JP2019019225A - Method for producing thermoplastic polyhydroxyurethane resin - Google Patents

Abstract

To provide a method for producing a thermoplastic polyhydroxyurethane resin capable of practical application, the method realizing performing a reaction of a 5-membered cyclic carbonate and an amine compound, and the method contributing to industrial spread of the thermoplastic polyhydroxyurethane resin which has excellent mechanical characteristics, is useful, and can be used as a binder of various products and the like.SOLUTION: Provided is a method for producing a thermoplastic polyhydroxyurethane resin, comprising: a step [1] of reacting a compound having a 5-membered cyclic carbonate group and a compound having an amino group in a solvent to obtain a preliminary reaction liquid (A) having a weight average molecular weight of 3000 to 20000; and a step [2] of obtaining a polyhydroxyurethane resin by supplying the preliminary reaction liquid (A) under a heated reduced pressure condition of 80 to 180°C and 10 to 200 torr and performing concentration of a substrate of the preliminary reaction liquid (A) by formation of a liquid film and evaporation, further polymerization, and solvent removal.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a polyhydroxyurethane compound by reacting a compound having a 5-membered cyclic carbonate group with a compound having an amino group, and in particular, has excellent mechanical properties, a film, a molding material, The present invention relates to a method for efficiently producing a thermoplastic polyhydroxyurethane compound that can be used as a binder for various coating agents and paints in a short time.

  The 5-membered cyclic carbonate group can be synthesized using carbon dioxide as a raw material. For this reason, the spread of technology that can use compounds having a 5-membered cyclic carbonate group as a raw material means that it can contribute to the reduction of greenhouse gases, which has become a global environmental problem in recent years. From a different perspective, this is a technology that should be noted.

  The reaction of a 5-membered cyclic carbonate group with an amino group is already known. For example, it is known that ethylene carbonate and ammonia are reacted to obtain a carbamate compound having the hydroxyl group (synonymous with a hydroxyurethane compound) (Non-patent Document 1).

  The reaction formula of a compound having a 5-membered cyclic carbonate group and a compound having an amino group is shown below. As shown below, since there are two types of cleavage of the 5-membered cyclic carbonate structure, when a compound having a 5-membered cyclic carbonate group is used as a raw material, two types of structures can be obtained. Are known.

  Here, when the compound having a 5-membered cyclic carbonate group is one using carbon dioxide as a raw material, the polyhydroxyurethane compound obtained by adding the amino group is also in the chemical structure. It becomes a compound that incorporates carbon dioxide. In addition, as described below, a polymerization reaction is performed using a compound having one or more 5-membered cyclic carbonate groups in one molecule and a compound having one or more amino groups in one molecule. There are also some reports on methods for producing polyhydroxyurethane compounds.

  For example, Patent Document 1 reports a method for producing a polyhydroxyurethane compound by reacting with bisphenol A-diglycidyl ether biscarbonate and hexamethylenediamine. However, according to the study by the present inventors, in the above reaction, the reaction proceeds relatively quickly in the initial stage of the reaction, but the reaction rate decreases as the reaction approaches the end point, and the desired reaction rate and molecular weight are obtained. Therefore, there is a problem that it takes a long time. For this reason, it has not been industrially spread.

  The above-mentioned polyhydroxyurethane compound is expected to be applied as a carbon offset material produced using carbon dioxide as a raw material, but on the other hand, it takes a long time to obtain the desired reaction rate and molecular weight. There is a problem that a large amount of power is consumed and carbon dioxide is discharged. For this reason, from the viewpoint of reducing greenhouse gases, which is a problem on a global scale, the above-mentioned polyhydroxyurethane compounds can be industrially disseminated by suppressing power consumption during production and reducing carbon dioxide emissions caused by power consumption. It needs to be minimized.

  On the other hand, when synthesizing a polyhydroxyurethane compound from a compound having a 5-membered cyclic carbonate group and a compound having an amino group for the purpose of improving the reaction rate, tertiary amines and various metal compounds are used as catalysts. It has been proposed to increase the stretching speed by being (see Patent Document 2).

  Regarding the consumption of electric power during production, it may be necessary to separate the polyhydroxyurethane compound obtained in the solution state into a polymer and a solvent. In that case, it is necessary to remove the solvent by drying or the like. In this case, power consumption also causes carbon dioxide emissions. Therefore, if the solvent removal can be performed efficiently, the emission of carbon dioxide can be suppressed, which can contribute to industrial spread. On the other hand, a method for removing an organic solvent from a resin solution composed of a thermoplastic polymer and an organic solvent has been studied. For example, in Patent Document 3, as an efficient solvent removal method from a resin solution composed of a styrene acrylic copolymer and an organic solvent, thermal and mechanical deterioration of the resin is caused by using a uniaxial thin film evaporator. A method for reducing the residual solvent to 1000 ppm or less has been proposed.

US Pat. No. 3,072,613 JP 2006-9001 A Japanese Patent Laid-Open No. 08-041123

F. Strain et. al. J. et al. Am. Chem. Soc. 72, 1254 (1950)

  However, according to the study by the present inventors, it is necessary to add a large amount of any of the catalyst substances described in Patent Document 2 relating to the technique for improving the reaction rate described above in order to obtain a sufficient effect. However, the reaction time has not been shortened to an industrially useful level or high molecular weight has not been achieved. Further, the use of such a large amount of catalyst is not preferable from the viewpoint of safety because the production cost increases and the catalyst remains in the final product.

  On the other hand, the technique described in Patent Document 3 described above relates to a method for effectively removing an organic solvent, and aims to promote polymerization (improvement of reaction rate) as a problem of the present invention. It is not what I did.

  Therefore, the object of the present invention is to solve the problems of the prior art, realize an efficient and short-time reaction between a compound having a 5-membered cyclic carbonate group and a compound having an amino group, and mechanically. Provided is a method for producing a thermoplastic polyhydroxyurethane resin that has excellent characteristics and contributes to the industrial spread of useful thermoplastic polyhydroxyurethane resins that can be used as binders in various products. There is. In addition, the purpose of the present invention is to minimize the consumption of electric power during the production of a thermoplastic polyhydroxyurethane resin that can be synthesized using carbon dioxide as a raw material, which can contribute to reducing greenhouse gases. In addition to the raw material surface, another object of the present invention is to provide a method for producing a thermoplastic polyhydroxyurethane resin which can contribute to the reduction of carbon dioxide emission and can be put into practical use.

  As a result of intensive studies to solve the above problems, the present inventors produce a thermoplastic polyhydroxyurethane resin by polyaddition reaction of a compound having a 5-membered cyclic carbonate group and a compound having an amino group. In contrast, a production method capable of obtaining a thermoplastic polyhydroxyurethane resin having a sufficient molecular weight, and optimally a thermoplastic polyhydroxyurethane resin containing almost no non-volatile content, in a shorter time than in the conventional method. As a result, the present invention has been completed. In the present invention, as defined below, the liquid used in the step [2] is a reaction between the compound having a 5-membered cyclic carbonate group and the compound having an amino group in the step [1] performed before that. In this specification, the liquid prepared in step [1] is referred to as a “preliminary reaction liquid” because the liquid is a liquid in which a product (polymer) is partially mixed.

That is, the above object is achieved by the present invention described below. The present invention
[1] A step [1] of obtaining a preliminary reaction liquid (A) having a weight average molecular weight of 3000 to 20000 by reacting a compound having a 5-membered cyclic carbonate group with a compound having an amino group in a solvent. The preliminary reaction solution (A) obtained in the step [1] is supplied at 80 to 180 ° C. and 10 to 200 torr of heated and reduced pressure to form a liquid film and devolatilize the preliminary reaction solution (A). And a step [2] of obtaining a polyhydroxyurethane resin by concentration of the substrate, further polymerization and solvent removal, and a method for producing a thermoplastic polyhydroxyurethane resin.

（式中のＲは、水素原子又はメチル基である。）

〔７〕前記５員環環状カーボネート基を有する化合物が、エポキシ化合物と二酸化炭素を原料として製造されたものであり、前記工程［２］で得られるポリヒドロキシウレタン化合物中の−Ｏ−ＣＯ−結合が、二酸化炭素由来のものである〔１〕〜〔６〕のいずれかに記載の熱可塑性ポリヒドロキシウレタン樹脂の製造方法。 Preferred embodiments of the present invention further include those having the following requirements.
[2] The method for producing a thermoplastic polyhydroxyurethane resin according to [1], wherein in the step [2], the preliminary reaction liquid (A) is continuously supplied to an apparatus for carrying out the heating and decompression conditions.
[3] The method for producing a thermoplastic polyhydroxyurethane resin according to [1] or [2], wherein the polyhydroxyurethane resin obtained in the step [2] has a nonvolatile content of 99.0% or more.
[4] The method for producing a thermoplastic polyhydroxyurethane resin according to any one of [1] to [3], wherein the polyhydroxyurethane resin obtained in the step [2] has a weight average molecular weight of 20,000 to 100,000.
[5] The method for producing a thermoplastic polyhydroxyurethane resin according to any one of [1] to [4], wherein the apparatus for carrying out the heating and decompressing condition used in the step [2] is a thin film evaporation apparatus.
[6] The compound having a 5-membered cyclic carbonate group is any one of [1] to [5], wherein X in the general formula (1) is selected from the structural group represented by the following formula (2) The manufacturing method of the thermoplastic polyhydroxyurethane resin in any one.

(R in the formula is a hydrogen atom or a methyl group.)

[7] The compound having a 5-membered cyclic carbonate group is produced using an epoxy compound and carbon dioxide as raw materials, and the —O—CO— bond in the polyhydroxyurethane compound obtained in the step [2]. The method for producing a thermoplastic polyhydroxyurethane resin according to any one of [1] to [6], wherein is derived from carbon dioxide.

  According to the production method of the present invention, in the reaction of a compound having a 5-membered cyclic carbonate group and a compound having an amino group, the reaction rate decreases as the reaction approaches the end point, and the desired reaction rate and molecular weight are obtained. Therefore, it is possible to synthesize a high molecular weight thermoplastic polyhydroxyurethane compound by performing the above reaction efficiently and in a short time. For this reason, according to the production method of the present invention, it is possible to realize a reduction in energy required for production, and in accordance with this, a reduction in the amount of carbon dioxide generated during production is also realized. The remarkable effect that it can reduce is acquired. Furthermore, according to the production method of the present invention, as described above, in addition to obtaining an effect of reducing the amount of carbon dioxide generated during production by realizing the efficiency of the reaction, various five members using carbon dioxide as a raw material. By using a cyclic carbonate compound and reacting with a compound having an amino group, various polyhydroxyurethane resins can be efficiently synthesized, so that it is possible to provide technology that contributes to resource saving and environmental protection. Furthermore, the thermoplastic polyhydroxyurethane resin produced by the production method of the present invention is a useful environment-friendly material, and an effect of increasing the value of a product using the same can be expected.

  Next, the present invention will be described in more detail with reference to preferred embodiments for carrying out the invention. The method for producing the thermoplastic polyhydroxyurethane resin of the present invention comprises a compound having at least one 5-membered cyclic carbonate group in one molecule and a compound having at least one amino group in one molecule. When a polyhydroxyurethane compound is obtained by a polyaddition reaction, it is configured as follows. First, in step [1], a compound having a 5-membered cyclic carbonate group and a compound having an amino group are reacted in a solvent to obtain a preliminary reaction liquid (A) having a weight average molecular weight of 3000 to 20000. . In Step [2], the preliminary reaction liquid (A) obtained in Step [1] is supplied under heating and reduced pressure conditions of 80 to 180 ° C. and 10 to 200 torr to form a preliminary by liquid film formation and devolatilization. Concentration of the substrate of the reaction solution (A), further polymerization, and solvent removal are performed to obtain a polyhydroxyurethane resin having a sufficient molecular weight and sufficient solvent removal. The inventors of the present invention comprise the production method of the present invention by the above-described steps [1] and [2], whereby the reaction between a compound having a 5-membered cyclic carbonate group and a compound having an amino group is performed. The reason why efficiency has been achieved is considered as follows.

  In the above step [1], by using a high reaction rate in the initial stage, a compound having a 5-membered cyclic carbonate group, a compound having an amino group, and a solvent were partially reacted by heating and stirring. A preliminary reaction liquid (A) which is a polymerization intermediate having a weight average molecular weight of 3000 to 20000 is prepared. Then, in the next step [2], the preliminary reaction liquid (A) obtained in the above step [1] is supplied under heating and decompression conditions of 80 to 180 ° C. and 10 to 200 torr, thereby forming a liquid film. The concentration of the pre-reaction solution (A) in the state of heating and decompression, and devolatilization from the reaction system can increase the substrate concentration of the pre-reaction solution (A), thereby increasing the reactivity. A thermoplastic polyhydroxyurethane resin having a molecular weight and simultaneously desolventized to reduce nonvolatile content can be efficiently produced. With the above configuration, the problem that the conventional manufacturing method has become a problem, the reactivity decreases as the reaction approaches the end point, takes a long time, and efficient resin production cannot be solved, and the high molecular weight nonvolatile content is solved. Can be efficiently produced. More specifically, it becomes possible to efficiently produce a thermoplastic polyhydroxyurethane resin having a weight average molecular weight of 20,000 to 100,000 and a non-volatile content of 99.0% or more.

  As described above, in a preferred embodiment of the present invention, the preliminary reaction liquid (A) described above is continuously supplied under the above-described heating and decompression conditions to form a liquid film, and concentrated and devolatilized by heating and decompression. By performing the step [2] characterizing the present invention, which increases the substrate concentration and thereby increases the reactivity, the production of the desired high molecular weight thermoplastic polyhydroxyurethane is achieved by the prior art. Compared to, it is realized to be much more efficient. The apparatus for carrying out the step [2] defined in the present invention is called a thin film evaporator, thin film vacuum evaporator, or rotating thin film evaporator, and removes the solvent from the solution or dispersion by heating and decompressing. Any device intended to do this can be used. The apparatus will be described later.

Hereinafter, each structure in the manufacturing method of this invention is demonstrated in detail.
The thermoplastic polyhydroxyurethane resin obtained by the production method of the present invention is a monomer comprising a compound having one or more 5-membered cyclic carbonate groups in one molecule and a compound having one or more amino groups in one molecule. The unit is obtained by the polyaddition reaction. As described above, since there are two types of cleavage of the five-membered cyclic carbonate group as shown below, the resulting hydroxyurethane compound has two types of structures.

  Therefore, for example, when a bifunctional compound is reacted, a polymer resin obtained by polyaddition reaction of a compound having two 5-membered cyclic carbonate groups and an amine compound having two amino groups is It is considered that four types of chemical structures of the following formulas (4) to (7) are generated and exist at random.

[Step [1]]
In the production method of the present invention, in step [1], a compound having a 5-membered cyclic carbonate group (hereinafter sometimes referred to as a cyclic carbonate compound) and a compound having an amino group (hereinafter sometimes referred to as an amine compound). To obtain a preliminary reaction liquid (A) having a weight average molecular weight of 3000 or more and 20000 or less.

  The conditions for the reaction between the cyclic carbonate compound and the amine compound in the step [1] are not particularly limited. For example, in the presence of a solvent, the cyclic carbonate compound and the amine compound are used at an equivalent ratio of about equivalent. A preliminary reaction liquid (A) can be obtained by reacting at a temperature of 40 to 120 ° C. for 0.5 to 4 hours. More preferably, it is obtained by reacting at a temperature of 80 to 120 ° C. for 0.5 to 3 hours, and further for 0.5 to 2 hours. The preliminary reaction liquid (A) thus obtained is a mixture of a polyhydroxyurethane compound comprising a cyclic carbonate compound and an amine compound, and a partially unreacted cyclic carbonate compound, an amine compound and a solvent.

  The weight average molecular weight of the preliminary reaction liquid (A) obtained in step [1] of the production method of the present invention is in the range of 3000 to 20000. According to the study by the present inventors, when the molecular weight is less than 3000, when such a preliminary reaction liquid (A) is used in the next step [2], the cyclic carbonate compound and the amine compound are A large amount remains unreacted and is removed under heating and reduced pressure in a thin film state, so that the equivalence ratio is shifted and a high molecular weight product cannot be obtained.

  Further, when the molecular weight of the preliminary reaction liquid (A) is more than 20000, the reaction time for producing the preliminary reaction liquid (A) is increased, and in addition, the functional group is deactivated (side reaction). In step [2], the molecular weight is hardly increased even when the step under the heating and decompressing conditions specified in the present invention is performed, and the effect obtained by carrying out step [2] is small.

Hereinafter, the compound having a 5-membered cyclic carbonate group and the compound having an amino group used in the step [1] will be described.
<Cyclic carbonate compound>
The compound having a 5-membered cyclic carbonate group used in the present invention is not particularly limited, and any compound having one or more 5-membered cyclic carbonate groups in one molecule can be used. For example, a compound having a benzene skeleton, an aromatic polycyclic skeleton, a condensed polycyclic aromatic skeleton, or an aliphatic or alicyclic compound can be used.

  The cyclic carbonate compound is preferably a compound having two or more 5-membered cyclic carbonate groups in consideration of polymerizability and the like, and X in the general formula (1) is represented by the following formula (2). It is preferably any compound selected from the structural group.

上記一般式（１）中のＸは、以下の式（２）に示す構造のいずれかである。

（式中のＲは、水素原子又はメチル基を示す）

X in the general formula (1) is one of the structures shown in the following formula (2).

(Wherein R represents a hydrogen atom or a methyl group)

Examples of the compound having a cyclic carbonate group having a benzene skeleton, an aromatic polycyclic skeleton, or a condensed polycyclic aromatic skeleton include the following structures. R in the following formula is H or CH ₃ .

Examples of the aliphatic and alicyclic cyclic carbonate compounds include the following compounds. R in the following formula is H or CH ₃ .

  The cyclic carbonate compounds listed above for use in the present invention can be obtained by the reaction of an epoxy compound and carbon dioxide. By using the cyclic carbonate compound obtained by the reaction of the epoxy compound and carbon dioxide in the production method of the polyhydroxyurethane resin of the present invention, the obtained polyhydroxyurethane compound is -O-CO in the urethane bond. -The structural part is a component derived from carbon dioxide. Since the polyhydroxyurethane compound in which carbon dioxide is immobilized in its structure is useful as a material to cope with environmental problems, the production method of the present invention uses a cyclic carbonate compound using carbon dioxide as a raw material. It is preferable to do.

  Specifically, it is preferable to use a cyclic carbonate compound obtained as follows. For example, an epoxy compound as a raw material is reacted in the presence of a catalyst at a temperature of 0 ° C. to 160 ° C. in a carbon dioxide atmosphere pressurized to about atmospheric pressure to about 1 MPa for 4 to 24 hours. As a result, a cyclic carbonate compound in which carbon dioxide is immobilized at the ester moiety can be obtained.

  Examples of the catalyst used for the reaction between the epoxy compound and carbon dioxide include halogenated salts such as lithium chloride, lithium bromide, lithium iodide, sodium chloride, sodium bromide, sodium iodide, and quaternary ammonium salts. Is preferable. The amount used is preferably 1 to 50 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the raw material epoxy compound. Further, triphenylphosphine or the like may be used at the same time in order to improve the solubility of salts serving as these catalysts.

  The reaction between the epoxy compound and carbon dioxide can also be performed in the presence of an organic solvent. Any organic solvent can be used as long as it dissolves the above-mentioned catalyst. Specifically, amide solvents, alcohol solvents, and ether solvents are preferable organic solvents.

  As described above, the polyhydroxyurethane compound produced using the cyclic carbonate compound synthesized from carbon dioxide as a raw material has an —O—CO— bond in which carbon dioxide is immobilized in its structure. It will be a thing. The content of carbon dioxide-derived —O—CO— bonds (carbon dioxide immobilization amount) in the hydroxyurethane compound should be as high as possible from the standpoint of effective use of carbon dioxide. For example, as described above, By using such a cyclic carbonate compound, carbon dioxide can be contained in the range of 1 to 40% by mass in the structure of the hydroxyurethane compound.

<Amine compound>
As the compound having an amino group used in the present invention, any conventionally known compound can be used, but a compound having two or more amino groups is preferably used. For example, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane (hexamethylenediamine), 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane Chain aliphatic polyamines such as, norbornanediamine, cyclic aliphatic polyamines such as 1,3- (bisaminomethyl) cyclohexane, aliphatic polyamines having aromatic rings such as xylylenediamine, fragrances such as metaphenylenediamine and diaminodiphenylmethane Group polyamines.

<Solvent>
Any solvent can be used as the solvent used for the reaction between the cyclic carbonate compound and the amine compound as long as the solvent is inert to the raw materials used and the compound obtained. Examples of preferred ones include methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, butyl acetate, acetone, cyclohexanone, tetrahydrofuran, dioxane, toluene, Xylene, dimethylformamide, dimethyl sulfoxide, perchlorethylene, trichloroethylene, methanol, ethanol, propanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol methyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, etc. It is done. The reaction concentration is preferably 30 to 90%, more preferably 40 to 80%. If the reaction concentration exceeds 90%, the viscosity becomes high and it is difficult to control the reaction.

  Since the cyclic carbonate compound is solid at room temperature and has a high melting point, when reacting with an amine compound, the solvent mentioned above is used as a reaction solvent, and the reaction is carried out in the solvent for a short time. Thus, the preliminary reaction liquid (A) and the final thermoplastic polyhydroxyurethane resin can be produced by uniformly controlling the reaction.

<Other ingredients>
The reaction between the cyclic carbonate compound and the amine compound can be carried out without using a catalyst. However, in order to accelerate the reaction, it can also be carried out in the presence of a catalyst as listed below. For example, basic catalysts such as triethylamine, tributylamine, diazabicycloundecene (DBU) triethylenediamine (DABCO), pyridine, and Lewis acid catalysts such as tetrabutyltin and dibutyltin dilaurate can be used. The preferable usage-amount of these catalysts is 0.01-10 mass parts with respect to the total amount (100 mass parts) of the carbonate compound and amine compound which are used for reaction.

[Step [2]]
In the production method of the present invention, the preliminary reaction liquid (A) obtained in the step [1] as described above is supplied under heating and decompression conditions of 80 to 180 ° C. and 10 to 200 torr to form a liquid film. It comprises a step [2] of obtaining a polyhydroxyurethane resin sufficiently desolvated by concentration of the substrate of the preliminary reaction liquid (A) by devolatilization, further polymerization and desolvation. As heating and decompression conditions in the step [2], the temperature is more preferably in the range of 80 to 170 ° C., and the pressure is more preferably 10 to 90 torr.

  Further, by continuously supplying the preliminary reaction liquid (A) obtained in the step [1], the step [2] performed under the above-described heating and decompression conditions is continuously performed. The thermoplastic polyhydroxyurethane resin having a high non-volatile content after solvent removal is continuously and efficiently produced. In the present invention, it is preferable to use a thin film evaporation apparatus described below, which is an apparatus capable of continuously performing the step [2].

<Thin film evaporator>
In the present invention, as a method for obtaining thermoplastic polyhydroxyurethane having a high molecular weight and a low volatile content (solvent content) from the preliminary reaction solution (A) obtained in the step [1], the preliminary reaction solution defined in the present invention is used. As long as (A) is within the range of 80 to 180 ° C. and 10 to 200 torr of heating and decompressing conditions, various specific methods can be used without particular limitation within a range that can be industrially realized. Specific examples include a method of forming a liquid film of a solution by a wiper on the inner wall of a cylindrical evaporation tower, a method of forming a liquid film of a solution by a natural flow of a raw material on a flat or cylindrical evaporator, and a stirrer A method of discharging a reaction solution from a connected single tube to a tube wall by centrifugal force during stirring and forming a liquid film of the solution on the reactor tube wall can be exemplified.

  The thickness of the liquid film of the preliminary reaction liquid (A) formed in the present invention is preferably thinner because evaporation and devolatilization of the reaction solvent are promoted and the solvent can be efficiently removed. Specifically, the thickness of the liquid film is preferably about 0.1 to 5 mm, and more preferably about 0.1 to 2 mm.

  Under the heating and decompression conditions of 80 to 180 ° C. and 10 to 200 torr as defined in the present invention, a liquid film is formed, the substrate is concentrated by devolatilization, and further polymerization and solvent removal are performed to sufficiently remove the solvent. Specifically, the method for obtaining the polyhydroxyurethane resin means the following method. Forming a liquid film with the above-described reaction solvent, a reaction product of a cyclic carbonate compound and an amine compound, and a pre-reaction solution (A) comprising a mixture of a partially unreacted cyclic carbonate compound and an amine compound, and heating. The apparatus used for removing volatile components by e.g., evaporating, devolatilizing, etc. (in the present invention, this is referred to as “thin film evaporation”) (in the present invention, this is referred to as “thin film evaporator”) The method of using is mentioned. As the apparatus, various specific apparatuses can be used without particular limitation as long as the step [2] defined in the present invention can be industrially realized. Specific examples include Wiperen (trade name) and Exeva (trade name) manufactured by Shinko Environmental Solutions, Contro (trade name, vertical / horizontal) and Inclined Wing Contro (trade name), Sakura, manufactured by Hitachi, Ltd. Examples include, but are not limited to, a high evaporator (trade name) manufactured by Seisakusho Co., Ltd. and a wall wetter (trade name) manufactured by Kansai Chemical Machinery Co., Ltd. The volatilized solvent can be condensed and recovered. As a form of condensation of the generated volatile matter, either an external condenser system having a condensing part outside the thin film evaporator or an internal condenser system having a condensing part inside the thin film evaporator can be used.

  In step [2], the preliminary reaction liquid (A) obtained in step [1] described above is supplied to, for example, a device that performs heating and decompression conditions as described above, preferably continuously. Then, a liquid film of the preliminary reaction liquid (A) is formed, and the liquid is concentrated to increase the concentration of the reaction substrate, thereby promoting the reaction to obtain a high molecular weight thermoplastic polyhydroxyurethane. In the present invention, it is preferable that at least a part of the step [2] is performed using an apparatus using a corrosion-resistant material. In the present invention, it is preferable that the apparatus used for the above-described thin film evaporation uses a corrosion-resistant material. The material of the evaporator can be a material composed of an arbitrary component such as a SUS component, a glass component, a Teflon (registered trademark) component or the like, but is preferably a corrosion-resistant material as described above. . However, this is not particularly true.

  In the known “thin film evaporator” mentioned above, various conditions can be applied to the operation conditions as necessary. For example, generally, the operating conditions can be selected within the range of a temperature of 50 to 250 ° C. and a pressure of 0.1 to 760 torr. In the case where the boiling point of the volatile component to be removed is high, for example, a temperature of 100 to 200 ° C. and a pressure of 0.1 to 200 torr are preferably used as conditions for efficient removal.

  In the production method of the present invention, it is necessary to perform step [2] under the heating and decompression conditions specified in the present invention. Therefore, the operating conditions in the above-mentioned “thin film evaporator” are a temperature range of 80 ° C. or higher and 180 ° C. or lower, preferably 80 ° C. or higher and 170 ° C. or lower, and a pressure condition of 10 to 200 torr, 10 to 90 torr. If the temperature at the time of thin film evaporation is higher than 180 ° C., a decomposition reaction occurs in step [2], and the molecular weight of the resulting thermoplastic polyhydroxyurethane resin does not increase. Further, as described above, since the unreacted amino group remains in the preliminary reaction liquid (A), when the temperature is increased to over 180 ° C., the material is corroded. Therefore, in order to obtain a high molecular weight polyhydroxyurethane resin without causing a decomposition reaction, the temperature during the thin film evaporation is set to 180 ° C. or lower, preferably 170 ° C. or lower. When the pressure exceeds 200 torr, the solvent is not sufficiently removed in the step [2] while the preliminary reaction liquid (A) is retained in the thin film evaporator (hereinafter referred to as “residence time”). Finally, the desired fully desolvated solvent such as a non-volatile resin of 99.0% or more is not obtained. If the solvent is not sufficiently removed, it cannot be used as a thermoplastic material as it is. On the other hand, when the pressure is less than 10 torr, the solvent evaporates, the viscosity becomes high, and it becomes difficult to form a thin film. According to the study by the present inventors, when the thin film is evaporated, if necessary, a small amount of a gas component of an inert gas such as nitrogen or argon is supplied into the evaporator to efficiently remove the volatilized component. Therefore, it is preferable to configure in this way.

  The residence time varies depending on the state of the apparatus, the set temperature, the pressure, etc., and it is difficult to define the time itself. However, it can be adjusted to some extent by adjusting the supply rate of the preliminary reaction liquid (A), the degree of pressure reduction, the set temperature, etc., and it can also be balanced by adjusting the distillation rate of the solvent and resin used. Can do. As a result, the residence time can be further shortened, and the thermoplastic content of the raw material cyclic carbonate compound and amine compound used in the solvent in step [1] is high, for example, 99.0% or more. It is possible to further shorten the reaction time (hereinafter referred to as “total process time”) required to obtain the polyhydroxyurethane resin. The shortening of the “total process time” that can be achieved by the production method of the present invention means that the amount of carbon dioxide generated when using electric power or the like is reduced, and the production method of the present invention is a resin In addition to being able to use carbon dioxide as a raw material, this is also a useful method that can contribute to the reduction of greenhouse gas emissions.

  Next, the present invention will be described more specifically with reference to production examples, synthesis examples, examples and comparative examples, but the present invention is not limited to these examples. In the following examples, “part” and “%” are based on mass unless otherwise specified.

<Production of cyclic carbonate compound>
[Production Example 1: Synthesis of cyclic carbonate compound (I)]
100 parts of a bisphenol A type epoxy resin having an epoxy equivalent of 187 [Epototo YD-128 (trade name), manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.], 20 parts of sodium iodide (manufactured by Wako Pure Chemical Industries, Ltd.), and N-methyl-2-pyrrolidone 150 parts were charged into a reaction vessel equipped with a stirrer and a refluxer with an atmosphere opening. Subsequently, carbon dioxide was continuously blown in with stirring, and the reaction was performed at 100 ° C. for 10 hours. Thereafter, 300 parts of water was added to the reaction solution to precipitate the product, which was filtered off. The obtained white powder was recrystallized from toluene to obtain 52 parts of white powder (yield 42%).

When the obtained powder was analyzed by IR (FT / IR-350, manufactured by JASCO Corp., others measured with the same apparatus), the peak derived from the raw material epoxy in the vicinity of 910 cm ⁻¹ disappeared, and 1800 cm A peak derived from a carbonyl of a carbonate group that was not present in the raw material was observed near ^-1 . Moreover, as a result of analysis by HPLC [LC-2000 (trade name), manufactured by JASCO Corporation, column: FinePakSIL C18-T5, mobile phase: acetonitrile + water], the peak of the raw material disappeared, and a new peak was observed on the high polarity side. Appeared and its purity was 98%. As a result of DSC (Differential Scanning Calorimetry) measurement, the melting point was 178 ° C., and the melting point range was ± 5 ° C.

  From the above, it was confirmed that the white powder obtained above was a compound having a structure represented by the following formula in which a cyclic carbonate group was introduced by a reaction between an epoxy group and carbon dioxide. Hereinafter, this is referred to as Compound (I). The proportion of the component derived from carbon dioxide in the chemical structure of this compound (I) was 20.5% (calculated value).

[Production Example 2: Synthesis of cyclic carbonate compound (II)]
Instead of the epoxy compound used in Production Example 1, neopentyl glycol diglycidyl ether having an epoxy equivalent of 138 (Denacol EX211 (trade name), manufactured by Nagase ChemteX Corporation) was used in the same manner as in Production Example 1. Manufactured. The obtained cyclic carbonate compound was oily and analyzed by IR. As a result, the peak derived from the raw material epoxy near 910 cm ⁻¹ disappeared, and the carbonate group derived from carbonyl of the carbonate group not present in the raw material near 1800 cm ^−1. The peak of was confirmed. As a result of analyzing by HPLC under the same conditions as in Production Example 1, the peak of the raw material disappeared, a new peak appeared on the high polarity side, and the purity was 97%.

  From the above, this substance was confirmed to be a compound having a structure represented by the following formula in which a cyclic carbonate group was introduced by a reaction between an epoxy group and carbon dioxide. Hereinafter, this oily compound is referred to as compound (II). The proportion of the component derived from carbon dioxide in the chemical structure of this compound (II) was 24.2% (calculated value).

<Synthesis of preliminary reaction liquid (A)>
[Synthesis Example 1: Synthesis of preliminary reaction solution (A-1)]
In a reaction vessel equipped with a stirrer and a reflux opening with an air opening, 78.7 parts of compound (I) obtained in Production Example 1 as a cyclic carbonate compound and hexamethylenediamine (abbreviation: HMD, Asahi Kasei) as an amine compound 21.3 parts of Chemicals, the same applies hereinafter) and 100 parts of N, N-dimethylformamide (DMF) as a reaction solvent were added. And it stirred for 0.5 hour, stirring at the temperature of 100 degreeC, and obtained the preliminary reaction liquid (A-1).

The obtained preliminary reaction liquid (A-1) was subjected to GPC measurement using N, N-dimethylformamide as a mobile phase [GPC-8220 (trade name), manufactured by Tosoh Corporation, column: SuperAW2500 + AW3000 + AW4000 + AW5000]. The molecular weight was 5000 (polystyrene conversion). Moreover, when the obtained preliminary reaction liquid (A-1) was analyzed by IR, the absorption derived from the urethane bond carbonyl group was confirmed by 1760cm < ^-1 > vicinity. By this, it can confirm that a polymer and an unreacted substance coexist in the reaction container. The same applies to the other synthesis examples described below.

[Synthesis Example 2: Synthesis of preliminary reaction liquid (A-2)]
A preliminary reaction liquid (A-2) was obtained in the same manner as in Synthesis Example 1 except that the reaction time of Synthesis Example 1 which was 0.5 hour was changed to 1 hour. The obtained preliminary reaction liquid (A-2) had a weight average molecular weight of 9500 (in terms of polystyrene). Moreover, when the obtained preliminary reaction liquid (A-2) was analyzed by IR, the absorption derived from the carbonyl group of a urethane bond was confirmed by 1760 cm < ^-1 > vicinity.

[Synthesis Example 3: Synthesis of Preliminary Reaction Solution (A-3)]
A preliminary reaction liquid (A-3) was obtained in the same manner as in Synthesis Example 1 except that the reaction time of Synthesis Example 1 which was 0.5 hour was changed to 2 hours. The obtained preliminary reaction liquid (A-3) had a weight average molecular weight of 17000 (polystyrene conversion). Moreover, when the obtained preliminary reaction liquid (A-3) was analyzed by IR, the absorption derived from the urethane bond carbonyl group was confirmed by 1760cm < ^-1 > vicinity.

[Synthesis Example 4: Synthesis of Preliminary Reaction Solution (A-4)]
Synthetic Example 1 except that 68.2 parts of Compound (I) used in Synthetic Example 1 and 31.8 parts of dodecadiamine (manufactured by Kokura Synthesis Co., Ltd.) were used instead of hexamethylenediamine used in Synthetic Example 1. Similarly, a preliminary reaction liquid (A-4) was obtained. The obtained preliminary reaction liquid (A-4) had a weight average molecular weight of 6000 (polystyrene conversion). Moreover, when the obtained preliminary reaction liquid (A-4) was analyzed by IR, the absorption derived from the urethane bond carbonyl group was confirmed by 1760cm < ^-1 > vicinity.

[Synthesis Example 5: Synthesis of preliminary reaction solution (A-5)]
As a cyclic carbonate compound, 38.6 parts of compound (I) obtained in Production Example 1 and compound (II) obtained in Production Example 2 were placed in a reaction vessel equipped with a stirrer and a reflux vessel with an air opening. 38.6 parts, 23.4 parts of hexamethylenediamine as an amine compound, and 100 parts of N, N-dimethylformamide as a reaction solvent were added. And it reacted for 0.5 hour, stirring at the temperature of 100 degreeC, and obtained the preliminary reaction liquid (A-5). The obtained preliminary reaction liquid (A-5) had a weight average molecular weight of 5500 (in terms of polystyrene). Moreover, when the obtained preliminary reaction liquid (A-5) was analyzed by IR, the absorption derived from the carbonyl group of the urethane bond was confirmed by 1760 cm < ^-1 > vicinity.

[Synthesis Example 6: Synthesis of preliminary reaction solution (A-6)]
A preliminary reaction liquid (A-6) was obtained in the same manner as in Synthesis Example 1 except that the reaction temperature in Synthesis Example 1 was changed to 80 ° C. The obtained preliminary reaction liquid (A-6) had a weight average molecular weight of 2300 (in terms of polystyrene) and was smaller than that defined in the present invention. Moreover, when the obtained preliminary reaction liquid (A-6) was analyzed by IR, the absorption derived from the carbonyl group of the urethane bond was confirmed by 1760 cm < ^-1 > vicinity.

[Synthesis Example 7: Synthesis of preliminary reaction solution (A-7)]
A preliminary reaction liquid (A-7) was obtained in the same manner as in Synthesis Example 1 except that the reaction time of Synthesis Example 1 which was 0.5 hour was changed to 8 hours. The obtained preliminary reaction liquid (A-7) had a weight average molecular weight of 24000 (in terms of polystyrene) and was larger than that defined in the present invention. Moreover, when the obtained preliminary reaction liquid (A-7) was analyzed by IR, the absorption derived from the carbonyl group of the urethane bond was confirmed by 1760 cm < ^-1 > vicinity.

<Manufacture of thermoplastic polyhydroxyurethane resin>
[Example 1]
Using Exeva (registered trademark) EX-02 (manufactured by Shinko Environmental Solution Co., Ltd.), which is a thin film evaporator for high viscosity liquid, supplying the preliminary reaction liquid (A-1) obtained in Synthesis Example 1, Under conditions of 50 torr of heat and reduced pressure, formation of a liquid film and concentration of the substrate of the preliminary reaction solution by devolatilization, further polymerization and desolvation were performed to obtain a polyhydroxyurethane resin melted from the outlet. More specifically, in the apparatus, a liquid film having a thickness of about 2 mm made of the preliminary reaction liquid (A-1) is formed, and devolatilized to concentrate the substrate of the preliminary reaction liquid (A-1), Further polymerization and solvent removal were performed to polymerize the resin and distill off the reaction solvent. The obtained polyhydroxyurethane resin had a high non-volatile content of 99.8%, a weight average molecular weight of 28,000, and had a sufficient molecular weight. The residence time of the preliminary reaction liquid (A-1) was 25 minutes.

[Example 2]
Step [2] was carried out in the same manner as in Example 1 except that the preliminary reaction solution (A-1) used in Example 1 was changed to the preliminary reaction solution (A-2) obtained in Synthesis Example 2. A molten polyhydroxyurethane resin was obtained from the outlet. The obtained non-volatile content of the polyhydroxyurethane resin was as high as 99.7%, the weight average molecular weight was 31,000, and it had a sufficient molecular weight. The residence time of the preliminary reaction liquid (A-2) was 25 minutes.

[Example 3]
Step [2] was carried out in the same manner as in Example 1 except that the preliminary reaction solution (A-1) used in Example 1 was changed to the preliminary reaction solution (A-3) obtained in Synthesis Example 3. A molten polyhydroxyurethane resin was obtained from the outlet. The obtained non-volatile content of the polyhydroxyurethane resin was as high as 99.7%, the weight average molecular weight was 47,000, and the molecular weight was sufficient. The residence time of the preliminary reaction liquid (A-3) was 25 minutes.

[Example 4]
The process [2] was carried out in the same manner as in Example 1, except that the conditions of the thin-film evaporator Exeva used in Example 1 were 130 ° C. and 20 torr, and the pressure was lower than that in Example 1. A molten polyhydroxyurethane resin was obtained from the outlet. The obtained non-volatile content of the polyhydroxyurethane resin was as high as 99.9%, the weight average molecular weight was 34,000, and it had a sufficient molecular weight. The residence time of the preliminary reaction liquid (A-1) was 30 minutes.

[Example 5]
Step [2] was carried out in the same manner as in Example 1, except that the conditions of the thin-film evaporator Exeva used in Example 1 were changed to 150 ° C. and 50 torr, which was higher than in Example 1. A molten polyhydroxyurethane resin was obtained from the outlet. The obtained polyhydroxyurethane resin had a high non-volatile content of 99.8%, a weight average molecular weight of 29000, and had a sufficient molecular weight. The residence time of the preliminary reaction liquid (A-1) was 20 minutes.

[Example 6]
Step [2] was carried out in the same manner as in Example 1 except that the preliminary reaction solution (A-1) used in Example 1 was changed to the preliminary reaction solution (A-4) obtained in Synthesis Example 4. A molten polyhydroxyurethane resin was obtained from the outlet. The obtained non-volatile content of the polyhydroxyurethane resin was as high as 99.8%, the weight average molecular weight was 35000, and it had a sufficient molecular weight. The residence time of the preliminary reaction liquid (A-4) was 25 minutes.

[Example 7]
The preliminary reaction liquid (A-1) used in Example 1 was changed to the preliminary reaction liquid (A-5) obtained in Synthesis Example 5, and the conditions of the thin film evaporator Exeva used in Example 1 were set to 100. The process [2] was carried out in the same manner as in Example 1 except that the temperature and the pressure were changed to 10 ° C. and 10 torr, and the polyhydroxyurethane resin melted from the outlet was obtained. . The obtained non-volatile content of the polyhydroxyurethane resin was as high as 99.7%, the weight average molecular weight was 30000, and it had a sufficient molecular weight. The residence time of the preliminary reaction liquid (A-5) was 35 minutes.

[Comparative Example 1]
While putting the preliminary reaction liquid (A-1) obtained in Synthesis Example 1 into a normal pressure reaction vessel equipped with a stirrer and a vacuum distillation device, raising the temperature to 130 ° C. and reducing the pressure in the reaction vessel. The solvent was distilled off. Since this method is a batch process and does not form a liquid film, it must be performed while preventing foaming and the like, and it took 2.5 hours for the reaction vessel to reach 50 torr. The resulting polyhydroxyurethane resin had a non-volatile content of 98.2%, a non-volatile value lower than that of the resin obtained in Example 1, a weight average molecular weight of 20000, and a molecular weight higher than that of the resin obtained in Example 1. Was small. Further, the reaction time of the preliminary reaction liquid (A-1) was 3 hours, which was much longer than the residence time of Example 1.

[Comparative Example 2]
In a reaction vessel equipped with a stirrer and a reflux opening with an air opening, 78.7 parts of compound (I), which is the cyclic carbonate compound obtained in Production Example 1, and 21.3 parts of hexamethylenediamine were added, and 100 While stirring at a temperature of ° C., the reaction was carried out for 8 hours to synthesize a polyhydroxyurethane resin. Although the reaction product was reacted for 8 hours, some of the compound (I) was not reacted and was opaque. The non-volatile content of the obtained polyhydroxyurethane resin was 91.5%, the value of the non-volatile content was much lower than that of the resin obtained in Example 1, and the weight average molecular weight was 3700, which was obtained in Example 1. The molecular weight was much smaller than that of the resin.

[Comparative Example 3]
Example 1 except that the conditions of the thin film evaporator Exeva used in Example 1 were changed to 70 ° C. and 5 torr, which are outside the range defined in the present invention, and lower temperature and low pressure than those in Example 1. In the same manner, a molten polyhydroxyurethane resin was obtained from the outlet. The non-volatile content of the obtained polyhydroxyurethane resin was 93.8%, the non-volatile content was lower than that of the resin obtained in Example 1, and the weight average molecular weight was 9000, which was much higher than that of the resin obtained in Example 1. The molecular weight was small. The residence time of the preliminary reaction liquid (A-1) was 45 minutes.

[Comparative Example 4]
Except that the conditions of the thin-film evaporator Exeva used in Example 1 were 185 ° C. and 100 torr, a temperature higher than that defined in the present invention and a pressure higher than that in Example 1, and In the same manner, a molten polyhydroxyurethane resin was obtained from the outlet. The obtained polyhydroxyurethane resin had a non-volatile content of 99.1%, slightly lower than that of Example 1, a weight average molecular weight of 14500, and a molecular weight smaller than that of the resin obtained in Example 1. The residence time of the preliminary reaction liquid (A-1) was 15 minutes.

[Comparative Example 5]
Example 1 Except that the conditions of the thin-film evaporator Exeva used in Example 1 were 130 ° C. and 300 torr, the same temperature as in Example 1 and a higher pressure than specified in the present invention. The molten polyhydroxyurethane resin was obtained from the outlet. The non-volatile content of the obtained polyhydroxyurethane resin is 95.2%, which is lower than that of the resin obtained in Example 1. The weight average molecular weight is 19000, which is higher than that of the resin obtained in Example 1. The molecular weight was small. The residence time of the preliminary reaction liquid (A-1) was 15 minutes.

[Comparative Example 6]
The preliminary reaction liquid (A-1) used in Example 1 was smaller than that defined in the present invention having a weight average molecular weight of 2300, except that it was the preliminary reaction liquid (A-6) obtained in Synthesis Example 6. In the same manner as in Example 1, step [2] was performed to obtain a melted polyhydroxyurethane resin from the outlet. The obtained polyhydroxyurethane resin had a non-volatile content of 99.2%, slightly lower than that of Example 1, a weight average molecular weight of 12,000, and a molecular weight smaller than that of the resin obtained in Example 1. The residence time of the preliminary reaction liquid (A-6) was 20 minutes.

[Comparative Example 7]
The preliminary reaction liquid (A-1) used in Example 1 was larger than that defined in the present invention having a weight average molecular weight of 24,000, except that the preliminary reaction liquid (A-7) obtained in Synthesis Example 7 was used. In the same manner as in Example 1, step [2] was performed to obtain a melted polyhydroxyurethane resin from the outlet. The non-volatile content of the obtained polyhydroxyurethane resin was 99.1%, slightly lower than that of Example 1, the weight average molecular weight was 25000, and was not much different from the molecular weight of the pre-reaction solution (A-7) before the reaction. It was. The residence time of the preliminary reaction liquid (A-7) was 28 minutes.

  Tables 2 and 3 show reaction conditions in the production methods of Examples and Comparative Examples. The residence time in the table is the time taken for the process using Exeva, which is a thin film evaporator for high viscosity liquids. Since the non-volatile content of the supplied preliminary reaction liquid (A) is 50%, the speed of sending to Exeva was adjusted so that the amount of solvent distilled out and the amount of resin discharged after treatment were the same per hour. . In Comparative Examples 1 and 2, since Exeva was not used, each reaction time was described in the table.

[Evaluation]
The polyurethane resin production methods obtained by the production methods of Examples and Comparative Examples were evaluated by the following methods and criteria. Tables 4 and 5 collectively show the measurement results and the evaluation results.

[Weight average molecular weight]
Each resin obtained in Examples and Comparative Examples was subjected to GPC measurement using N, N-dimethylformamide as a mobile phase, and the weight average molecular weight was measured. The GPC measurement was GPC-8220 (trade name) manufactured by Tosoh Corporation, and the weight average molecular weight was measured using Super AW 2500 + AW 3000 + AW 4000 + AW 5000 as a column. In Tables 4 and 5, measured values were shown as molecular weights.

[Non-volatile content]
About 3.0 g of each of the resins obtained in Examples and Comparative Examples was weighed, heated in an oven at 150 ° C. for 1 hour, then cooled in a desiccator, and then weighed again. And using the obtained measured value, it calculated with the weight after a heating / weight before a heating x100, and it was set as the non volatile matter (%).

[Total process time]
Tables 4 and 5 show the total process time as a total process time from the compound having a 5-membered cyclic carbonate group as a raw material and the compound having an amino group to obtain a polyhydroxyurethane resin, respectively. . Specifically, in the examples, it is the sum of the time taken for the step [1] to obtain the preliminary reaction liquid (A) and the residence time of the next step [2]. The same applies to Comparative Examples 3 to 7 using Exeva, which is a thin film evaporator for high viscosity liquid, and the time required to obtain the pre-reaction liquid (A) and the retention of the pre-reaction liquid (A) in Exeva. The sum of time was shown. In Comparative Example 1, since the preliminary reaction liquid (A) was placed in the reaction vessel of the vacuum distillation apparatus and then distilled under reduced pressure, the time required to obtain the preliminary reaction liquid (A) and the time taken for vacuum distillation The sum of In Comparative Example 2, the polymerization time of compound (I), which is a cyclic carbonate compound, and hexamethylene diamine, which was carried out in a reaction vessel equipped with a reflux opening having an air opening, was shown.

[Strength at break]
With each polyhydroxyurethane resin obtained in Examples and Comparative Examples, a film was prepared and used as an evaluation sample, and the breaking strength of each of the obtained films was measured according to JISK6251. Specifically, using polyhydroxyurethane resins obtained in Examples and Comparative Examples, press films having a thickness of 500 μm were obtained and obtained under conditions of a temperature of 140 ° C., a time of 5 minutes, and a pressure of 100 kg / cm ² . After cutting out a JIS No. 3 dumbbell from the film, it was measured at room temperature (25 ° C.) with an autograph. And the measured value of the obtained breaking point strength was divided into the following five stages A to E and evaluated. In addition, those which were brittle and could not be molded were considered unmoldable. In the present invention, A and B were accepted, and C, D, and E were rejected.
A: 50 MPa or more B: 30 MPa or more to less than 50 MPa C: 20 MPa or more to less than 30 MPa D: 10 MPa or more to less than 20 MPa E: less than 10 MPa

[Moldability]
A film was produced in the same manner as in the method for producing the evaluation sample used for measuring the strength at break, and it was confirmed whether or not bubbles were contained in an area of 10 cm × 10 cm of the obtained film. The number of bubbles was evaluated in three stages. In addition, those which are brittle and cannot be molded are described in Tables 4 and 5 as unmoldable.
○: The number of bubbles is 0 to 2 Δ: The number of bubbles is 3 to 5 ×: The number of bubbles is 6 or more

  In each of Examples 1, 4, 5 and Comparative Examples 3 to 5, the same preliminary reaction solution (A) obtained by using compound (I) as the cyclic carbonate compound and hexamethylenediamine as the amine compound. -1) is used, and this preliminary reaction liquid (A-1) is supplied to the same thin film type evaporator to carry out the process in the thin film type evaporator. As shown, the temperature and pressure conditions in the thin film evaporator process are changed. As a result, as shown in Tables 4 and 5, the weight average molecular weight of the finally obtained thermoplastic polyhydroxyurethane resin due to the difference in temperature and pressure conditions in the thin film evaporator process, It was confirmed that the difference in mechanical strength and non-volatile content was greatly affected. When comparing the effects of temperature and pressure conditions in the thin film evaporator process on moldability, in the examples satisfying the conditions defined in the present invention, the mechanical strength is sufficient molecular weight, and moldability is also a problem. It was found that a resin with a high non-volatile content was obtained.

  On the other hand, the production method of Comparative Example 1 uses the preliminary reaction liquid (A-1), but does not form a liquid film of the preliminary reaction liquid as in the example. Specifically, it is a batch type that is placed in a normal pressure reaction vessel attached with a vacuum distillation apparatus and reacts by distilling off the solvent while reducing the pressure, resulting in a temperature drop due to the heat of vaporization of the solvent. Therefore, it takes time to concentrate, and as the viscosity increases with concentration, it becomes difficult to completely remove the solvent as shown in Table 5. The reaction product obtained by the production method in which the reaction was performed while refluxing in the atmosphere of Comparative Example 2 had a weight average molecular weight of 3700 and did not have a sufficient molecular weight. From this, it can be understood that since the compound (I) used for the cyclic carbonate compound to be reacted with hexamethylenediamine is solid and has a high melting point, the reaction is difficult without using a solvent.

  The production methods of Comparative Examples 6 and 7 satisfy the requirements of the step [2] defined in the present invention, but the weight average molecular weight of the preliminary reaction solution supplied to the step [2] is 3000 or more and 20000 or less defined in the present invention. As shown in Table 5, in this case, the remarkable effects of the present invention cannot be sufficiently obtained. As shown in Comparative Example 6, if the molecular weight is smaller than the range defined in the present invention, a resin having a sufficient molecular weight cannot be obtained. Further, as shown in Comparative Example 7, when the molecular weight is larger than the range defined in the present invention, a long time is required in the step [1] for obtaining a preliminary reaction liquid to be supplied to the step [2]. In addition, the molecular weight is hardly increased in step [2], and the object of the present invention, which is to efficiently produce a thermoplastic polyhydroxyurethane compound in a short time, cannot be achieved.

  On the other hand, as shown in Examples 1 to 7, the weight average molecular weight of the preliminary reaction solution supplied in step [2] obtained in step [1] is 3000 or more and 20000 or less as defined in the present invention. Within the range, even if the types of the cyclic carbonate compound and the amine compound are changed, the thermoplastic polyhydroxyurethane resin can be efficiently produced in a short time, and the finally obtained thermoplastic polyhydroxyl Since the urethane resin has a high non-volatile content, has a sufficient molecular weight, and is excellent in breaking strength and moldability, the production method of the present invention is industrially useful.

  As an application example of the present invention, in the production method for obtaining a polyhydroxyurethane compound by a polyaddition reaction using a cyclic carbonate compound and an amine compound as raw materials, the preliminary reaction liquid (A) defined in the present invention is defined in the present invention. By conducting further polyaddition reaction under specific heating and decompression conditions, various polyhydroxyurethane compounds can be obtained efficiently in a short time, so the production that contributes to the industrial spread of thermoplastic polyhydroxyurethane resins As a method, its use is expected. Further, according to the present invention, the above-described useful resin can be obtained efficiently in a short time, so that it is useful in terms of protecting the global environment, and in addition, it is synthesized using carbon dioxide as a raw material. Since carbon dioxide can be fixed in the produced resin by using the membered ring carbonate compound, this point is also excellent in terms of protecting the global environment and is expected to be used industrially.

Claims (7)

A step [1] of obtaining a preliminary reaction liquid (A) having a weight average molecular weight of 3000 or more and 20000 or less by reacting a compound having a 5-membered cyclic carbonate group with a compound having an amino group in a solvent;
The preliminary reaction liquid (A) obtained in the step [1] is supplied at 80 to 180 ° C. and 10 to 200 torr of heated and reduced pressure to form the liquid film and devolatilize the preliminary reaction liquid (A). And a step [2] of obtaining a polyhydroxyurethane resin by concentration of the substrate, further polymerization and solvent removal, and a method for producing a thermoplastic polyhydroxyurethane resin.   The method for producing a thermoplastic polyhydroxyurethane resin according to claim 1, wherein in the step [2], the preliminary reaction liquid (A) is continuously supplied to an apparatus for carrying out the heating and decompression conditions.   The method for producing a thermoplastic polyhydroxyurethane resin according to claim 1 or 2, wherein the polyhydroxyurethane resin obtained in the step [2] has a nonvolatile content of 99.0% or more.   The method for producing a thermoplastic polyhydroxyurethane resin according to any one of claims 1 to 3, wherein the polyhydroxyurethane resin obtained in the step [2] has a weight average molecular weight of 20,000 to 100,000.   The method for producing a thermoplastic polyhydroxyurethane resin according to any one of claims 1 to 4, wherein the apparatus for carrying out the heating and decompression condition used in the step [2] is a thin film evaporation apparatus. 6. The compound according to any one of claims 1 to 5, wherein the compound having a 5-membered cyclic carbonate group is any one selected from the structural group represented by the following formula (2) in which X in the general formula (1). The manufacturing method of thermoplastic polyhydroxyurethane resin of description.

(R in the formula is a hydrogen atom or a methyl group.)   The compound having a 5-membered cyclic carbonate group is produced using an epoxy compound and carbon dioxide as raw materials, and the —O—CO— bond in the polyhydroxyurethane compound obtained in the step [2] It is a thing derived from carbon, The manufacturing method of the thermoplastic polyhydroxyurethane resin of any one of Claims 1-6.