JPH09151249A - Polymer and method for producing the same - Google Patents

Abstract

(57) Abstract: It is an object of the present invention to provide a novel degradable resin that does not produce a substance harmful to the living body or the environment in the degradation process. A cyclic dimer of the amino acid tyrosine,
3,6-bis [(4-hydroxyphenyl) methyl]-
A novel decomposable polyiminocarbonate obtained by reacting 2,5-diketopiperazine with cyanogen bromide, and a method for producing the same.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a carbonate polymer containing a derivative of tyrosine which is an amino acid as a basic skeleton, and a method for producing the same. The present invention provides 3,6-bis [(4
-Hydroxyphenyl) methyl] -2,5-diketopiperazine as a raw material, and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Synthetic polymers have been used since Carothers
It has penetrated all parts of life and industry and has come to be used in large quantities. The physical properties required for these polymer materials are required depending on the application, such as high strength, high elasticity, heat insulation, insulation, etc., but basically it was an essential condition that they were tough and did not deteriorate. . However, in recent years, the importance of global or local ecology has attracted attention, and the situation regarding synthetic polymers has changed. That is, in consideration of problems such as incineration treatment or landfill treatment of waste, marine pollution, etc., there has been a rapid increase in social demand for an organic material having environmentally friendly characteristics that decomposes after disposal without polluting the environment. Against this background, attempts have been made to impart degradability to polycarbonate.

Most of the polycarbonates on the market are bisphenol-A type polycarbonates.
Among engineering plastics, polycarbonate has strong polarity, strong intermolecular force, heat resistance, and
Due to its excellent properties of impact resistance, dimensional stability, creep resistance and transparency, it has been expanding the demand by replacing glass and metal products, and recently it is used for CD (compact disc). Demand is growing.

Journal of Biomedic
al Materials Research, 28
Vol., 919 to 930 (1994), relates to a technique relating to a method for producing a polycarbonate derivative using a tyrosine derivative as a raw material, biodegradability of the polycarbonate derivative, and further usefulness of the polycarbonate derivative as a biodegradable biomaterial. Sex, etc. are disclosed.
The polycarbonate using the above-mentioned conventional tyrosine derivative as a raw material has problems in at least the following two points. First, desaminotyrosyl-tyrosine alkyl ester, desaminotyrosyl-tyramine, N-benzyloxycarbonyl-tyrosyl-tyrosine alkyl ester (NZ-tyrosyl-tyrosine alkyl ester).
And the like as raw materials, but it is industrially disadvantageous because a condensing agent such as dicyclohexylcarbodiimide (DCC) needs to be used for the synthesis of these raw materials. Second, harmful compounds in the decomposition process of polyiminocarbonate (eg, desaminotyrosine, tyramine, alcohols such as methyl alcohol and hexyl alcohol, benzyloxycarbonyl group (Z group), and Z).
This is a problem in that there is a possibility that (toluene, etc. generated from the group) may be generated.

[0005]

The present invention, which has been difficult to achieve by the prior art, exhibits excellent toughness at the time of use and, after disposal, produces noxious products in the decomposition process. The object is to provide a carbonate polymer which is expected not to occur.

[0006]

As a result of intensive studies to solve the above problems, the present inventors have found that 3,6-bis [(4-hydroxyphenyl) methyl] -2,5-diketopiperazine. It was found that the carbonate polymer synthesized using as a raw material produced only tyrosine as a decomposition product derived from the raw material in the decomposition process, and completed the present invention. Tyrosine is an amino acid and is expected to have high safety. The invention according to the present application is the invention described in any of the following items. Carbonate monomer unit represented by the formula (1) (Chemical formula 4)

[0007]

Embedded image A polymer having in the molecule. 3,6-bis [(4-hydroxyphenyl) methyl] -2,5-diketopiperazine represented by the formula (2)

[0008]

Embedded image A polymer obtained by reacting with phosgene. 3,6-bis [(4-hydroxyphenyl) methyl] -2,5-diketopiperazine represented by the formula (2)

[0009]

[Chemical 6] A method for producing a polymer, which comprises the step of reacting phosgene with phosgene.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

[Concept of word used in claims and specification of the present application] (1) Concept of word "polymer" The concept of a word "polymer" used in claims and specification of the present application is ""Polymer","polymer",
Mutually equivalent to the terms "macromolecule" or "macromolecule" and includes homopolymers and copolymers. The term "copolymer" as used in the claims and specification of this application is mutually equivalent to the term "copolymer". The arrangement of the copolymer (copolymer) may be any of random copolymer, alternating copolymer, block copolymer, graft copolymer and the like. The polymer may be linear, macrocyclic, branched, star-shaped, three-dimensional network, or the like.

(2) Concept of the term "degradable" The term "degradable" used in the claims and the specification of the present application refers to an organic material, and the term used for a specific purpose is It also includes a function of maintaining material properties that match the purpose and weakening and harmless in the natural environment or the in-vivo environment after the purpose is finished or after disposal. As used in the claims and specification of the present application, the concept of the term "degradable" includes, for example, "New Edition Dictionary of Polymers" (edited by The Polymer Society of Japan, Asakura Shoten, Tokyo, 1988).
Year)) ", including the concept of" disintegration "described in the section" Disintegrating polymer "on page 424, right column to page 425, left column. The description is a matter or a disclosure that can be directly and uniquely derived by those skilled in the art in view of the matter or the disclosure described in the specification of the present application by reference. The concept of the term "degradable" used in the claims and the specification of the present application includes, for example, "New Edition Polymer Dictionary (edited by The Polymer Society of Japan, Asakura Shoten, Tokyo, 1988)", page 369, left column. It also includes the concept of "photodisintegration" described in the section of "photodisintegration". The description is a matter or a disclosure that can be directly and uniquely derived by those skilled in the art in view of the matter or the disclosure described in the specification of the present application by reference. The term "degradable" as used in the claims and specification of the present application includes, for example, "Maruzen High Polymer Dictionary-Conc".
is Encyclopedia of Polym
er Science and Engineererin
g (edited by Kroschwitz, translated by Tatsuhisa Mita, Maruzen, Tokyo, 1994) ”, 539, including the concept of“ biodegradable ”described in the section“ Biodegradable Polymer ”on the left column to the right column on page 540. To do. The description is a matter or a disclosure that can be directly and uniquely derived by those skilled in the art in view of the matter or the disclosure described in the specification of the present application by reference.

The concept of "degradable" as used in the claims and the specification of the present application also includes the concept of "composable". The evaluation of "degradability" includes, for example, an embedding test in soil, a decomposition test using a cultured microorganism, a decomposition test using an enzyme preparation, an in-vitro decomposition test in serum, and an in-vivo decomposition test using in vivo implantation. , Light irradiation test, etc., and more specifically, for example, AST
MD5209-91 (biodegradability test) and ASTM D
5338-92 (compostability (soil regression performance) test).

(3) Concept of the word "derivative" The concept of the word "derivative" used in the claims and specification of the present application includes a hydrogen atom of a specific compound,
Including those substituted by another atom or atomic group R. Here, R is a monovalent hydrocarbon group containing at least one carbon atom, and more specifically, an aliphatic group, an alicyclic group having substantially low aromaticity, a group combining these, or These are hydroxyl group, carboxyl group, amino group,
It may be a divalent residue bound by nitrogen, silicon sulfide, phosphorus or the like, and among these, those having an aliphatic structure in a narrow sense are particularly preferable. R is a group obtained by substituting the above with a hydroxyl group, an alkyl group, a cycloalkyl group, an allyl group, an alkoxyl group, a cycloalkoxyl group, an allyloxyl group, a halogen (F, Cl, Br, etc.) group. May be. By properly selecting these substituents, various properties of the polymer according to the present invention (heat resistance, toughness, degradability, strength properties, elongation properties, flexibility, plasticity, shapeability, transparency, adhesion Properties, gas barrier properties, degradability, etc.) can be controlled.

(4) Concept of the term "carbonate polymer" The term "carbonate polymer" used in the claims and the specification of the present application includes a monomer unit or a repeating unit having a carbonate bond. It includes a polymer compound or its derivative in the molecule. The term "carbonate polymer" as used in the claims and specification of this application includes polycarbonates and copolycarbonates.

[3,6-Bis [(4-hydroxyphenyl) methyl] -2,5-diketopiperazine (Tyr-D
KP)] 3,6 used in the production method according to the present invention
-Bis [(4-hydroxyphenyl) methyl] -2,5
-Diketopiperazine (hereinafter referred to as Tyr-DKP)
Is a cyclic dimer of tyrosine (Tyr). Tyr-DKP used in the production method according to the present invention is L-form-
It may be any of L-form, L-form-D form, and D-form-D form. The production method and purification method of Tyr-DKP are not particularly limited. Examples of a method for producing Tyr-DKP and a method for purifying Tyr-DKP include JP-A-6-1775 and JP-A-6-175.
The method disclosed in No. 321916 can also be adopted.

[JP-A-6-1775] JP-A-6-17
No. 75 contains Tyr-D containing tyrosine as a contaminant.
Techniques for purifying KP are disclosed. That is, Tyr-DKP containing at least tyrosine as a contaminant
Is dissolved in an alkaline aqueous solution, and then an acid is added to adjust the pH to precipitate Tyr-DKP crystals, and a method for purifying Tyr-DKP is disclosed. For example, tyrosine methyl ester is heated without solvent to perform synthesis, and then pH is adjusted in an alkaline aqueous solution to separate tyrosine which is a by-product to obtain high-purity Tyr-DKP. .

[JP-A-6-321916] JP-A-6-
321916, from tyrosine alkyl ester,
A technique for producing Tyr-DKP in an organic solvent and easily isolating and purifying it is disclosed. That is, a method for producing Tyr-DKP by heating a tyrosine alkyl ester in an aprotic organic solvent is disclosed. Further, a method for purifying Tyr-DKP is disclosed, which comprises adding an organic solvent having a dipole moment of 1.5 to 2.7 to a solution containing Tyr-DKP and performing crystallization. For example, tyrosine methyl ester is heated in an aprotic polar organic solvent such as N-methylpyrrolidone for synthesis, and then reprecipitated with ethyl acetate, acetone or the like as a poor solvent to obtain high purity Tyr- DKP
Can be obtained in high yield.

[Reaction of Tyr-DKP and phosgene] The mode of reaction of Tyr-DKP and phosgene in the production method according to the present invention is not particularly limited. The reaction between Tyr-DKP and phosgene in the production method according to the present invention is
The synthesis method of bisphenol A type polycarbonate can be applied. Various modes of synthesizing bisphenol A-type polycarbonate are described, for example, in “Plastic Material Course [5] Polycarbonate Resin / Mikio Matsugane et al.” (Nikkan Kogyo Shimbun, Tokyo, 1969), “Plastic Material Course [17]. Polycarbonate, Toshihisa Tachikawa et al. ”(Nikkan Kogyo Shimbun, Tokyo, 1936).
For example, a pyridine method performed in a non-aqueous system using pyridine as an acid binder, an interfacial polycondensation method performed in an alkaline aqueous solution as an acid binder, and the like can be mentioned. In particular, the interfacial polycondensation method is an industrially widely used method for producing polycarbonate.

[Pyridine Method] An embodiment of the method for producing the carbonate polymer according to the present invention by the pyridine method will be described below. In the pyridine method, Tyr-DKP is dissolved or suspended in pyridine or a mixed solvent of pyridine and another organic solvent, and phosgene is added thereto. Phosgene may be blown into the reaction system as it is as a gas, or a solution dissolved in an organic solvent may be added dropwise. Alternatively, a solution or suspension of Tyr-DKP may be added dropwise to an organic solvent in which phosgene is dissolved.

The same amount of phosgene added to the reaction system is generally sufficient with respect to Tyr-DKP, but if a small excess of the theoretical amount is added, a polymer having a high molecular weight can be easily obtained. Usually, 1.0 to 1.5 times equivalent is preferable, and 1.2 to 1.3 times equivalent is more preferable.

The organic solvent used in the reaction system is
There is no particular limitation as long as it is substantially inert to the reaction with phosgene. Specific examples of the organic solvent used in the reaction system include hydrocarbons such as toluene and xylene, dichloromethane, chloroform, carbon tetrachloride, and o-.
Halogenated hydrocarbons such as dichlorobenzene, tetrahydrofuran, cyclic ethers such as dioxane, dimethylformamide (DMF), N-methylpyrrolidone (NM
P), N, N-dimethylimidazolidinone (DMI), and other aprotic polar solvents can be used, and these can be used alone or in combination. It is preferable to use these solvents after thoroughly dehydrating them. The reaction temperature is not particularly limited as long as the reaction substantially proceeds and substantially does not involve an undesired side reaction, but in general, -10 to 50 ° C is preferable, 0 to 40 ° C is more preferable, 10-30 degreeC is more preferable.

The reaction concentration is not particularly limited as long as the reaction substantially proceeds and is not accompanied by an undesired side reaction, but it is generally 1 to 1 in terms of the charged concentration of Tyr-DKP. The range of 50 wt% is preferable, and the range of 5 to 25 wt% is more preferable. For the carbonate polymers produced by the reaction, most organic solvents are poor solvents. Therefore, if the organic solvent used in the reaction system is a poor solvent for the carbonate polymer produced by the reaction, the produced carbonate polymer is obtained as a precipitate in the reaction system and is easily isolated by a normal filtration operation. be able to.

[Interfacial Polymerization Method] An embodiment of the method for producing the carbonate polymer according to the present invention by the interfacial polymerization method will be described below. An organic solvent immiscible with water is added to an alkaline aqueous solution of Tyr-DKP, phosgene is added, and a catalyst and an alkaline aqueous solution are further added to react.

The amount of phosgene added to the reaction system is generally preferably in excess of the theoretical amount in consideration of hydrolysis with an aqueous alkali solution, and usually Tyr-D.
Add 1.0 to 1.5 equivalents to KP. Phosgene may be blown into the reaction system as a gas as it is,
A solution dissolved in an organic solvent may be added dropwise. Or,
A solution or suspension of Tyr-DKP may be added dropwise to an organic solvent in which phosgene is dissolved.

The aqueous alkali solution used in the reaction system is not particularly limited as long as it is an aqueous solution that substantially maintains alkalinity and does not inhibit the reaction in the course of the reaction. Specific examples of the alkaline aqueous solution used in the reaction system include, for example, an alkali metal hydroxide, or
Examples thereof include aqueous solutions of alkaline earth metal hydroxides, and more specifically, aqueous solutions of sodium hydroxide, potassium hydroxide, cesium hydroxide, calcium hydroxide and the like.
The amount of alkali used in the reaction system is not particularly limited as long as it is not substantially accompanied by an undesirable side reaction,
Generally, it is preferable to use the same amount as the stoichiometric amount, usually 0.8 to 1.2 times equivalent amount of the stoichiometric amount is preferable, and 1.0 times equivalent amount is more preferable.

The stoichiometric amount is the amount that completely neutralizes the hydrochloric acid produced by the reaction and the hydrochloric acid and carbonic acid produced by the hydrolysis of phosgene added in excess. If the amount is less than the stoichiometric amount, the carbonate bond-forming reaction may not be sufficient. If the amount is more than the stoichiometric amount, hydrolysis of the active chloroformate group or phosgene produced by the reaction may be accelerated.

The water-immiscible organic solvent used in the reaction system is not particularly limited as long as it is substantially insoluble in water and substantially inert to the reaction with phosgene. Specific examples of the water-immiscible organic solvent used in the reaction system include aliphatic halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, trichloroethane, tetrachloroethane, dichloropropane. Aromatic hydrocarbons such as chlorobenzene and o-dichlorobenzene, aliphatic hydrocarbons such as hexane, heptane and cyclohexane, and aromatic hydrocarbons such as toluene, xylene and ethylbenzene, which may be used alone or in combination. Can be used.

The catalyst used in the reaction system is not particularly limited as long as it is a compound that substantially accelerates the reaction.
Those that act as a phase transfer catalyst are preferred. Specific examples of the catalyst used in the reaction system include tertiary amine, quaternary ammonium salt, tertiary phosphine, quaternary phosphonium salt, nitrogen-containing heterocyclic compound and its salt, imino ether and its salt, and the like. These can be used alone or as a mixture.

The tertiary amine catalyst used in the reaction system is preferably a trialkylamine having 1 to 8 carbon atoms, and specific examples thereof include triethylamine, tri-n-propylamine and diethyl-n. -Propylamine, diisopropyl-n-ethylamine, tri-n-butylamine, N, N-dimethylcyclohexylamine, N, N-diethylcyclohexylamine, N-
Ethyl piperidine and the like can be mentioned, and these can be used alone or in a mixture.

Specific examples of the quaternary ammonium salt catalyst used in the reaction system include, for example, benzyltriethylammonium chloride, benzyltriethylammonium bromide, trioctylmethylammonium chloride, trioctylmethylammonium bromide, tetrabutylammonium chloride and tetrabutylammonium chloride. Butyl ammonium bromide, tetrabutyl ammonium iodide, etc. are mentioned, and these can be used individually or in mixture.

Specific examples of the quaternary phosphonium salt catalyst used in the reaction system include, for example, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium bromide, etc. It can be used with or in a mixture.
The amount of the catalyst used in the reaction system is not particularly limited as long as it is an amount that substantially accelerates the reaction. The amount of the catalyst used in the reaction system is generally preferably 0.001 to 20 mol% based on Tyr-DKP, and 0.00
It is more preferably 5 to 10 mol%.

The reaction concentration is not particularly limited as long as the reaction substantially proceeds and is not accompanied by an undesired side reaction, but it is generally 1 to 1 in terms of the concentration of Tyr-DKP. The range of 50 wt% is preferable, and the range of 5 to 25 wt% is more preferable. The reaction temperature, unless the reaction substantially progresses and is accompanied by substantially no undesirable side reaction,
Although not particularly limited, in general, −10 to 50 ° C. is preferable, 0 to 40 ° C. is more preferable, and 10 to 30 ° C. is further preferable. Usually, if the temperature is excessively low, the reaction rate becomes remarkably slow, and if the temperature is excessively high, hydrolysis of active chloroformate or phosgene produced by the reaction may proceed.

For the carbonate polymers produced by the reaction, most organic solvents are poor solvents. For the carbonate polymers produced by the reaction, most organic solvents are poor solvents. Therefore, if the water-immiscible organic solvent used in the reaction system is a poor solvent for the carbonate polymer produced by the reaction, the produced carbonate polymer is obtained as a precipitate in the reaction system, and is obtained by a normal filtration operation. It can be easily isolated.

The carbonate polymer according to the present invention uses Tyr-DKP as a monomer raw material. Tyr-DKP produced in the decomposition process of the carbonate polymer according to the present invention is also excellent in decomposability. Therefore,
The carbonate polymer according to the present invention is excellent in decomposability. Hereinafter, the present invention will be described in more detail with reference to examples. In the specification of the present application, examples, production examples, and aspects are provided to assist understanding of the content of the invention according to the present application, and the description thereof is not intended to limit the content of the invention according to the present application. Not of nature.

[0035]

【Example】

[Intrinsic viscosity of polymer] Intrinsic viscosity of polymer is N, N
-Using dimethylimidazolidinone (DMI) as a solvent,
It was measured at a concentration of 0.5% by weight and a temperature of 25 ° C. using an Ubbelohde viscometer, and calculated by the following formula. Where t: outflow time of the solution (sec) t ₀ : outflow time of the solvent (sec) C: concentration of the solution (g / dl)

[BOD method defined in MITI method] Ty
The biodegradability test of r-DKP was performed by the BOD method defined in the MITI method. That is, the Tyr-DKP sample was prepared by using the standard activated sludge concentration of 30 ppm and the sample concentration of 100 p.
300 ml of an inorganic medium was prepared by adding so as to be pm (sample number, n = 4). In addition, an aniline-added group and a non-added group (basic respiration) for blank correction were set as standard substances that serve as indicators of the activity of standard activated sludge. The culture period was 14 to 28 days.

Example 1 (1) Reaction 10.12 g (30.7 mmol) of Tyr-DKP and 2.85 g (36 mmol) of pyridine were dissolved in 116.0 g of N-methylpyrrolidone (NMP). As a result of blowing phosgene as a gas into the solution for 25 minutes, about 3.6 g (36 mmol) of phosgene was introduced into the reaction system. This solution was stirred at room temperature for 1 hour and triethylamine 15.
5 mg was added and reacted at room temperature for 12 hours. The obtained reaction solution was discharged into 1000 ml of acetone for reprecipitation, and the obtained precipitate was collected by filtration, washed and dried.

(2) Analysis The obtained polymer had a yield of 8.02 g and a yield of 74.2%. The intrinsic viscosity of the obtained polymer is η = 0.20.
(Dl.g). The elemental analysis values of the obtained polymer are shown below. When the obtained polymer was analyzed by Fourier transform infrared spectroscopy (FT-IR) by the KBr tablet method, it was assigned to a carbonate bond, 1770 cm ^{−1 to} 1773 cm.
A peak of ^-1 was confirmed.

Example 2 (1) Reaction 5 g (15.1 mmo) of Tyr-DKP was added to NaOH.
45 g of an aqueous solution containing 1.752 g (43.8 mmol)
Was dissolved. 1.8 g (18.2 mm) of phosgene was added to the solution.
ol) was dissolved and added dropwise to a 1,2-dichloroethane (EDC) solution cooled to -9 ° C over 15 minutes. further,
2.4 mg of triethylamine was added and reacted at -9 ° C for 2 hours and at room temperature for 10 hours. The product obtained as a precipitate in the reaction system was collected by filtration, washed with EDC and water, and dried in a nitrogen stream at 50 ° C. with hot air.

(2) Analysis The yield of the obtained polymer was 4.93 g, and the yield was 92.7%. The intrinsic viscosity of the obtained polymer is η = 0.25.
(Dl / g). The elemental analysis values of the obtained polymer are shown below. When the obtained polymer was analyzed by FT-IR by the KBr tablet method, it was assigned to a carbonate bond, 1770.
peak of cm ^-1 ~1773cm ^-1 was confirmed.

Example 3 By the BOD method defined in MITI method, Tyr-DK
A biodegradability test of P was performed. The results are shown in Table 1.

[0042]

The monomer (Tyr-DKP) produced by the decomposition process of the carbonate polymer according to the present invention is composed of tyrosine which is an amino acid, and has excellent biodegradability as shown in Table 1. Therefore, the carbonate polymer according to the present invention has biodegradability, and there is no fear of producing a substance harmful to the living body in the decomposition process.

[0044]

EFFECTS OF THE INVENTION According to the present invention, while exhibiting excellent toughness during use, which was difficult to achieve by the prior art, no harmful products are generated in the decomposition process after disposal. It is expected that the carbonate polymer can be provided.

Front Page Continuation (72) Inventor Akihiro Yamaguchi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (3)

[Claims] 1. A carbonate monomer unit represented by the formula (1) (chemical formula 1): A polymer having in the molecule. 2. The 3,6-bis [(4
-Hydroxyphenyl) methyl] -2,5-diketopiperazine (Chemical Formula 2) A polymer obtained by reacting with phosgene. 3. 3,6-bis [(4
-Hydroxyphenyl) methyl] -2,5-diketopiperazine (Chemical Formula 3) A method for producing a polymer, which comprises the step of reacting phosgene with phosgene.