JP2006016436A - Thermosetting composition and biodegradable plastic produced by curing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermosetting composition easily producible on an industrial scale at a relatively low cost and having excellent biodegradability and provide a biodegradable plastic obtained by curing the composition. <P>SOLUTION: The thermosetting composition contains an epoxide expressed by general formula (1) ((C<SB>3</SB>H<SB>4</SB>O<SB>2</SB>) is lactic acid residue; X is a residue of a compound having a cyclic ether terminal; and n is an integer of 1-10) and an acid anhydride. More concretely, the epoxide is an epoxide mixture composed of two or more epoxides having different n values (n is 1-10). A biodegradable plastic is produced by curing the thermosetting composition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel thermosetting composition and a biodegradable plastic obtained by curing the composition, and can be used for various applications such as adhesives, molding materials, and inks.

  In recent years, biodegradable plastics have been rapidly developed from the viewpoint of environmental problems. Recent developments of such plastics include, for example, biodegradable polyesters obtained by copolymerizing an aliphatic diol component derived from a modified poly (3-hydroxybutyrate) and an aromatic dicarboxylic acid component. (Refer to Patent Document 1), polyether copolymer obtained by reacting a copolymer of lactide and polyethylene glycol and a copolymer of lactide and polypropylene glycol using a chain extender (see Patent Document 2), specific From a composition obtained by reacting a polybasic acid anhydride and an epoxide compound in the presence of a cellulose derivative, a polyether polyester obtained by copolymerizing a polyether polyester having a structural unit of the following and lactide (see Patent Document 3) Cellulose derivative molded product (see Patent Document 4).

Examples of structures that are easily biodegradable include aliphatic polyesters that are easily hydrolyzed, and copolymers having hydroxyl groups that are easily oxidized by microorganisms. As described in Patent Document 4, cellulose derivatives having an unsubstituted hydroxyl group generally do not have excellent biodegradability unless polyesters composed of epoxide and dibasic acid anhydride are mixed. is the current situation. However, even if these are mixed, sufficient biodegradability is not obtained.
That is, when a polyester is obtained using a commercially available epoxide and a dibasic acid anhydride, the polyester does not have a sufficient structure to be biodegradable. This is because the epoxide does not have a structure exhibiting biodegradability.

  On the other hand, polylactic acid is well known as one of biodegradable resins. However, polylactic acid is generally produced by synthesizing a lactic acid oligomer by dehydration polycondensation of an aqueous lactic acid solution, cyclizing this by depolymerization to form lactide, and ring-opening polymerization of the lactic acid oligomer. In short, there are problems in terms of productivity and manufacturing cost.

JP-A-9-157364 (Claims) Japanese Patent Laid-Open No. 11-35655 (Claims) JP-A-8-295727 (Claims) JP-A-7-292001 (Claims)

  Therefore, an object of the present invention is to provide a thermosetting composition excellent in biodegradability, which can be easily produced industrially at a relatively low cost, and a novel biodegradable plastic obtained by curing it. There is to do.

（但し、（Ｃ₃Ｈ₄Ｏ₂）は乳酸残基を表わし、Ｘは末端が環状エーテルとなる化合物の残基を表わし、ｎは１〜１０の整数である。） In order to achieve the above object, according to the present invention, there is provided a thermosetting composition comprising an epoxide represented by the following general formula (1) and an acid anhydride.

(However, (C ₃ H ₄ O ₂ ) represents a lactic acid residue, X represents a residue of a compound whose terminal is a cyclic ether, and n is an integer of 1 to 10.)

（但し、（Ｃ₃Ｈ₄Ｏ₂）は乳酸残基を表わし、Ｒは水素原子又はメチル基を表わし、ｎは１〜１０の整数である。） According to a preferred aspect, there is provided the thermosetting composition, wherein the epoxide is an epoxide represented by the following general formula (2).

(However, (C ₃ H ₄ O ₂ ) represents a lactic acid residue, R represents a hydrogen atom or a methyl group, and n is an integer of 1 to 10.)

According to a further preferred aspect, the epoxide is obtained by reacting a compound represented by the following general formula (3) with epihalohydrin.

According to a more preferred specific embodiment, there is provided a thermosetting composition characterized in that the epoxide is an epoxide mixture comprising at least two different n number of epoxides of n = 1 to 10. The
The thermosetting composition may further contain another epoxide.
According to another aspect of the present invention, there is provided a biodegradable plastic obtained by curing the thermosetting composition.

  Since the epoxide contained in the thermosetting composition of the present invention has a cyclic ether group such as an epoxy group or an oxetanyl group at one end, it reacts with an acid anhydride or the like and polymerizes. Since it has a hydroxyl group, it is easily oxidized by microorganisms, and because of a condensate of lactic acid such as lactyl lactic acid, it has a structure that has more ester bonds than a monomer and is easily hydrolyzed. Therefore, a cured product of a composition characterized by containing this epoxide or a mixture of epoxides or a mixture of these with other epoxides and an acid anhydride, for example, a plastic, has excellent biodegradability, and It can be manufactured at a relatively low cost with good productivity.

  As a result of intensive studies to solve the above problems, the present inventor has found that the epoxide represented by the general formula (1), particularly the epoxide represented by the general formula (2), preferably n = A composition comprising an epoxide mixture comprising at least two different n-number epoxides of 1 to 10 and an acid anhydride is useful for various applications such as adhesives, molding materials and inks. In addition, the present inventors have found that the cured product exhibits excellent biodegradability and have completed the present invention.

  That is, the epoxide, which is one component of the thermosetting composition of the present invention, has a cyclic ether group such as an epoxy group or an oxetanyl group at one end, so that it reacts with an acid anhydride to polymerize, and the other Since it has a hydroxyl group at the terminal and an ester bond in the molecule, it is easily hydrolyzed. Therefore, a cured product obtained by curing this epoxide or a mixture of epoxides or a mixture of these with other epoxides and a thermosetting composition containing an acid anhydride exhibits excellent biodegradability. Furthermore, since the epoxide has a terminal hydroxyl group, it has excellent adhesion to various materials and can be reacted with other resins.

  By the way, although this inventor found out that the epoxide of lactic acid gave the structure which shows biodegradability, it is difficult to obtain only this structure. This is because lactic acid is relatively stable in an aqueous solution. For example, in a 90% aqueous solution, a condensate of lactic acid such as lactyl lactic acid is several percent in a 50% aqueous solution. (In this specification, a lactic acid aqueous solution containing a lactic acid condensate such as lactyl lactic acid may be collectively referred to as a lactyl lactic acid-containing lactic acid aqueous solution). In order to obtain an epoxide, since it is heated during the synthesis, lactic acid is further condensed, and it is industrially difficult to epoxidize only the lactic acid monomer. However, the cured product obtained using the oligomer epoxide condensed in this way also exhibits excellent biodegradability for the reasons described above. Therefore, in the epoxide synthesis process used in the present invention, in a strict sense, an epoxide mixture composed of epoxides having different n numbers in the general formula (1) can be obtained, but it is not necessary to separate and purify them. It can be used as it is, and is an industrially inexpensive method.

Hereinafter, the thermosetting composition of the present invention and the biodegradable plastic obtained by curing the composition will be described in detail.
First, an epoxide that is one component of the thermosetting composition of the present invention will be described. This epoxide can be obtained by various methods. For example, (A) a method of reacting lactic acid and its condensate with epihalohydrin using an alkali metal hydroxide or an aqueous solution thereof, and (B) a lactic acid and its condensate using an alkali metal hydroxide or an aqueous solution thereof. And epihalohydrin are reacted using a quaternary basic salt compound and / or a crown ether compound as a catalyst, and (C) a method such as a desalting reaction between an alkali metal salt of lactic acid and its condensate and oxetane.

Here, lactic acid may be an optically active substance such as a D-form or L-form having a structure represented by the following formulas (A) and (B), or a D, L-form that is a mixture thereof. Moreover, as a structure of the condensate of lactic acid, the compound shown by following formula (C)-(E) etc. are mentioned, for example. The lactic acid residues (C ₃ H ₄ O ₂ ) represented by the general formulas (1) to (3) are comprehensively represented including the residues (C) to (E). .

In the general formulas (1) to (3), n represents an integer of 1 to 10, but preferably n is an integer of 1 to 7. Also in the mixture, n represents an integer of 1 to 10, and preferably n is an integer of 1 to 7. If n exceeds 10, it may become diepoxy, so it is not preferable that n exceeds 10.
Furthermore, industrially, a mixture of epoxides consisting of at least two different n-numbers of n = 1 to 10 is produced, and epoxides having n-numbers of 1, 2, or 3 are individually produced from these mixtures. It is difficult to separate and purify. Therefore, it is generally commercialized as an epoxide mixture.

In the production method (A), 50 to 90% lactyl lactic acid-containing lactic acid aqueous solution and epihalohydrin are charged into a reaction vessel, and while stirring, the alkali metal hydroxide is added while maintaining the reaction temperature at room temperature to 80 ° C. The reaction is carried out while distilling off the water in the reaction system at 40 to 80 ° C. under normal pressure or reduced pressure. However, it is preferable to proceed the reaction under a reduced pressure of about 20 to 100 mmHg from the viewpoint of suppressing side reactions. When the reaction temperature is outside the above range, that is, higher than 80 ° C., the raw material epoxy compound has a high molecular weight, and a good target product cannot be obtained. On the other hand, when the temperature is lower than room temperature, the reaction is difficult to proceed. The reaction proceeds, for example, as shown in the following reaction formula (4).

  Although the said reaction can be performed in a solvent or without a solvent, since epihalohydrin has a function as a reaction solvent, it is not necessary to use the reaction solvent generally used conventionally. However, if necessary, an organic solvent inert to the reaction such as a lower aliphatic hydrocarbon such as cyclohexane or n-hexane or an aromatic hydrocarbon such as benzene, toluene or xylene is mixed with epihalohydrin and used. be able to. However, it is not preferable to use a large amount of these solvents (excluding epihalohydrin) because the volumetric efficiency of the reaction kettle is reduced and a high molecular weight product is easily generated.

  Examples of the epihalohydrin include epichlorohydrin, epibromohydrin, epiiodohydrin, epifluorohydrin, and the like, but epichlorohydrin is industrially used. The usage-amount of epihalohydrin is 2-15 equivalent with respect to 1 equivalent of carboxyl groups of lactic acid and its condensate, Preferably the range of 5-10 equivalent is preferable. When the amount of epihalohydrin used is less than 2 equivalents, the reaction is slow, while when it exceeds 15 equivalents, the volumetric efficiency is unfavorable.

  The alkali metal hydroxide has a function as a catalyst for an addition reaction between a glycidyl group and a carboxyl group of epihalohydrin and a ring-closing reaction after the addition reaction. Examples of the alkali metal hydroxide include sodium hydroxide and potassium hydroxide. These alkali metal hydroxides can be used as a solid or an aqueous solution. When used in a solid state, a pulverized product is preferable because the reaction rate becomes high. It is preferable that the usage-amount of an alkali metal hydroxide is 1.0-2.0 equivalent with respect to 1 equivalent of hydroxyl groups to glycidyl-etherify.

  After completion of the reaction, the solution is filtered, or after neutralizing residual alkali metal hydroxide with methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, cation exchange resin, etc., filtered to separate and remove by-product salts, Next, excess epihalohydrin is distilled off under reduced pressure to obtain the desired epoxide.

  In the production method (B), a 50-90% lactyl lactic acid-containing lactic acid aqueous solution and epihalohydrin are charged into a reaction vessel, and while stirring, in a solvent or without solvent, while maintaining the reaction temperature at room temperature to 80 ° C., a catalyst Add quaternary basic salt compounds and / or crown ether compounds such as quaternary ammonium hydroxide, quaternary phosphonium hydroxide, quaternary ammonium halide, etc., and stir and mix at the same temperature for 0.1 to 3 hours Then, an alkali metal hydroxide is added, and the reaction is carried out at 40 to 80 ° C. while distilling off the water in the reaction system at normal pressure or reduced pressure. However, it is preferable to proceed the reaction under a reduced pressure of about 20 to 100 mmHg from the viewpoint of suppressing side reactions.

  When the reaction temperature is outside the above range, that is, exceeds 80 ° C., the raw material epoxy compound has a high molecular weight, and a good target product cannot be obtained. On the other hand, when the temperature is lower than room temperature, the reaction is difficult to proceed. In addition, when the reaction time (stir mixing time) is less than 0.1 hour, a quaternary basic salt compound such as quaternary ammonium hydroxide, quaternary phosphonium hydroxide, quaternary ammonium halide and / or crown ether. Since the complex salt formation between the compound and the carboxyl group becomes insufficient, the glycidyl etherification rate is lowered, which is not preferable. On the other hand, even if it exceeds 3 hours, complex salt formation is in an equilibrium state, and a long-time reaction (stirring and mixing) is not preferable from the viewpoint of productivity.

  Examples of the quaternary basic salt compound include tetraalkylammonium chlorides such as tetramethylammonium chloride, tetramethylammonium bromide, tetraethylammonium chloride, tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide; Trialkylbenzylammonium halides such as ammonium halide and triethylbenzylammonium bromide; Tetraalkylammonium bicarbonates such as tetramethylammonium bicarbonate and tetraethylammonium bicarbonate; Tetraalkylammonium benzoates such as tetramethylammonium benzoate and tetraethylammonium benzoate Ates: quaternary ammonium salts such as bis (tetraalkylammonium) phthalates such as bis (tetramethylammonium) phthalate, and quaternary phosphoniums such as tetraethylphosphonium chloride, dimethyldicyclohexylphosphonium chloride, and triphenylmethylphosphonium iodide Halide salts, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetramethylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetra Propylphosphonium Hydroxai , It may be mentioned tetraalkyl phosphonium hydroxide such as tetrabutylphosphonium hydroxide. These can be used alone or in admixture of two or more. These are used in a solid or liquid state.

  Among the quaternary basic salt compounds, quaternary ammonium halide, quaternary ammonium hydroxide, or quaternary phosphonium hydroxide is preferable. As the quaternary ammonium halide, for example, tetrabutylammonium chloride and tetrabutylammonium bromide are preferable from the viewpoint of reaction yield, and as the quaternary ammonium hydroxide, for example, tetramethylammonium hydroxide, tetraethylammonium hydroxide, Tetrapropylammonium hydroxide and tetrabutylammonium hydroxide are preferable, and as the quaternary phosphonium hydroxide, tetramethylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetrapropylphosphonium hydroxide, and tetrabutylphosphonium hydroxide are preferable. Furthermore, among these quaternary basic salt compounds, quaternary ammonium hydroxides or quaternary phosphonium hydroxides can be easily decomposed and removed after the reaction, and a high-quality product is obtained, which is particularly preferable. .

  The quaternary basic salt compound is used in an amount of 0.001 to 2 equivalents, preferably 0.05 to 0.2 equivalents, relative to 1 equivalent of the carboxyl group of the compound represented by the general formula (3) or a mixture thereof. Used in range. When the amount is less than 0.001 equivalent, the effect is hardly exhibited. On the other hand, even when an amount exceeding 2 equivalents is added, no further improvement in the effect is observed.

  Although the said reaction can be performed in a solvent or without a solvent, since epihalohydrin has a function as a reaction solvent, it is not necessary to use the reaction solvent generally used conventionally. However, if necessary, an organic solvent inert to the reaction such as a lower aliphatic hydrocarbon such as cyclohexane or n-hexane or an aromatic hydrocarbon such as benzene, toluene or xylene is mixed with epihalohydrin and used. be able to. However, it is not preferable to use a large amount of these solvents (excluding epihalohydrin) because the volumetric efficiency of the reaction kettle is reduced and a high molecular weight product is easily generated.

  About the said epihalohydrin and an alkali metal hydroxide, it is as having demonstrated the said manufacturing method (A). Therefore, as in the production method (A), the amount of epihalohydrin used is preferably in the range of 2 to 15 equivalents, preferably 5 to 10 equivalents, with respect to 1 equivalent of carboxyl group of lactic acid and its condensate. It is preferable that the usage-amount of a hydroxide is 1.0-2.0 equivalent with respect to 1 equivalent of hydroxyl groups to glycidyl-etherify.

  After completion of the reaction, the solution is filtered, or after neutralizing residual alkali metal hydroxide with methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, cation exchange resin, etc., filtered to separate and remove by-product salts. Subsequently, excess epihalohydrin is distilled off under reduced pressure to obtain the desired epoxide.

On the other hand, in the production method (C), a 50-90% aqueous solution of lactic acid and an alkali metal salt of a condensate thereof and oxetane, for example, 3-alkyl-3-halogenated methyl-oxetane are charged in a reaction vessel and stirred. However, in a solvent or in the absence of a solvent, a tertiary amine or the quaternary basic salt compound and / or a crown ether compound is added as a catalyst, and water in the reaction system is removed from the system under normal pressure or reduced pressure. The reaction is carried out at 70 to 130 ° C. for 30 minutes to 30 hours while distilling off. The reaction proceeds, for example, as shown in the following reaction formula (5).

  The amount of the oxetane used is preferably in the range of 1 to 10 moles with respect to 1 mole of lactic acid and its alkali metal salt. Further, the catalyst such as tertiary amine such as triethylamine and the quaternary basic salt compound is preferably in the range of 0.001 to 0.1 mol with respect to 1 mol of alkali metal salt of lactic acid and its condensate. .

  After completion of the reaction, the reaction mixture is filtered to separate and remove by-product salts, and then the excess 3-alkyl-3-halogenated methyl-oxetane is distilled off under reduced pressure. ) To obtain the desired epoxide.

  The thermosetting composition of the present invention can further contain other epoxides. Other epoxides include, for example, methyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, decyl glycidyl ether, stearyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, p-sec-butylphenyl glycidyl ether, p-tert -Butylphenyl glycidyl ether, butoxypolyene glycol glycidyl ether, glycidol, higher alcohol glycidyl ether, dibromophenyl glycidyl ether, N-glycidyl phthalimide, glycidyl methacrylate, o-phenylphenol glycidyl ether, styrene oxide, etc. And / or other monocarboxylic acids and / or alcohols, It may also be.

  Examples of other monocarboxylic acids include saturated fatty acids such as formic acid, acetic acid, propionic acid, butyric acid and caproic acid, unsaturated fatty acids such as acrylic acid, crotonic acid, isocrotonic acid and oleic acid, n-propyl acetate and benzylic acid. , P-methoxyphenylacetic acid, isonicotinic acid, diphenyl-4-carboxylic acid, benzoic acid and the like.

  Examples of alcohols include methanol, ethanol, butanol, isobutanol, octanol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, 2-hydroxyethyl methacrylate, cyclohexanol, and cyclopentanol. Is mentioned.

  Examples of the acid anhydride which is another component used in the thermosetting composition of the present invention include, for example, methyltetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, nadic anhydride, Alicyclic dibasic acid anhydrides such as 3,6-endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride; succinic anhydride, maleic anhydride, itaconic anhydride, octenyl succinic anhydride , Pentadodecenyl succinic anhydride, phthalic anhydride, trimellitic anhydride, or other aliphatic or aromatic dibasic acid anhydrides; or biphenyl tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride, butane tetracarboxylic dianhydride , Cyclopentane tetracarboxylic acid Anhydride, pyromellitic acid anhydride, an aliphatic or aromatic tetracarboxylic acid dianhydride such as benzophenone tetracarboxylic acid dianhydride and the like, can be used one or two or more of these. Among these, alicyclic dibasic acid anhydrides, particularly succinic anhydride and maleic anhydride are preferable from the viewpoint of biodegradability.

  The epoxide or epoxide mixture or a mixture of these and other epoxides and a thermosetting composition containing an acid anhydride are cured to obtain the biodegradable plastic according to the present invention. Alternatively, the charge ratio of the mixture of these and other epoxides and the acid anhydride is in a molar ratio (epoxide or epoxide mixture or a mixture of these and other epoxides) / acid anhydride = 0.3-3. preferable. If this ratio is less than 0.3, there is a possibility that the polymer cannot be polymerized, and if it exceeds 3, a low molecular weight can be produced, and the softening point may be lowered.

  The curing reaction is performed at 50 to 280 ° C., preferably 100 to 250 ° C. under normal pressure, increased pressure or reduced pressure. For example, acetate esters such as propylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether acetate, methyl ethyl ketone, Ketones such as cyclohexanone and methyl isobutyl ketone, aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene, halogenated carbonization such as pentachloroethane, 1,2-dichlorobenzene and 1,2,4-trichlorobenzene In the presence or absence of organic solvents such as hydrogen, and mixed solvents thereof, tertiary amines such as triethylamine, quaternary ammonium salts such as triethylbenzylammonium chloride, imidazole, 2-ethyl-4-methylimidazole, 3 -Benzyl Imidazole compounds such as 2-methylimidazole, phosphorus compounds such as triphenyl phosphine, lithium compound such as lithium chloride, an alkali metal compound such as sodium hydroxide, adding a catalyst thereto, such as, or is carried out in the absence of a catalyst.

  In the thermosetting composition of the present invention, if necessary, barium sulfate, barium titanate, silicon oxide powder, finely divided silicon oxide, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, Known and commonly used inorganic fillers such as magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, mica, etc., rubber fine particles, powder epoxy resin (eg, TEPIC manufactured by Nissan Chemical Industries, Ltd.), urethane resin, melamine resin, benzoguanamine resin (For example, M-30, S, MS manufactured by Nippon Shokubai Co., Ltd.), urea resin, cross-linked acrylic polymer (for example, MR-2G, MR-7G manufactured by Soken Chemical Co., Ltd., techpolymer manufactured by Sekisui Plastics Co., Ltd.), etc. An organic filler can be mix | blended individually or in mixture of 2 or more types. The blending amount of the filler is appropriately 1 to 200 parts by mass, preferably 10 to 50 parts by mass with respect to 100 parts by mass of the composition.

  The thermosetting composition of the present invention may further include known and commonly used colorants such as phthalocyanine blue, phthalocyanine green, iodin green, disazo yellow, crystal violet, titanium oxide, carbon black, and naphthalene black as necessary. Such known and commonly used additives can be blended.

  Furthermore, the thermosetting composition of this invention can mix | blend flame retardants, such as a halogenated flame retardant, a phosphorus flame retardant, and an antimony flame retardant, for the purpose of obtaining a flame retardance. The blending amount of the flame retardant is usually 1 to 100 parts by mass, preferably 5 to 50 parts by mass with respect to 100 parts by mass of the composition.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated more concretely, it cannot be overemphasized that this invention is not limited to the following Example. In the following description, “part” means “part by mass” unless otherwise specified.

Synthesis example 1
A 2-liter four-necked flask was charged with 184.1 parts of a 90% lactyl lactic acid-containing lactic acid aqueous solution, 920.52 parts of epichlorohydrin, and 42.1 parts of tetraethylammonium bromide, and stirred at 40-50 ° C. for 1 hour. . Subsequently, 167 parts of 48% sodium hydroxide aqueous solution was dripped over 2 to 3 hours, stirring at 40-50 degreeC. Thereafter, the pressure in the flask was reduced to 80 mmHg, and the reaction was performed at 40 to 50 ° C. for 6 hours. After completion of the reaction, the reaction solution was filtered and unreacted epichlorohydrin was removed using an evaporator to obtain 263 parts of a colorless liquid.
This reaction product has an epoxy equivalent (determined according to JIS K 7236) of about 170 g / eq, and a hydroxyl value (determined according to the standard method for analyzing fats and oils (published by Japan Oils and Chemicals Association)) of about 330 mgKOH. / G, acid value (obtained based on the standard method for analysis of fats and oils (published by Japan Oils and Fats Chemical Society)) is 1 mgKOH / g or less, and in the general formula (2), n is 1.33 on average. there were. The infrared absorption spectrum (measured using a Fourier transform infrared spectrophotometer FT-IR) and the nuclear magnetic resonance spectrum (solvent CDCl ₃ , reference material TMS (tetramethylsilane)) of the obtained epoxide mixture are shown in FIG. 1 and FIG. It is shown in 2. For reference, the nuclear magnetic resonance spectrum (solvent DMSO-d6, reference substance TMS (tetramethylsilane)) of 90% lactyl lactic acid-containing lactic acid aqueous solution and the chromatogram by gel permeation chromatography are shown in FIGS. 3 and 4, respectively. Show. Table 1 below shows the data read by the apparatus from when the peak of the chromatogram by gel permeation chromatography appears until it disappears.

Synthesis example 2
A 2-liter four-necked flask was charged with 183.3 parts of a 90% lactyl lactic acid-containing lactic acid aqueous solution and 922.4 parts of epichlorohydrin, and stirred at 40 to 50 ° C. for 1 hour. Subsequently, 167 parts of 48% sodium hydroxide aqueous solution was dripped over 2 to 3 hours, stirring at 40-50 degreeC. Thereafter, the pressure in the flask was reduced to 80 mmHg, and the reaction was performed at 40 to 50 ° C. for 6 hours. After completion of the reaction, the reaction solution was filtered and unreacted epichlorohydrin was removed using an evaporator to obtain 227 parts of a colorless liquid.
This reaction product has an epoxy equivalent (determined according to JIS K 7236) of about 200 g / eq, and a hydroxyl value (determined according to the standard method for analyzing fats and oils (published by Japan Oils and Chemicals Association)) of about 280 mgKOH. / G, acid value (obtained based on the standard method for analysis of fats and oils (published by Japan Oils and Fats Chemical Society)) is about 1 mgKOH / g or less, and in the general formula (2), n is 1.75 on average Met. The infrared absorption spectrum (measured using a Fourier transform infrared spectrophotometer FT-IR) and the nuclear magnetic resonance spectrum (solvent DMSO-d6, reference substance TMS (tetramethylsilane)) of the resulting epoxide mixture are shown in FIG. As shown in FIG.

Example 1
A 1-liter four-necked flask was charged with 246 parts of the epoxide mixture obtained in Synthesis Example 1, 142.1 parts of maleic anhydride, and 0.99 parts of imidazole. For 3 hours and then at 180 to 190 ° C. for 90 minutes. After completion of the reaction, acetone was added to swell the reaction product, taken out from the flask, and filtered. Subsequently, the filtrate was washed with acetone and then dried with a vacuum dryer to obtain 71.27 parts of a polymer. The infrared absorption spectrum (measured using a Fourier transform infrared spectrophotometer FT-IR) and the TG curve obtained by thermogravimetry (TG) are shown in FIGS. 7 and 8, respectively.
Further, the obtained polymer was hot-pressed at ² to 10 kgf / cm ² and 180 ° C. to produce a film having a thickness of about 0.5 mm, a length of about 5 cm, and a width of about 2 cm. As a result, it was visually confirmed that it was biodegraded as if it had been eaten by insects.

Example 2
In a 1 liter four-necked flask, 218.9 parts of the epoxide mixture obtained in Synthesis Example 2 and 124.9 parts of maleic anhydride were charged, and the mixture was stirred at 140 to 150 ° C. for 3 hours with stirring in an argon atmosphere. The reaction was performed at 190 to 200 ° C. for 90 minutes. After completion of the reaction, dimethylformamide was added to swell the reaction product, removed from the flask, and filtered. Next, the filtrate was washed with dimethylformamide, further washed with acetone, and dried in a vacuum dryer to obtain 150 parts of a polymer. The infrared absorption spectrum (measured using a Fourier transform infrared spectrophotometer FT-IR) and the TG curve obtained by thermogravimetry (TG) are shown in FIGS. 9 and 10, respectively.
Further, the obtained polymer was hot-pressed at ² to 10 kgf / cm ² and 180 ° C. to produce a film having a thickness of about 0.5 mm, a length of about 5 cm, and a width of about 2 cm. As a result, it was visually confirmed that it was biodegraded as if it had been eaten by insects.

Example 3
A 1 liter four-necked flask was charged with 170.6 parts of the epoxide mixture obtained in Synthesis Example 2, 88.5 parts of maleic anhydride, and 496 parts of 1,2,4-trichlorobenzene, and stirred in an argon atmosphere. The reaction was performed at 160 to 170 ° C. for 90 minutes. After completion of the reaction, methanol and acetone were added to swell the reaction product, taken out from the flask, and filtered. Subsequently, the filtrate was washed with acetone and dried with a vacuum dryer to obtain 25 parts of a polymer having a hydroxyl value of about 180 mgKOH / g. Infrared absorption spectrum (measured using Fourier transform infrared spectrophotometer FT-IR), TG curve by thermogravimetry (TG), chromatogram by gel permeation chromatography, and nuclear magnetic resonance spectrum ( Solvent heavy water and the reference substance Sodium 3- (trimethylsilyl) propionate-2,2,3,3-D ₄ ) are shown in FIGS. 11, 12, 13, and 14, respectively.
Further, the obtained polymer was hot-pressed at ² to 10 kgf / cm ² and 180 ° C. to produce a film having a thickness of about 0.5 mm, a length of about 5 cm, and a width of about 2 cm. Melted in.

Example 4
Into a 1 liter four-necked flask, 226.9 parts of the epoxide mixture obtained in Synthesis Example 2 and 76.8 parts of maleic anhydride were charged, and the reaction was performed at 140 to 150 ° C. for 6 hours with stirring in an argon atmosphere. went. After completion of the reaction, water was added to swell the reaction product, taken out from the flask, and filtered. Next, the filtrate was washed with methanol and dried in a vacuum dryer to obtain 50 parts of a polymer having a hydroxyl value of about 200 mgKOH / g. The infrared absorption spectrum (measured using a Fourier transform infrared spectrophotometer FT-IR) and TG curves obtained by thermogravimetry (TG) are shown in FIGS. 15 and 16, respectively.
Further, the obtained polymer was hot-pressed at ² to 10 kgf / cm ² and 180 ° C. to produce a film having a thickness of about 0.5 mm, a length of about 5 cm, and a width of about 2 cm. Melted in.

Example 5
A 1 liter four-necked flask is charged with 324.5 parts of the epoxide mixture obtained in Synthesis Example 2 and 110 parts of maleic anhydride, and stirred at 140 to 150 ° C. for 15 hours while stirring in an argon atmosphere, and further 170 to Reaction was performed at 180 degreeC for 3 hours. After completion of the reaction, tetrahydrofuran was added to swell the reaction product, taken out from the flask, and filtered. Next, the filtrate was washed with tetrahydrofuran and dried in a vacuum dryer to obtain 52 parts of a polymer. The infrared absorption spectrum (measured using a Fourier transform infrared spectrophotometer FT-IR) of the obtained polymer and the TG curve by thermogravimetry (TG) are shown in FIGS. 17 and 18, respectively.
Further, the obtained polymer was hot-pressed at ² to 10 kgf / cm ² and 180 ° C. to produce a film having a thickness of about 0.5 mm, a length of about 5 cm, and a width of about 2 cm. As a result, it was visually confirmed that it was biodegraded as if it had been eaten by insects.

Example 6
A 1 liter four-necked flask was charged with 124.3 parts of the epoxide mixture obtained in Synthesis Example 2, 72.06 parts of maleic anhydride, and 0.31 part of lithium chloride. The reaction was carried out at ˜150 ° C. for 15 hours and further at 170-180 ° C. for 8 hours. After completion of the reaction, tetrahydrofuran was added to swell the reaction product, taken out from the flask, and filtered. Next, the filtrate was washed with acetone and dried in a vacuum dryer to obtain 55.6 parts of a polymer. The infrared absorption spectrum (measured using a Fourier transform infrared spectrophotometer FT-IR) and the TG curve obtained by thermogravimetry (TG) are shown in FIGS. 19 and 20, respectively.
Further, the obtained polymer was hot-pressed at ² to 10 kgf / cm ² and 180 ° C. to produce a film having a thickness of about 0.5 mm, a length of about 5 cm, and a width of about 2 cm. As a result, it was visually confirmed that it was biodegraded as if it had been eaten by insects.

  As described above, the epoxide, which is one component of the thermosetting composition of the present invention, is excellent in thermal reactivity, and thus easily reacts and polymerizes with an acid anhydride, and the obtained plastic Since it has a hydroxyl group at the terminal and has many ester bonds in the molecule, it exhibits excellent biodegradability.

2 is a graph showing an infrared absorption spectrum of an epoxide mixture obtained in Synthesis Example 1. FIG. 2 is a graph showing a nuclear magnetic resonance spectrum of the epoxide mixture obtained in Synthesis Example 1. FIG. It is a graph which shows the nuclear magnetic resonance spectrum of 90% lactyl lactic acid containing lactic acid aqueous solution. It is a graph which shows the chromatogram by the gel permeation chromatography of 90% lactyl lactic acid containing lactic acid aqueous solution. 3 is a graph showing an infrared absorption spectrum of an epoxide mixture obtained in Synthesis Example 2. FIG. 6 is a graph showing a nuclear magnetic resonance spectrum of the epoxide mixture obtained in Synthesis Example 2. 2 is a graph showing an infrared absorption spectrum of the plastic obtained in Example 1. FIG. 2 is a graph showing a TG curve by thermogravimetry (TG) of the plastic obtained in Example 1. FIG. 4 is a graph showing an infrared absorption spectrum of the plastic obtained in Example 2. FIG. It is a graph which shows the TG curve by the thermogravimetry (TG) of the plastic obtained in Example 2. 6 is a graph showing an infrared absorption spectrum of the plastic obtained in Example 3. FIG. It is a graph which shows the TG curve by the thermogravimetry (TG) of the plastic obtained in Example 3. 6 is a graph showing a chromatogram obtained by gel permeation chromatography of the plastic obtained in Example 3. FIG. 6 is a graph showing a nuclear magnetic resonance spectrum of the plastic obtained in Example 3. 6 is a graph showing an infrared absorption spectrum of the plastic obtained in Example 4. It is a graph which shows the TG curve by the thermogravimetry (TG) of the plastic obtained in Example 4. 6 is a graph showing an infrared absorption spectrum of the plastic obtained in Example 5. FIG. It is a graph which shows the TG curve by the thermogravimetry (TG) of the plastic obtained in Example 5. 7 is a graph showing an infrared absorption spectrum of the plastic obtained in Example 6. It is a graph which shows the TG curve by the thermogravimetry (TG) of the plastic obtained in Example 6.

Claims (5)

A thermosetting composition comprising an epoxide represented by the following general formula (1) and an acid anhydride.

(However, (C ₃ H ₄ O ₂ ) represents a lactic acid residue, X represents a residue of a compound whose terminal is a cyclic ether, and n is an integer of 1 to 10.) The thermosetting composition according to claim 1, wherein the epoxide is an epoxide represented by the following general formula (2).

(However, (C ₃ H ₄ O ₂ ) represents a lactic acid residue, R represents a hydrogen atom or a methyl group, and n is an integer of 1 to 10.) The thermosetting composition according to claim 1 or 2, wherein the epoxide is an epoxide mixture composed of at least two different n-numbers of epoxides of n = 1 to 10. Furthermore, another epoxide is contained, The thermosetting composition as described in any one of Claims 1 thru | or 3 characterized by the above-mentioned. A biodegradable plastic obtained by curing the thermosetting composition according to any one of claims 1 to 4.

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