JP2000159886A - Increased-molecular-weight polysuccinimide (co)polymer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an increased-molecular-weight (co)polymer by melting under heating a polysuccinimide (co)polymer in the presence of water. SOLUTION: This (co)polymer is obtained by mixing a starting polysuccinimide (co)polymer with water in a ratio of the (co)polymer to the water of 1/(0.1-10) by weight and melting the moistened (co)polymer by heating to 100-250 deg.C in the presence of a chain extender and an acid catalyst being sulfuric acid. The starting polysuccinimide (co)polymer is produced from a starting materials being aspartic acid, ammonium maleate, or maleamide and is exemplified by a succinimide copolymer containing at most 50% repeating units other than succinimide rings or a polysuccinimide derivative prepared by opening or modifying the succinimide rings. The chain extender used is a compound having at least two functional groups reactive with an amino or a carboxyl and is exemplified by ammonium aspartate, aspartic diamide, or diammonium fumarate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high molecular weight polysuccinimide (co) polymer and a method for producing the same.
More specifically, it relates to a high molecular weight polysuccinimide-based (co) polymer having a higher molecular weight than the raw material polysuccinimide-based (co) polymer and a method for easily producing such a high-molecular-weight polysuccinimide-based (co) polymer. .

[0002]

2. Description of the Related Art Polysuccinimide (co) polymers are:
Due to its main chain structure, it has high mechanical strength and is expected to be used in fields where such properties are required.In addition, the aspartic acid main chain generated by opening the imide ring has biodegradability. Therefore, it is expected as a biodegradable material precursor. Specifically, for example, polyaspartic acid obtained by hydrolyzing polysuccinimide is useful as a chelating agent, a scale inhibitor, a detergent builder, a dispersant, and the like.

However, currently available polysuccinimide (co) polymers have a low molecular weight and at most 6,000.
Since it is about 7000, the usable applications are limited, and even if it can be used, not so high performance is obtained.

A method for obtaining a high molecular weight polysuccinimide is described in, for example, Japanese Patent Application Laid-Open No. 8-239468.
A method for polycondensing aspartic acid in the presence of a polymerization catalyst such as phosphoric acid or sulfuric acid is described. Also, a method of obtaining a high-molecular-weight polysuccinimide-based (co) polymer by graphing amino acids in the polysuccinimide-based (co) polymer (Japanese Patent Application Laid-Open No. 9-235372), and using a phosphite ester as the polymerization system. A method for obtaining a polysuccinimide (co) polymer having a high molecular weight (JP-A-9-278883), a method for obtaining a high-molecular-weight polysuccinimide (co) polymer by adding a catalyst and a polymerization accelerator to a polymerization system, JP-A-9-3
02088), a method of adding a compound having two oxazoline structures as a chain extender to the polymerization system and polymerizing to obtain a polysuccinimide (co) polymer (JP-A-10-1476)
44) are also known.

[0005]

However, none of these methods is necessarily satisfactory as an industrial production method because the steps are complicated and the catalyst used is expensive. The present invention replaces the conventional method for producing a high molecular weight polysuccinimide-based (co) polymer,
The present invention relates to a method for increasing the molecular weight of a polysuccinimide-based (co) polymer, specifically, by increasing the molecular weight of a low-molecular-weight polysuccinimide-based (co) polymer to produce a high-molecular-weight polysuccinimide-based (co) polymer. It seeks to provide a simple way to obtain it.

[0006]

According to the study of the present inventors, when a polysuccinimide (co) polymer is heated in the presence of water, it melts and is higher than the raw polysuccinimide (co) polymer. It was found that a polysuccinimide (co) polymer having a molecular weight, that is, a high molecular weight polysuccinimide (co) polymer was obtained. The present invention
It has been completed based on such knowledge.

That is, the present invention is a high molecular weight polysuccinimide (co) polymer obtained by heating a polysuccinimide (co) polymer in the presence of water.

Further, the present invention is a method for producing a high molecular weight polysuccinimide (co) polymer, which comprises heating the polysuccinimide (co) polymer in the presence of water.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The raw material polysuccinimide-based (co) polymer to be increased in molecular weight in the present invention is not particularly limited as long as it has at least a succinimide ring as a repeating unit. Includes all that are referred to as (co) polymers. Specifically, for example, polysuccinimide, a succinimide copolymer having a repeating unit other than a succinimide ring (for example, 50% of repeating units other than a succinimide ring
The following copolymers), and polysuccinimide derivatives in which the succinimide ring of these polymers or copolymers is appropriately opened or modified. Of course, there is no particular limitation on the starting material and the preparation method of such a polysuccinimide-based (co) polymer, and for example, it can be produced by a conventionally known method using aspartic acid, ammonium maleate or maleic amide as a starting material. Can be.

The molecular weight of the starting polysuccinimide (co) polymer is not particularly limited, and according to the present invention, the polysuccinimide (co) polymer having any molecular weight is
The molecular weight can be easily increased to increase the molecular weight. At present, those having a molecular weight of about 6,000 to 7000 can be manufactured or generally available, but according to the present invention, such a raw material polysuccinimide-based (co) polymer can also have a high molecular weight. This molecular weight was measured by the method described in the examples.

According to the present invention, the raw material polysuccinimide (co) polymer is heated to high molecular weight in the presence of water. The degree of heating is not particularly limited as long as the raw material polysuccinimide-based (co) polymer melts, and is usually 100 to 250 ° C, preferably 110 to 210 ° C, more preferably 130 to 180 ° C. It is.

The amount of water used is 0.1 to 10, preferably 0.2 to 2, more preferably 0.3 to 1.5 based on the weight of the polysuccinimide (co) polymer 1. It is.

In the present invention, if a chain extender is further present during the heating, the molecular weight can be increased more effectively. The term "chain extender" means an organic compound having a functional group capable of reacting with an amino group and / or a carboxylic acid group and capable of reacting with a polysuccinimide (co) polymer to form the same repeating unit. I do.

The above chain extender may have at least two functional groups (and / or salts thereof) capable of reacting with an amino group or a carboxyl group. For example, amino acids, hydroxycarboxylic acids, hydroxycarboxylic acid amides, ammonium salts of hydroxycarboxylic acids, aminocarboxylic acids, aminocarboxylic acid amides, ammonium salts of aminocarboxylic acids, dicarboxylic acids, ammonium salts of dicarboxylic acids,
Examples thereof include dicarboxylic amides, and more specifically, monoammonium aspartate, diammonium aspartate, monoamide aspartate, diamide aspartate, monoammonium maleate, diammonium maleate, monoammonate maleate, maleic acid In addition to diamide, monoammonium fumarate, diammonium fumarate, monoamide fumarate, diamide fumarate and the like, polysuccinimide, polyaspartic acid and the like can be mentioned.

In the present invention, if an acid catalyst is further present during the heating, the molecular weight can be more effectively increased. At this time, the above chain extender may be present at the same time. Typical examples of the acid catalyst include sulfuric acid, phosphoric acid, boric acid, p-toluenesulfonic acid and the like.

The amounts of the chain extender and the acid catalyst to be used can be appropriately determined according to the degree of high molecular weight.

The high molecular weight polysuccinimide (co) polymer of the present invention can be used as a molded article material, specifically, for example, as a water absorbent resin material. In particular, the high molecular weight polysuccinimide (co) polymer of the present invention is
When hydrolyzed by adding an alkali, it becomes biodegradable polyaspartic acid, so disposal treatment is easy,
It is useful as a biodegradable resin material.

[0018]

According to the present invention, the polysuccinimide (co) polymer can be easily made to have a high molecular weight by a simple method.

[0019]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

Preparation Example 245 g of maleic anhydride and 500 g of water were placed in an eggplant-shaped flask and dissolved. Add 25% ammonia water 170
g was slowly dropped so as not to bump. When uniform, use a rotary evaporator to transfer the solution to a water bath temperature of 10
The mixture was concentrated under reduced pressure while heating at 0 ° C. until the crystal was precipitated. The obtained monoammonium maleate was placed on a stainless steel pad, and heated at 180 ° C. for 3 hours using a hot air drier. After cooling, polysuccinimide (PSI) with a molecular weight of 6720 was obtained.

The molecular weight was measured by GPC under the following conditions.

<Molecular Weight Measurement Method> Detector: RI Column: Shodex Ohpak KB-G Ohpak SB-805HQ Ohpak KB-803 Ohpak KB-803 Ohpak KB-802.5 Carrier: NaH2PO4.2.1Hg 15.6 g 1000.0 g pH 7.0 Flow rate: 1 mg / min Calibration curve is Scientific Polymer Product (Scientific Polymer Product)
t) Prepared using polyethylene glycol standard manufactured by the company. Regarding the molecular weight of each sample, the peak top value was adopted as the molecular weight because all samples were relatively monodisperse (within Mw / Mn = 2).

Example 1 Using the polysuccinimide obtained in the preparation example as a raw material, 50 g of the raw polysuccinimide and 50 g of water were heated and melted at 160 ° C. for 3 hours using a hot air drier, and then dried.
The resulting high molecular weight polysuccinimide has a molecular weight of 71.
48. Example 2 Using the polysuccinimide obtained in the preparation example as a raw material, 50 g of the raw material polysuccinimide, 50 g of water and 5 g of maleic monoamide were heated and melted at 160 ° C. for 3 hours using a hot-air drier, and then dried. The molecular weight of the obtained high molecular weight polysuccinimide was 7,332.

Example 3 Using the polysuccinimide obtained in the preparation example as a raw material, 30 g of the raw material polysuccinimide, 30 g of water and 3 g of phosphoric acid
Was heated at 160 ° C. for 3 hours using a hot air drier, melted, and then dried. The molecular weight of the obtained high molecular weight polysuccinimide was 7,405.

Example 4 Using the polysuccinimide obtained in the preparation example as a raw material, 30 g of the raw material polysuccinimide, 30 g of water, 10 g of maleic acid monoamide and 3 g of phosphoric acid were mixed in a hot air drier.
After heating and melting at 60 ° C. for 3 hours, it was dried. The molecular weight of the obtained high molecular weight polysuccinimide was 8,509.

The above results are summarized in Table 1.

[0027]

[Table 1]

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J001 DA01 DD07 DD13 EA12 EA33 EA36 EB03 EB04 EB25 EE14D EE16D EE20D GE16 JB17 JB50 4J043 PA02 QB06 QB21 QC01 RA34 SA05 SB01 TA12 TA21 TB01 YA06 ZB45

Claims (4)

[Claims] 1. A high molecular weight polysuccinimide (co) polymer obtained by heating a polysuccinimide (co) polymer in the presence of water. 2. A method for producing a high molecular weight polysuccinimide (co) polymer, comprising heating the polysuccinimide (co) polymer in the presence of water. 3. The method according to claim 2, further comprising heating in the presence of a chain extender. 4. The method according to claim 2, further comprising heating in the presence of an acid catalyst.