JP2834630B2 - Novel cyclic ester compound and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel cyclic ester compound useful as a raw material for a polymer, a derivative thereof, and a method for producing them.

[0002]

2. Description of the Related Art Various cyclic esters have been known, and these are widely used as raw materials for polyesters and the like.

[0003] For example, an aliphatic cyclic lactone represented by ε-caprolactone is used as a polymer raw material because of its easy ring-opening polymerization. Glycolide and lactide have been synthesized as cyclic diesters, and their polymerizability has been studied.

Other cyclic esters other than the above-mentioned compounds include a cyclic dimer obtained during the synthesis of polyethylene phthalate by heating and melt-polymerizing isophthalic acid and ethylene glycol (Journal of Polymer Science, 19th edition).
55, vol. 15, 80, P591) or a heat-melt polymerization of terephthalic acid and ethylene glycol, that is, a cyclic trimer obtained as a by-product during the synthesis of polyethylene terephthalate is known. ° C
It has not been synthesized for the purpose of utilization because of its high point and low polymerization ability.

A cyclic carbonate oligomer synthesized by using bis (chloroformate) of bisphenol A as a reaction intermediate is also known, which uses toxic phosgene and further involves an interface reaction of methylene chloride / water system. And there is a problem in the manufacturing process.

As described above, in particular, at present, a cyclic ester having an aromatic ring as a part of its ring structure is hardly used for synthesis.

[0007]

An object of the present invention is to provide a novel cyclic ester and a derivative thereof.
More specifically, an object of the present invention is to provide a cyclic tetraester and a derivative thereof which are advantageous for producing a ring-opened polymer of polyester. Another object of the present invention is to provide a method for efficiently producing the above-mentioned cyclic tetraester and its derivative.

[0008]

That is, the present invention provides a compound represented by the following formula (I):

[0009]

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[Wherein, R _{1 to} R ₁₀ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. However, these do not all become hydrogen atoms at the same time. And a method for producing the same.

Hereinafter, the present invention will be described in detail.

In the above formula (I), R _{1 to} R ₁₀ are each independently selected from a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and an isopropyl group. However, all of R _{1 to} R ₁₀ are not simultaneously hydrogen atoms. That is, at least one of R _{1 to} R ₁₀ is an alkyl group.

Each of R _{1 to} R ₈ is preferably a hydrogen atom or a methyl group.

[0014]

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The divalent residue represented by the above is preferably an ethylene residue or a propylene residue.

As R ₉ and R ₁₀ , a hydrogen atom and a methyl group are preferred.

The structural formulas as specific examples of the compound represented by the above formula (I) are shown in the following formulas IV-a to IV-p. Of the structural formulas represented, the formulas IV-a, b, IV-d, e, IV-g,
h, IV-n, o are each structural isomers of each other,
Usually obtained as a mixture. There are also compounds obtained as a single compound such as IV-1.

[0018]

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[0019]

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[0020]

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[0021]

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The above-mentioned novel cyclic ester is represented by the following formula (II)
A linear ester oligomer or polymer obtained from an isophthalic acid optionally having a substituent and / or an ester-forming derivative thereof and a diol represented by the following formula (III) is heated and reacted in the presence of a catalyst. It can be obtained by: Preferably, it is obtained by subjecting the oligomer or polymer to a heat reaction in the presence of a catalyst to form a sublimate.

[0023]

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[R ₁₁ in the formula (II) and R _{12 to} R ₁₅ in the formula (III) each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Specific examples of the dicarboxylic acid represented by the formula (II) include isophthalic acid, 4-methylisophthalic acid, and 5-methylisophthalic acid. Of these, isophthalic acid and 4-methylisophthalic acid are preferred. Examples of the ester-forming derivatives include lower alkyl esters, aryl esters, and acid chlorides.

Further, specific examples of the diol represented by the formula (III) include ethylene glycol, propylene glycol, 1,2-dihydroxybutane, and 2,3-dihydroxybutane. Of these,
Ethylene glycol and propylene glycol are preferred.

The method for synthesizing the linear ester oligomer or polymer is not particularly limited, but, for example, a transesterification method, an acid chromatography method, a direct esterification method and the like can be used. Of these, transesterification and direct esterification are preferred. As a production method using a transesterification method or a direct esterification method, a conventionally known method in the art can be used.

For example, in the transesterification method, dimethyl ester is used as a dicarboxylic acid component.
2 to 2.5 equivalents of the diol component are heated and reacted,
The desired linear ester oligomer or polymer can be obtained by distilling off the generated methanol and, if necessary, distilling off the diol component.

The molecular weight of the linear oligomer and / or polymer obtained by these methods is not particularly limited, but may be, for example, a phenol / 1,1,2,2-tetrachloroethane mixed solvent (weight ratio: 60 / 40), the intrinsic viscosity measured at a concentration of 1.2 g / dl and a temperature of 35 ° C. is 0.1.
It is preferable to set it to 1 or more.

Next, the step of subjecting the linear oligomer or polymer to a heat reaction in the presence of a catalyst to synthesize a desired cyclic ester will be described.

As the catalyst, acid catalysts such as p-toluenesulfonic acid and sulfuric acid, or Sb, Ge, Sn,
Inorganic salts such as Zn, Pb, Ti, Mn, and Ca, and organic metal compounds can be used. These are also known as conventionally known transesterification catalysts, and in particular, have an advantage that a reaction system obtained by synthesizing a linear polymer or oligomer by transesterification in the previous step can be used as it is. Of these, (BuO) ₄ Ti is preferred. Further, the amount of the catalyst used is preferably 0.001 to 1 mol%, more preferably 0.01 to 0.5 mol%.

The reaction temperature is 150 to 350 ° C., preferably 200 to 300 ° C., particularly preferably 260 to 280 ° C.
It is. When the temperature is low, a cyclic substance is not obtained, and when the temperature is too high, a linear oligomer is also obtained as a sublimate. formula
The optimum reaction temperature for producing the compounds represented by IV-a and IV-b is 260 ° C., and the compound represented by IV-l is 280 ° C. The reaction is performed under an atmosphere of an inert gas such as N ₂ or Ar.
It is preferable to carry out the process under a reduced pressure of 10 mmHg or less.

The time required for the reaction depends on the reaction temperature, the degree of pressure reduction,
Although it depends on the type of the raw material, it is usually 0.5 to 20 hours, preferably 1 to 10 hours.

The step of producing the above-mentioned linear oligomer or polymer and the step of heat-reacting the same in the presence of a catalyst can be carried out continuously without distinction. For example, in the above-mentioned transesterification method, the catalyst used as a transesterification catalyst is used as a catalyst during the production of a cyclic ester compound, and the linear ester oligomer or polymer is continuously isolated in the same reaction system without isolation. The desired cyclic ester compound can be obtained by a simple process by heating and reacting.

As the reaction proceeds, a polymer having a high molecular weight may be formed in the reaction solution. In this case, the pressure is released once, the corresponding glycol component (III) is added, and reflux is performed to decompose the polymer. By reducing the pressure again, the cyclic ester can be obtained more efficiently.

By the above method, the desired cyclic ester compound is obtained as a sublimate.

Depending on the isophthalic acid and / or its ester-forming derivative (II) and the diol (III) component used, the resulting cyclic ester compound can be obtained as a mixture of structural isomers, or as a single compound. You can also get.

That is, in another embodiment of the present invention,
A catalyst comprising a linear ester oligomer or polymer obtained from isophthalic acid optionally having a substituent represented by the above formula (II) and / or an ester-forming derivative thereof and a diol represented by the above formula (III) And a method for producing a composition consisting essentially of the cyclic ester compound represented by the above formula (I).

The thus obtained cyclic ester compound has high purity and can be used for various applications as it is, but it is also preferable to purify it by recrystallization or the like in some cases. Preferred examples of the recrystallization solvent include ethers such as tetrahydrofuran and dioxane, alcohols such as ethanol and propanol, and ketones such as methyl ethyl ketone and methyl butyl ketone. Of these, dioxane is particularly preferred.

[0039]

Industrial Applicability The cyclic ester compound and its derivative of the present invention have a low melting point, can be polymerized at a low temperature, are useful as a novel ring-opening polymerizable monomer raw material, and are used as a raw material for molding resins. Can be used.

Further, according to the present invention, a method for efficiently producing the above-mentioned cyclic tetraester and its derivative can be provided. Therefore, its significance is significant in industry.

[0041]

The present invention will be described below in detail with reference to examples. In addition, the infrared absorption spectrum (IR) was measured by a KBr disk method. Nuclear magnetic resonance spectrum (NMR)
The measurement was performed using deuterated dimethyl sulfoxide as a solvent and tetramethylsilane as a standard.

The present invention is not limited by these embodiments.

[0043]

Example 1 <Synthesis of Cyclic Ester Having Structures IV-a and IV-b>
After 200 g of dimethyl isophthalate, 156.8 g of propylene glycol, and 0.05 g of titanium tetrabutoxide were charged into a 1-liter three-necked flask and zeolite was added, the transesterification proceeded at 230 ° C. under a nitrogen atmosphere. Is formed in a theoretical amount (about 12
3 ml) Warmed until distilled.

The obtained viscous liquid was further heated to 250 ° C., held for 30 minutes, and reduced under a reduced pressure of 10 to 15 mmHg for 30 minutes.
The reaction was further continued for 0.5 minute under a reduced pressure of 0.5 mmHg.

At the top of the flask, 21 g of the compounds IV-a and IV-b obtained as sublimates were obtained. The melting point of this cyclic ester mixture was 207 to 210 ° C. by DSC measurement. IR and ¹ H-NMR are as shown in FIGS. In addition, according to the mass spectrometry spectrum, a molecular weight
2 was confirmed. As a result of elemental analysis, this compound was found to have 63.70% of C, 31.43% of O, and 4.87 of H.
% (Theoretical CHN, C 64.08, H4.
85, O 31.07).

[0046]

Example 2 <Synthesis of IV-l> Instead of dimethyl isophthalate, 4-
Example 1 was repeated except that dimethyl methyl isophthalate was replaced with ethylene glycol instead of propylene glycol.
IV-1 was obtained in the same manner as described above. The melting point of this cyclic ester was 200 to 203 ° C. using a Yanagimoto melting point measuring device. IR is as shown in FIG. In addition, the mass spectrometry spectrum confirmed that the molecular weight was 412. As a result of elemental analysis, this compound was found to contain 64.02% of C,
H was 4.88% and O was 31.10%.

[0047]

Example 3 <Synthesis of IV-c> 100 g of dimethyl isophthalate, 3
2 g of ethylene glycol, 39 g of propylene glycol, 0.05 g of titanium tetrabutoxide
A cc three-necked flask was charged, and after adding zeolite, the mixture was heated at 230 ° C. in a nitrogen atmosphere until the theoretical amount of MeOH (about 33 ml) was distilled off by the progress of the transesterification reaction.

The obtained viscous liquid was further heated to 250 ° C., held for 30 minutes, and reduced under reduced pressure of 10 to 15 mmHg for 30 minutes.
The reaction was further continued for 0.5 minute under a reduced pressure of 0.5 mmHg.

At the top of the flask, 6 g of a compound obtained as a sublimate was obtained. This compound has IV-c, IV-a, IV-
Since it was obtained as a mixture containing b, the melting point was widely observed at 218 to 247 ° C. by a Yanagimoto melting point measuring apparatus. IR is as shown in FIG.

[Brief description of the drawings]

FIG. 1 shows an IR spectrum of the compound obtained in Example 1.

FIG. 2 shows an NMR spectrum of the compound obtained in Example 1.

FIG. 3 shows an IR spectrum of the compound obtained in Example 2.

FIG. 4 shows an IR spectrum of the compound obtained in Example 3.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C07D 323/00 C08G 63/08 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A compound represented by the following formula (I): [In the formula (I), R _{1 to} R ₁₀ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. However, not all of them are hydrogen atoms at the same time. ] The novel cyclic ester compound represented by these. 2. An optionally substituted isophthalic acid represented by the following formula (II) and / or an ester-forming derivative thereof, and a compound represented by the following formula (III): [In the formulas (II) and (III), R _{11 to} R ₁₅ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ]
The method for producing a novel cyclic ester according to claim 1, wherein the linear ester oligomer or polymer obtained from the diol is subjected to a heat reaction in the presence of a catalyst to form a sublimate.