can be obtained in a shorter reaction time.

Claims

1. A polyurea which is a reaction product of a diamine compound and carbon dioxide as raw materials, and in which the b value of pellets made from the reaction product is 5.0 or less.

2. The method for producing a polyurea according to claim 1, wherein the diamine compound is reacted with carbon dioxide in the presence of a condensing agent.

3. The method for producing a polyurea according to claim 2 , wherein the amount of the condensing agent used is less than 1.0 mol per 1 mol of the diamine compound.

4. The method for producing a polyurea according to claim 2 or 3, wherein the condensing agent is a carbodiimide compound.

5. The method for producing a polyurea according to claim 2 or 3, wherein the diamine compound and carbon dioxide are reacted at a pressure of less than 5.0 MPa.

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