JPH10139880A - Polysuccinimide-based resin formed article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polysuccinimide-based resin formed article excellent in biodegradability and melting properties, and useful as a packing container, a packing material, an agricultural material, etc., by melting with heating a specific polysuccinimide derivative, and forming. SOLUTION: This polysuccinimide-based resin formed article is obtained by melting with heating a polysuccinimide derivative obtained by reacting a polysuccinimide (preferably having 1000-500000 weight averaged molecular weight) with preferably 0.03-1 equivalent (based on 1 equivalent imide ring group in the polysuccinimide) monoamine compound such as a linear chain alkyl primary amine such as laurylamine, and having 2000-2000000 weight averaged molecular weight, and forming the resin by a compression molding, an injection molding, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polysuccinimide-based resin molded product. More specifically, the present invention relates to a molded article of a polysuccinimide-based resin expected to have excellent biodegradability and meltability.

[0002]

2. Description of the Related Art Recently, polyaspartic acid and its derivatives have attracted attention as polymers having excellent biodegradability, and their use in various applications such as builders of detergents has been proposed. As a method for producing polyaspartic acid, a method is known in which L-aspartic acid is polycondensed to produce polysuccinimide as an intermediate, and then the imide ring in the polysuccinimide main chain is hydrolyzed. Since polysuccinimide obtained as an intermediate has no melting point below the thermal decomposition temperature, it cannot be molded by a method used for ordinary thermoplastic resins. Therefore, its use has been limited exclusively to raw materials for producing polyaspartic acid. On the other hand, regarding polysuccinimide derivatives, a reaction product with an alkylamine or the like is effective as a tartar adhesion inhibitor (US Pat. No. 5,266,305) or a scale inhibitor (Table 8-502690). A hydroxyalkylamide derivative obtained by reacting succinimide with an amino alcohol has properties of a plasma supplement (Japanese Patent Publication No. 48-20938).
No.) has been reported, but no attempt has been made to process a polysuccinimide derivative like a general-purpose thermoplastic resin.

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a polysuccinimide having a biodegradable polysuccinimide-based main chain, excellent in meltability, and formed by heating and melting in the same manner as a normal thermoplastic resin. It is an object of the present invention to provide a resin molded article.

[0004]

Means for Solving the Problems As a result of intensive studies by the present inventors, the polysuccinimide derivative obtained by the reaction of polysuccinimide with a monoamine has a melting point below the thermal decomposition temperature. Heading,
The present invention has been achieved. That is, the gist of the present invention resides in a polysuccinimide-based resin molded product obtained by heating and melting a polysuccinimide derivative obtained by reacting a polyamino compound with a polysuccinimide.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The polysuccinimide derivative according to the present invention is an amino compound having one amino group selected from primary or secondary amino groups on the imide ring of the polysuccinimide (in the present specification, a monoamino compound and a monoamino compound). It is considered that the amino group (hereinafter referred to as) is opened by an addition reaction. The monoamino compound for obtaining such a derivative is not particularly limited as long as it has one amino group in the molecule that reacts with the imide ring in the polysuccinimide main chain. Specifically, methylamine, ethylamine, butylamine, laurylamine, linear alkyl primary amines such as stearylamine, alicyclic amines such as cyclohexylamine, dimethylamine, diethylamine, linear alkyl secondary amines such as dibutylamine, Alkylamines having 1 to 40 carbon atoms such as branched-chain alkyl primary amines such as isopropylamine and 2-ethylhexylamine; aliphatic and aromatic carbon atoms having an unsaturated double bond such as oleylamine and benzylamine having 6 to 40 carbon atoms. Amines. Further, for example, compounds having a substituent other than the amino group such as ethanolamine and aminomethoxystilbene can also be used. Among these amines, linear primary alkylamines are preferred. More preferably, it is a linear primary alkylamine having 3 to 30 carbon atoms.

These monoamino compounds may be used alone or in combination of two or more. The amount of the monoamino compound used in the reaction is 0.03 to 1 equivalent, preferably 0.05 to 1 equivalent, and more preferably 0.1 to 1 equivalent, relative to 1 equivalent of the imide ring in the main chain of polysuccinimide. . In the present specification, polysuccinimide is assumed to consist entirely of succinimide units,
Polysuccinimide consisting of a succinimide unit corresponding to 1 mole of succinimide is referred to as "1 equivalent of imide ring group"
Defined. In addition, one amino group reacts with one imide ring. If the amount of the monoamino compound is less than 0.03 equivalent, the resulting polysuccinimide derivative becomes poor in processability, which is not preferable. If the amount exceeds 1 equivalent, unreacted amine remains, which is not preferable. The polysuccinimide derivative according to the present invention can be prepared by reacting a polysuccinimide with a monoamino compound as described below, or by adding a monoamino compound during a polysuccinimide-forming reaction such as polycondensation of aspartic acid. It can be obtained by, for example, a method of reacting a monoamino compound in parallel.

(1) Reaction of Polysuccinimide with Monoamino Compound The production method of polysuccinimide as a raw material is not particularly limited. For example, L-aspartic acid is heated in the presence or absence of phosphoric acid. can get.
(Japanese Patent Publication No. 48-20638, P. Neri et a
l. , J. et al. Med. Chem. , 16, 893 (197)
3)). Although the molecular weight of polysuccinimide is not particularly limited, the weight average molecular weight is preferably from 1,000 to 500,000 in consideration of moldability and mechanical properties of a molded article.
0, preferably 5,000 to 300,000, and more preferably 10,000 to 200,000.

The reaction between the polysuccinimide and the monoamino compound may be carried out without a solvent, or may be carried out by dissolving in a solvent and reacting in a solution or slurry. Solvents that completely dissolve the polysuccinimide and the monoamino compound include N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidinone, tetramethylurea, dimethyl Aprotic polar solvents such as sulfoxide, sulfolane, hexamethylphosphoramide and the like are preferred. The amount of the solvent used is 1 to 100 parts by weight of polysuccinimide.
5,000 parts by weight, preferably 5 to 2,000 parts by weight. The method of adding the monoamino compound is not particularly limited, and may be added at once or gradually. When a plurality of monoamino compounds are used, they may be mixed or added separately, or may be added at different times in some cases. When the timing is shifted, it is preferable to add the monoamino compound having a small carbon number in consideration of reactivity. The reaction is carried out at 0-80 ° C., preferably 2
0.1 to 24 hours at 0 to 50 ° C., preferably 0.5 to
It is performed under stirring for 12 hours, more preferably 0.5 to 5 hours. The substantial end point of the reaction is when the monoamino compound disappears from the reaction system. If the reaction temperature is lower than 0 ° C., the reaction does not proceed easily. If the reaction temperature is higher than 80 ° C., it is not economically preferable because a decomposition product is generated or thermal efficiency is not good.

(2) Parallel reaction between polysuccinimide formation and monoamino compound As monomers for producing polysuccinimide, aspartic acid (L-form, D-form, DL-form), maleamic acid,
There is no particular limitation on the monomer that produces polysuccinimide, such as a reaction product of maleic acid and ammonia, and a mixture thereof. The polycondensation reaction is carried out with or without a solvent in the presence or absence of a polymerization catalyst. As the solvent, aromatic hydrocarbons, halogenated hydrocarbons, ethers, and esters are preferable, and particularly, solvents having a boiling point of 100 ° C. or higher, preferably 130 ° C. or higher are preferable. These solvents can be used alone or as a mixture. Specifically, cumene, chlorotoluene, mesitylene, 1,3-dimethyl-2-imidazolidinone, sulfolane and the like are preferably used. The solvent is monomer 1
It can be used in an amount of 1 to 5,000 parts by weight, preferably 5 to 2,000 parts by weight, based on 00 parts by weight.

The polymerization catalyst is not particularly limited as long as it produces polysuccinimide. For example, inorganic acid catalysts such as sulfuric acid, sulfuric anhydride, phosphoric acid, metaphosphoric acid, condensed phosphoric acid, phosphoric anhydride, phosphorous acid, etc., organic phosphorus catalysts, p-toluenesulfonic acid, trichloroacetic acid, trifluoroacetic acid, trifluoromethane An organic acid catalyst such as sulfonic acid can be used. Among these, phosphoric acid is preferably used in that a polymer can be easily obtained in a high yield. The amount of the catalyst used is 0.002 to 30 parts by weight, preferably 0.02 to 2 parts by weight, per 100 parts by weight of the monomer.
0 parts by weight. The polycondensation reaction is carried out by charging a monomer, a polymerization catalyst and, if necessary, a solvent into a reactor and stirring the mixture so as to be uniform. The reaction mode may be a batch type or a continuous type. Since water is generated in the polymerization reaction, it is preferable to carry out the reaction under reduced pressure or under normal pressure under an inert gas flow, and discharge the generated water to the outside of the system. The reaction temperature is 100 to 350 ° C, preferably 130 to 300.
° C. If the temperature is lower than 100 ° C., the reaction does not easily proceed, which is not preferable. On the other hand, when the temperature exceeds 350 ° C., decomposition products are generated and thermal efficiency is deteriorated, which is not economically preferable.

The method of adding the monoamino compound is not particularly limited, and may be at the time of charging the monomer or at the initial, middle or late stage of the polysuccinimide formation reaction. When two or more monoamino compounds are used, they can be mixed or added separately, or in some cases, at different times. In consideration of the reactivity, it is preferable to add the monoamino compound having a smaller number of carbon atoms in order. The reaction time varies depending on the apparatus and reaction mode, but is usually 0.1 to 24 hours, preferably 0.5 to 12 hours.
Time, more preferably 0.5 to 5 hours. The reaction product of the polysuccinimide and the monoamino compound obtained in the above reaction (1) or (2) is, for example, reprecipitated,
Furthermore, after purifying by a conventional means such as washing with water or a low boiling point solvent such as methanol, it can be formed into a powdery form, a pellet form or the like, and subjected to a molding process.

The weight average molecular weight of the polysuccinimide derivative to be processed is from 2,000 to 2,000,000.
0, preferably 3,000 to 1,800,000, more preferably 5,000 to 1,500,000. The polysuccinimide derivative thus obtained can be used alone, but other additional components can be blended according to the purpose as long as the properties are not impaired. Specifically, carbon fibers, inorganic fibrous reinforcing materials such as silica fibers, aramid fibers, polyimide fibers, organic fibrous reinforcing materials such as fluororesin fibers, graphite, solid lubricants such as molybdenum disulfide, paraffin oil and the like. Various additives such as a plasticizer, an antioxidant, a heat stabilizer, an ultraviolet absorber, a lubricant, a compatibilizer, a slip agent, a dispersant, and a colorant are exemplified.

Thus, by reacting polysuccinimide with a monoamino compound to form a polysuccinimide derivative, it has a melting point below the thermal decomposition temperature and can be molded by heating and melting. As a molding method, a method using a molding machine applied to a normal thermoplastic resin can be applied. Specific examples include compression molding, injection molding, vacuum molding, lamination molding, blow molding, extrusion molding, and press molding. The molded product of the present invention obtained from the polysuccinimide derivative is expected to have excellent biodegradability in the main chain similarly to polyaspartic acid, and is excellent in transparency, so that the molded product is promptly discarded after use. It is preferably applied to products and agricultural materials. The shape of the molded body is not particularly limited, and examples thereof include a film, a sheet, a tray, a packaging container, and a packaging material.

[0014]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. The methods for measuring the weight average molecular weight and melting point of the resin in the examples are as follows. Weight average molecular weight “TLGEL 5 μm manufactured by Polymer Laboratory Co., Ltd.”
MIX ED-C ”column and 20
It was determined in terms of polystyrene by a GPC chromatograph (detector: differential refractometer) using an N, N-dimethylformamide solution of mM LiBr. Melting point 10m sample using DSC220 manufactured by Shimadzu Corporation
g was measured by raising the temperature at 10 ° C./min under a nitrogen atmosphere, and the apex of the melting peak was defined as the melting point.

Embodiment 1 Neri et al. , J. et al. Med. Che
m. , 16, 8, 893 (1973), 9.7 g of polysuccinimide (0.1 equivalent of imide ring group) was dissolved in 50 ml of dimethylformamide (DMF), and 18.5 g of laurylamine (0. 1 mol,
A solution obtained by dissolving (1 equivalent to the imide ring group) in 50 ml of DMF was added dropwise and stirred for 24 hours. Next, the reaction mixture was dropped into 500 ml of methanol, and the obtained precipitate was washed with methanol, filtered under reduced pressure, and dried under reduced pressure at 60 ° C. for 12 hours to obtain a white powdery polysuccinimide derivative 2
6.9 g were obtained. When the melting point of this derivative was measured by DSC, it was 222 ° C. and the weight average molecular weight by GPC was 66,500. When this derivative was processed into a film by a tabletop hot press, a highly transparent film having a thickness of 20 μm was obtained. The polysuccinimide used as a starting material had a weight average molecular weight of 65,
At 000, there was no DSC and visual melting point.

Example 2 The same operation as in Example 1 was carried out except that 9.3 g (0.05 mol) of laurylamine was used (0.5 equivalent of amine to imide ring group). 18.0 g of a white powdery polysuccinimide derivative was obtained. The melting point of this derivative measured by DSC was 222 ° C., and the weight average molecular weight by GPC was 87,400. When this derivative was processed into a film by a tabletop hot press, the thickness was 20 μm.
A film having high transparency was obtained.

EXAMPLE 3 13.5 g of stearylamine (0.05 mol)
l) and 9.3 g (0.05 mol) of laurylamine
The same operation as in Example 1 was performed (the total amount of the monoamino compound was 1 equivalent relative to the imide ring group). 28.0 g of a white powdery polysuccinimide derivative was obtained. The melting point of this derivative measured by DSC was 217.
C., GPC gave a weight average molecular weight of 65,000. When this derivative was processed into a film by a desktop hot press, a highly transparent film having a thickness of 20 μm was obtained.

Example 4 200 equipped with stirrer, water separator and cooler, thermometer
25.0 g of L-aspartic acid in a ml four-necked flask
(0.19 equivalents of an imide ring group as a conversion rate of 100%), 5.0 g of phosphoric acid as a catalyst, and mesitylene 5 as a reaction solvent.
6.0 g and 24.0 g of sulfolane were added. The flask was inserted into an oil bath set at 190 ° C., and a polycondensation reaction was started under a nitrogen stream. One hour after the reaction system started refluxing, stirring was performed while removing water from the system, and 17.7 g (0.09 mol, 100% conversion) of laurylamine was added thereto.
(0.5 equivalent based on the imide ring group). 1
After an hour, the product was washed with methanol and water, and dried under reduced pressure to obtain 34.5 g of a polysuccinimide derivative. The melting point of this derivative measured by DSC was 2
The weight average molecular weight obtained by GPC at 20 ° C. was 63,700. When this derivative was processed into a film by a tabletop hot press, a highly transparent film having a thickness of 20 μm was obtained.

Comparative Example 1 0.093 g (0.0005 mol) of laurylamine
The same operation as in Example 1 was performed. 9.5 g of a white powdery polysuccinimide derivative was obtained. The melting point was not indicated by DSC or visual observation, and the weight average molecular weight by GPC was 65,000.

[0020]

According to the present invention, by reacting polysuccinimide with a monoamino compound, a resin having a polysuccinimide-based main chain excellent in biodegradability can be heated and melted by the same means as a general-purpose thermoplastic resin. It is possible to apply and mold. The molded article of the present invention is expected to have excellent biodegradability.

Claims (6)

[Claims] 1. A polysuccinimide resin molded article obtained by heating and melting a polysuccinimide derivative obtained by reacting a polyamino compound with a polysuccinimide. 2. The polysuccinimide-based resin molded article according to claim 1, wherein the polysuccinimide derivative is obtained by reacting 0.03 to 1 equivalent of a monoamino compound with 1 equivalent of an imide ring group in the polysuccinimide. . 3. The polysuccinimide-based resin molded product according to claim 1, wherein the weight average molecular weight of the polysuccinimide is 1,000 to 500,000. 4. The polysuccinimide-based resin molded product according to claim 1, wherein the polysuccinimide derivative has a weight average molecular weight of 2,000 to 2,000,000. 5. The polysuccinimide-based resin molded article according to claim 1, wherein the monoamino compound is a linear alkyl primary amine. 6. The method of molding by heating and melting is a method selected from compression molding, injection molding, vacuum molding, lamination molding, blow molding, extrusion molding, and press molding. The polysuccinimide-based resin molded article according to any one of the above.