JPH11181034A - Biodegradable elastic body and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a biodegradable elastic body concurrently having rubber elasticity and biodegradability, and to provide a method for producing the same. SOLUTION: This biodegradable elastic body is obtained by subjecting (A) at least one kind selected from the group consisting of (a1) an aliphatic polyfunctional alcohol and an aliphatic unsaturated polybasic acid, (a2) an aliphatic unsaturated oligoester and (a3) an aliphatic unsaturated polyester, and (B) at least one kind selected from the group consisting of (b1) an aliphatic polyfunctional alcohol and an aliphatic saturated polybasic acid, (b2) an aliphatic hydroxycarboxylic acid, (b3) an aliphatic saturated oligoester and (b4) an aliphatic saturated polyester to a heating dehydration reaction in an organic solvent in the presence of a catalyst and a polymerization inhibitor while removing at least a part of the organic solvent containing generated water and/or excess monomer from the reaction mixture, and charging additive organic solvent containing water and/or the monomer in a concentration lower than or equal to the concentration of water and/or monomer contained in the removed organic solvent to the reaction mixture to obtain an aliphatic polyester containing the aliphatic unsaturated polybasic acid, and crosslinking the aliphatic polyester as a polymer constituting component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a biodegradable elastic body and a method for producing the same. The biodegradable elastic body according to the present invention is characterized in that an aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component is crosslinked. The biodegradable elastic body according to the present invention can provide a molded product or a processed product utilizing advantageous characteristics.

[0002]

2. Description of the Related Art As is well known, aliphatic polyhydric alcohols and aliphatic polybasic acids have a high molecular weight (here, the high molecular weight is about 15,000 or more in terms of weight average molecular weight).
Several methods for synthesizing aliphatic polyesters are known.

[0003] The inventors of the present application have already disclosed in Japanese Patent Application Laid-Open No. 7-228675 and US Pat. No. 5,401,796.
No. 796, an aliphatic polyhydric alcohol or a mixture thereof and an aliphatic polybasic acid or a mixture thereof, or an oligomer thereof are converted into an organic solvent (preferably, anisole,
Phenetol, diphenyl ether, etc.) in a reaction mixture containing water and an excess of monomer being distilled out of the reaction system together with an organic solvent, while being subjected to heavy direct heat dehydration condensation reaction. , 0
A technique for producing 00 or more aliphatic polyesters has been disclosed. According to this technique, it is possible to provide an aliphatic polyester useful for medical use, which has a high molecular weight, contains no impurities, has a low coloring degree, and is hydrolyzed and absorbed even in a living body. However, among these techniques, only aliphatic saturated polyesters are disclosed, and there is no disclosure or suggestion of aliphatic unsaturated polyesters or biodegradable elastic materials having different chemical properties.

[US Pat. No. 4,888,413] US Pat. No. 4,888,413 discloses that the weight average molecular weight is about 5%.
Techniques relating to a poly (propylene glycol fumarate) composition of 00 to 3000 are disclosed. According to this technique, the ratio of the terminal groups, the weight average molecular weight and the number average molecular weight are specified, and the mechanical properties and biodegradability are improved,
It is possible to provide a composition having high reproducibility and useful for biomedical applications such as bone cement. However, there is no disclosure or suggestion of a biodegradable elastic body in this technology.

[Japanese Patent Laid-Open No. Hei 7-133333]
No. 133333 discloses (A) 95-99.9 mol% of an aliphatic saturated dicarboxylic acid (or anhydride), 0.1-5 mol% of an aliphatic unsaturated dicarboxylic acid (or anhydride), and (B) an aliphatic unsaturated dicarboxylic acid (or anhydride). Alternatively, an unsaturated polyester [I] having a weight average molecular weight of 30,000 or more obtained by polycondensation with a cycloaliphatic polyhydric alcohol and an unsaturated group capable of polymerizing at least 1 equivalent to 100 equivalents of the terminal group (C). And (D) an unsaturated unsaturated polyester composition obtained by mixing a polyester [II] having a weight average molecular weight of 30,000 or more and copolymerizing unsaturated bonds with each other using an organic peroxide. Have been. According to this technique, it is possible to provide a method for producing a biodegradable high molecular weight polyester having practically sufficient physical properties, stably increasing the weight average molecular weight as compared with the number average molecular weight, and suppressing variation in viscosity. it can.
In addition, there is no disclosure of a technique for efficiently subjecting an aliphatic polyester containing an unsaturated bond to condensation polymerization to form a biodegradable elastic body.

[0006]

The problem to be solved by the present invention is that under natural environment, under compost conditions,
It has excellent degradability under hydrolysis conditions, and furthermore, conventionally used elastomers (for example, elastic bodies such as natural rubber, synthetic rubber, and silicone rubber)
An object of the present invention is to provide a biodegradable elastic body having substantially the same rubber elasticity as the above.

The present inventors have conducted intensive studies on a method for producing a high-molecular-weight aliphatic polyester containing an aliphatic polyhydric alcohol and an aliphatic polybasic acid as polymer constituents. By cross-linking a high-molecular-weight aliphatic polyester having an unsaturated bond in the synthesized molecule, it was found that an elastic body having both excellent degradability and excellent rubber properties was obtained, which led to the completion of the present invention. Was.

[0008]

Means for Solving the Problems The invention according to the present application is specified by the following items [1] to [22]. [1] A method for producing a biodegradable elastic body, comprising crosslinking an aliphatic polyester containing an aliphatic unsaturated polybasic acid synthesized in the presence of a polymerization inhibitor as a polymer component.

[2] The method for producing a biodegradable elastic body according to [1], wherein the polymerization inhibitor is at least one selected from quinones, hydroquinones, phenols, and amine hydrochlorides.

[3] The method for producing a biodegradable elastic body according to [2], wherein the polymerization inhibitor is a hydroquinone. [4] The method for producing a biodegradable elastic body according to [3], wherein the polymerization inhibitor is hydroquinone.

[5] The aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer constituent component is (a1) an aliphatic polyhydric alcohol and an aliphatic unsaturated polybasic acid,
2) at least one (A) selected from the group consisting of an aliphatic unsaturated oligoester, (a3) an aliphatic unsaturated polyester, and (b1) an aliphatic polyhydric alcohol and an aliphatic saturated polybasic acid, b2) aliphatic hydroxycarboxylic acid (b3) aliphatic saturated oligoester, (b
4) A reaction mixture of at least one type (B) selected from the group consisting of aliphatic saturated polyesters in an organic solvent in the presence of a catalyst in the presence of a catalyst and at least a part of an organic solvent containing water and / or excess monomer. Obtained by performing a heat dehydration reaction while charging an additional organic solvent having a water and / or monomer concentration less than or equal to the water and / or monomer concentration contained in the removed organic solvent into the reaction mixture. The method for producing a biodegradable elastic body according to [1], which is an aliphatic unsaturated polyester.

[6] An aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component is 15,000.
The method for producing a biodegradable elastic body according to any one of [1] to [5], having the above weight average molecular weight.

[7] The aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component is an amorphous polymer having a glass transition temperature of 25 ° C. or less. [1]
The method for producing a biodegradable elastic body according to any one of claims 1 to 6.

[8] The polymer according to any one of [1] to [7], wherein the aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component is a crystalline polymer having a melting point of 25 ° C. or less. Of producing a biodegradable elastic body.

[9] the aliphatic unsaturated polybasic acid is at least one selected from the group consisting of fumaric acid, maleic acid, itaconic acid, citraconic acid and anhydrides thereof; 1] The method for producing a biodegradable elastic body according to any one of [8].

[10] An aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component contains an ethylene glycol polymer represented by the general formula (1) [Chemical Formula 2] as a polymer component. Characterized in that
The method for producing a biodegradable elastic body according to any one of [1] to [8].

[0017]

Embedded image HO — (— CH 2 CH 2 O—) n —H (1) (2 ≦ n ≦ 10) [11] n is 2 ≦ n ≦ 3, described in [9]. Of producing a biodegradable elastic body.

[12] The method for producing a biodegradable elastic body according to any one of [1] to [10], wherein the crosslinking is performed by thermal polymerization. [13] The method for producing a biodegradable elastic body according to any one of [1] to [10], wherein the crosslinking is performed by photopolymerization. [14] The method for producing a biodegradable elastic body according to any one of [1] to [10], wherein the crosslinking is performed by electron beam polymerization. [15] The method for producing a biodegradable elastic body according to any one of [1] to [13], wherein a polymerization initiator and / or a sensitizer is used for crosslinking.

[16] The method according to any one of [1] to [15], wherein the amount of the polymerization initiator and / or the sensitizer is at least equimolar to the polymerization inhibitor contained in the aliphatic polyester. A method for producing a biodegradable elastic body. [17] A biodegradable elastic body obtained by the production method according to any one of [1] to [16]. [18] The elastic modulus at 25 ° C. is 1 × 10 ⁵ [P
a] The biodegradable elastic body according to [17], which is not less than 1 × 10 ⁸ [Pa]. [19] The biodegradable elastic body according to [18], wherein a hardness evaluated by a hardness test specified in JIS-K-6301 is 80 or less.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The biodegradable elastic body according to the present invention comprises:
In a preferred embodiment, it is obtained by crosslinking an aliphatic polyester containing an aliphatic unsaturated polybasic acid having a weight average molecular weight of 15,000 or more as a polymer component. In the present invention, the aliphatic polyester containing an aliphatic unsaturated polybasic acid used as a polymer component may be an aliphatic unsaturated polybasic acid or an aliphatic unsaturated polybasic acid and an aliphatic unsaturated polybasic acid as the polybasic acid. It is obtained by polycondensing a mixture of basic acids with an aliphatic polyhydric alcohol. Further, an aliphatic hydroxycarboxylic acid may be contained as a polymer component.

[Polymerization Inhibitor] The polymerization inhibitor used in the present invention suppresses radical polymerization, and specifically includes quinone-based compounds such as parabenzoquinone, naphthoquinone, and 2,5-diphenylparabenzoquinone. , Hydroquinones such as hydroquinone, para-t-butylcatechol and mono-t-butylhydroquinone; phenols such as di-t-butylparacresol and α-naphthol; amine hydrochlorides such as triethylamine salts and dimethylaniline hydrochloride; Is mentioned. Further, these compounds may be used as a mixture. Preferably, a hydroquinone-based compound, particularly preferably, hydroquinone is used. The amount of the polymerization inhibitor used is 0.001 to 5 mol%, preferably 0.005 to 3 mol%, more preferably 0.05 to 3 mol%.
It is 0.5 to 2 mol%. If the amount used is small, the viscosity of the liquid increases during the polymerization, stirring becomes difficult, and the decatalyzing treatment and the concentration operation of the reaction liquid become difficult. Furthermore, mixing with a plasticizer or an initiator for cross-linking becomes difficult, and the elastic body becomes non-uniform, so that a desired elastic body cannot be obtained. [Aliphatic unsaturated polybasic acid] As the aliphatic unsaturated polybasic acids used in the present invention, dibasic acids are generally preferred. Specific examples of the aliphatic polybasic acids used in the present invention,
Examples include fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, and citraconic anhydride. In general, the amount of the aliphatic unsaturated polybasic acid used in the present invention is preferably 0.1 to 20 mol% of the polybasic acid used, and
10 mol% is more preferable, and 1 to 5 mol% is further preferable.

[Aliphatic saturated polybasic acids] Specific examples of the aliphatic saturated polybasic acids used in the present invention include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid and suberic acid. , Azelaic acid, sebacic acid, and anhydrides thereof.
The aliphatic saturated polybasic acids used in the present invention may contain a small amount of trifunctional or higher polybasic acids such as butanetetracarboxylic acid.

[Polyhydric alcohol] As the polyhydric alcohol used in the present invention, a bifunctional alcohol is generally preferred. Specific examples of the polyhydric alcohols used in the present invention include, for example, ethylene glycol, diethylene glycol, triethylene glycol,
Polyethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4
-Butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, polytetramethylene glycol and the like. Further, it may contain a small amount of trifunctional or higher alcohol such as glycerin and trimethylolpropane. Among these, generally, a polymer of ethylene glycol represented by the general formula (1) [Formula 3] is preferable, and diethylene glycol and triethylene glycol are particularly preferable.

[0024]

HO-(-CH2CH2O-) n-H (1) (2≤n≤10)

[Hydroxycarboxylic acid] Specific examples of the hydroxycarboxylic acid used in the present invention include, for example, glycolic acid, lactic acid, 6-hydroxycaproic acid or a combination of at least two or more of these cyclic esters. Can be In particular, a combination of components of lactic acid and 6-hydroxycaproic acid is preferred. The composition ratio is preferably 30 to 70 mol% of lactic acid and 70 to 30 mol% of 6-hydroxycaproic acid.
More preferably, 0 mol% and 50 mol% of 6-hydroxycaproic acid are used. As a combination of these components, when the resulting aliphatic polyester is a crystalline polymer,
Those having a melting point of 25 ° C. or lower are preferable, and those having an amorphous polymer having a glass transition point of 25 ° C. or lower are preferable. For example, polyester with a mixture of diethylene glycol and succinic acid and fumaric acid, polyester with a mixture of triethylene glycol and succinic acid and fumaric acid, polyester with a mixture of diethylene glycol and adipic acid and fumaric acid, triethylene glycol and adipic acid And polyesters with a mixture of fumaric acid. For example, polyester of a mixture of lactic acid, 6-hydroxycaproic acid, itaconic acid and triethylene glycol, polyester of a mixture of lactic acid, 6-hydroxycaproic acid, itaconic acid and diethylene glycol, lactic acid, 6-hydroxycaproic acid and fumaric acid And a mixture of diethylene glycol and the like.

[Production Method of Aliphatic Polyester Containing Aliphatic Unsaturated Polybasic Acid] The aliphatic polyester containing an aliphatic unsaturated polybasic acid of the present invention is not particularly limited, and may be produced by any production method. May be used. For example, a method of producing by esterification of an aliphatic polyhydric alcohol and an aliphatic polybasic acid followed by a deglycolization reaction under a high vacuum, or US Pat. No. 5,401,796.
Polyhydric alcohol and an aliphatic polybasic acid, or (a1) an aliphatic polyhydric alcohol and an aliphatic unsaturated polyether according to the method for producing an aliphatic polyester described in US Pat. (A2) at least one member selected from the group consisting of (a2) an aliphatic unsaturated oligoester, and (a3) an aliphatic unsaturated polyester; and (b1) an aliphatic polyhydric alcohol and aliphatic saturation. A method of dehydrating and condensing at least one kind (B) selected from the group consisting of polybasic acids, (b2) aliphatic saturated oligoesters, and (b3) aliphatic saturated polyesters in an organic solvent in the presence of a catalyst. Can be manufactured.

Particularly, a method of performing dehydration condensation in the presence of an organic solvent is advantageous in terms of equipment. In this method, the produced water and / or excess monomer is distilled out of the reaction system together with the organic solvent, and water and / or water dissolved in the distilled organic solvent are dissolved.
Alternatively, a high molecular weight aliphatic polyester is obtained by reacting while charging an organic solvent containing water and / or a monomer having an amount of the monomer or less as an additional solvent into the reaction system. Generally, 1 × 10 -5 to 1 × 1 per gram
Those having 0-2 moles of unsaturated bonds are preferred. Aliphatic polyester containing an aliphatic unsaturated polybasic acid of the present invention,
In general, those having 1 × 10 −5 to 1 × 10 −3 mol of unsaturated bonds per gram are preferred.

[Organic Solvent] Specific examples of the organic solvent used in the present invention include, for example, toluene, xylene,
Hydrocarbon solvents such as mesitylene, chlorobenzene, bromobenzene, iodobenzene, dichlorobenzene, 1,
Halogen-based solvents such as 1,2,2-tetrachloroethane, p-chlorotoluene, 3-hexanone, acetophenone,
Ketone solvents such as benzophenone, dibutyl ether,
Anisole, phenetole, o-dimethoxybenzene,
ether solvents such as p-dimethoxybenzene, 3-methoxytoluene, dibenzyl ether, benzyl phenyl ether, methoxy naphthalene, phenyl sulfide,
Thioether solvents such as thioanisole, methyl benzoate, methyl phthalate, ester solvents such as ethyl phthalate, diphenyl ether, or 4-methylphenyl ether, 3-methylphenyl ether, alkyl-substituted diphenyl ether such as 3-phenoxytoluene, or ,
4-bromophenyl ether, 4-chlorophenyl ether, 4-bromodiphenyl ether, 4-methyl-
Halogen-substituted diphenyl ether such as 4'-bromodiphenyl ether, or alkoxy-substituted diphenyl ether such as 4-methoxydiphenyl ether, 4-methoxyphenyl ether, 3-methoxyphenyl ether, 4-methyl-4'-methoxydiphenyl ether, or dibenzofuran, xanthene And diphenyl ether solvents such as cyclic diphenyl ethers, and these may be used as a mixture. As the solvent, those which can be easily separated and separated from water are preferable.Especially, in order to obtain an aliphatic polyester containing an aliphatic unsaturated polybasic acid having a high average molecular weight, an ether solvent, an alkyl-aryl ether solvent and diphenyl ether are used. Solvents are more preferred, but alkyl-aryl ether solvents and diphenyl ether solvents are particularly preferred. The use amount of these solvents is preferably 10 to 80% in terms of the concentration of the obtained polymer.

[Distillation of generated water and / or excess monomer out of the reaction system] In this method, in order to distill the generated water and / or excess monomer out of the reaction system, the organic solvent used and It is preferable to use azeotropic distillation with water or a monomer. If the amount of water or monomer contained in the organic solvent distilled off by azeotropic distillation is greater than the solubility of water or monomer in the organic solvent, the water or monomer may be removed by liquid separation and then returned to the reaction system, Further, in order to remove water or the monomer dissolved in the used organic solvent, dehydration, treatment with a demonomerizing agent, or reduction of the content of water or the monomer by distillation or the like may be performed before returning to the reaction system.
Instead of the organic solvent distilled off by azeotropic distillation, fresh water or an organic solvent having a low monomer content may be charged. Further, water or excess monomer is removed under reduced pressure at the beginning of the reaction, and then an organic solvent is added, and a part of the organic solvent is removed from the reaction mixture containing the organic solvent, whereby water or monomer in the reaction mixture is removed. It may be a predetermined value.

That is, the condensation reaction proceeds at least at a certain stage of the reaction while using a solvent to remove water or the monomer. In this embodiment, the solvent may or may not azeotrope with the water or the monomer. It may or may not separate with water or monomer.
Further, other embodiments include a method in which an excess solvent is charged in advance and dehydration is performed by simply extracting the solvent, a method in which the reaction solvent is dried using another solvent, and the like. As a further modification, moisture may be removed while the reaction solvent itself remains liquid. Further, regarding the reaction temperature of the present invention,
Since the solvent azeotropes with water, the reaction may be performed at a predetermined temperature even if the boiling point is lowered.

[Weight average molecular weight] The average molecular weight of the aliphatic polyester containing an aliphatic unsaturated polybasic acid also depends on the amount of water or monomer of the organic solvent charged into the reaction system, and depends on the type of the solvent. When the solvent has a high water content of 400 to 500 ppm, the weight average molecular weight of the aliphatic polyester containing the aliphatic unsaturated polybasic acid obtained is 10.0 or less.
00 or less. It is surprising that aliphatic polyesters containing an aliphatic unsaturated polybasic acid having a weight average molecular weight of 15,000 or more can be obtained by using a diphenyl ether-based solvent or orthodichlorobenzene or the like even with the above high water content and high monomer content. is there. In order to obtain an aliphatic polyester containing an aliphatic unsaturated polybasic acid having a higher average molecular weight, it is desirable that the amount of water or monomer in the organic solvent to be charged into the reaction system be low, and the organic solvent distilled off by azeotropic distillation. Is dehydrated, treated with a demonomerizing agent to remove or reduce water, and returned to the reaction system, or by charging a new organic solvent having a low water content to reduce the amount of water or monomer to be charged to 500.
It is possible to obtain an aliphatic polyester containing an aliphatic unsaturated polybasic acid having a weight average molecular weight of not more than 15,000 and a weight average molecular weight of 15,000 or more. Further, by setting the water content to 50 ppm or less, an aliphatic polyester containing an aliphatic unsaturated polybasic acid having a weight average molecular weight of 50,000 or more can be obtained.

[Dehydrating Agent / Demonomerizing Agent] Specific examples of the dehydrating agent / demonomerizing agent used to obtain an aliphatic polyester containing an aliphatic unsaturated polybasic acid having a high average molecular weight include, for example, molecular sieve 3A, Molecular sieves such as molecular sieve 4A, molecular sieve 5A, molecular sieve 13X, alumina, silica gel, calcium chloride, calcium sulfate, diphosphorus pentoxide,
Concentrated sulfuric acid, magnesium perchlorate, barium oxide, calcium oxide, potassium hydroxide, sodium hydroxide, or metal hydride such as calcium hydride, sodium hydride, lithium aluminum hydride, or alkali metal such as sodium Among these, molecular sieves are generally preferred from the viewpoint of ease of handling and regeneration.

[Reaction conditions] The reaction temperature in this method is preferably from 80 to 200 ° C. in consideration of the production rate of the polymer and the thermal decomposition rate of the produced polymer.
More preferably, it is 110-170 degreeC. The condensation reaction is usually performed at normal pressure at the distillation temperature of the organic solvent used. When a high-boiling organic solvent is used to adjust the reaction temperature to a preferable range, the reaction may be performed under reduced pressure. When a low-boiling organic solvent is used, the reaction may be performed under pressure.

[Catalyst] In this reaction, a catalyst may or may not be used.
Examples include metals of groups II, III, IV, and V of the periodic table, oxides thereof, and salts thereof. Specific examples of the catalyst include, for example, metals such as zinc powder, tin powder, aluminum, magnesium, titanium, and germanium; metal oxides such as tin oxide, antimony oxide, zinc oxide, aluminum oxide, magnesium oxide, and titanium oxide; Metal halides such as stannous, stannic chloride, stannous bromide, stannic bromide, antimony fluoride, zinc chloride, magnesium chloride and aluminum chloride, and sulfuric acid such as tin sulfate, zinc sulfate and aluminum sulfate Salts, carbonates such as magnesium carbonate, zinc carbonate, etc., organic carboxylate salts such as tin acetate, tin octoate, zinc acetate, aluminum acetate, tin trifluoromethanesulfonate, zinc trifluoromethanesulfonate, magnesium trifluoromethanesulfonate, methane Organic sulfonates such as tin sulfonate, tin p-toluene sulfonate and the like. That. Other specific examples of the catalyst include, for example, an organometallic oxide of the above metal such as dibutyltin oxide, or a metal alkoxide of the above metal such as titanium isopropoxide, or an alkyl metal of the above metal such as diethylzinc, Alternatively, an ion exchange resin such as Dowex or Amberlite may be used. The amount used is preferably 0.0001 to 10% by weight of the aliphatic polyhydric alcohol and aliphatic polybasic acid used, or an oligomer thereof, and is preferably 0.001 to 2% by weight in view of economy.

[Operation of Reaction] This reaction is preferably carried out in an inert gas atmosphere so that moisture does not enter from outside the system, and the reaction is carried out while substituting with an inert gas or bubbling with an inert gas. You may go while doing. In this method, the reaction can be performed while distilling the water or the monomer generated in the reaction together with the organic solvent out of the reaction system.Preferably, the generated water or the monomer is distilled out of the reaction system together with the organic solvent, The reaction can be carried out while charging an organic solvent having the same or lower water or monomer amount as water or a monomer dissolved in the distilled organic solvent into the reaction system.A preferred example of the embodiment is diethylene glycol and It is described below using succinic acid and fumaric acid in a molar ratio of 9: 1.

A water separator (eg, Dean Stark)
and a predetermined amount of diethylene glycol, succinic acid, fumaric acid, and a predetermined amount of a catalyst and a polymerization inhibitor. The reactor is heated, and the generated water is distilled off. Guide to separator. Water having a solubility equal to or higher than the solubility of the solvent is separated by a water separator and removed outside the system, and the solvent containing water for the solubility is returned to the reaction system. At this stage, diethylene glycol and succinic acid and fumaric acid are oligomerized. The weight average molecular weight at this stage is 500 to 1,000.
0 and the weight average molecular weight may be up to about 5,000. The reaction time during this period is approximately 0.5 hours to several hours. This oligomerization reaction may be carried out in advance in another reactor without solvent, without catalyst or under reduced pressure, or may be carried out without solvent using a solvent. At the solvent distillation temperature as it is, the water generated as the reaction proceeds may be removed, and the reaction may be continued while returning the solvent saturated with water to the reaction system.However, after reacting for several hours, depending on the type of the solvent, Those having a weight average molecular weight of 15,000 to 50,000 are obtained. To obtain a higher molecular weight polymer, after the water in the raw material has almost distilled off, remove the water separator,
Attach a tube filled with a desiccant such as molecular sieve and allow the solvent to be distilled to reflux through this tube, or treat the distilled solvent in another reactor containing a desiccant to react. Return to the vessel or charge the reactor with fresh low water content solvent. The amount of water dissolved in the solvent is reduced to 50 ppm or less by these methods, and the reaction is continued for several tens of hours. Thus, depending on the type of the solvent, an aliphatic unsaturated polybase having a weight average molecular weight of 50,000 to 500,000 is used. An acid can be obtained. After the reaction,
Any treatment method may be used to obtain the desired degradable polymer composition.For example, pyrophosphoric acid may be added to the reaction solution, heated, neutralized with calcium carbonate, filtered by hot filtration, and then concentrated. Thus, an aliphatic polyester containing the desired aliphatic unsaturated polybasic acid is obtained.

The weight average molecular weight of the aliphatic polyester containing an aliphatic unsaturated polybasic acid obtained by this method is determined by the type of solvent, the type and amount of catalyst, the reaction temperature, the reaction time,
Various substances can be obtained by changing the treatment method of the solvent distilled off by azeotropic distillation, but about 15,000 to 50
It is 0000.

[Removal of catalyst] In this method, when the condensation reaction is carried out in the presence of a catalyst, the remaining catalyst in the polymer may affect the thermal stability and weather resistance of the polymer. It is preferable to remove the catalyst therein. A preferred removal method is a method in which the condensation reaction solution is brought into contact with an acidic substance while stirring. Specific examples of the acidic substance include, for example, an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, pyrophosphoric acid, and polyphosphoric acid, and an organic acid such as acetic acid and p-toluenesulfonic acid. Hydrochloric acid, sulfuric acid, nitric acid and the like are preferable, and pyrophosphoric acid and polyphosphoric acid are particularly preferable. The amount of the acidic substance used is preferably 0.0001 to 5.0 mol / 100 parts by weight, more preferably 0.001 to 1 mol / 100 parts by weight, based on the polymer. Usually, when the amount is less than 0.0001 mol, the effect of removing the catalyst is deteriorated. On the contrary, when the amount is more than 5.0 mol, problems such as deterioration of the polymer may occur. Preferred conditions for contacting the polymer with the acidic substance include, for example,
The following are mentioned. Contact atmosphere: Solid content concentration in organic solvent: about 3 to 40% by weight Contact temperature: 60 to 160 ° C. (preferably 80
~ 130 ° C) Contact time 0.1 hour to 24 hours (preferably about 0.5 to 8 hours)

[Removal of acidic substance] Specific examples of the base to be neutralized include alkali metals such as calcium carbonate, potassium carbonate, magnesium carbonate, sodium hydrogen carbonate and sodium carbonate, and alkaline earth carbonates. Is mentioned. After completion of the neutralization, the insolubles are removed by filtration together with the catalyst precipitate. The amount of the base used is 1 to 1 with respect to the acidic substance.
It is 0 molar equivalent, preferably 1-3 molar equivalent.
Usually, when the amount is less than 1 molar equivalent, the acidic substance remains, which may cause a problem such as deterioration of the polymer. The conditions for neutralization with a base are the same as the conditions for contacting the polymer with the acidic substance, and the neutralization time is about 0.1 to 2 hours, particularly preferably about 0.2 to 1 hour. Also,
As an operation method other than the neutralization treatment, for example, there is an operation method of adsorbing and separating with a solid carrier. Specific examples of solid carriers that can be used include, for example, mineral products,
Any substance capable of adsorbing acidic substances such as inorganic oxide compounds and ion exchange resins may be used.Examples include diatomaceous earth, bentonite, activated clay, zinc oxide, aluminum oxide, titanium oxide, magnesium silicate, calcium phosphate, and silica gel. , Aluminum silica gel, activated carbon, zeolite, starch, cellulose and the like. Of these, mineral products such as diatomaceous earth, bentonite, and activated clay are generally preferred.

In general, the amount of the solid carrier used is preferably 0.5 to 100% by weight based on the weight of the polymer.
30% by weight is more preferred. Usually, when the amount is too small, the acidic substance cannot be adsorbed completely, and the effect of removing the catalyst is reduced. On the other hand, when the amount is too large, there is a problem that a load is imposed on the separation operation of the solid support. The adsorption time on the solid support is not particularly limited as long as the acidic substance is substantially sufficiently adsorbed on the solid support. The adsorption time on the solid carrier is generally determined by bringing the solid carrier into contact with the aliphatic polyester solution, preferably for at least 10 minutes, more preferably for at least 30 minutes, and stirring the mixture. Perform the adsorption operation. The adsorption temperature on the solid support is not particularly limited as long as the acidic substance is substantially sufficiently adsorbed on the solid support. The adsorption temperature on the solid support is generally the same as the temperature for treating with an acidic substance. Since there is an advantage that the contacting step of the acidic substance and the adsorption step to the solid carrier can be performed simultaneously, the acidic substance and the solid carrier are
The treatment may be carried out by simultaneously charging the reaction system. Alternatively, a treatment in which an acidic substance previously adsorbed on a solid carrier may be charged into a reaction system and treated.

[Urethane Bond] In the present invention, the aliphatic polyester containing an aliphatic unsaturated polybasic acid may contain a small amount of a urethane bond. In the present invention, the aliphatic polyester containing an aliphatic unsaturated polybasic acid may be one obtained by chain-extending the aliphatic polyester obtained by the above-described method with a binder such as a diisocyanate compound. The biodegradable elastic body according to the present invention is obtained by crosslinking the aliphatic polyester containing an aliphatic unsaturated polybasic acid having a weight average molecular weight of 15,000 or more thus obtained. When the weight-average molecular weight of the aliphatic polyester is lower than 15,000, usually, even if crosslinked, it has tackiness and an elastic body cannot be obtained.

[Crosslinking] In the present invention, the method of crosslinking an aliphatic polyester containing an aliphatic unsaturated polybasic acid is not particularly limited. In the present invention, specific examples of the method of crosslinking an aliphatic polyester containing an aliphatic unsaturated polybasic acid include thermal polymerization by heat, photopolymerization by ultraviolet rays, and polymerization by gamma rays. Generally, in the case of thermal polymerization, crosslinking takes several hours to several tens of hours, whereas in the case of photopolymerization, it can be cured in a few seconds to several minutes, and the scale of the required equipment For example, photopolymerization using ultraviolet light can be suitably employed. The radical generator in the thermal polymerization, that is, the radical polymerization initiator is not particularly limited, and known benzoyl peroxide, p-chlorobenzoyl peroxide, lauroyl peroxide, acetyl peroxide, di-t-butyl peroxide,
1,1-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butylperoxypivalate,
t-butylperoxy-2-ethylhexanoate, t
Peroxides such as -butylperoxybenzoate, bis (4-t-butylcyclohexyl) peroxydicarbonate, diisopropylperoxydicarbonate and t-butylperoxyisopropylcarbonate and azo compounds such as azobisisobutyronitrile; Used.
These are used alone or in combination of two or more.
These radical initiators are used in an amount of 0.00% by weight based on 100 parts by weight of the aliphatic polyester containing the aliphatic unsaturated polybasic acid.
It is used in an amount of 5 to 5 parts by weight, preferably 0.01 to 3 parts by weight, but is preferably used in an amount of at least equimolar to the polymerization inhibitor contained in the aliphatic polyester. In the case of curing by a thermal polymerization method, the polymerization temperature and the polymerization time are appropriately selected depending on the radical polymerization initiator to be used, the size of the cured product, and the like.

The radical generator, that is, the sensitizer, in the photopolymerization by ultraviolet rays is not particularly limited, and known 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, 4-t-butyl-trichloroacetophenone, Diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1one, 1-
(4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1, benzoin , Benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoisobutyl ether, benzyl dimethyl ketal, benzophenone, benzoyl benzoic acid, methyl benzoyl benzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide 3,3′-dimethyl-4-methoxybenzophenone, thioxanthone, 2-chlorothioxanthone,
2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone,
2,4-diisopropylthioxanthone, 1-phenyl-1,2-propanedione-2 (o-ethoxycarbonyl) oxime, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, methylphenylglyoxylate, benzyl, 9 , 10-phenanthrenequinone,
Camphorquinone, dibenzosuberone, 2-ethylanthraquinone, 4 ', 4 "-diethylisophthalophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, etc. are used. Are used singly or in combination of two or more.The sensitizer is an aliphatic polyester 1 containing an aliphatic unsaturated polybasic acid.
It is used in an amount of 0.005 to 5 parts by weight, preferably 0.01 to 3 parts by weight, based on 00 parts by weight. Further, the above-mentioned radical polymerization initiator can be used in combination with the sensitizer. In the polymerization by gamma rays, a radical polymerization initiator is not particularly required.

[Use] The biodegradable elastic body according to the present invention obtained according to the above disclosure has both excellent biodegradability and excellent rubber-like elasticity, and can be suitably used for various uses. it can. In a typical embodiment, the biodegradable elastic body according to the present invention has an elastic modulus at 25 ° C. of 1 × 10 ⁵ [P
a] or more and 1 × 10 ⁸ [Pa] or less. In a typical embodiment, the biodegradable elastic body according to the present invention is JIS-K
Hardness evaluated by a hardness test specified in -6301 is 80 or less. In a typical embodiment, the biodegradable elastic body according to the present invention has a hardness of 80 or less as evaluated by a hardness test specified in ASTM D 676-58T. As a method of giving the shape of a product to be put to practical use,
After cross-linking, a method of cutting or cutting into a desired shape may be used, or a method of pouring the resin before cross-linking into a mold gypsum or the like in which the shape of the product has been copied in advance and then cross-linking may be adopted.

The use of the biodegradable elastic body according to the present invention is not particularly limited, but specific examples include tires (for example, for vehicles, automobiles, inline skates,
Roller skates, casters, toys, etc., brake shoes (eg, for vehicles, automobiles, disc brakes, etc.), power transmission belts (eg, for internal combustion engines, etc.), bearing members (eg, balls and rolls) Etc.), shoe materials (eg, sole materials, heel materials, cushion materials, etc.), shoes (eg, rubber shoes, rubber boots, etc.), industrial materials, civil engineering materials, general materials (eg, non-slip materials) Timber,
Insulation material, sliding material, rubberized cloth, pylon, rubber hose,
Rubber sheets, rubber pipes, flexible pipes, rubber rolls, helmets, vibration proof materials, seismic materials, seismic isolation materials, paints, adhesives, etc., grip materials (eg, grip materials for baseball bats, golf clubs, etc.), binding materials (Eg, rubber bands, hair bands, etc.), canvas (eg, sail boats, yachts, board sailing, hang gliders, etc.), clothing supplies (eg, belts, hats, raincoats, ponchos, etc.), thread rubber materials Gather materials (eg diapers, socks,
Underwear, thread rubber materials and gather materials for sanitary products, etc., elastic materials for women's foundations (eg, girdle,
Elastic materials for brassiere, lingerie, slips, etc.), covering materials / insulating materials (eg, covering materials / insulating materials such as electric wires, cables, optical fibers, etc.), sealing materials (eg, packing materials, O-rings, rubber stoppers) , Lining materials for crowns and screw caps, linings, sealing materials, caulking materials, putty materials, etc.), cushioning materials, cushioning materials, absorbent materials (for example, sponge, foam rubber, mattress,
Foams, nets, etc.), rubber products for contraception (eg, condoms, pessaries, rings, etc.), fishing gear (eg, lures, artificial baits, floats, rods, etc.), fishing goods (eg, aba, buoys, toro boxes) Hunting equipment (eg, decoys, shot cartridges, etc.), mountaineering equipment (eg, mountain climbing shoes, trekking boots, etc.), camping equipment (eg, tents, tents, etc.), marine leisure goods / sports goods (eg, swimwear, Uniform, etc.), ball (for example, baseball, golf,
Balls used for soccer, rugby, volleyball, basketball, bowling, etc.), ice hockey equipment (eg, pucks, armor such as helmets, face guards, leg guards, shoulder guards, gloves,
Mitts, sticks, skates, mouthpieces, etc.),
Baseball equipment (for example, armor such as helmet, mask, leg guard, glove, mitt, bat, spike shoes, etc.), ski / snowboard equipment (for example, ski shoes,
Snowboard shoes, goggles, stocks, etc.), toys (eg, balloons, rubber dolls, etc.), childcare products (eg, nipples (nipples), shovels, tooth compaction, etc.), stationery (eg,
Erasers, writing implement shafts), cooking utensils (eg, spatula, tongues, etc.), automotive parts and components (eg, steering,
Console box, dashboard, armrest,
Mudguard, fender, child seat, etc.), ISF
Alternatives to general-purpose resins such as (internal skin foam) can be mentioned. The biodegradable elastic body according to the present invention is not limited to the above specific examples, and can be suitably used for various applications by utilizing its excellent properties.

[Additives] The biodegradable elastic body according to the present invention is used for various applications.
Fillers, plasticizers, release agents, thickeners, coloring agents, and the like can be used in combination. In order to facilitate the processability of the biodegradable elastic body according to the present invention and to further improve the physical properties for special applications, a filler can be blended. Specific examples of the filler include calcium carbonate, clay, talc, diatomaceous earth,
Inorganic compounds such as kaolin, activated calcium fluoride, alumina white, aluminum sulfate, barium sulfate, calcium sulfate, graphite, glass fiber, asbestos, carbon black, and activated carbon are the mainstream, but cellulose powder, recycled rubber, ebonite powder, Organic substances such as ceramics, wood flour, coconut husk flour, cork flour, cotton linter, and powdered rubber can also be used as fillers.

[0047]

EXAMPLES Examples will be shown below, but the present invention is not limited to these examples. [Method of measuring physical properties in Examples] The evaluation methods used in the Examples are as follows. Weight average molecular weight The weight average molecular weight (Mw) of the unsaturated polyester was determined by gel permeation chromatography (GPC, column temperature 40 ° C, chloroform solvent) in comparison with a polystyrene standard sample. Measurement of water content in solvent The measurement was carried out using a Karl Fischer moisture meter (MKC-210, manufactured by Kyoto Electronics Industry Co., Ltd.). Ultraviolet curing device An ultraviolet curing device (manufactured by Iwasaki Electric Co., Ltd.) was used. Upward irradiation 107 mW / cm ² Downward irradiation 102 mW / cm ² Energy 6060 seconds, 12540 (mJ / cm 2)
). Differential heat analysis The differential scanning calorimeter (DSC-3100, manufactured by Mac Science) analyzed in the range of -100 ° C to 230 ° C.

Hardness The hardness of the sample was measured according to JIS-K-6301. The hardness of the sample was determined according to ASTM D 676-58.
It can also be measured according to T. Viscoelasticity Measured with a viscoelasticity analyzer RSA-II (manufactured by Rheometric Scientific). Measurement conditions Measurement jig: φ4.78 mm parallel plate compression Frequency: w = 6.28 rad / s = 1 Hz Temperature: −70 to 200 ° C. Test mode: Temperature dependence (Temperature)
Ramp Test) Degradable films were embedded in compost at room temperature for 30 days. Before and after embedding, the tensile strength was measured, and the degradability was evaluated.

Example 1 Preparation of polymer 106.1 g of diethylene glycol and 106. succinic acid.
3 g, fumaric acid 11.6 g, and further stannous oxide 0.9
4 g and further hydroquinone 0.02 g are added, and at a temperature of 150 ° C./1 atm for 2.5 hours while flowing nitrogen, then
The mixture was heated and stirred at 150 ° C./15 mmHg for 0.5 hour while distilling water out of the system to oligomerize. To this, 464 g of orthodichlorobenzene was added and a tube filled with 40 g of molecular sieve 5A was attached, so that the distilled solvent was returned to the reactor through the molecular sieve layer. Thereafter, the reaction was performed at 170 ° C./500 mmHg for 14 hours. The water content in the solvent after passing through the molecular sieve layer was 2 ppm. 6 in the reaction mass
Add 60 g of orthodichlorobenzene and add pyrophosphoric acid 1
After adding 0 g and stirring at 110 ° C. for 2 hours, the mixture was neutralized with 22.5 g of calcium carbonate and filtered by hot filtration. The filtrate was concentrated under reduced pressure, and the solvent was distilled off to obtain a polymer. Physical Properties of Polymer The weight average molecular weight of the obtained polymer measured by GPC was 159,000, and the weight average molecular weight was 500,0.
No ultrahigh molecular weight components of more than 00 were found. When the polymer was subjected to differential thermal analysis, the glass transition point was −25.0.
The value of ° C was shown. Preparation of Elastic Sample 10 g of the obtained polymer was added to an initiator (1-phenyl-2).
-Hydroxy-2-methylpropan-1-one) 0.3
g was added, and the mixture was placed in a glass petri dish (diameter: 20 mm) and irradiated with an eye ultraviolet curing device (manufactured by Iwasaki Electric Co., Ltd.) to be cured. Hardness Measurement The hardness of the elastic body sample was measured according to JIS-K-6301 with a sample thickness of 12 mm or more and a load of 1 kg. The irradiation time and measured hardness values are shown in the following table [Table 1].

[0050]

[Table 1] Viscoelasticity The elastic sample cured for an irradiation time of 60 sec was measured with a viscoelasticity analyzer RSA-II (manufactured by Rheometric Scientific). As a result, the elastic modulus at 25 ° C. was 2.0 × 10 ⁵ [Pa]. Was. Degradability As a result of slicing the elastic sample into a film and performing a degradability test, the film was deteriorated to a point where the strength could not be measured.

Comparative Example Production of Polymer The reaction was carried out in the same manner as in Example 1 except that hydroquinone was not used. However, the viscosity of the reaction solution was significantly increased, stirring became difficult, and the isolation operation (catalyst) Removal, solvent removal) could not be performed. As a result of GPC measurement, the ultrahigh molecular weight component having a weight average molecular weight of 500,000 or more
% Or more.

Example 2 Production of Polymer 106.1 g of diethylene glycol and adipic acid 13
3.6 g, fumaric acid 11.7 g, further stannous oxide 0.94 g, further added hydroquinone 0.04 g,
While flowing nitrogen, the mixture was heated and stirred at 150 ° C./1 atm for 2.5 hours and then at 150 ° C./15 mmHg for 0.5 hour while distilling water out of the system to carry out oligomerization. To this, 464 g of orthodichlorobenzene was added and a tube filled with 40 g of molecular sieve 5A was attached, so that the distilled solvent was returned to the reactor through the molecular sieve layer. Thereafter, the reaction was performed at 170 ° C./500 mmHg for 20 hours. The water content in the solvent after passing through the molecular sieve layer was 2 ppm. 660 g of orthodichlorobenzene was added to the reaction mass, 10 g of pyrophosphoric acid was added, and the mixture was stirred at 110 ° C. for 2 hours, neutralized with 22.5 g of calcium carbonate, and filtered by hot filtration. The filtrate was concentrated under reduced pressure, and the solvent was distilled off to obtain a polymer.

Physical Properties of Polymer The weight average molecular weight of the obtained polymer measured by GPC was 43,000, and the weight average molecular weight was 500,00.
No ultrahigh molecular weight components of 0 or more were found. When the polymer was subjected to differential thermal analysis, the glass transition point was -47.0 ° C.
The value of was shown. Preparation of Elastic Sample 10 g of the obtained polymer was added to an initiator (1-phenyl-2).
-Hydroxy-2-methylpropan-1-one) 0.3
g was added, and the mixture was placed in a glass petri dish (diameter: 20 mm) and irradiated with an eye ultraviolet curing device (manufactured by Iwasaki Electric Co., Ltd.) to be cured. Hardness Measurement The hardness of the elastic body sample was measured according to JIS-K-6301 with a sample thickness of 12 mm or more and a load of 1 kg. The irradiation time and measured hardness values are shown in the following table [Table 2].

[0054]

[Table 2] Degradability As a result of slicing the sample into a film and performing a degradability test, the film was so deteriorated that its strength could not be measured.

Example 3 Preparation of polymer 102.3 g of 88% lactic acid and 6-hydroxycaproic acid 1
31.4 g, 6.26 g of triethylene glycol, 5.42 g of itaconic acid, 1.15 g of stannous oxide and 0.06 g of hydroquinone were added, and the mixture was added at 150 ° C./10
The mixture was heated and stirred at 0 mmHg for 2 hours while flowing water out of the system to form an oligomer. To this, 210 g of orthodichlorobenzene was added, a Dean Starktrap was attached, an azeotropic dehydration reaction was carried out at 140 ° C./250 mmHg for 4 hours to remove water, and then Dean Stark.
The trap was removed, a tube filled with 60 g of molecular sieve 5A was attached, and the solvent distilled off by reflux was returned to the system through the molecular sieve. Thereafter, the reaction was performed at 170 ° C./500 mmHg for 20 hours. The water content in the solvent after passing through the molecular sieve layer was 2 ppm. 660 g in the reaction mass
Ortho dichlorobenzene was added, and 7.1 g of pyrophosphoric acid was added.
And 8.7 g of Celite were added and stirred at 110 ° C. for 2 hours, followed by hot filtration. The filtrate was concentrated under reduced pressure, and the solvent was distilled off to obtain a polymer. Physical Properties of Polymer The weight average molecular weight of the obtained polymer was 54,000, and no ultrahigh molecular weight component having a weight average molecular weight of 500,000 or more was found. When the polymer was subjected to differential thermal analysis, the glass transition point showed a value of -42.0 ° C.

Preparation of Elastic Sample -1 [Photocuring] The obtained polymer was treated with an initiator (1-
Then, 0.3 g of phenyl-2-hydroxy-2-methylpropan-1-one) was added, and the mixture was placed in a glass petri dish (diameter: 20 mm), and irradiated with an eye ultraviolet curing device (manufactured by Iwasaki Electric Co., Ltd.) to cure. -2 [Thermal curing] To 10 g of the obtained polymer, 0.3 g of an initiator (t-butyl peroxide) was added, and the mixture was placed in a glass (20 mm diameter) petri dish, kneaded well with a spatula, and dried at 60 ° C. in a drier. After performing a defoaming operation for 30 minutes, the mixture was cured in a dryer at 100 ° C. for 60 minutes. Hardness Measurement The hardness of the sample was measured at a thickness of 12 mm or more and a load of 1 kg according to JIS-K-6301. The curing method and the measured hardness values are shown in the following table [Table-3].

[0057]

[Table 3] Viscoelasticity The cured sample is transferred to a viscoelasticity analyzer RSA-II.
(Manufactured by Rheometric Scientific), the elastic modulus at 25 ° C. was 1.7 × 10 ⁵ [P
a). Degradability As a result of slicing the sample into a film and performing a degradability test, the film was so deteriorated that its strength could not be measured.

Example 4 Preparation of polymer 102.3 g of 88% lactic acid and 6-hydroxycaproic acid 1
31.4 g, 3.0 g of triethylene glycol, 2.6 g of itaconic acid, 1.15 g of stannous oxide and 0.02 g of hydroquinone were added, and 150 ° C./100 mmHg
The mixture was heated and stirred for 2 hours while flowing water out of the system to form an oligomer. To this, 210 g of diphenyl ether was added, and Dean Starktrap was attached.
An azeotropic dehydration reaction was carried out at 4 ° C./30 mmHg for 4 hours to remove water, then the Dean Starktrap was removed, a tube filled with molecular sieve 5A, 60 g was attached, and the solvent distilled by reflux was passed through the molecular sieve. I returned to the system again. After that, 170 ° C /
The reaction was performed at 250 mmHg for 20 hours. The amount of water in the solvent after passing through the molecular sieve layer was 2 pp
m. 660 g of orthodichlorobenzene was added to the reaction mass, and 5.6 g of pyrophosphoric acid was added.
, And neutralized with 12.6 g of calcium carbonate, followed by hot filtration. The filtrate was concentrated under reduced pressure, and the solvent was distilled off to obtain a polymer. Physical Properties of Polymer The weight average molecular weight of the obtained polymer was 52,000, and no ultrahigh molecular weight component having a weight average molecular weight of 500,000 or more was found. As a result of differential thermal analysis of the polymer, the glass transition point showed a value of -41.4 ° C.

Preparation of Elastic Body Sample To 10 g of the obtained polymer, 0.3 g of an initiator (t-butyl peroxide) was added, and the mixture was made of glass (diameter: 20 m).
m) Put in a Petri dish, knead well with a spatula, 60
After performing a defoaming operation in a dryer at 30 ° C for 30 minutes,
Cured for 60 minutes in a dryer. Hardness Measurement The hardness of the sample was measured at a thickness of 12 mm or more and a load of 1 kg according to JIS-K-6301. The measured value was 4. Degradability As a result of slicing the sample into a film and performing a degradability test, the film was so deteriorated that its strength could not be measured.

[0060]

The present invention is characterized in that an aliphatic polyester containing at least one kind of aliphatic unsaturated polybasic acid is crosslinked as a polymer component. According to the present invention, elasticity and biodegradability are combined. The present invention can provide an aliphatic polyester-based biodegradable elastic body having the same and a method for producing the same. The present invention is characterized in that an aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component is crosslinked,
According to the present invention, a biodegradable elastic body having both excellent rubber elasticity and excellent biodegradability and a method for producing the same can be provided.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Terado 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Masanobu Amioka 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Chemical Co., Ltd.

Claims (19)

[Claims] 1. A method for producing a biodegradable elastic body, comprising crosslinking an aliphatic polyester containing an aliphatic unsaturated polybasic acid synthesized in the presence of a polymerization inhibitor as a polymer constituent. 2. The method for producing a biodegradable elastic body according to claim 1, wherein the polymerization inhibitor is at least one selected from quinones, hydroquinones, phenols, and amine hydrochlorides. Method. 3. The method for producing a biodegradable elastic body according to claim 2, wherein the polymerization inhibitor is a hydroquinone. 4. The method for producing a biodegradable elastic body according to claim 3, wherein the polymerization inhibitor is hydroquinone. 5. An aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component, wherein (a1) an aliphatic polyhydric alcohol and an aliphatic unsaturated polybasic acid, and (a2) an aliphatic unsaturated oligoester. , (A3) at least one member selected from the group consisting of aliphatic unsaturated polyesters, (b1) an aliphatic polyhydric alcohol and an aliphatic saturated polybasic acid, (b2) an aliphatic hydroxycarboxylic acid, (B3) aliphatic saturated oligoester, (b4)
At least one type (B) selected from the group consisting of aliphatic saturated polyesters is removed from the reaction mixture in an organic solvent in the presence of a catalyst and at least a portion of the formed organic solvent containing water and / or excess monomer. And an aliphatic solvent obtained by heating and dehydrating while adding an additional organic solvent having a water and / or monomer concentration lower than or equal to the water and / or monomer concentration contained in the removed organic solvent into the reaction mixture. The method for producing a biodegradable elastic body according to claim 1, which is an unsaturated polyester. 6. The biodegradable elastic body according to claim 1, wherein the aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component has a weight average molecular weight of 15,000 or more. Manufacturing method. 7. An aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component is an amorphous polymer having a glass transition temperature of 25 ° C. or less.
The method for producing a biodegradable elastic body according to any one of the above. 8. The biodegradable product according to claim 1, wherein the aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component is a crystalline polymer having a melting point of 25 ° C. or less. A method for manufacturing an elastic body. 9. The method according to claim 1, wherein the aliphatic unsaturated polybasic acid is at least one selected from the group consisting of fumaric acid, maleic acid, itaconic acid, citraconic acid and anhydrides thereof. 9. The method for producing a biodegradable elastic body according to any one of the above items. 10. An aliphatic polyester containing an aliphatic unsaturated polybasic acid as a polymer component, and a polymer of ethylene glycol represented by the general formula (1) [formula 1] as a polymer component. 2. The method according to claim 1, wherein
10. The method for producing a biodegradable elastic body according to any one of claims to 9. HO-(-CH2CH2O-) n-H (1) (2≤n≤10) 11. The method for producing a biodegradable elastic body according to claim 10, wherein n is 2 ≦ n ≦ 3. 12. The method for producing a biodegradable elastic body according to claim 1, wherein the crosslinking is performed by thermal polymerization. 13. The method for producing a biodegradable elastic body according to claim 1, wherein the crosslinking is performed by photopolymerization. 14. The method for producing a biodegradable elastic body according to claim 1, wherein the crosslinking is performed by electron beam polymerization. 15. The method for producing a biodegradable elastic body according to claim 1, wherein a polymerization initiator and / or a sensitizer is used for crosslinking. 16. The amount of the polymerization initiator and / or the sensitizer used is determined based on the amount of the polymerization inhibitor contained in the aliphatic polyester.
The method for producing a biodegradable elastic body according to any one of claims 1 to 15, wherein the amount is equal to or more than equimolar. 17. A biodegradable elastic body obtained by the production method according to claim 1. 18. An elastic modulus at 25 ° C. of 1 × 10 ⁵
18. It is not less than [Pa] and not more than 1 × 10 ⁸ [Pa].
The biodegradable elastic body described in 1. 19. The hardness evaluated by a hardness test specified in JIS-K-6301 is 80 or less.
7. The biodegradable elastic body described in 7.