JP3495830B2 - Method for producing polyhydroxycarboxylic acid - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a high molecular weight polyhydroxycarboxylic acid which has sufficient mechanical strength as a molded product and is useful as a degradable polymer as a substitute for medical materials and general-purpose resins.

[0002]

2. Description of the Related Art Polyhydroxycarboxylic acid is not only excellent in mechanical, physical and chemical properties, but is also decomposed in a natural environment without harming others, and finally it is decomposed by microorganisms into water. It has a decomposable function of becoming carbon dioxide gas. For this reason, it is a plastic that has recently been used as a substitute for medical materials and general-purpose resins, and has received particular attention in various fields. Now that environmental issues are being highlighted, these plastics can be said to meet the needs of the times.

Generally, as a method for producing a polyhydroxycarboxylic acid, in the case of a hydroxycarboxylic acid such as lactic acid or glycolic acid, it is dehydrated and dimerized to obtain a cyclic dimer, and then a catalyst (Sn catalyst) is used. It is known that a high molecular weight polymer can be obtained by ring-opening melt polymerization in the presence. However, in this method, the operation of the reaction is complicated, the obtained polymer is not only expensive, and since the production method is a method of directly obtaining a product as pellets after melt polymerization, the obtained polymer form is Limited to pellets. Further, some hydroxycarboxylic acids do not form a cyclic dimer, and in this case, this method cannot be used.

On the other hand, some methods for obtaining polyhydroxycarboxylic acids by direct dehydration polycondensation from hydroxycarboxylic acids and their oligomers (hereinafter referred to as direct dehydration condensation method) have been disclosed (JP-A-56-45920).
JP-A-61-28521 and JP-A-62-64823
issue). However, in these methods, the weight average molecular weight of the obtained polymer is about 35,000 at the limit, does not have sufficient mechanical properties, and cannot be used depending on its application and purpose.

In the direct dehydration condensation method, when a hydroxycarboxylic acid or an oligomer thereof is azeotropically dehydrated in the presence of a catalyst in an organic solvent to produce polyhydroxycarboxylic acid, the solvent to be distilled off is a desiccant. After processing
A method for returning the system to the system is disclosed (US Pat.
nt No. 5,310,865). Further, a method for producing a polyhydroxycarboxylic acid by a direct dehydration condensation method using an aromatic ether solvent is disclosed (JP-A-6-
172502). However, in order to obtain a polyhydroxycarboxylic acid having a weight average molecular weight of 100,000 or more by these direct dehydration condensation methods, a long reaction time of about 30 to 50 hours is required, depending on the kind of the hydroxycarboxylic acid. However, the reaction rate is very slow, and it cannot be said to be an industrially advantageous method.

In order to obtain a high molecular weight polyhydroxycarboxylic acid in a short period of time, several methods for extending the polyhydroxycarboxylic acid by reacting with a binder when the molecular weight increases to some extent have been disclosed.

For example, in Japanese Unexamined Patent Publication No. 62-280220, thionyl chloride or acid chloride is reacted with polylactide or polyglycolide in a solvent to activate the terminal, followed by desolvation and further melt polycondensation. However, not only is there a large number of steps, but it also takes a long time, which is industrially disadvantageous.

[0008] In JP-A-1-156319, the molecular weight is increased by reacting glycol with polylactide or polyglycolide, but at the time of polycondensation with glycol, high temperature and low pressure conditions are required. However, under the conditions, the polymer is not a little disadvantageous in that it thermally decomposes to form a cyclic dimer.

US Patent No. 5,302,
In 694, polylactic acid is reacted with carbodiimide, phosgene, a sulfonyl compound, a carbonic acid ester compound, etc. with the polymer, but the molecular weight of polylactic acid cannot be increased simply by adding these binders. In order to obtain a satisfactory molecular weight, it is practically necessary to add an amine and the like, which not only takes time and labor for the reaction, but also labor for removing the amine and the like after the reaction. The conditions for reacting with polylactic acid are extremely limited, so that it is not industrially suitable.

Further, in the method of JP-A-5-148352, diisocyanate is reacted with the polyhydroxycarboxylic acid obtained by the direct dehydration condensation method in the absence of a catalyst / solvent. The direct dehydration method without a catalyst and a solvent has a very slow reaction rate and requires a long reaction time. In addition, only a polymer having a weight average molecular weight Mw of about 30,000 can be obtained. Even if it is used, it is difficult to raise the molecular weight sufficiently, and if the molecular weight is too low, the molecular weight may not increase even if diisocyanate is used.

Further, when diisocyanate is used in a stage where the molecular weight is low, a large amount of diisocyanate component is contained in the polymer, so that a large amount of undecomposed portion remains, and even when the polymer is decomposed, the binder There is also a problem that many components are released to nature.

As described above, each of the conventional methods for producing polyhydroxycarboxylic acid has advantages and disadvantages, including the method using a binder. Generally, 100,000 or more is desirable for polyhydroxycarboxylic acid to stably exhibit sufficient mechanical properties for film applications and molded article applications, and 150,000 or more is desirable for some applications. Until now, there has been no production method which is capable of obtaining a polyhydroxycarboxylic acid having a high molecular weight and a low content of a binder component in a short time and which is industrially suitable.

[0013]

An object of the present invention is to decompose a high molecular weight polyhydroxycarboxylic acid which exhibits stable and sufficient mechanical properties industrially efficiently, easily, inexpensively and during production. An object of the present invention is to provide a production method capable of producing stably without causing side reactions such as reactions.

A further object of the present invention is to introduce another structure into the polyhydroxycarboxylic acid and adjust the content thereof to impart new physical properties to the polymer. Specifically, the crystallinity is destroyed to obtain an amorphous polymer, and the mechanical properties and heat resistance of the polymer are improved.

[0015]

Means for Solving the Problems The inventors of the present invention have made earnest studies on a production method capable of producing a high molecular weight polyhydroxycarboxylic acid industrially in a short time, efficiently, easily and inexpensively. In the process of producing a hydroxycarboxylic acid, a binder is added to an organic solvent solution of polyhydroxycarboxylic acid whose molecular weight has been increased to a certain extent by a direct dehydration condensation method using an organic solvent, and the reaction is carried out. It was found that a polyhydroxycarboxylic acid was obtained, and the present invention was completed.

That is, according to the present invention, a hydroxycarboxylic acid or its oligomer is dehydrated and condensed in a reaction liquid containing the hydroxycarboxylic acid or its oligomer and an organic solvent in the substantial absence of water to give a weight average molecular weight of 5
50,000 or more polyhydroxycarboxylic acid is obtained, and then a reaction mixture containing the polyhydroxycarboxylic acid is added.
(1) Polyvalent isocyanate compound, (2) Polybasic acid anhydride, (3) Cyclic iminoesters, (4) Cyclic iminoethers, (5) Aromatic hydroxycarboxylic acid, (6)
Polyvalent amine compounds, (7) polyhydric alcohols, (8) epoxy compounds, (9) polyfunctional aziridine compounds, (1
Polyhydroxy having a weight average molecular weight of 100,000 or more by adding and reacting one or more binders selected from 0) lactams, (11) lactones and (12) diethylene glycol bischloroformate A method for producing a polyhydroxycarboxylic acid, which comprises obtaining a carboxylic acid.

A feature of the present invention is that a binder is added during the reaction for obtaining the polyhydroxycarboxylic acid to dramatically increase the molecular weight of the polyhydroxycarboxylic acid in a short time. Further, a feature of the present invention is a method for producing a polyhydroxycarboxylic acid having a weight average molecular weight of 50,000 or more in an organic solvent by a direct dehydration condensation method before adding the binder, whereby the binder is added. It is possible to control the molecular weight at that time to be high. For this reason,
It is possible to increase the molecular weight of the polyhydroxycarboxylic acid obtained by adding and reacting the binder and controlling the content of the binder in the polyhydroxycarboxylic acid to be small.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. Specific examples of the hydroxycarboxylic acids used in the method of the present invention include glycolic acid, lactic acid, 2-hydroxybutanoic acid, 2-hydroxypentanoic acid, 2-hydroxyhexanoic acid, and 2-hydroxyhexanoic acid.
-Hydroxyheptanoic acid, 2-hydroxyoctanoic acid, 2-hydroxy-2-methylpropanoic acid, 2-hydroxy-2-methylbutanoic acid, 2-hydroxy-2-ethylbutanoic acid , 2-hydroxy-2-methylpentanoic acid, 2-hydroxy-2-ethylpentanoic acid, 2-hydroxy-2-propylpentanoic acid, 2-hydroxy-2-butylpentanoic acid, 2 -Hydroxy-2-methylhexanoic acid, 2-hydroxy-2-ethylhexanoic acid, 2-hydroxy-2-propylhexanoic acid, 2-hydroxy-2-butylhexanoic acid, 2-hydroxy -2-Pentyl hexanoic Cid, 2-hydroxy-2-methylheptanoic acid, 2-hydroxy-2-ethylheptanoic acid, 2-hydroxy-2-propylheptanoic acid, 2-hydroxy-2-butylheptanoic acid, 2-hydroxy-2-pentyl heptanoic acid, 2-hydroxy-2-
Hexyl heptanoic acid, 2-hydroxy-2
-Methyl octanoic acid, 2-hydroxy-2
-Ethyl octanoic acid, 2-hydroxy-2
-Propyl octanoic acid, 2-hydroxy-
2-Butyl octanoic acid, 2-hydroxy-
2-pentyl octanoic acid, 2-hydroxy-2-hexyl octanoic acid, 2-hydroxy-2-heptyl octanoic acid, 3-hydroxypropanoic acid, 3-hydroxybutanoic acid, 3- Hydroxypentanoic acid, 3-hydroxyhexanoic acid, 3-hydroxyheptanoic acid, 3-hydroxyoctanoic acid, 3-hydroxy-3-methylbutanoic acid, 3-hydroxy-3-methylpenta Noic acid, 3-hydroxy-3-ethylpentanoic acid, 3-hydroxy-3-methylhexanoic acid, 3-hydroxy-3-ethylhexanoic acid, 3-hydroxy-3-propylhexanoic acid Acid, -Hydroxy-3-methyl heptanoic acid, 3-hydroxy-3-ethyl heptanoic acid, 3-hydroxy-3-propyl heptanoic acid, 3-hydroxy-3-butyl heptanoic acid, 3-hydroxy -3-Methyloctanoic acid, 3-hydroxy-3-ethyloctanoic acid, 3-hydroxy-3-propyloctanoic acid, 3-hydroxy-3-butyloctanoic acid, 3-hydroxy-3 -Pentyl octanoic acid, 4-hydroxybutanoic acid, 4-hydroxypentanoic acid, 4
-Hydroxyhexanoic acid, 4-hydroxyheptanoic acid, 4-hydroxyoctanoic acid, 4-hydroxy-4-methylpentanoic acid, 4-hydroxy-4-methylhexanoic acid, 4-hydroxy -4-Ethylhexanoic acid, 4-hydroxy-4-methylheptanoic acid, 4-hydroxy-4-ethylheptanoic acid, 4-hydroxy-4-propylheptanoic acid, 4-hydroxy-4 -Methyl octanoic acid, 4-hydroxy-4-ethyl octanoic acid, 4-hydroxy-4-propyl octanoic acid, 4-hydroxy-4-butyl octanoic acid, 5-hydroxypentanoic acid , 5-hydroxy Hexanoic acid, 5-hydroxyheptanoic acid, 5-hydroxyoctanoic acid, 5-hydroxy-5-methylhexanoic acid, 5-hydroxy-5-methylheptanoic acid, 5-hydroxy-5 -Ethylheptanoic acid, 5-hydroxy-5-methyloctanoic acid, 5-hydroxy-5-ethyloctanoic acid, 5-hydroxy-5-propyloctanoic acid, 6-hydroxyhexanoic acid , 6-hydroxyheptanoic acid, 6-
Hydroxy octanoic acid, 6-hydroxy-
6-methylheptanoic acid, 6-hydroxy-
6-methyloctanoic acid, 6-hydroxy-
6-ethyloctanoic acid, 7-hydroxyheptanoic acid, 7-hydroxyoctanoic acid, 7-hydroxy-7-methyloctanoic acid, 8-hydroxyoctanoic acid and the like or a mixture thereof.

The above-mentioned hydroxycarboxylic acids may have optically active carbon and may take the form of D-form, L-form or D / L-form. There is no limit. Further, these polymers may be a mixture, and the polymer composition thereof is not limited at all.

The weight average molecular weight according to the present invention is 50,0.
The production of polyhydroxycarboxylic acid of 00 or more is available in US
Patent No. It can be conveniently carried out by the method described in 5,310,865.

The reaction between the polyhydroxycarboxylic acid of the present invention and the binder is selected from hydrocarbon-based organic solvents, halogenated hydrocarbon-based organic solvents, ether-based organic solvents, ester-based organic solvents, and ketone-based organic solvents. It is carried out in one or more organic solvents.

Specific examples of the hydrocarbon-based organic solvent include aliphatic hydrocarbons and aromatic hydrocarbons, and the aliphatic hydrocarbons include n-hexane, 2,2-dimethylbutane and 2,3-. Dimethylbutane, 2-methylpentane, 3-methylpentane, n-heptane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3-ethylpentane, 2-methylhexane, 3- Methylhexane, 2,2,3-trimethylbutane, n-octane, 2,2-dimethylhexane, 2,
3-dimethylhexane, 2,4-dimethylhexane,
3,3-dimethylhexane, 3,4-dimethylhexane, 3-ethylhexane, 3-ethyl-2-methylpentane, 3-ethyl-3-methylpentane, 2-methylheptane, 3-methylheptane, 4-methyl Heptane,
2,2,3,3-tetramethylbutane, 2,2,3-trimethylpentane, 2,2,4-trimethylpentane,
2,3,3-trimethylpentane, 2,3,4-trimethylpentane, n-nonane, 2,3-dimethylheptane, 2,4-dimethylheptane, 2,5-dimethylheptane, 3,3-dimethylheptane, 3,4-dimethylheptane, 3,5-dimethylheptane, 4-ethylheptane, 2-methyloctane, 3-methyloctane, 4-methyloctane, 2,2,4-trimethylhexane, 2,
2,5-trimethylhexane, 2,3,5-trimethylhexane, n-decane, 3,4-diethylhexane,
2,6-dimethyloctane, 3,3-dimethyloctane, 3,5-dimethyloctane, 4,4-dimethyloctane, 3-ethyl-3-methylheptane, 2-methylnonane, 3-methylnonane, 4-methylnonane, 5 -Methylnonane, n-undecane, n-dodecane, 2-methylundecane, 3-methylundecane, 2,2,4,6,6
6-pentamethylheptane, n-tridecane, 4-methyldodecane, n-tetradecane, n-pentadecane, n
-Hexadecane, 2,2,4,4,6,8,8-heptamethylnonane, n-heptadecane, n-octadecane,
n-nonadecane, 2,6,10,14-tetramethylpentadecane, n-eicosane, n-heneicosane, n-
Docosane, n-tricosane, n-tetracosane, cyclohexane, dimethylbutene, ethylbutene, hexene,
Methylcyclopentane, methylpentene, cycloheptane, dimethylcyclopentane, dimethylpentene, ethylcyclopentane, ethylpentene, heptene, methylcyclohexane, methylhexene, trimethylbutene,
Cyclooctane, dimethylcyclohexane, dimethylhexene, ethylcyclohexane, ethylhexene, methylheptene, octene, propylcyclopentene, trimethylpentene, diethylcyclopentane, dimethylheptene, ethylmethylcyclohexane, isopropylcyclohexane, n-propylcyclohexane, methyloctene, nonene, Trimethylcyclohexane, trimethylhexene, butylcyclohexane, t-butylcyclohexane, decene, isobutylcyclohexane, isopropylmethylcyclohexane, methylnonene, pentylcyclopentane, amylcyclohexane, undecene,
Cyclododecane, dodecene, hexylcyclohexane,
2,2,4,6,6-pentamethylheptene, triisobutylene, heptylcyclohexane, tridecene, tetradecene, octylcyclohexane, cyclopentadecane, pentadecene, nonylcyclohexane, decylcyclohexane, hexadecene, tetraisobutylene, heptadecene, undecylcyclohexane, Octadecene,
Dodecylcyclohexane, nonadecene, tridecylcyclohexane, eicosene, docosene, tricosene, cyclohexene, dimethylbutadiene, hexadiene, methylcyclopentene, methylpentadiene, cycloheptene, ethylcyclopentene, heptadiene, methylcyclohexene, methylenecyclohexane, methylhexadiene, norbornane, cyclooctene, dimethyl. Hexadiene, methylheptadiene, octadiene, allylcyclohexane, hydrindane, methyloctadiene, nonadiene, decadiene, decalin, undecadiene, bicyclohexyl, cyclododecene, dodecadiene, tetradecadiene and the like can be mentioned.

As aromatic hydrocarbons, toluene, o-xylene, m-xylene, p-xylene, naphthalene, 1
-Methylnaphthalene, 2-methylnaphthalene, 1-ethylnaphthalene, 2-ethylnaphthalene, 1,2-dimethylnaphthalene, 1,3-dimethylnaphthalene, 1,4-
Dimethylnaphthalene, 1,5-dimethylnaphthalene,
1,6-dimethylnaphthalene, 1,7-dimethylnaphthalene, 1,8-dimethylnaphthalene, 2,3-dimethylnaphthalene, 2,6-dimethylnaphthalene, 2,7-dimethylnaphthalene, 1,2-diethylnaphthalene, 1 ，
3-diethylnaphthalene, 1,4-diethylnaphthalene, 1,5-diethylnaphthalene, 1,6-diethylnaphthalene, 1,7-diethylnaphthalene, 1,8-diethylnaphthalene, 2,3-diethylnaphthalene, 2,6
-Diethylnaphthalene, 2,7-diemethylnaphthalene, 1-methyl-2-ethylnaphthalene, 1-methyl-
3-ethylnaphthalene, 1-methyl-4-ethylnaphthalene, 1-methyl-5-ethylnaphthalene, 1-methyl-6-ethylnaphthalene, 1-methyl-7-ethylnaphthalene, 1-methyl-8-ethylnaphthalene, 2-methyl-1-ethylnaphthalene, 2-methyl-3-ethylnaphthalene, 2-methyl-4-ethylnaphthalene, 2-methyl-5-ethylnaphthalene, 2-methyl-6-ethylnaphthalene, 2-methyl-7 -Ethylnaphthalene, 2-
Methyl-8-ethylnaphthalene, 1-methoxynaphthalene, 2-methoxynaphthalene, 1-ethoxynaphthalene, 2-ethoxynaphthalene, 1-acetonaphthone, 2
-Acetonaphthone, 1,4-dihydronaphthalene, 1,
2,3,4-tetrahydronaphthalene, biphenyl, 2
-Methylbiphenyl, 3-methylbiphenyl, 4-methylbiphenyl, 2-ethylbiphenyl, 3-ethylbiphenyl, 4-ethylbiphenyl, 2,2'-dimethylbiphenyl, 3,3'-dimethylbiphenyl, 4,4'-
Dimethylbiphenyl, 2,2'-diethylbiphenyl,
3,3'-diethylbiphenyl, 4,4'-diethylbiphenyl, 2-methoxybiphenyl, 3-methoxybiphenyl, 4-methoxybiphenyl, 2-ethoxybiphenyl, 3-ethoxybiphenyl, 2,2'-dimethoxybiphenyl, 3 , 3'-dimethoxybiphenyl, 4,
4'-dimethoxybiphenyl etc. are mentioned.

The halogenated hydrocarbon-based organic solvent includes aliphatic halogenated hydrocarbons and aromatic halogenated hydrocarbons, and the aliphatic halogenated hydrocarbons include trichloromethane, tetrachloromethane and 1,1-dichloroethane. , 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,
1-trichloroethylene, 1,1,1,2-tetrachloroethane, 1,1,2,2-tetrachloroethane, 1-
Chloropropane, 1-chlorobutane, 1-chloropentane, 1-chlorohexane, 1-chlorooctane, 1-chlorodecane, 1-chlorotetradecane, 1,3-dichloropropane, 1,4-dichlorobutane, 1,5-dichloropentane , 1,6-dichlorohexane, 1,8-dichlorooctane, 1,10-dichlorodecane, 1,2-dibromoethane, 1,1,1-tribromoethane, 1,
1,2-tribromoethane, 1,1,1-tribromoethylene, 1,1,1,2-tetrabromoethane, 1,
1,2,2-tetrabromoethane, 1-bromopropane, 1-bromobutane, 1-bromopentane, 1-bromohexane, 1-bromooctane, 1-bromodecane,
1,3-dibromopropane, 1,4-dibromobutane,
1,5-dibromopentane, 1,6-dibromohexane, 3-bromo-1-propene, 1-bromo-2-chloropropane, 1-bromo-2-chloroethane, 1-bromo-5-chloropentane, hexachloroethane, etc. Is mentioned.

Examples of the aromatic halogenated hydrocarbon include chlorobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, (2-chloroethyl) benzene, o-chloroethylbenzene, o-dichlorobenzene and m-dichlorobenzene. , P-dichlorobenzene,
2,3-dichlorotoluene, 2,4-dichlorotoluene, 2,5-dichlorotoluene, 2,6-dichlorotoluene, 3,4-dichlorotoluene, 1,2,3-trichlorobenzene, 1,2,4- Trichlorobenzene, 1,
3,5-trichlorobenzene, α, α, α-trichlorobenzyl, α, 2,4-trichlorobenzyl, α, 2
6-trichlorobenzyl, α, 3,4-trichlorobenzyl, bromobenzene, o-bromotoluene, m-bromotoluene, p-bromotoluene, o-dibromobenzene, m-dibromobenzene, p-dibromobenzene,
2,3-dibromotoluene, 2,4-dibromotoluene, 2,5-dibromotoluene, 2,6-dibromotoluene, 3,4-dibromotoluene, 1-bromoethylbenzene, 2-bromoethylbenzene, o-bromoethylbenzene, 1,2,3-tribromobenzene, 1,2,3
4-tribromobenzene, 1,3,5-tribromobenzene, iodobenzene, o-iodotoluene, m-iodotoluene, p-iodotoluene, 1-fluoronaphthalene, 2-fluoronaphthalene, 1-iodonaphthalene , 2-iodonaphthalene, 2-chlorobiphenyl, 3
-Chlorobiphenyl, 4-chlorobiphenyl, 2-bromobiphenyl, 3-bromobiphenyl, 4-bromobiphenyl, 2-fluorobiphenyl, 3-fluorobiphenyl, 4-fluorobiphenyl, 2-iodobiphenyl, 3-yo- Dobiphenyl, 4-iodobiphenyl and the like can be mentioned. These may be used alone or as a mixture of two or more. In particular, aromatic halogenated hydrocarbons are preferable solvents because they have a high polymerization rate and a higher molecular weight.

As the ether organic solvent, an aliphatic ether is used.
Examples thereof include tellurium-based organic solvents and aromatic ether-based organic solvents, and halogenated compounds thereof. Aliphatic ether-based organic solvents include n-propyl ether, isopropyl ether, allyl ether, butyl ethyl ether,
Butyl vinyl ether, n-butyl ether, isobutyl ether, amyl ether, isoamyl ether, n
-Hexyl ether, n-heptyl ether, n-octyl ether, di (2-ethylhexyl) ether, monoglyme, diglyme, triglyme, tetrahydrofuran, tetrahydropyran, dioxane and the like.

Examples of the aromatic ether organic solvent include anisole, ethoxybenzene, propoxybenzene, butoxybenzene, pentoxybenzene, 2,4-dimethoxybenzene, 2-chloromethoxybenzene, 2-bromomethoxybenzene and 4-chloromethoxy. Benzene, 4-
Alkyl-substituted diphenyl ethers such as bromomethoxybenzene, 2,4-dichloromethoxybenzene, diphenyl ether, 4,4'-dimethyldiphenyl ether, 3,3'-dimethyldiphenylether, 3-methyldiphenylether, 4,4'-dibromodiphenylether , 4,4′-dichlorodiphenyl ether, 4-bromodiphenyl ether, 4-methyl-4-bromodiphenyl ether and other halogen-substituted diphenyl ethers,
Examples thereof include alkoxy-substituted diphenyl ethers such as 4-methoxydiphenyl ether, 4,4′-dimethoxydiphenyl ether, 3,3′-dimethoxydiphenyl ether and 4-methyl-4′-methoxydiphenyl ether, and cyclic diphenyl ethers such as dibenzofuran and xanthene.

Examples of the ester-based organic solvent include aliphatic ester-based organic compounds and aromatic ester-based compounds. Examples of the aliphatic ester-based organic compounds include ethyl acetate, propyl acetate, butyl acetate, amyl acetate, pentyl acetate and hexyl. Acetate, cyclohexyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, methoxybutyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol diacetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, methyl monochloroacetate, methyl pro Pionate, ethyl propionate, butyl propionate, ethyl butyrate, butyl butyrate Door, isobutyl isobutyrate,
Isoamyl butyrate, methyl caproate, ethyl caproate, methyl caprylate, ethyl caprylate, methyl caprate, ethyl caprate, ethyl isovalerate, methyl maleate, ethyl maleate, butyl maleate, butyl sebacate, butyl Stearate, amyl stearate, methyl oleate, ethyl oleate, ethyl oxalate, butyl oxalate,
Examples thereof include ethyl carbonate, ethyl acrylate and ethyl methacrylate.

Examples of aromatic ester organic compounds include methylbenzoate, ethylbenzoate, propylbenzoate, isoamylbenzoate, butylbenzoate, benzylbenzoate, dimethylphthalate, diethylphthalate, benzylacetate and ethylcinnamate. In particular, aromatic ester organic compounds are preferable solvents because they have a high polymerization rate and a higher molecular weight.

Examples of the ketone-based organic solvent include aliphatic ketone-based organic solvents and aromatic ketone-based organic solvents. The aliphatic ketones include acetylacetone, methyl ethyl ketone, 3-pentanone, 4-methyl-2-pentanone,
Cyclopentanone, 2-cyclopenten-1-one, cyclohexanone, 1,2-cyclohexadione, 1,3
-Cyclohexanedione, 1,4-cyclohexanedione, cycloheptanone, cyclooctanone, 4-methylcyclohexanone, 4-ethylcyclohexanone, 2-
tert-Butylcyclohexanone, 4-tert-butylcyclohexanone, cyclohexenyl cyclohexanone, cycloundecanone, cyclotridecanone, benzylacetone, 1-phenyl-2-butanone, 2-methoxyphenylacetone, 3-methoxyphenylacetone, 4-methoxy Examples thereof include phenylacetone and cyclohexylketone.

Acetophenone as the aromatic ketone,
2'-methylacetophenone, 3'-methylacetophenone, 4'-methylacetophenone, 4'-ethylacetophenone, 4'-ethoxyacetophenone, 2 ',
4'-dimethylacetophenone, 3 ', 4'-dimethylacetophenone, acetylacetophenone, propiophenone, 4'-methylpropiophenone, 4'-methoxypropiophenone, butyrophenone, isobutyrophenone, 4'-butylacetophenone, cyclopentyl Phenyl ketone, benzophenone, anthraquinone, 4-
Examples include naphthoquinone.

The amount used is such that the polymer concentration is 3 to 90.
It can be carried out in a range so as to be in the range of, preferably 15 to 80% by weight, more preferably 30 to 70% by weight.
The range is preferably such that the weight% is reached. If it is more than 90% by weight, the viscosity of the polymer when heated and dissolved becomes extremely high,
In some cases, handling such as liquid transfer and operations such as stirring become difficult. On the other hand, when it is less than 3% by weight, there is no problem in the reaction and the post-treatment, but the volume efficiency is poor and it is disadvantageous in terms of productivity.

The weight average molecular weight according to the present invention is 50,0.
The production of a polyhydroxycarboxylic acid of 00 or more needs to be carried out at a water content of 50 ppm or less in the reaction mixture. It should preferably be 20 ppm or less, more preferably 5 ppm or less. Therefore, water produced by the dehydration condensation reaction is distilled out of the reaction system together with the organic solvent, and an organic solvent having a water content of 50 ppm or less is charged as an additional solvent into the reaction system for the reaction. When the distilled organic solvent is used as the additional solvent, a method of passing the distilled organic solvent through a dehydrator and returning the dried organic solvent to the system again can be used.

When using a dehydrator, an inorganic desiccant such as molecular sieves (3A, 4A, 5A, etc.) or silica gel, diphosphorus hydroxide, phosphorus pentoxide, calcium hydride, sodium hydride, lithium hydride, etc. The solvent to be distilled can be dried using a dehydration column packed with a metal hydride, an alkali metal and an alkaline earth metal such as sodium, lithium, potassium and calcium, or a dehydrating agent such as an ion exchange resin. In addition, a method of separating and removing water in the solvent to be distilled off by using an apparatus equipped with a distillation separation capability, or once the distilled off distillate is allowed to flow out of the reaction system, it is separated by distillation and dehydrated. A method of returning the solvent to the reaction system may be used, and it is sufficient that water in the solvent to be returned to the reaction system is substantially removed, and there is no limitation on the method.

When a dehydrator is used, an inorganic desiccant such as molecular sieves (3A, 4A, 5A, etc.) or silica gel, diphosphorus hydroxide, phosphorus pentoxide, calcium hydride, sodium hydride, lithium hydride, etc. The solvent to be distilled can be dried using a dehydration column packed with a metal hydride, an alkali metal and an alkaline earth metal such as sodium, lithium, potassium and calcium, or a dehydrating agent such as an ion exchange resin. In addition, a method of separating and removing water in a solvent which is refluxed by using an apparatus having a distillation separation ability is used, or the reflux distillate is once discharged out of the reaction system, and then distilled and separated to be dehydrated. A method of returning the solvent to the reaction system may be used, and it is sufficient that the water in the solvent to be returned to the reaction system is substantially removed, and there is no limitation on the method.

In the method of the present invention, it is preferable to use a catalyst in order to shorten the reaction time. Examples of the catalyst include metals of Group I, II, III, IV and V of the Periodic Table of the Elements, or salts thereof. For example, zinc,
Metals such as tin, aluminum and magnesium, tin oxide, antimony oxide, zinc oxide, aluminum oxide, magnesium oxide, metal oxides such as titanium oxide, zinc chloride, stannous chloride, stannic bromide, antimony fluoride, Metal halides such as magnesium chloride and aluminum chloride, sulfates such as tin sulfate, zinc sulfate and aluminum sulfate, hydroxides such as tin hydroxide and zinc hydroxide, carbonates such as magnesium carbonate, zinc carbonate and calcium carbonate, Examples thereof include organic carboxylates such as tin acetate, tin octoate, tin lactate, zinc acetate and aluminum acetate, and organic sulfonates such as tin trifluoromethanesulfonate and tin p-toluenesulfonate. Other examples include organic metal oxides of the above metals such as dibutyltin oxide or metal alkoxides of the above metals such as titanium isopropoxide or alkyl metals of the above metals such as diethylzinc or ion exchange resins such as Dowex and Amberlite. To be The amount used is preferably 0.0001 to 10% by weight of the hydroxycarboxylic acid or the oligomer thereof.

A polycondensation reaction may be carried out by adding a coloring inhibitor in order to suppress coloring due to heat deterioration during polymerization. As the coloring inhibitor used, phosphorus compounds such as phosphoric acid, triphenyl phosphate, pyrophosphoric acid, phosphorous acid and triphenyl phosphite are preferable. The amount added is 0.01 to 5% by weight, more preferably 0.5 to 2% by weight with respect to the polymer.
% By weight. If it is 0.01% by weight or less, the effect of the anti-coloring agent becomes small, and if it is 5% by weight or more, no further effect can be expected in the effect of the anti-coloring agent and the degree of polymerization may not be increased.

The polymerization conditions are usually the boiling point of the organic solvent used, but may be under normal pressure or under reduced pressure, and the temperature can be up to the reflux temperature of the solvent used, preferably 50 to 220 ° C. , More preferably 100 to 1
70 ° C is good. If the temperature is lower than 50 ° C., the efficiency of removing the water generated by the reaction from the reaction system is deteriorated, and the reaction rate is significantly reduced. Further, if the temperature exceeds 220 ° C., the polymer is deteriorated, and thus the reaction liquid is colored, which may deteriorate the quality of the obtained product, which is not preferable.

With such a method, the weight average molecular weight is 50,
Polyhydroxycarboxylic acid of about 000 to 100,000 can be easily obtained in a relatively short time, but the dehydration condensation reaction is continued as it is, and the weight average molecular weight is 10
It takes a long time to obtain a high molecular weight polyhydroxycarboxylic acid of 10,000 or more. Therefore, when the weight average molecular weight of the polyhydroxycarboxylic acid reaches 50,000 or more, the polymerization time is drastically shortened by adding the binder described in detail below. It is also possible to expect new physical properties for the high molecular weight polyhydroxycarboxylic acid obtained by adjusting the amount.

The molecular weight of the polyhydroxycarboxylic acid at the time of adding the binder is 50,000 in terms of weight average molecular weight.
To 150,000, preferably 60,000 to 14
10,000, more preferably 70,000 to 120,
000, most preferably 80,000 to 100,000
The range is 0.

Even if the weight average molecular weight of the polyhydroxycarboxylic acid is added in a range of less than 50,000, it does not necessarily mean that the polymerization degree does not increase unless the weight average molecular weight is 20,000 or less. However, when the molecular weight of polyhydroxycarboxylic acid is low and a binder is added to increase the molecular weight, the number of terminals is large,
This is not preferable because it requires a large amount of binder. When a large amount of a binder is incorporated into the degradable polyhydroxycarboxylic acid skeleton, a large amount of undecomposed portion remains, and even when the polyhydroxycarboxylic acid is decomposed, a large amount of the binder component is released to nature. This is because there are drawbacks. It is surprising that when the weight average molecular weight of the polyhydroxycarboxylic acid is 20,000 or less, even if the amount of the binder is increased, the weight average molecular weight of 100,000 or more cannot be obtained. This is probably because many molecular ends remain at the stage where the molecular weight is low, and dehydration condensation reaction is likely to occur, so that the generated water reacts with the functional group of the binder or contributes to the polymer chain extension as a side reaction. It is considered that this is because a functional group that does not exist is generated. For these reasons, the weight average molecular weight of the polymer before adding and reacting the binder needs to be 50,000 or more.

When the weight average molecular weight exceeds 150,000, the effect becomes less effective because the number of reaction terminals decreases even if the binder is added. Also, 150,00
It takes labor and time to obtain more than 0 polyhydroxycarboxylic acid by the direct dehydration polymerization method.

The polyvalent isocyanate used as a binder in the present invention is, for example, hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate. Mixture with isocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate, isophorone diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate Isocyanate, 2,3
-Butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate,
2,6-diisocyanatomethyl caproate, 1,3
-Cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 4,4'-methylenebis (cyclohexyl isocyanate), methyl-2,4-cyclohexane diisocyanate, methyl- 2,6-cyclohexane diisocyanate, 1,4-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanatomethyl) cyclohexane, dicyclohexyl-4,4-methane-diisocyanate, phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-
Naphthalene diisocyanate, 3,3,5-trimethyl-1-isocyanato-3-isocyanatomethylcyclohexane, di (2-isocyanatoethyl) bicyclo [2,2,1] hept-5-ene-2,3 -Dicarboxylate, 4,4'-toluidine diisocyanate, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, ω, ω'-diisocyanate-1,4-diethylbenzene, 1,3- Tetramethyl xylylene diisocyanate, 1,4-tetramethyl xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate and the like, among them, trimer Possible are viewlet join type,
Trimers such as adduct type and nurate type can also be used.

The polybasic acid anhydride used as the binder in the present invention is, for example, maleic anhydride, succinic anhydride, itaconic anhydride, glutaric anhydride, adipic anhydride, phthalic anhydride, citraconic anhydride, tricarboxylic anhydride. Mellitic acid, pyromellitic dianhydride, 2,3-benzophenone dicarboxylic acid anhydride, 3,4-benzophenone dicarboxylic acid anhydride,
2,3-dicarboxyphenyl-phenyl-ether anhydride, 3,4-dicarboxyphenyl-phenyl-ether anhydride, 3,4-biphenyldicarboxylic acid anhydride,
2,3-dicarboxyphenyl-phenyl-sulfonic anhydride, 2,3-dicarboxyphenyl-phenyl-sulfide, 1,2-naphthalenedicarboxylic anhydride,
2,3-naphthalenedicarboxylic acid anhydride, 1,8-naphthalenedicarboxylic acid anhydride, 2,3-anthracene dicarboxylic acid anhydride, 1,9-anthracene dicarboxylic acid anhydride, ethylene tetracarboxylic acid dianhydride, cyclopentane Tetracarboxylic dianhydride, 3,3 ', 4,4'-
Benzophenone tetracarboxylic dianhydride, 2,2 ',
3,3′-benzophenone tetracarboxylic acid dianhydride,
3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl ) Propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfonic acid dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ) Ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride,
1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1 , 4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4 , 9,10-berylenetetracarboxylic dianhydride, 2,3,6,7-anthracenecarboxylic dianhydride, 1,2,7,8-phenanthrenecarboxylic dianhydride and the like.

Examples of the cyclic iminoesters used as the binder in the present invention include an oxazolone compound having a 5-membered iminoester ring, an oxazinone compound or a benzoxazinone compound having a 6-membered iminoester ring. To be

Examples of the oxazolone compound include 2
-Oxazoline-5-one, 3-oxazoline-5-one, 2-oxazoline-4-one, 3-oxazoline-
2-one, 4-oxazoline-2-one, 4-methyl-
2-oxazolin-5-one, 2-methyl-3-oxazoline-5-one, 5-methyl-2-oxazoline-4
-One, 5-methyl-3-oxazolin-2-one,
2,2'-bis (5 (4H) -oxazolone), 2,2
'-Methylenebis (5 (4H) -oxazolone), 2,
2'-ethylenebis (5 (4H) -oxazolone),
2,2'-tetramethylenebis (5 (4H) -oxazolone), 2,2'-hexamethylenebis (5 (4H)-
Oxazolone), 2,2'-decamethylene bis (5 (4
H) -oxazolone), 2,2'-p-phenylenebis (5 (4H) -oxazolone), 2,2'-m-phenylenebis (5 (4H) -oxazolone), 2,2'-naphthalenebis ( 5 (4H) -oxazolone), 2,2 '
-Diphenylene bis (5 (4H) -oxazolone),
2,2 '-(1,4-cyclohexylene) bis (5 (4
H) -oxazolone), 2,2'-bis (4-methyl-
5 (4H) -oxazolone), 2,2'-methylenebis (4-methyl-5 (4H) -oxazolone), 2,2 '
-Ethylenebis (4-methyl-5 (4H) -oxazolone), 2,2'-tetramethylenebis (4-methyl-5)
(4H) -oxazolone), 2,2'-hexamethylenebis (4-methyl-5 (4H) -oxazolone), 2,
2'-decamethylene bis (4-methyl-5 (4H) -oxazolone), 2,2'-p-phenylene bis (4-methyl-5 (4H) -oxazolone), 2,2'-m-phenylene bis (4-methyl-5 (4H) -oxazolone), 2,2'-naphthalene bis (4-methyl-5 (4
H) -oxazolone), 2,2'-diphenylenebis (4-methyl-5 (4H) -oxazolone), 2,2 '
-(1,4-Cyclohexylene) bis (4-methyl-5)
(4H) -Oxazolone), 2,2'-bis (4,4-
Dimethyl-5 (4H) -oxazolone), 2,2'-methylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2'-ethylenebis (4,4-dimethyl-)
5 (4H) -oxazolone), 2,2′-tetramethylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2′-hexamethylenebis (4,4-dimethyl-5 (4H) -Oxazolone), 2,2'-octamethylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2'-decamethylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2'-p-phenylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2,2'-m-phenylenebis (4,4-dimethyl-5 (4H) -oxazolone), 2, 2'-naphthalene bis (4,4-dimethyl-5 (4H) -oxazolone), 2,2'-diphenylene bis (4,4-dimethyl-5 (4H) -oxazolone), 2,2 '-(1 , 4-
Cyclohexylene) -bis (4,4-dimethyl-5 (4
H) -oxazolone), 2,2'-bis (4-isopropyl-5 (4H) -oxazolone), 2,2'-methylenebis (4-isopropyl-5 (4H) -oxazolone), 2,2'-ethylene Bis (4-isopropyl-5
(4H) -oxazolone), 2,2'-tetramethylenebis (4-isopropyl-5 (4H) -oxazolone), 2,2'-hexamethylenebis (4-isopropyl-5 (4H) -oxazolone), 2 , 2'-p-phenylene bis (4-isopropyl-5 (4H) -oxazolone), 2,2'-m-phenylene bis (4-isopropyl-5 (4H) -oxazolone), 2,2'-naphthalene bis (4-Isopropyl-5 (4H) -oxazolone), 2,2'-bis (4-isobutyl-5 (4H)-
Oxazolone), 2,2'-methylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2'-ethylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2'-tetramethylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2'-hexamethylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2'-p-phenylenebis (4-isobutyl-5 ( 4H) -oxazolone), 2,2'-m-phenylenebis (4-isobutyl-5 (4H) -oxazolone), 2,2'-m-naphthalenebis (4-isobutyl-5 (4H) -oxazolone), etc. , Especially 2
-Oxazolin-5-one, 2,2'-bis (5 (4
H) -oxazolone) is preferred.

Examples of the oxazinone compound include:
2,2'-bis (3,1-benzoxazin-4-one), 2,2'-methylenebis (3,1-benzoxazin-4-one), 2,2'-ethylenebis (3,1-)
Benzoxazin-4-one), 2,2′-tetramethylenebis (3,1-benzoxazin-4-one),
2,2'-hexamethylenebis (3,1-benzoxazin-4-one), 2,2'-decamethylenebis (3,3
1-benzoxazin-4-one), 2,2'-p-phenylenebis (3,1-benzoxazin-4-one), 2,2'-m-phenylenebis (3,1-benzoxazine-4) -One), 2,2'-naphthalene bis (3,1-benzoxazin-4-one), 2,2'-
(4,4'-Diphenylene) bis (3,1-benzoxazin-4-one), 2,2'-bis (4,5-dihydro-1,3,6H-oxazin6-one), 2,2 ´－
Methylenebis (4,5-dihydro-1,3,6H-oxazin6-one), 2,2'-ethylenebis (4,5-
Dihydro-1,3,6H-oxazin6-one), 2,
2'-tetramethylene bis (4,5-dihydro-1,
3,6H-oxazin6-one), 2,2'-p-phenylenebis (4,5-dihydro-1,3,6H-oxazin6-one), 2,2'-m-phenylenebis (4,4)
5-dihydro-1,3,6H-oxazin6-one),
2,2'-bis (4-methyl-5-hydro-1,3,6
H-oxazin-6-one), 2,2'-bis (4-methyl-5-hydro-1,3,6H-oxazin-6-one), 2,2'-ethylenebis (4-methyl-5) -Hydro-1,3,6H-oxazin-6-one), 2,2 '
-P-phenylene bis (4-methyl-5-hydro-1,
3,6H-oxazin-6-one), 2,2'-m-phenylenebis (4-methyl-5-hydro-1,3,6H
-Oxazin-6-one), 2,2'-p-phenylenebis (4-hydro-5-methyl-1,3,6H-oxazin-6-one), 2,2'-m-phenylenebis (4
-Hydro-5-methyl-1,3,6H-oxazine-6
-One) and the like, with 2,2'-bis (3,1-benzoxazin-4-one) being most preferred.

Examples of the benzoxazinone compound include 2,8-dimethyl-4H, 6H-benzo [1,2-
d: 5,4-d '] bis- [1,3] -oxazine-
4,6-dione, 2,7-dimethyl-4H, 9H-benzo [1,2-d: 4,5-d '] bis- [1,3] -oxazine-4,9-dione, 2,8 -Diphenyl-4
H, 8H-benzo [1,2-d: 5,4-d '] bis-
[1,3] -Oxazine-4,6-dione, 2,7-diphenyl-4H, 9H-benzo [1,2-d: 4,5-
d '] bis- [1,3] -oxazane-4,6-dione, 6,6'-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-bis (2-ethyl-4H, 3,1-benzoxazin-4-one),
6,6'-bis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6'-methylenebis (2
-Methyl-4H, 3,1-benzoxazin-4-one), 6,6'-methylenebis (2-phenyl-4H,
3,1-benzoxazin-4-one), 6,6'-ethylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-ethylenebis (2-phenyl-) 4H, 3,1-benzoxazin-4-one),
6,6'-butylene bis (2-methyl-4H, 3,1-
Benzoxazin-4-one), 6,6′-butylene bis (2-phenyl-4H, 3,1-benzoxazine-
4-one), 6,6'-oxybis (2-methyl-4)
H, 3,1-benzoxazin-4-one), 6,6 '
-Oxybis (2-phenyl-4H, 3,1-benzoxazin-4-one), 6,6'-sulfonylbis (2
-Methyl-4H, 3,1-benzoxazin-4-one), 6,6'-sulfonylbis (2-phenyl-4)
H, 3,1-benzoxazin-4-one), 6,6 '
-Carbonylbis (2-methyl-4H, 3,1-benzoxazin-4-one), 6,6'-carbonylbis (2-phenyl-4H, 3,1-benzoxazine-4
-On), 7,7'-methylenebis (2-methyl-4)
H, 3,1-benzoxazin-4-one), 7,7 '
-Methylenebis (2-phenyl-4H, 3,1-benzoxazin-4-one), 7,7'-bis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,
7'-ethylenebis (2-methyl-4H, 3,1-benzoxazin-4-one), 7,7'-oxybis (2
-Methyl-4H, 3,1-benzoxazin-4-one), 7,7'-sulfonylbis (2-methyl-4H,
3,1-benzoxazin-4-one), 7,7′-carbonylbis (2-methyl-4H, 3,1-benzoxazin-4-one) and the like, 2,8-dimethyl-
Most preferred is 4H, 6H-benzo [1,2-d: 5,4-d '] bis- [1,3] -oxazine-4,6-dione.

The cyclic iminoethers used in the present invention include an oxazoline compound having a 5-membered iminoether ring and an oxazine compound having a 6-membered iminoether ring.

Examples of the oxazoline compound include 2
-Oxazoline, 4-methyl-2-oxazoline, 5-
Methyl-2-oxazoline, 4,5-dimethyl-2-oxazoline, 2,2'-bis (2-oxazoline),
2,2'-bis (4-methyl-2-oxazoline),
2,2'-bis (4-ethyl-2-oxazoline),
2,2'-bis (4,4'-diethyl-2-oxazoline), 2,2'-bis (4-propyl-2-oxazoline), 2,2'-bis (4-butyl-2-oxazoline) , 2,2'-bis (4-hexyl-2-oxazoline), 2,2-bis (4-cyclohexyl-2-oxazoline), 2,2'-bis (4-phenyl-2-oxazoline), 2, 2'-bis (4-benzyl-2-oxazoline), 2,2'-o-phenylenebis (2-oxazoline), 2,2'-m-phenylenebis (2-oxazoline), 2,2'-p -Phenylenebis (2-oxazoline), 2,2'-o-phenylenebis (4-methyl-2-oxazoline), 2,2'-m-phenylenebis (4-methyl-2-oxazoline), 2,2 ′ -P-phenylene bis (4-methyl- - oxazoline), 2,
2'-o-phenylene bis (4,4'-dimethyl-2-
Oxazoline), 2,2'-m-phenylene bis (4,
4'-dimethyl-2-oxazoline), 2,2'-p-
Phenylene bis (4,4'-dimethyl-2-oxazoline), 2,2'-ethylene bis (2-oxazoline),
2,2'-tetramethylene bis (2-oxazoline),
2,2'-hexamethylenebis (2-oxazoline),
2,2-octamethylenebis (2-oxazoline),
2,2-decamethylene bis (2-oxazoline), 2,
2-ethylenebis (4-methyl-2-oxazoline),
2,2'-tetramethylene bis (4,4'-dimethyl-
2-oxazoline), 2,2′-9,9′-diphenoxyethanebis (4,4′-dimethyl-2-oxazoline), 2,2′-cyclohexylenebis (2-oxazoline) and the like. Yes, but 2,2'-bis (2
-Oxazoline) is most preferred. Examples of the oxazine compound include 1,2-oxazine, 2,2′-bis (5,6-dihydro-4H-1,3-oxazine),
2,2'-methylenebis (5,6-dihydro-4H-
1,3-oxazine), 2,2'-ethylenebis (5,5
6-dihydro-4H-1,3-oxazine), 2,2 '
-Propylenebis (5,6-dihydro-4H-1,3-
Oxazine), 2,2'-butylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-hexamethylenebis (5,6-dihydro-4H-1,3-oxazine), 2 , 2'-p-phenylene bis (5,6-dihydro-4H-1,3-oxazine), 2,2'-m-
Phenylene bis (5,6-dihydro-4H-1,3-oxazine), 2,2'-naphthylene bis (5,6-dihydro-4H-1,3-oxazine), 2,2'-p, p
′ -Diphenylene bis (5,6-dihydro-4H-1,
3-oxazine) and the like, but 2,2 '
Most preferred is -bis (5,6-dihydro-4H-1,3-oxazine).

The aromatic hydroxycarboxylic acid used as a binder in the present invention is, for example, o-hydroxybenzoic acid, m-hydroxybenzoic acid, p-hydroxybenzoic acid, 1-carboxy-2-hydroxynaphthalene, 1-
Carboxy-3-hydroxynaphthalene, 1-carboxy-4-hydroxynaphthalene, 1-carboxy-5-
Hydroxynaphthalene, 1-carboxy-6-hydroxynaphthalene, 1-carboxy-7-hydroxynaphthalene, 1-carboxy-8-hydroxynaphthalene, 1
-Hydroxy-2-carboxynaphthalene, 1-hydroxy-3-carboxynaphthalene, 1-hydroxy-6
-Carboxynaphthalene, 1-hydroxy-7-carboxynaphthalene, 2-carboxy-3-hydroxynaphthalene, 2-carboxy-6-hydroxynaphthalene,
2-carboxy-7-hydroxynaphthalene, 3-carboxy-3'-hydroxybiphenyl, 3-carboxy-4'-hydroxybiphenyl, 3-hydroxy-4 '
-Carboxybiphenyl, 4-carboxy-4'-hydroxybiphenyl and the like can be mentioned.

The polyvalent amine compound used as the binder in the present invention is, for example, 1,4-diaminobenzene, 1,
3-diaminobenzene, 1,2-diaminobenzene,
2,3-diaminotoluene, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,6-diaminotoluene, 1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopropane, 1 , 2-diaminobutane, 1,3-diaminobutane, 1,4-diaminobutane, 1,3-diamino-2-methylpropane, 4,4 ′
-Diaminobiphenyl, 3,4-diaminobiphenyl,
3,3′-diaminobiphenyl, bis (3-aminophenoxy) methane, bis (4-aminophenoxy) methane, bis (3-aminophenoxy) ethane, bis (4-
Aminophenoxy) ethane, 2,2-bis (3-aminophenoxy) propane, 2,2-bis (4-aminophenoxy) propane, bis (3-aminophenoxy) ether, bis (4-aminophenoxy) ether, bis (3-aminophenoxy) ketone, bis (4-aminophenoxy) ketone, bis (3-aminophenoxy) sulfone, bis (4-aminophenoxy) sulfone, bis (3-aminophenoxy) sulfide, bis (4-aminophenoxy) ) Sulfide, bis (3-aminophenoxy) sulfoxide, bis (4-aminophenoxy) sulfoxide, melamine, 1,2,3-triaminobenzene, 1,2,4-triaminobenzene, 1,3,5-tri Aminobenzene, 1,2,3-triaminocyclohexane, 1,2,4-tri Mino cyclohexane, 1,
3,5-triaminocyclohexane, 1,2,3-triaminonaphthalene, 1,2,4-triaminonaphthalene, 1,2,5-triaminonaphthalene, 1,2,6-
Triaminonaphthalene, 1,2,7-triaminonaphthalene, 1,2,8-triaminonaphthalene, 1,3,5
-Triaminonaphthalene, 1,3,6-triaminonaphthalene, 1,3,7-triaminonaphthalene, 1,3
8-triaminonaphthalene, 1,4,5-triaminonaphthalene, 1,4,6-triaminonaphthalene, 1,
4,7-triaminonaphthalene, 1,6,7-triaminonaphthalene, 1,6,8-triaminonaphthalene,
2,3,6-triaminonaphthalene, 2,3,7-triaminonaphthalene, 3,3′-diaminobenzidine,
1,2,3,4-tetraaminobenzene, 1,2,3
5-tetraaminobenzene, 1,2,4,5-tetraaminobenzene, 3,3 ', 4,4'-tetraaminophenyl ether, 3,3', 4,4'-tetraaminophenyl sulfone, 3, 3 ', 4,4'-tetraamino phenyl ketone etc. are mentioned.

Examples of the polyhydric alcohols used as the binder in the present invention include ethylene glycol, 1,3
-Propanediol, 1,2-propanediol, 1,
4-butanediol, 1,3-butanediol, 1,2
-Butanediol, 1,2-pentanediol, 1,3
-Pentanediol, 1,4-pentanediol, 1,
5-pentanediol, 2,3-pentanediol,
2,4-pentadiol, 1,6-hexanediol,
1,5-hexanediol, 1,4-hexanediol, 1,3-hexanediol, 1,2-hexanediol, 2,3-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 3 , 5-hexanediol, 1,10-decanediol, neopentyl glycol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5-pentanediol,
3,3-dimethyl-1,3-propanediol, 1,4
-Cyclohexanedimethanol, 1,4-benzenedimethanol, polymethylene glycol, polyethylene glycol, polyvinyl alcohol, polyhydroxyethyl methacrylate, polyhydroxypropyl methacrylate, glycerin, trimethylolethane, trimethylolpropane, trimethylolbutane, trimethylolpentane , Pentaerythritol, sorbitol, castor oil, hydrogenated bisphenol A, bisphenol dihydroxypropyl ether, 1,3,5-tri (hydroxymethyl) pentane, 1,3,3,5-tetra (hydroxymethyl) pentane, 1,2,2. 6-trihydroxyhexane, 1,2,2,6-tetrahydroxyhexane and the like can be mentioned, as well as arabinose, ribose, deoxyribose, xylose. , Saccharides such as glucose, fructose, mannose, galactose, and disaccharides, oligosaccharides, and polysaccharides which are condensates of these, and those having optical activity include D-form, L-form, and DL-form. Good.

The epoxy compound used as the binder in the present invention includes ethylene oxide, propylene oxide, butylene oxide, styrene oxide, butyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, epichlorohydrin, cyclohexane vinyl monooxide, Dipentene monooxide, cresyl glycidyl ether, α-pinene oxide, glycidyl methacrylate, butadiene monoepoxide,
1,2-epoxy-7-octene, glycidyl acrylate, glycidyl undecylate, methyl vinyl glycidyl amine, vinyl-3,4-epoxycyclohexane, allyl-3,4-epoxycyclohexane, 3,4
-Epoxycyclohexyl acrylate, 2,3-epoxypropyl-4-vinylphenyl ether, 2,3-
Epoxy cinnamyl acrylate, 9,10-epoxy oleyl acrylate, 2,3-epoxybutyl methacrylate, methyl glycidyl methacrylate, bisphenol A glycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, aryl glycidyl ether, 3,4-epoxycyclohexylmethyl methacrylate, glycerol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, resorcin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydroquinone di Glycidyl ether, bisphenol S diglycidyl ether, adipic acid di Glycidyl ester, o- phthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether bird,
Examples thereof include methylolpropane polyglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether and the like. Among these epoxy compounds, easy handling, low price, miscibility,
From the viewpoint of low vapor pressure, glycidyl acrylate and glycidyl methacrylate are particularly preferable.

Examples of the polyfunctional aziridine compound used as the binder in the present invention include 2,2-bishydroxymethylbutanol tris [3- (1-aziridinyl) propionate] and ethylene glycol-bis [3.
-(1-aziridinyl) propionate], polyethylene glycol-bis- [3- (1-aziridinyl) propionate], propylene glycol-bis [3- (1
-Aziridinyl) propionate], polypropylene glycol-bis [3- (1-aziridinyl) propionate], tetramethylene glycol-bis [3- (1-
Aziridinyl) propionate], polytetramethylene glycol-bis [3- (1-aziridinyl) propionate] and the like.

Examples of the lactams used as the binder in the present invention include ε-caprolactam, ω-laurolactam, 2-pyrrolidone, 2-piperidone, 2-azacyclobutanone, 2-azacyclooctanone, 2- Azacyclononanone, glycosiamidine, oxindole,
Isatin, N, N'-terephthalylbiscaprolactam and the like can be mentioned.

Examples of the lactone used as the binder in the present invention include glycolide, lactide and 1,4-
Dioxanone, ε-caprolactone, 1,5-dioxysepan-2-one, trimethylene carbonate, β-butyrolactone, β-propiolactone, δ-valerolactone, γ-butyrolactone, enanthlactone, caprylolactone, β-methylpropioo Lactone, β-dimethylpropiolactone, δ-caprolactone, ethylene oxalate, ethylene malonate, ethylene succinate, ethylene adipate, propylene oxalate, propylene malonate, propylene succinate, propylene adipate, tetramethylene oxalate, tetramethylene Malonate, tetramethylene succinate, tetramethylene adipate, {o-α-D-glucopyranosyl- (1 → 4)} 4-D′-glucono-1,5-lactone, β-methyl-δ-vale Lactone, and the like.

In addition, diethylene glycol bischloroformate is effective as a binder.

The amount of the binder to be added depends on the molecular weight of the polyhydroxycarboxylic acid at the time of addition and its type or the type of the binder, but 0.0001 to 10% by weight based on the polyhydroxycarboxylic acid, Preferably 0.00
A range of 1 to 8% by weight, more preferably 0.01 to 5% by weight, and most preferably 0.5 to 3% by weight is preferable.
On the contrary, if the binder is added in an amount of 10% by weight or more, the molecular weight may be decreased, or the reaction between the binders may not be added preferentially. Further, if the addition amount is large, the influence on the natural environment when the polyhydroxycarboxylic acid is decomposed may not be negligible.

The amount of water in the reaction mixture at the time of adding the binder must be 50 ppm or less. It should preferably be 20 ppm or less, more preferably 5 ppm or less. Therefore, it is necessary to distill the water produced by the dehydration condensation reaction out of the reaction system together with the organic solvent,
In an organic solvent containing 50 ppm or more of water, the added binder may react with water.

The reaction temperature after the addition of the binder depends on the kind of the solvent and the polyhydroxycarboxylic acid, but it is 50 to 250 ° C., preferably 60 to 220 ° C., more preferably 80 to 200 ° C., further preferably 90 to 16
0 ° C., most preferably 100 to 140 ° C. If the temperature is lower than 50 ° C, the reaction does not proceed sufficiently, and if the temperature exceeds 250 ° C, the polyhydroxycarboxylic acid may be colored or deteriorated.

The reaction pressure after adding the binder may be any of reduced pressure, normal pressure and increased pressure. Further, it is preferable to carry out in an inert gas atmosphere so that water does not enter from the outside of the reaction system, and it may be carried out while substituting with an inert gas or while bubbling with an inert gas.

The reaction time after adding the binder was 0.
A range of 1 to 5 hours is preferred. If the reaction time is less than 0.1 hours, the effect may not be sufficient depending on the reaction conditions. Even if the reaction is performed for more than 5 hours, the molecular weight of the polyhydroxycarboxylic acid will reach the ceiling, and the effect will not change even if the reaction is continued for a longer time. Disappear.

By the above method, a high molecular weight polyhydroxycarboxylic acid having a weight average molecular weight of 100,000 or more can be obtained in a short time. The polyhydroxycarboxylic acid obtained by the method of the present invention is isolated and purified by a known method such as cooling and crystallization in a solvent used for polymerization, filtration, washing with methanol, and drying. be able to.

[0065]

EXAMPLES Examples of the method of the present invention will be described below, but the present invention is not limited to the methods and apparatuses described below. The molecular weights of the polymers described herein were determined by GPC (gel permeation chromatography) in comparison with polystyrene standard samples. The analysis conditions of GPC are described below. GPC: Shodex system 11 (manufactured by Showa Denko) Used column: K-805L × 2, K-800P (pre-column) Column temperature: 40 ° C. Solvent: Chloroform Flow rate: 1.0 ml / min Sample concentration: 3 mg / 1 ml Sample injection amount: 100 μl

Example 1 75.0 g of 90% L-lactic acid was heated and stirred at 150 ° C./50 mmHg for 3 hours while removing water out of the system, and then 325 g of o-dichlorobenzene and 0.4 g of tin powder were added thereto. In addition, a tube filled with 75 g of molecular sieve 3A was attached so that the solvent to be distilled out returned to the system through the molecular sieve and the reaction conditions were 140 ° C / 250 mmH.
The reaction was set to g. After a reaction time of 12 hours, the sample was sampled and the molecular weight was measured. As a result, the weight average molecular weight was 80,000. 0.75 g of xylene diisocyanate was added to the reaction mass, and the reaction was continued at 140 ° C./nitrogen atmosphere. The viscosity of the reaction mass rapidly increased, and the reaction was completed 2 hours after the addition. After the reaction was completed, 400 ml of chloroform was added to the reaction mass to dissolve it, and suction filtration was performed to remove tin powder. 1,400 ml of methanol was added to the obtained chloroform solution, and the precipitated yellow-white solid polymer was separated by filtration and dried. The weight average molecular weight of the polymer is 200,
It was 000.

Example 2 325 g of m-xylene instead of o-dichlorobenzene
Using 1 to 1 reaction immediately before the addition of xylene diisocyanate
An experiment was conducted in the same manner as in Example 1 except that the experiment was conducted at 40 ° C./nitrogen atmosphere. The weight average molecular weight immediately before the addition of xylene diisocyanate was 70,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 190,0.
It was 00.

Example 3 Diphenyl ether 3 was used instead of o-dichlorobenzene.
An experiment was performed in the same manner as in Example 1 except that 25 g was used and the reaction immediately before the addition of xylene diisocyanate was performed at 130 ° C./15 mmHg. The weight average molecular weight immediately before the addition of xylene diisocyanate was 89,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 21.
It was 10,000.

Example 4 325 g of naphthalene was used instead of o-dichlorobenzene, and the reaction immediately before the addition of xylene diisocyanate was performed.
An experiment was conducted in the same manner as in Example 1 except that the experiment was performed at 0 ° C / 50 mmHg. The weight average molecular weight immediately before the addition of xylene diisocyanate was 74,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 184,000.
It was 0.

Example 5 An experiment was carried out in the same manner as in Example 1 except that 325 g of n-butylbenzoate was used instead of o-dichlorobenzene, and the reaction immediately before the addition of xylene diisocyanate was carried out at 140 ° C./25 mmHg. The weight average molecular weight immediately before the addition of xylene diisocyanate was 65,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 169,000.

Example 6 Example 1 was repeated except that 325 g of cyclohexyl ketone was used instead of o-dichlorobenzene and the reaction immediately before the addition of xylene diisocyanate was carried out at 140 ° C./10 mmHg.
An experiment was conducted in the same manner as in. The weight average molecular weight immediately before the addition of xylene diisocyanate was 68,000, and 2
The weight average molecular weight of the polymer isolated by reacting for a time is 1
It was 73,000.

Example 7 An experiment was conducted in the same manner as in Example 1 except that 0.75 g of 2,4-tolylene diisocyanate was used instead of xylene diisocyanate. The weight average molecular weight immediately before the addition of 2,4-tolylene diisocyanate was 80,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 226,000.

Example 8 The reaction time until the addition of xylene diisocyanate was 20 hours, and the amount of xylene diisocyanate added was 0.37.
An experiment was conducted in the same manner as in Example 1 except that the amount was 5 g. The weight average molecular weight immediately before the addition of xylene diisocyanate is 15
The weight average molecular weight of the polymer isolated after the reaction was 2 hours after the addition was 305,000.

Example 9 The reaction time until the addition of xylene diisocyanate was 18 hours, and the amount of xylene diisocyanate added was 0.53.
An experiment was conducted in the same manner as in Example 1 except that g was used. The weight average molecular weight immediately before the addition of xylene diisocyanate is 12
The weight average molecular weight of the polymer isolated after the reaction was 2 hours after the addition was 237,000.

Example 10 The reaction time until the addition of xylene diisocyanate was 15 hours, and the amount of xylene diisocyanate added was 0.6 g.
An experiment was conducted in the same manner as in Example 1 except that The weight average molecular weight immediately before the addition of xylene diisocyanate is 100,
The weight average molecular weight of the polymer isolated by the reaction for 2 hours after the addition was 196,000.

Example 11 The reaction time until the addition of xylene diisocyanate was 8 hours, and the amount of xylene diisocyanate added was 2.25 g.
An experiment was conducted in the same manner as in Example 1 except that The weight average molecular weight immediately before the addition of xylene diisocyanate is 50,0.
The weight average molecular weight of the polymer isolated after the reaction for 2 hours after the addition was 150,000.

Example 12 An experiment was conducted in the same manner as in Example 1 except that the amount of xylene diisocyanate added was 1.5 g. The weight average molecular weight immediately before the addition of xylene diisocyanate was 80,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 152,000.

Example 13 An experiment was conducted in the same manner as in Example 1 except that the amount of xylene diisocyanate added was 2.25 g. The weight average molecular weight immediately before the addition of xylene diisocyanate was 80,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 104,000.

Example 14 An experiment was conducted in the same manner as in Example 1 except that 81 g of 70% glycolic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of xylene diisocyanate was 68,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 185,000.

Example 15 An experiment was conducted in the same manner as in Example 1 except that 75 g of 90% DL-lactic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of xylene diisocyanate was 70,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 206,000.

Example 16 Instead of L-lactic acid, 90% L-lactic acid 67.5 g and 70%
An experiment was conducted in the same manner as in Example 1 except that 8.1 g of glycolic acid was used. The weight average molecular weight immediately before the addition of xylene diisocyanate was 78,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 198,0.
It was 00.

Example 17 90% L-lactic acid (75.0 g) was heated and stirred at 150 ° C./50 mmHg for 3 hours while removing water out of the system, and then 325 g of diphenyl ether and 0.4 g of tin powder were added,
Furthermore, a tube filled with 75 g of molecular sieve 3A was attached so that the solvent distilled out by reflux returned to the system through the molecular sieve, and the reaction conditions were 130 ° C / 15 m.
The reaction was set to mHg. After a reaction time of 10 hours, sampling was performed and the molecular weight was measured. As a result, the weight average molecular weight Mw was 50,000. 0.75 g of pyromellitic dianhydride was added to the reaction mass, and the reaction was continued at 130 ° C./normal pressure / nitrogen atmosphere. The viscosity of the reaction mass rapidly increased, and the reaction was completed 2 hours after the addition. After the reaction was completed, 400 ml of chloroform was added to the reaction mass to dissolve it, and suction filtration was performed to remove tin powder. 1,400 ml of methanol was added to the obtained chloroform solution, and the precipitated yellow-white solid polymer was separated by filtration and dried. The weight average molecular weight of the polymer was 300,000.

Example 18 3,3 ', 4,4' instead of pyromellitic dianhydride
-Benzophenone tetracarboxylic dianhydride 0.75 g
An experiment was conducted in the same manner as in Example 17 except that was used. Three
The weight average molecular weight immediately before the addition of 3 ′, 4,4′-benzophenonetetracarboxylic dianhydride is 50,000,
The weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 250,000.

Example 19 The same experiment as in Example 17 was carried out except that 81 g of 70% glycolic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of pyromellitic dianhydride was 51,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 270,000.

Example 20 The same experiment as in Example 17 was carried out except that 75 g of 90% DL-lactic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of pyromellitic dianhydride was 54,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 295,000.

Example 21 An experiment was conducted in the same manner as in Example 17, except that the reaction time until the addition of the acid dianhydride was 15 hours. The weight average molecular weight immediately before the addition of pyromellitic dianhydride was 100,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 320,000.

Example 22 75.0 g of 90% L-lactic acid was heated and stirred at 150 ° C./50 mmHg for 3 hours while removing water out of the system, and then 325 g of diphenyl ether and 0.4 g of tin powder were added thereto.
Furthermore, a tube filled with 75 g of molecular sieve 3A was attached so that the solvent distilled out by reflux returned to the system through the molecular sieve, and the reaction conditions were 130 ° C / 15 m.
The reaction was set to mHg. After a reaction time of 10 hours, sampling was performed and the molecular weight was measured. As a result, the weight average molecular weight was 50,000. 2,2'- in the reaction mass
0.75 g of bis (5 (4H) -oxazolone) was added, and the reaction was continued at 130 ° C./normal pressure / nitrogen atmosphere. The viscosity of the reaction mass rapidly increased, and the reaction was completed 2 hours after the addition. After the reaction is completed, chloroform 400 is added to the reaction mass.
After adding and dissolving ml, suction filtration was performed to remove tin powder. 1,400 ml of methanol was added to the obtained chloroform solution, and the precipitated yellow-white solid polymer was separated by filtration and dried. The weight average molecular weight of the polymer was 250,000.

Example 23 Example 2 was repeated except that 0.75 g of 2,2'-bis (3,1-benzoxazin-4-one) was used instead of 2,2'-bis (5 (4H) -oxazolone). The experiment was conducted in the same manner as in Example 22. The weight average molecular weight immediately before addition of 2,2'-bis (3,1-benzoxazin-4-one) is 50,000.
The weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 230,000.

Example 24 Instead of 2,2'-bis (5 (4H) -oxazolone), 2,8-dimethyl-4H, 6H-benzo [1,2-
d: 5,4-d '] bis- [1,3] -oxazine-
An experiment was conducted in the same manner as in Example 22 except that 0.75 g of 4,6-dione was used. 2,8-Dimethyl-4H, 6H-
Benzo [1,2-d: 5,4-d '] bis- [1,3]
The weight average molecular weight immediately before the addition of -oxazine-4,6-dione was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 220,000.

Example 25 An experiment was conducted in the same manner as in Example 22 except that 0.75 g of 2,2'-bis (2-oxazoline) was used instead of 2,2'-bis (5 (4H) -oxazolone). went. 2,2 '
The weight average molecular weight immediately before the addition of -bis (2-oxazoline) was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 230,000.

Example 26 Instead of 2,2'-bis (5 (4H) -oxazolone), 2,2'-bis (5,6-dihydro-4H-1,3-
The experiment was conducted in the same manner as in Example 22 except that 0.75 g of oxazine) was used. The weight average molecular weight immediately before the addition of 2,2′-bis (5,6-dihydro-4H-1,3-oxazine) was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was It was 240,000.

Example 27 2,2'-bis (5 (4H) -oxazolone) 0.75
An experiment was conducted in the same manner as in Example 22 except that 1.5 g of 2,2′-bis (5 (4H) -oxazolone) and 0.75 g of N, N′-terephthalylbiscaprolactam were used in combination instead of g. 2,2'-bis (5 (4H) -oxazolone) and N, N'-terephthalylbiscaprolactam had a weight average molecular weight of 50,000 immediately before the addition of 2
The weight average molecular weight of the polymer isolated by reaction for 2 hours was 2
It was 80,000.

Example 28 An experiment was conducted in the same manner as in Example 22 except that 81 g of 70% glycolic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of 2,2′-bis (5 (4H) -oxazolone) was 51,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 250,000.

Example 29 An experiment was conducted in the same manner as in Example 22 except that 75 g of 90% DL-lactic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of 2,2′-bis (5 (4H) -oxazolone) was 54,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 250,000.

Example 30 An experiment was conducted in the same manner as in Example 22 except that the reaction time until the addition of 2,2'-bis (5 (4H) -oxazolone) was 15 hours. The weight average molecular weight immediately before the addition of 2,2'-bis (5 (4H) -oxazolone) was 100,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 290,000.

Example 31 75.0 g of 90% L-lactic acid was stirred with heating at 150 ° C./50 mmHg for 3 hours while removing water out of the system, and then 325 g of diphenyl ether and 0.4 g of tin powder were added thereto.
Furthermore, a tube filled with 75 g of molecular sieve 3A was attached so that the solvent distilled out by reflux returned to the system through the molecular sieve, and the reaction conditions were 130 ° C / 15 m.
The reaction was set to mHg. After a reaction time of 10 hours, sampling was performed and the molecular weight was measured. As a result, the weight average molecular weight Mw was 50,000. 0.75 g of p-hydroxybenzoic acid was added to the reaction mass, and 130 ° C./15
The reaction was continued at mmHg. The viscosity of the reaction mass rapidly increased, and the reaction was completed 2 hours after the addition. After the reaction was completed, 400 ml of chloroform was added to the reaction mass to dissolve it, and suction filtration was performed to remove tin powder. 1,400 ml of methanol was added to the obtained chloroform solution, and the precipitated yellow-white solid polymer was separated by filtration and dried. The weight average molecular weight of the polymer was 250,000.

Example 32 An experiment was conducted in the same manner as in Example 31 except that 0.75 g of o-hydroxybenzoic acid was used instead of p-hydroxybenzoic acid. The weight average molecular weight immediately before the addition of o-hydroxybenzoic acid was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 210,000.

Example 33 The same experiment as in Example 31 was carried out except that 81 g of 70% glycolic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of p-hydroxybenzoic acid was 51,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 245,000.

Example 34 The same experiment as in Example 31 was carried out except that 75 g of 90% DL-lactic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of p-hydroxybenzoic acid was 54,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 265,000.

Example 35 An experiment was conducted in the same manner as in Example 31 except that the reaction time until the addition of p-hydroxybenzoic acid was changed to 15 hours. The weight average molecular weight immediately before the addition of p-hydroxybenzoic acid is 100,
The weight average molecular weight of the polymer isolated by the reaction for 2 hours after the addition was 290,000.

Example 36 An experiment was conducted in the same manner as in Example 31 except that the reaction time until the addition of p-hydroxybenzoic acid was 5 hours and the amount of p-hydroxybenzoic acid added was 1.5 g. The weight average molecular weight immediately before the addition of p-hydroxybenzoic acid was 24,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 150,000.

Example 37 90% L-lactic acid (75.0 g) was heated and stirred at 150 ° C./50 mmHg for 3 hours while removing water out of the system, and then 325 g of diphenyl ether and 0.4 g of tin powder were added,
Furthermore, a tube filled with 75 g of molecular sieve 3A was attached so that the solvent distilled out by reflux returned to the system through the molecular sieve, and the reaction conditions were 130 ° C / 15 m.
The reaction was set to mHg. After a reaction time of 10 hours, sampling was performed and the molecular weight was measured. As a result, the weight average molecular weight was 50,000. 0.75 g of 1,4-diaminobenzene was added to the reaction mass, and 130 ° C./normal pressure /
The reaction was continued under a nitrogen atmosphere. The viscosity of the reaction mass rapidly increased, and the reaction was completed 2 hours after the addition. After the reaction was completed, 400 ml of chloroform was added to the reaction mass to dissolve it, and suction filtration was performed to remove tin powder. 1,400 ml of methanol was added to the obtained chloroform solution, and the precipitated yellow-white solid polymer was separated by filtration and dried. The weight average molecular weight of the polymer was 270,000.

Example 38 An experiment was conducted in the same manner as in Example 37 except that 0.75 g of 1,2-diaminoethane was used instead of 1,4-diaminobenzene. The weight average molecular weight immediately before the addition of 1,2-diaminoethane was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 220,000.
Met.

Example 39 An experiment was conducted in the same manner as in Example 37 except that 81 g of 70% glycolic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of 1,4-diaminobenzene is 51,000.
The weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 240,000.

Example 40 An experiment was conducted in the same manner as in Example 37 except that 75 g of 90% DL-lactic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of 1,4-diaminobenzene was 54,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 260,000.

Example 41 The reaction time until the addition of 1,4-diaminobenzene was 15
An experiment was conducted in the same manner as in Example 37 except that the time was set.
The weight average molecular weight immediately before the addition of 1,4-diaminobenzene was 100,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 300,000.

Example 42 Melamine 0.75 instead of 1,4-diaminobenzene
An experiment was conducted in the same manner as in Example 37 except that g was used.
The weight average molecular weight immediately before the addition of melamine was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 260,000.

Example 43 An experiment was conducted in the same manner as in Example 37 except that 0.75 g of 1,3,5-triaminobenzene was used instead of 1,4-diaminobenzene. The weight average molecular weight immediately before addition of 1,3,5-triaminobenzene was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 215,000.

Example 44 75.0 g of 90% L-lactic acid was heated and stirred at 150 ° C./50 mmHg for 3 hours while removing water out of the system, and then 325 g of diphenyl ether and 0.4 g of tin powder were added thereto,
Furthermore, a tube filled with 75 g of molecular sieve 3A was attached so that the solvent distilled out by reflux returned to the system through the molecular sieve, and the reaction conditions were 130 ° C / 15 m.
The reaction was set to mHg. After a reaction time of 10 hours, sampling was performed and the molecular weight was measured. As a result, the weight average molecular weight was 50,000. 0.75 g of maleic anhydride was added to the reaction mass, and the reaction was continued at 130 ° C./normal pressure / nitrogen atmosphere. After 2 hours, 0.75 g of 1,4-diaminobenzene was added to the reaction mass,
The reaction was continued under an atmosphere of ° C / normal pressure / nitrogen. The viscosity of the reaction mass rapidly increased, and the reaction was completed 2 hours after the addition.
After the reaction was completed, 400 ml of chloroform was added to the reaction mass to dissolve it, and suction filtration was performed to remove tin powder. 1,400 ml of methanol was added to the obtained chloroform solution, and the precipitated yellow-white solid polymer was separated by filtration and dried. The weight average molecular weight of the polymer was 310,000.

Example 45 An experiment was conducted in the same manner as in Example 44 except that 0.75 g of 1,2-diaminoethane was used instead of 1,4-diaminobenzene. The weight average molecular weight immediately before the addition of maleic anhydride was 50,000, and after 2 hours, 1,2-
0.75 g of diaminoethane was added and reacted for 2 hours,
The weight average molecular weight of the isolated polymer was 290,000.

Example 46 Melamine 0.75 in place of 1,4-diaminobenzene
An experiment was conducted in the same manner as in Example 44 except that g was used. The weight average molecular weight immediately before the addition of maleic anhydride is 50,000.
After 2 hours, 0.75 g of melamine was further added and reacted for 2 hours, and the weight average molecular weight of the isolated polymer was 245,000.

Example 47 An experiment was conducted in the same manner as in Example 44 except that 0.75 g of 1,3,5-triaminobenzene was used instead of 1,4-diaminobenzene. The weight average molecular weight immediately before the addition of maleic anhydride was 50,000. After 2 hours, 0.75 g of 1,3,5-triaminobenzene was further added and reacted for 2 hours. The molecular weight was 235,000.

Example 48 1,2,4,5-instead of 1,4-diaminobenzene
An experiment was conducted in the same manner as in Example 44 except that 0.75 g of tetraaminobenzene was used. The weight average molecular weight immediately before the addition of maleic anhydride was 50,000, and after 2 hours,
Furthermore, 1,2,4,5-tetraaminobenzene 0.75
g was added and reacted for 2 hours, and the weight average molecular weight of the isolated polymer was 200,000.

Example 49 An experiment was conducted in the same manner as in Example 44 except that 81 g of 70% glycolic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of maleic anhydride was 51,000,
After the lapse of time, 0.75 of 1,4-diaminobenzene was further added.
g was added and the mixture was reacted for 2 hours, and the weight average molecular weight of the isolated polymer was 255,000.

Example 50 An experiment was conducted in the same manner as in Example 44 except that 75 g of 90% DL-lactic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of maleic anhydride was 54,000, and after 2 hours, 0.75 g of 1,4-diaminobenzene was further added.
Was added and reacted for 2 hours, and the weight average molecular weight of the isolated polymer was 255,000.

Example 51 An experiment was conducted in the same manner as in Example 44 except that the reaction time until the addition of maleic anhydride was changed to 15 hours. The weight average molecular weight immediately before the addition of maleic anhydride is 100,000.
After the lapse of time, 0.75 of 1,4-diaminobenzene was further added.
g and the reaction was carried out for 2 hours. The weight average molecular weight of the isolated polymer was 320,000.

Example 52 75.0 g of 90% L-lactic acid was stirred with heating at 150 ° C./50 mmHg for 3 hours while removing water out of the system, and then 325 g of diphenyl ether and 0.4 g of tin powder were added thereto,
Furthermore, a tube filled with 75 g of molecular sieve 3A was attached so that the solvent distilled out by reflux returned to the system through the molecular sieve, and the reaction conditions were 130 ° C / 15 m.
The reaction was set to mHg. After a reaction time of 10 hours, sampling was performed and the molecular weight was measured. As a result, the weight average molecular weight was 50,000. 0.2 g of 1,4-butanediol was added to the reaction solution, and 130 ° C./15 mmH
The reaction was continued at g. The viscosity of the reaction mass rapidly increased, and the reaction was completed 2 hours after the addition. After the reaction was completed, 400 ml of chloroform was added to the reaction mass to dissolve it, and suction filtration was performed to remove tin powder. 1,400 ml of methanol was added to the obtained chloroform solution, and the precipitated white solid polymer was separated by filtration and dried. The weight average molecular weight of the polymer is 167,
It was 000.

Example 53 An experiment was conducted in the same manner as in Example 52 except that 0.1 g of pentaerythritol was used instead of 1,4-butanediol. The weight average molecular weight immediately before the addition of pentaerythritol was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 198,000.

Example 54 An experiment was conducted in the same manner as in Example 52 except that 81 g of 70% glycolic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of 1,4-butanediol was 51,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 127,000.

Example 55 An experiment was conducted in the same manner as in Example 52 except that 75 g of 90% DL-lactic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of 1,4-butanediol was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 204,000.

Example 56 An experiment was conducted in the same manner as in Example 52 except that 0.75 g of ethylene glycol diglycidyl ether was used instead of 1,4-butanediol. The weight average molecular weight immediately before the addition of ethylene glycol diglycidyl ether is 50,0.
The weight average molecular weight of the polymer isolated after the reaction for 2 hours after the addition was 182,000.

Example 57 An experiment was conducted in the same manner as in Example 52 except that 0.75 g of diglycidyl terephthalate was used instead of 1,4-butanediol. The weight average molecular weight of the polymer immediately before the addition of terephthalic acid diglycidyl ester was 52,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 229000.

Example 58 Example 5 except that 0.4 g of 2,2-bishydroxymethylbutanol tris [3- (1-aziridinyl) propionate] was used instead of 1,4-butanediol.
The experiment was performed in the same manner as in 2. The weight average molecular weight immediately before addition of 2,2-bishydroxymethylbutanol tris [3- (1-aziridinyl) propionate] was 50,000, and the weight average molecular weight of the polymer isolated by reacting for 2 hours after the addition was 176, It was 000.

Example 59 Instead of 1,4-butanediol, 2-pyrrolidone
An experiment was conducted in the same manner as in Example 52 except that 2 g was used.
The weight average molecular weight immediately before the addition of 2-pyrrolidone is 50,000.
The weight average molecular weight of the polymer isolated was 0, and the polymer was isolated by reacting for 2 hours after the addition was 185,000.

Example 60 The same as Example 52 except that 0.1 g of 1,4-dioxanone was used in place of 1,4-butanediol and the reaction time after addition of 1,4-dioxanone was 5 hours. Made by way. The weight average molecular weight immediately before the addition of 1,4-dioxanone was 50,000, and the weight average molecular weight of the polymer isolated after reacting for 5 hours after the addition was 169,000.

Example 61 The procedure of Example 52 was repeated, except that 0.1 g of diethylene glycol bischloroformate was used instead of 1,4-butanediol. The weight average molecular weight immediately before the addition of diethylene glycol bischloroformate is 5
5,000, and the polymer isolated by reacting for 2 hours after the addition had a weight average molecular weight of 184,000.

Comparative Example 1 75.0 g of 90% L-lactic acid was added at 140 ° C./160 mmHg.
After heating and stirring for 3 hours while removing water outside the system, heating and stirring was further continued at 220 ° C./10 mmHg. After a reaction time of 20 hours, sampling was performed and the molecular weight was measured. As a result, the weight average molecular weight was 7,000. Add 0.75 g of xylene diisocyanate to the reaction mass and add 2.
The reaction was continued at 20 ° C./nitrogen atmosphere. After the addition of xylene diisocyanate, sampling was performed over time to measure the weight average molecular weight.
It was 17,000 at 6,000 and 8 hours. Since the molecular weight of the polyhydroxycarboxylic acid before the addition of diisocyanate is low, many molecular terminals remain, and it is considered that the molecular weight did not increase sufficiently because a large amount of condensed water was generated and reacted with the isocyanate group.

Comparative Example 2 An experiment was conducted in the same manner as in Comparative Example 1 except that the amount of xylene diisocyanate added was 2.25 g. The weight average molecular weight immediately before the addition of xylene diisocyanate was 7,000. When the weight average molecular weight was measured by sampling the xylene diisocyanate over time and measuring the weight average molecular weight,
Reaction time 2 hours 20,000, 8 hours 21,000
Met. Since the molecular weight of the polyhydroxycarboxylic acid before the addition of diisocyanate is low, many molecular terminals remain, and it is considered that the molecular weight did not increase sufficiently because a large amount of condensed water was generated and reacted with the isocyanate group.

Comparative Example 3 An experiment was conducted in the same manner as in Comparative Example 1 except that the amount of xylene diisocyanate added was 3.75 g. The weight average molecular weight immediately before the addition of xylene diisocyanate was 7,000, and the addition of xylene diisocyanate was followed by sampling over time to measure Mw.
It was 22,000 hours and 23,000 hours in 8 hours.
Since the molecular weight of the polyhydroxycarboxylic acid before the addition of diisocyanate is low, many molecular terminals remain, and it is considered that the molecular weight did not increase sufficiently because a large amount of condensed water was generated and reacted with the isocyanate group.

Comparative Example 4 An experiment was conducted in the same manner as in Comparative Example 1 except that 81 g of 70% glycolic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of xylene diisocyanate was 6,000, and the addition of xylene diisocyanate was followed by sampling over time to measure Mw.
It was 19,000 hours and 19,000 hours.
Since the molecular weight of the polyhydroxycarboxylic acid before the addition of diisocyanate is low, many molecular terminals remain, and it is considered that the molecular weight did not increase sufficiently because a large amount of condensed water was generated and reacted with the isocyanate group.

Comparative Example 5 An experiment was conducted in the same manner as in Comparative Example 1 except that 75 g of 90% DL-lactic acid was used instead of L-lactic acid. The weight average molecular weight immediately before the addition of xylene diisocyanate was 7,000, and the addition of xylene diisocyanate was followed by sampling over time to measure Mw.
It was 18,000 hours and 19 hours in 8 hours.
Since the molecular weight of the polyhydroxycarboxylic acid before the addition of diisocyanate is low, many molecular terminals remain, and it is considered that the molecular weight did not increase sufficiently because a large amount of condensed water was generated and reacted with the isocyanate group.

Comparative Example 6 Instead of L-lactic acid, 90% L-lactic acid 67.5 g and 70%
An experiment was conducted in the same manner as in Comparative Example 1 except that 8.1 g of glycolic acid was used. The weight average molecular weight immediately before the addition of xylene diisocyanate was 7,000, and after the addition of xylene diisocyanate, sampling was performed with time to obtain Mw.
The reaction time was 2 hours and 21,000 and 8
It was 22,000 hours. Since the molecular weight of the polyhydroxycarboxylic acid before the addition of diisocyanate is low, many molecular terminals remain, and it is considered that the molecular weight did not increase sufficiently because a large amount of condensed water was generated and reacted with the isocyanate group.

Comparative Example 7 In the same manner as in Example 1, 75.0 g of 90% L-lactic acid was added at 140 ° C.
/ 160 mmHg for 3 hours while heating and stirring while removing water to the outside of the system, and then 325 g of o-dichlorobenzene,
Add 0.4 g of tin powder and add 75 g of molecular sieve 3A
A tube filled with was attached so that the solvent distilled out by reflux returned to the system through the molecular sieve, and the reaction condition was set to 130 ° C./15 mmHg for reaction. When the relationship between the reaction time and the molecular weight was examined by sampling with time, a weight average molecular weight of 50
000, reaction time 15 hours 100,000, reaction time 20 hours 150,000, reaction time 30 hours 25
Although it reached to 10,000, it can be seen that it is necessary for a long time to obtain a polymer having a high molecular weight as compared with Example 1.

Comparative Example 8 The same experiment as in Comparative Example 7 was conducted except that 81 g of 70% glycolic acid was used instead of 90% L-lactic acid. When the relationship between the reaction time and the molecular weight was examined by sampling over time, a weight average molecular weight of 49.00 was obtained after a reaction time of 8 hours.
0, reaction time 15 hours 89,000, reaction time 20 hours 135,000, reaction time 30 hours 210,00
Although it reached 0, it can be seen that it is necessary for a long time to obtain a high molecular weight polymer as compared with Example 14.

Comparative Example 9 An experiment was performed in the same manner as in Comparative Example 7 except that 75 g of 90% DL-lactic acid was used instead of 90% L-lactic acid. When the relationship between the reaction time and the molecular weight was examined by sampling over time, a weight average molecular weight of 49,000 was obtained when the reaction time was 8 hours.
The reaction time of 15 hours reached 98,000, the reaction time of 20 hours reached 144,000, and the reaction time of 30 hours reached 260,000, which is longer than that of Example 15 in order to obtain a high molecular weight polymer. I understand.

Comparative Example 10 Instead of L-lactic acid, 90% L-lactic acid 67.5 g and 70%
An experiment was conducted in the same manner as in Comparative Example 7 except that 8.1 g of glycolic acid was used. When the relationship between the reaction time and the molecular weight was examined by sampling over time, the weight average molecular weight was 51,000 at a reaction time of 8 hours and 85.0 at a reaction time of 15 hours.
00, reaction time 20 hours 126,000, reaction time 3
Although it reached 235,000 at 0 hour, it can be seen that it is necessary for a long time to obtain a polymer having a high molecular weight as compared with Example 16.

[0137]

EFFECT OF THE INVENTION The molecular weight of polyhydroxycarboxylic acid can be efficiently and dramatically increased in a short time by a simple method. The process is simple, only added during the reaction, does not affect the isolation and purification steps, and is a method industrially suitable.

   ─────────────────────────────────────────────────── ─── Continued front page    (31) Priority claim number Japanese Patent Application No. 6-292775 (32) Priority date November 28, 1994 (November 28, 1994) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 6-303410 (32) Priority date December 7, 1994 (December 1994) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 6-303411 (32) Priority date December 7, 1994 (December 1994) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 6-318188 (32) Priority date December 21, 1994 (December 21, 1994) (33) Priority claiming country Japan (JP) (72) Inventor Mitsuhiko Miyamoto               Mitsuihigashi, 30 Asamu-cho, Omuta-shi, Fukuoka               Pressure Chemical Co., Ltd. (72) Inventor Shoji Obuchi               Mitsuihigashi, 30 Asamu-cho, Omuta-shi, Fukuoka               Pressure Chemical Co., Ltd. (72) Inventor Masahiro Ota               Mitsuihigashi, 30 Asamu-cho, Omuta-shi, Fukuoka               Pressure Chemical Co., Ltd.                (56) References JP-A-6-65360 (JP, A)                 JP-A-5-148352 (JP, A)

Claims (8)

(57) [Claims] 1. A hydroxycarboxylic acid or its oligomer is dehydrated and condensed in a reaction liquid containing the hydroxycarboxylic acid or its oligomer and an organic solvent in the substantial absence of water to give a weight average molecular weight of 50,000. The above polyhydroxycarboxylic acid is obtained, and then the reaction mixture containing the polyhydroxycarboxylic acid is added to (1) a polyvalent isocyanate compound, (2) a polybasic acid anhydride, (3) a cyclic iminoester, (4) ) Cyclic imino ethers,
(5) Aromatic hydroxycarboxylic acid, (6) Polyvalent amine compound, (7) Polyhydric alcohol, (8) Epoxy compound, (9) Polyfunctional aziridine compound, (10) Lactam, (11) Lactone And (12) a polyhydroxycarboxylic acid having a weight average molecular weight of 100,000 or more by adding and reacting one or more binders selected from diethylene glycol bischloroformate Method for producing hydroxycarboxylic acid. 2. The reaction solution, wherein at least a part of the organic solvent is removed, and an additional organic solvent having a water content less than or equal to that of the removed organic solvent is charged to the reaction solution. The method described. 3. The method according to claim 2, wherein the organic solvent removed from the reaction solution is brought into contact with a desiccant to remove water, and is returned to the reaction solution as an additional solvent. 4. The method according to claim 3, wherein the desiccant is a molecular sieve. 5. The method according to claim 2, wherein the water content of the organic solvent additionally inserted into the reaction solution is 50 ppm or less. 6. The organic solvent is one or more organic solvents selected from hydrocarbon compounds, halogenated hydrocarbon compounds, ether compounds, ester compounds and ketone compounds . The method according to 2, 3, 4 or 5. 7. Sn, T as a catalyst for dehydration condensation
The method according to claim 2 , 3, 4, 5 or 6 , which is carried out in the presence of a metal selected from i and Ni or a compound thereof. 8. claim 1 hydroxycarboxylic acid is a mixture of lactic acid or lactic acid and other hydroxycarboxylic acid, 2,3,4,5,6 or 7 The method according.