JP2020164455A - Dicarboxylic acid having carbonate bond, derivative thereof, and methods for producing the same - Google Patents

Abstract

To provide a novel dicarboxylic acid and a derivative thereof which can be used as raw materials for biodegradable plastics having high biodegradability.SOLUTION: A dicarboxylic acid represented by the following formula (1) and a derivative thereof are provided. (In the formula, R1 represents a hydroxy group, an alkoxy group or a halogen atom, R2 represents an alkyl group, and R3 represents a hydrogen atom or an alkyl group). The compound of the formula (1) can be produced by reacting a 3-hydroxyalkanoic acid and/or a derivative thereof with a carbonate-forming compound such as phosgene and/or a carbonic diester.SELECTED DRAWING: None

Description

The present invention relates to a dicarboxylic acid containing a 3-hydroxyalkanoic acid (or 3HA) unit and a carbonate bond and a derivative thereof, a method for producing the same, and an application thereof.

From the viewpoint of environmental conservation and the realization of a sustainable society, some or all of the plastic raw materials are being converted to biomass, and bio-based plastics (or biodegradable plastics) are being used. Plastic is an indispensable material in human life, but plastic released into the environment floats on the ocean, collapses and is subdivided by ultraviolet rays, etc., and microplastics with a diameter of 5 mm or less are produced. In addition, when this microplastic is taken into a living body such as birds and fish, there is a concern that it may cause endocrine disruption.

In recent years, in order to solve the above-mentioned microplastic problem, for example, the addition of biodegradability to garbage bags has been promoted. Examples of biodegradable plastics include polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene succinate (PBS), polycaprolactone (PCL) and the like. However, these biodegradable plastics have low biodegradability (or biogasification) under anaerobic conditions and low biodegradability in the ocean. Since the biodegradable plastic has a high density and sinks in the ocean, it is necessary to develop a plastic having high biodegradability even under anaerobic conditions such as in the ocean in order to solve the microplastic problem.

H. Yagi et al., Polymer Degradation and Stability, 110, (2014), 278-283 (Non-Patent Document 1) evaluates the biodegradability of various biodegradable polyesters under anaerobic conditions, and PLA, It is disclosed that poly-3-hydroxybutyric acid (PHB) exhibits higher biodegradability under anaerobic conditions as compared with PCL and PBS. However, poly-3-hydroxyalkanoic acid such as PHB produced by microorganisms has not been widely used because it lacks the mechanical properties required for general-purpose plastic molded products and is not economical. It was.

According to Japanese Patent Application Laid-Open No. 2017-025138 (Patent Document 1), a biodegradable copolymer in which 3-hydroxybutyric acid (3HB) units are randomly introduced has high biodegradability under aerobic and anaerobic conditions. Is disclosed. Further, Patent Document 1 also describes that the biodegradation rate can be controlled by changing the ratio of 3HB units in the copolymer.

However, the biodegradable copolymer described in Patent Document 1 has a low reactivity of 3HB, which is a monomer, and is easily decomposed by intramolecular dehydration due to heat or acid, so that the molecular weight is increased. Difficult and inadequate mechanical properties.

Japanese Unexamined Patent Publication No. 2017-025138

H. Yagi et al., Polymer Degradation and Stability, 110, (2014), 278-283 (Table 1)

Therefore, an object of the present invention is to provide a novel carbonate bond-containing dicarboxylic acid and its derivative, which are useful as raw materials for biodegradable plastics having high biodegradability under aerobic and anaerobic conditions, and a method for producing the same. To do.

Another object of the present invention is to provide a carbonate bond-containing dicarboxylic acid and its derivative having high thermal stability even if it contains a 3-hydroxyalkanoic acid unit, and a method for producing the same.

3-Hydroxyalkanoic acid (3HA), such as 3-hydroxybutyric acid (3HB), has a highly reactive carboxyl group and a less reactive secondary alcohol. Therefore, when 3HA is used as a resin raw material (or monomer) to synthesize a polymer having 3HA units, the reactivity is low because 3HA has a secondary alcohol, and 3HA has a hydrogen atom at the α-position of the carboxylic acid. Since it has a hydroxy group (secondary alcohol) at the β-position, it easily undergoes intramolecular dehydration due to heating or acid and easily becomes an unsaturated monocarboxylic acid such as crotonic acid. It has been difficult to obtain a high molecular weight polymer having the above.

Therefore, as a result of diligent studies to achieve the above problems, the present inventors have reacted 3HA with a carbonate-forming compound such as phosgene or a carbonic acid ester, and the secondary alcohol of 3HA becomes a carbonate-forming compound. The reaction forms a carbonate bond (or carbonic acid ester bond) to obtain a dicarboxylic acid, and the dicarboxylic acid has high thermal stability, and the dicarboxylic acid is usually non-biodegradable. The present invention has been completed by finding that it has high biodegradability despite having a carbonate bond.

That is, the dicarboxylic acid having a carbonate bond of the present invention and its derivative are represented by the following formula (1).

(In the formula, R ¹ represents a hydroxy group, an alkoxy group, and a halogen atom, R ² represents an alkyl group, and R ³ represents a hydrogen atom or an alkyl group).

In the formula (1), R ² may be a C _1-3 alkyl group, R ³ may be a hydrogen atom or a methyl group, and R ¹ is a hydroxy group or a C _1-4 alkoxy group. You may. Further, in the above formula (1), it is preferable that R ² is a methyl group and R ³ is a hydrogen atom.

The present invention also includes a method for producing the dicarboxylic acid and / or its derivative by reacting 3-hydroxyalkanoic acid and / or a derivative thereof with a carbonate-forming compound such as phosgens and / or a carbonic acid diester. In the method, the 3-hydroxyalkanoic acid and / or a derivative thereof preferably contains 3-hydroxybutyric acid and / or a derivative thereof, and the 3-hydroxyalkanoic acid and / or a derivative thereof may be an R form. ..

The present invention also includes a dicarboxylic acid component as a polymerization component (or resin raw material, raw material monomer) of a biodegradable polyester or a biodegradable polyamide obtained by reacting with a diol component and / or a diamine component, and is used as the polymerization component. The dicarboxylic acid component may contain the dicarboxylic acid and / or a derivative thereof.

The present invention includes a method for imparting biodegradability to a polyester or polyamide obtained by reacting a dicarboxylic acid component with a diol component and / or a diamine component, and this method is derived from the dicarboxylic acid and / or a derivative thereof. The unit may be introduced as a constituent unit of the polyester or polyamide.

The present invention includes a method for improving the biodegradability of a polyester or polyamide obtained by reacting a dicarboxylic acid component with a diol component and / or a diamine component, and this method is derived from the dicarboxylic acid and / or a derivative thereof. The unit may be introduced as a constituent unit of the polyester or polyamide.

The present invention also includes a method of controlling the biodegradability (biodegradability) of polyester or polyamide obtained by the reaction of a dicarboxylic acid component with a diol component and / or a diamine component, and this method comprises the constitution of the polyester or polyamide. As a unit, a unit derived from the dicarboxylic acid and / or a derivative thereof may be introduced.

In the present specification and claims, "dicarboxylic acid" is used in the sense of including a salt of dicarboxylic acid in addition to dicarboxylic acid. Further, the term "derivative of dicarboxylic acid" is used in the sense of including a dicarboxylic acid ester-forming derivative such as a dicarboxylic acid ester or a dicarboxylic acid halide.

The dicarboxylic acid and its derivative having a carbonate bond of the present invention usually contain 3HA units even though they have a non-biodegradable carbonate bond, probably because they contain 3HA units under aerobic and anaerobic conditions. It has high biodegradability underneath. Further, it may be because the secondary alcohol derived from 3HA, which is involved in the low thermal stability of 3HA and the low reactivity in the polymerization reaction, reacts with a carbonate-forming compound such as phosgenes or a carbonic acid diester to form a carbonate bond. , The dicarboxylic acid of the present invention and its derivative have high thermal stability and high reactivity in the polymerization reaction as compared with 3HA. Therefore, the present invention provides a dicarboxylic acid component that is a polymer component (or resin raw material, raw material monomer) of biodegradable polyester or biodegradable polyamide obtained by reacting a dicarboxylic acid component with a diol component and / or a diamine component. By using dicarboxylic acid and / or a derivative thereof, it is possible to prepare a high molecular weight polymer having 3HA units, and biodegradability of biodegradable polyester and biodegradable polyamide having both high biodegradability and mechanical properties. A sex polymer can be obtained. Further, when a unit derived from the dicarboxylic acid and / or a derivative thereof of the present invention is introduced into a constituent unit of a copolymer such as polyester or polyamide obtained by reacting a dicarboxylic acid component with a diol component and / or a diamine component, the above It is possible to impart biodegradability to the copolymer or improve the biodegradability (or biodegradability) of the copolymer. Furthermore, the biodegradability (or biodegradation rate) of the copolymer can be easily controlled by introducing or adjusting (or adjusting) the introduction or the rate of introduction of the unit derived from the dicarboxylic acid of the present invention or a derivative thereof.

FIG. 1 is a ¹ H NMR spectrum of the dicarboxylic acid ethyl ester obtained in Example 1. FIG. 2 is a ¹³ C NMR spectrum of the dicarboxylic acid ethyl ester obtained in Example 1.

[Dicarboxylic acid having carbonate bond and its derivative]
The dicarboxylic acid having a carbonate bond of the present invention represented by the formula (1) and a derivative thereof have a carbonate-forming property such as phosgen or carbonic acid diester with a secondary alcohol of 3-hydroxyalkanoic acid (3HA) or a derivative thereof. Since it is obtained by reacting with a compound, it contains 3HA units and carbonate bonds in its structure.

In the above formula (1), the alkoxy group represented by R ¹ is a linear or branched C _1-20 alkoxy group such as a methoxy group, an ethoxy group, a propoxy group, an n-butoxy group, or a t-butoxy group. Examples thereof include a linear or branched C _1-10 alkoxy group, more preferably a C _1-4 alkoxy group, particularly a C _1-3 alkoxy group.

Examples of the halogen atom represented by R ¹ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Incidentally, two kinds of R ¹ in the dicarboxylic acid or a derivative thereof, which may be the same or different from each other, usually, it is often the same. Of these R ¹ , hydroxy groups and alkoxy groups are preferable, and hydroxy groups and C _1-4 alkoxy groups are particularly preferable, and hydroxy groups, methoxy groups, and ethoxy groups are preferable.

The alkyl group represented by R ^2, a methyl group, an ethyl group, a propyl group, an isopropyl group, n- butyl group, t- butyl group, n- pentyl group, n- hexyl, n- octyl, 2 Examples thereof include a linear or branched C _1-10 alkyl group such as an ethylhexyl group. The two types of R ² in the dicarboxylic acid or its derivative may be the same or different from each other, and are usually the same. Preferred R ² is a linear or branched C _1-6 alkyl group, more preferably a C _1-3 alkyl group, and a methyl group is particularly preferable from the viewpoint of biodegradability under anaerobic conditions.

R ³ represents a hydrogen atom or an alkyl group, and is the same as the alkyl group represented by R ² including a preferable embodiment as the alkyl group. Incidentally, two kinds of R ³ in the dicarboxylic acid or a derivative thereof, which may be the same or different from each other, usually, it is often the same. Preferred R ³ is a hydrogen atom, a C _1-2 alkyl group, more preferably a hydrogen atom or a methyl group, particularly a hydrogen atom.

The 3HA unit in the formula (1) may be either the R arrangement (R body) or the S arrangement (S body), but is usually the R arrangement (R body).

(Characteristics of dicarboxylic acid and its derivatives)
Since the dicarboxylic acid and its derivative of the present invention have 3HA units such as 3HB, they have high biodegradability under aerobic and anaerobic conditions. In particular, since it has high biodegradability even under anaerobic conditions, it can reduce the environmental load even if it is released into the environment such as in the ocean.

The biodegradability (or biogasification rate) of the dicarboxylic acid and its derivative after 7 days under anaerobic conditions (55 ° C.) is, for example, 10% by mass or more, preferably 20% by mass or more, and more preferably 30% by mass or more. It may be. The biodegradability (or biogasification rate) of the dicarboxylic acid and its derivative under anaerobic conditions can be measured by the method described in Examples.

Although the dicarboxylic acid and its derivative of the present invention have 3HA units derived from 3HA having low thermal stability, a secondary alcohol derived from 3HA reacts with phosgenes or a carbonic acid diester to form a carbonate bond. It has high thermal stability, probably because it forms.

The dicarboxylic acid and its derivative have a higher weight loss temperature as compared with 3HA and its derivative, and the 1% weight loss temperature (Td1) of the dicarboxylic acid and its derivative is in the range of about 80 to 250 ° C. It can be selected, preferably 100 to 200 ° C., more preferably 110 to 180 ° C., and particularly preferably 120 to 160 ° C. (for example, 130 to 140 ° C.). The 5% weight loss temperature (Td5) of the dicarboxylic acid and its derivative can be selected from the range of about 100 to 300 ° C., preferably 110 to 280 ° C. (for example, 120 to 250 ° C.), and more preferably 130 to 220 ° C. ° C. (eg 140-200 ° C.), particularly preferably 150-180 ° C. (eg 160-180 ° C.). The weight loss temperature can be measured using a differential thermogravimetric analyzer, and in detail, can be measured by the method described in Examples.

[Method for producing dicarboxylic acid and its derivatives]
The dicarboxylic acid having a carbonate bond and its derivative of the present invention can be produced by reacting 3HA or a derivative thereof (3HA or an ester-forming derivative thereof) with a carbonate-forming compound such as phosgene or a carbonic acid diester.

(3-Hydroxyalkanoic acid)
Examples of 3-hydroxyalkanoic acid (3HA) include 3-hydroxybutyric acid (3HB), 3-hydroxyvaleric acid, 3-hydroxyisovaleric acid, 3-hydroxyhexanoic acid, 3-hydroxyheptanic acid, and 3-hydroxyoctanoic acid. , 3-Hydroxy C _4-15 alkanoic acid such as 3-hydroxydecanoic acid, and the like, and examples of these 3HA ester-forming derivatives include 3-hydroxy alkanoic acid C _1-6 alkyl such as methyl ester and ethyl ester. Esters; examples include 3-hydroxyalkanoic acid halides such as acid chloride and acid bromide. These 3HA and its ester-forming derivative can be used alone or in combination of two or more.

Of these 3HAs, from the viewpoint of biodegradability under anaerobic conditions, 3-hydroxy C _4-7 alkanoic acid is preferable, and 3-hydroxybutyric acid, 3-hydroxyvaleric acid, particularly 3-hydroxybutyric acid is preferable. preferable. Further, preferred 3HA ester-forming derivatives are alkyl esters having a secondary alcohol, ester-forming reactive derivatives such as acid halides, and more preferably C _1-4 alkyl esters having a secondary alcohol.

These 3HA and its derivatives may be optical isomers (R-form or S-form) or racemic-form, but are preferably R-form.

(Carbonate-forming compound)
Examples of the carbonate-forming compound include phosgenes and carbonic acid diesters. Examples of phosgenes include phosgenes; phosgene multimers such as diphosgene and triphosgene. The carbonic acid diester, dialkyl carbonate, particularly dimethyl carbonate, di-C _1-4 alkyl carbonates such as diethyl carbonate; diaryl carbonates, specifically, diphenyl carbonate, di-C _6-12 aryl, such as dinaphthyl carbonate Examples include carbonate. These carbonate-forming compounds can be used alone or in combination of two or more. Among these carbonate-forming compounds, phosgenes, dialkyl carbonates, and more preferably phosgenes such as phosgene or a multimer thereof (triphosgene, etc.).

The ratio (charge ratio) of 3HA or its ester-forming derivative can be selected from the range of about 1.5 to 5 mol, preferably 1.8 to 1 mol, with respect to 1 mol of the carbonate-forming compound (monomer equivalent). It is 3 mol, more preferably 2 to 2.5 mol. When the carbonate-forming compound is phosgene, the number of moles of phosgene in the above ratio is used in the sense that it is based on phosgene (phosgene monomer) produced in the reaction system, and is used, for example, 3HA or When 1 mol of triphosgene is used with respect to 1 mol of the ester-forming derivative, it means that 3 mol is used based on the phosgene produced in the reaction system.

The reaction may be carried out in the presence of a base, if necessary, and the base may be either an organic base or an inorganic base. Examples of the organic base include tertiary amines such as triethylamine, heterocyclic tertiary amines such as pyridine and N-methylmorpholin, quaternary ammonium salts such as tetramethylammonium salt, and organics such as sodium acetate and potassium acetate. Examples thereof include alkali metal salts of acids. Examples of the inorganic base include alkali metals such as sodium hydroxide and calcium hydroxide, alkaline earth metal hydroxides, and the like. These bases can be used alone or in combination of two or more.

The amount of the base used can be selected from the range of about 0.5 to 2 mol, preferably 0.7 to 1.5 mol, more preferably 0.8 to 0.8 to 1 mol of 3HA or an ester-forming derivative thereof. 1.2 mol, especially 1 mol.

The reaction may be carried out in the presence or absence of a solvent, and the solvent is not particularly limited as long as it is a solvent inactive or non-reactive with respect to the 3HA and the carbonate-forming compound, for example. Examples thereof include ethers, ketones, esters, hydrocarbons, halogen-based solvents, nitriles, amides, pyrrolidones, sulfoxides and the like.

Examples of ethers include dialkyl ethers such as diethyl ether and dipropyl ether; and cyclic ethers such as 1,4-dioxane and tetrahydrofuran. Examples of the ketones include dialkyl ketones such as acetone, methyl ethyl ketone (or ethyl methyl ketone), diisopropyl ketone, and isobutyl methyl ketone. Examples of the esters include acetic acid esters such as methyl acetate, ethyl acetate and butyl acetate. Examples of the hydrocarbons include aromatic hydrocarbons such as hexane, cyclohexane, toluene, xylene and ethylbenzene. Examples of the halogen-based solvent include halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, tetrachloroethane, and trichloroethane. Examples of nitriles include acetonitrile and the like. Examples of the amides include N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMAc). Examples of pyrrolidones include 2-pyrrolidone and N-methyl-2-pyrrolidone. Examples of sulfoxides include dimethyl sulfoxide (DMSO) and the like. These solvents can be used alone or in combination of two or more.

3HA or an ester-forming derivative thereof and a carbonate-forming compound may be reacted by directly adding a carbonate-forming compound to 3HA or an ester-forming derivative thereof, but usually, they are often reacted in the presence of a solvent. .. Further, the carbonate-forming compound may be added at once to the reaction system in which 3HA or an ester-forming derivative thereof is present, but it is preferably added continuously or intermittently, and is continuously added dropwise. Is even more preferable.

Moreover, the reaction may be carried out in the air or in an atmosphere of an inert gas. Examples of the inert gas include nitrogen gas and argon gas. The reaction may be carried out under reduced pressure, but is usually carried out under pressurized pressure or normal pressure. The reaction temperature can be selected from, for example, in the range of about 0 to 200 ° C, preferably 10 to 180 ° C (for example, 20 to 170 ° C), and more preferably 40 to 160 ° C (for example, 60 to 150 ° C). In particular, it may be 80 to 130 ° C. The reaction may be carried out under reflux of the solvent.

After completion of the reaction, the dicarboxylic acid and its derivative are separated and purified by a conventional separation method, for example, a separation means such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, or a separation means combining these. it can.

[Use of dicarboxylic acid and its derivatives]
Since the dicarboxylic acid and its derivative (particularly, the dicarboxylic acid and its reactive derivative) of the present invention have high biodegradability, they are suitably used as a raw material for a biodegradable polymer or a biodegradable resin additive. it can.

Examples of the biodegradable polymer include biodegradable polyester and biodegradable polyamide obtained by reacting a dicarboxylic acid component containing at least the dicarboxylic acid of the present invention and a derivative thereof with a diol component and / or a diamine component. ..

The dicarboxylic acid component is, in addition to the dicarboxylic acid of the present invention and its derivative (hereinafter, may be referred to as the first dicarboxylic acid component), another mono or dicarboxylic acid and its derivative (hereinafter, the second dicarboxylic acid). It may be referred to as an ingredient).

Examples of the second dicarboxylic acid component include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, hydroxyalkanoic acids, aminocarboxylic acids, and ester-forming derivatives thereof.

Examples of the aliphatic dicarboxylic acid include aliphatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, maleic acid, and fumaric acid.

Examples of the alicyclic dicarboxylic acid include cyclohexanedicarboxylic acid and alicyclic dicarboxylic acid such as cyclopentenedicarboxylic acid.

Examples of the aromatic dicarboxylic acid include aromatic dicarboxylic acids such as benzenedicarboxylic acid, naphthalene dicarboxylic acid, biphenyldicarboxylic acid and terephthalic acid.

As the hydroxyalkanoic acid, glycolic acid, 2-hydroxypropanoic acid (lactic acid), 3-hydroxypropanoic acid, 2-hydroxybutanoic acid (2-hydroxybutyric acid), 4-hydroxybutanoic acid, 3-hydroxy-3-methyl- Butanoic acid, 2-hydroxypentanoic acid (2-hydroxyvaleric acid), 3-hydroxypentanoic acid, 5-hydroxypentanoic acid, 2-hydroxy-2-methyl-pentanoic acid, 3-hydroxyhexanoic acid, 6-hydroxyheptanoic acid , 3-Hydroxyheptanoic acid, 7-hydroxyheptanoic acid, 3-hydroxyoctanoic acid, 8-hydroxyoctanoic acid, 3-hydroxynanonic acid, 9-hydroxynanonic acid, 3-hydroxydecanoic acid, 10-hydroxydecanoic acid, etc. Hydroxy C _2-15 alkanoic acid and the like can be mentioned. In addition, these hydroxyalkanoic acids may be the corresponding lactones. Examples of the lactone include C _3-15 lactones such as β-propiolactone, β-dimethylpropiolactone, γ-butyrolactone, γ-dimethylbutyrolactone, δ-valerolactone, and ε-caprolactone.

Examples of the aminocarboxylic acid include amino C _2-20 alkyl-carboxylic acid such as 6-aminohexanoic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, and amino C _{5-10 cycloalcancarboxylic} acid such as aminocycloalcancarboxylic acid. _Examples include amino C _6-12 arylcarboxylic acids such as acids and aminobenzoic acids. These aminocarboxylic acids may be the corresponding lactams. Examples of the lactam include C _4-12 lactams such as γ-valerolactam, δ-valerolactam, ε-caprolactam, and ω-laurolactam.

These second dicarboxylic acids can be used alone or in combination of two or more.

Of these second dicarboxylic acid components, from the viewpoint of biodegradability, aliphatic dicarboxylic acids (for example, C _2-10 alcan-dicarboxylic acids such as adipic acid) and hydroxyalkanoic acids (for example, hydroxy C _4-8). Arcanoic acid) and aminocarboxylic acid (for example, amino C _4-8 carboxylic acid) are preferable, and aromatic dicarboxylic acid such as terephthalic acid is preferable from the viewpoint of heat resistance.

When the dicarboxylic acid component contains a second dicarboxylic acid component in addition to the first dicarboxylic acid component, the ratio of the first dicarboxylic acid component to the second dicarboxylic acid component in the total dicarboxylic acid component is the former. / The latter (molar ratio) can be selected from the range of about 1/99 to 99/1, and may be, for example, 2/98 to 90/10, preferably 3/97 to 80/20, and has mechanical properties. From the viewpoint, it may be, for example, 1/99 to 50/50, preferably 2/98 to 30/70, more preferably 3/97 to 20/80, and particularly 5/95 to 15/85.

Examples of the diol component include aliphatic diols, alicyclic diols, aromatic diols, and C _2-4 alkylene oxide adducts thereof.

Examples of the aliphatic diol include alkanediols such as ethylene glycol, 1,3-propanediol and 1,4-butanediol; and polyalkanediols such as diethylene glycol. Examples of the alicyclic diol include cycloC _5-8 alkanedi to hexaol such as cyclohexanediol; and alicyclic diols such as di (hydroxy C _1-4 alkyl) C _5-8 cycloalkane such as cyclohexanedimethanol. Be done. Examples of the aromatic diol include hydroxyarene such as hydroquinone; bisphenols such as bisphenol A; and aromatic diols such as biphenols such as p, p'-biphenol. These diols can be used alone or in combination of two or more.

Of these diol components, polyC _2-6 alkanediol is preferable from the viewpoint of biodegradability.

Examples of the diamine component include aliphatic diamines, alicyclic diamines, and aromatic diamines.

Examples of the aliphatic diamine include C _2-10 alkane diamines such as ethylenediamine, propylene diamine and hexamethylene diamine. Examples of the alicyclic diamine include isophorone diamine, hexahydroxylylenediamine, 4,4'-methylenebis (cyclohexylamine), N- (2-aminoethyl) piperazin and other alicyclic diamines. Examples of the aromatic diamine include aromatic diamines such as phenylenediamine, aminobenzylamine, and xylylenediamine. These diamines can be used alone or in combination of two or more.

Of these diamine components, an aliphatic diamine such as C _2-8 alkane diamine is preferable from the viewpoint of biodegradability.

Further, since the dicarboxylic acid and / or its derivative of the present invention has high biodegradability, the unit derived from the dicarboxylic acid and / or its derivative of the present invention (dicarboxylic acid unit of the present invention) can be used as described above. When introduced as a constituent unit of a copolymer such as polyester or polyamide obtained by reacting a dicarboxylic acid component with the diol component and / or the diamine component, the copolymer is imparted with biodegradability or biodegradability of the copolymer ( Biodegradation rate) can be improved.

Further, by introducing the polycarboxylic acid unit of the present invention as a constituent unit of the copolymer, the biodegradability (biodegradation rate) of the copolymer can be controlled, and the ratio of the polycarboxylic acid unit of the present invention (introduction ratio) can be controlled. The biodegradability (biodegradation rate) of the copolymer may be easily controlled (or controlled) by changing (or adjusting).

The proportion of the dicarboxylic acid unit of the present invention in the total constituent units of the copolymer can be selected from the range of about 0.1 to 50 mol%, for example, 0.5 to 30 mol%, preferably 1 to 20 mol%, and further. It is preferably 1.5 to 15 mol% (for example, 2 to 10 mol%).

The dicarboxylic acid and its derivatives of the present invention are compared with 3HA because a secondary alcohol derived from 3HA, which has low reactivity, reacts with a carbonate-forming compound such as phosgene or carbonic acid diester to have a carbonate bond. It has high reactivity. Furthermore, since the dicarboxylic acid and its derivative of the present invention have high heat resistance, the reaction can be further accelerated by heating, if necessary. Therefore, when the dicarboxylic acid of the present invention and its derivative are used as a resin raw material (or a polymerization component or a raw material monomer), a high molecular weight polymer containing 3HA units can be obtained. Therefore, the dicarboxylic acid and its derivative of the present invention are useful for preparing a biodegradable polymer having high biodegradability and high mechanical properties.

Further, the dicarboxylic acid of the present invention and its derivative can also be used as a resin additive such as a biodegradable plasticizer and a cross-linking agent.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. The evaluation methods in Examples and Comparative Examples are as follows.

[Thermal stability (weight loss temperature)]
Using a thermogravimetric differential thermal analyzer (TG-DTA, manufactured by Hitachi High-Tech Science Co., Ltd., "STA7200"), 1% weight loss temperature (Td1) and 5% weight under argon gas and air under the following conditions. The reduced temperature (Td5) was measured.

Measurement temperature range: 30-400 ° C
Temperature rise temperature: 10 ° C./min Gas atmosphere: Argon gas atmosphere or under air.

[Biodegradability under anaerobic conditions (biogasification rate)]
0.1 g of a test test product, dicarboxylic acid or a derivative thereof, was added to 20 ml of methane fermentation sludge, and the degradability (biogasification rate) was measured after 7, 14, and 22 days under high temperature anaerobic conditions at 55 ° C.

[Example 1]
Ethyl 3-hydroxybutyrate (8.73 g, 66.0 mmol), pyridine (5.23 g, 66.1 mmol), dehydrated tetrahydrofuran in a reaction vessel equipped with a stir bar, a dropping funnel, a reflux tube and a thermometer under an argon stream. (30 mL) was added, and the ethyl 3-hydroxybutyrate mixture was ice-cooled. Further, triphosgene (2.97 g, 10 mmol) is dissolved in dehydrated tetrahydrofuran, and this triphosgene solution is slowly added dropwise to the ethyl 3-hydroxybutyrate mixed solution over 1 hour while keeping the temperature in the system at 10 ° C. or lower. did. After completion of the dropping, the reaction vessel was reacted in an oil bath under heating and reflux conditions. After 24 hours, water (50 mL) was added dropwise to the reaction mixture, and dichloromethane (50 mL) was further added to separate the solutions. Further, the mixture was washed with 1N hydrochloric acid (50 mL), washed with water, dried over magnesium sulfate, and the solvent was distilled off to obtain a brown oily crude product (7.78 g). The obtained crude oily product was purified by silica gel chromatography (silica gel: 120 g, eluate: hexane / ethyl acetate (volume ratio) = 10/1 → 5/1 → 1/1) to form a colorless oil. The product (6.27 g, yield 72.0% by mass) was obtained. As a result of analyzing the obtained product by ¹ H NMR and ¹³ C NMR, a shift of protons derived from the methine group of ethyl 3-hydroxybutyrate was observed, and a peak of carbon derived from carbonate was observed. From this, it was confirmed that the target product was a dicarboxylic acid ethyl ester having a carbonate bond represented by the following formula (2). For the measurement of the NMR spectrum, "JNM-GSX270 (270 MHz)" manufactured by JASCO Corporation was used.

The NMR spectrum data of the obtained dicarboxylic acid ethyl ester are shown in FIGS. 1 and 2 and below.

^{1 H-NMR (270MHz, CDCl} 3): δ = 1.25 (t, 6H, C H 3 -CH 2 -), 1.35 (d, 6H, C H 3 -CH (O -) - CH 2 _{-), 2.48-2.75 (dd, 4H} , -CH (O -) - C H 2 -), 4.15 (q, 4H, CH 3 -C H 2 -), 5.15 (m _{, 2H, CH 3 -C H (} O-) CH 2 -);
^{13 C-NMR (67.5MHz, CDCl} 3): δ = 14.14 (C H 3 -CH 2 -), 19.83 (C H 3 -CH (O-) CH 2 -), 40.67 ( _{-CH (O -) - C H} 2 -), 60.60 (CH 3 - C H 2 -), 71.12 (CH 3 - C H (O-) CH 2 -), 153.33 (-O -C (= O) -O-), 169.68 (-CH ₂ - C (= O) -O-).

The obtained dicarboxylic acid ethyl ester was evaluated for thermal stability and biodegradability.

[Comparative Example 1]
The thermal stability of ethyl 3-hydroxybutyrate was evaluated.

The results of Example 1 and Comparative Example 1 are shown in Table 1.

As is clear from Table 1, in Example 1, the 1% weight loss temperature (Td1) and the 5% weight loss temperature (Td5) were higher in both the argon gas atmosphere and the air than in Comparative Example 1. It was higher than 97 ° C. Further, the dicarboxylic acid ethyl ester obtained in Example 1 showed high biodegradability under anaerobic conditions, and its decomposition rate (biogasification rate) was 7 days later: 38.6% by mass and 14 days later: 42. .1% by mass, after 22 days: 44.3% by mass. From these results, it was confirmed that the diester compound obtained in Example 1 has both high thermal stability and high biodegradability.

Since the dicarboxylic acid and its derivative of the present invention have high biodegradability, thermal stability, and reactivity, they can be used as resin raw materials and resin additives such as plasticizers and cross-linking agents. Fields that can be suitably used as resin raw materials and resin additives include various fields such as abrasives (such as scrubbing agents such as toothpaste, facial cleansers, and whole body cleaning agents), paints, antistatic agents, inks, and adhesives. Examples include adhesives and electrical / electronic materials. In particular, resins such as biodegradable polyesters and biodegradable polyamides containing the dicarboxylic acid of the present invention and its derivatives as polymerization components are molded bodies or molding members (for example, molded bodies such as casings and housings) and containers in various fields. Since it can be suitably used for (containers for food, daily necessities, electricity, electronic devices and parts), packaging materials such as films, sheets and bags, it is also useful for solving the problem of microplastics, which has become a new problem in recent years. Is. Since it contains a unit derived from 3HA such as 3HB and has biocompatibility, it can also be used in the medical field (for example, medical equipment). In addition, since it contains 3HA-derived units such as 3HB, it also has cell activation, whitening, and moisturizing effects on aged skin cells, and can be used in the cosmetics field.

Claims (12)

A dicarboxylic acid and / or a derivative thereof having a carbonate bond represented by the following formula (1).

(In the formula, R ¹ represents a hydroxy group, an alkoxy group, and a halogen atom, R ² represents an alkyl group, and R ³ represents a hydrogen atom or an alkyl group). The dicarboxylic acid and / or a derivative thereof according to claim 1, wherein R ² is a C _1-3 alkyl group in the formula (1). The dicarboxylic acid and / or a derivative thereof according to claim 1 or 2, wherein R ³ is a hydrogen atom or a methyl group in the formula (1). The dicarboxylic acid and / or a derivative thereof according to any one of claims 1 to 3, wherein R ¹ is a hydroxy group or a C _1-4 alkoxy group in the formula (1). The dicarboxylic acid and / or a derivative thereof according to any one of claims 1 to 4, wherein in the formula (1), R ² is a methyl group and R ³ is a hydrogen atom. The method for producing a dicarboxylic acid and / or a derivative thereof according to any one of claims 1 to 5 by reacting a 3-hydroxyalkanoic acid and / or a derivative thereof with a phosgene and / or a carbonic acid diester. The method according to claim 6, wherein the 3-hydroxyalkanoic acid and / or a derivative thereof comprises 3-hydroxybutyric acid and / or a derivative thereof. The method according to claim 6 or 7, wherein the 3-hydroxyalkanoic acid and / or a derivative thereof is an R form. The dicarboxylic acid component as a polymerization component of a biodegradable polyester or a biodegradable polyamide obtained by reacting with a diol component and / or a diamine component, wherein the dicarboxylic acid component is described in any one of claims 1 to 5. A polymerization component containing a dicarboxylic acid and / or a derivative thereof. The dicarboxylic acid and / or the method according to any one of claims 1 to 5, which is a method for imparting biodegradability to polyester or polyamide obtained by reacting a dicarboxylic acid component with a diol component and / or a diamine component. A method of introducing a unit derived from a derivative as a constituent unit of the polyester or polyamide. The dicarboxylic acid and / or the method according to any one of claims 1 to 5, which is a method for improving the biodegradability of polyester or polyamide obtained by reacting a dicarboxylic acid component with a diol component and / or a diamine component. A method of introducing a unit derived from a derivative as a constituent unit of the polyester or polyamide. A unit derived from the dicarboxylic acid and / or a derivative thereof according to any one of claims 1 to 5 is introduced as a constituent unit of polyester or polyamide obtained by reacting the dicarboxylic acid component with the diol component and / or the diamine component. A method for controlling the biodegradability of the polyester and / or polyamide.

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