JPH06145646A - Heat-sensitive copolymer having chelating ability - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer comprising a copolymer produced from acryloylbenzhydrazide and dimethylacrylamide in a specific ratio, causing a phase transfer by a thermal irritation in water, having a chelating ability, and useful for light-screening articles, temperature sensors, etc. CONSTITUTION:The objective copolymer comprises N-acryloylbenzhydrazide-N, N-dimethylacrylamide copolymer wherein the content of the N- acryloylbenzhydrazide is 7-18mol.%. The copolymer is obtained by radically copolymerizing N-acryloylbenzhydrazide with N,N-dimethylacrylamide in the presence of a polymerization initiator such as benzoyl peroxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-sensitive copolymer composed of N-acryloylbenzhydrazide and N, N-dimethylacrylamide copolymer, which undergoes a phase transition in water by thermal stimulation and has a chelating ability. Thus, it can be used for a light-shielding body such as a greenhouse, a temperature sensor, a toy, an interior, a printing agent, a display, a separation film, a mechanochemical element material, a copper ion indicator reagent, and a copper ion recovery.

[0002]

2. Description of the Related Art Some water-soluble polymer compounds show a special reversible dissolution behavior in which, when they are in an aqueous solution state, they become cloudy at a certain temperature (transition temperature or cloud point) or more, and become transparent when the temperature is below that temperature. These are also called hydrophilic-hydrophobic thermoreversible polymer compounds or thermosensitive polymer compounds, and have recently attracted attention as materials for light-shielding bodies such as greenhouses, temperature sensors and surfactant adsorbents. It has started to be done.

As such a heat-sensitive polymer compound,
So far, partially saponified polyvinyl acetate, polyvinyl methyl ether, methyl cellulose, polyethylene oxide, polyvinyl methyl oxazolidinone, and polyacrylamide derivative are known.

The following four methods can be considered to synthesize a thermosensitive polymer. 1. A method of introducing hydrophilic groups and hydrophobic groups into an existing polymer by polymer reaction. 2. A method of copolymerizing a hydrophilic monomer and a hydrophobic monomer. 3. A method of polymerizing one kind of monomer having a hydrophilic part and a hydrophobic part (heat-sensitive monomer). 4. A method of copolymerizing a thermosensitive monomer and another monomer.

[0005]

DISCLOSURE OF THE INVENTION The present invention aims to provide a heat-sensitive copolymer having a chelating ability, which undergoes a phase transition by thermal stimulation in water in order to expand the utilization range of the heat-sensitive polymer compound. It was done for the purpose.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted diligent research to develop a heat-sensitive copolymer which undergoes a phase transition in water by thermal stimulation and has a chelating ability.
N, N-dimethylacrylamide is water-soluble, but poly-N-acryloylbenzhydrazide has the ability to selectively chelate copper ions (Shigeo Tazuke and Akiko Na
kamura, Macromolekulare Chemie 85, 92 (1965)), and because they are water-insoluble, they focus on heat-sensitive copolymers that have a chelating ability and undergo a phase transition by thermal stimulation in water if these two monomers are copolymerized. The present invention has been completed.

In the N-acryloylbenzhydrazide-N, N-dimethylacrylamide copolymer of the present invention which undergoes a phase transition in water by thermal stimulation and has a chelating ability,
Acryloyl benzhydrazide composition is 7-18 mol%
Is.

The N-acryloylbenzhydrazide-N, N-dimethylacrylamide copolymer of the present invention, which undergoes a phase transition in water by thermal stimulation and has a chelating ability, is a radical of N-acryloylbenzhydrazide and N, N-dimethylacrylamide. It can be produced by copolymerization. This copolymerization is usually carried out by a solution copolymerization method or a bulk copolymerization method, using a peroxide such as benzoyl peroxide or peracetic acid, or an azo compound such as azobisisobutyronitrile as a polymerization initiator, or an ultraviolet ray. It can be performed by irradiation with actinic rays such as radiation, electron beams, and plasma. The amount of the polymerization initiator used at this time is 0.005 to 5% by weight, particularly 0.001% by weight based on the weight of the monomer.
A range of up to 2% by weight is suitable. The solvent is not particularly limited as long as it can uniformly dissolve the N-acryloylbenzhydrazide and N, N-dimethylacrylamide mixture. For example, alcohols, ketones, N, N
-Using dimethylformamide, dimethylsulfoxide, water or mixtures thereof.

In the N-acryloylbenzhydrazide-N, N-dimethylacrylamide copolymer of the present invention which has a chelating ability and undergoes a phase transition in water, the N-
Acryloyl benzhydrazide composition is 7-18 mol%
It consists of what is. When the composition of N-acryloylbenzhydrazide of the copolymer is less than 7 mol%, it exhibits water solubility, and when it exceeds 18 mol%, it exhibits water insolubility. The composition of the copolymer must be selected within the above range in order to undergo a phase transition in water by thermal stimulation.

[0010]

The heat-sensitive copolymer of the present invention undergoes a phase transition in water by thermal stimulation and has a chelating ability. These polymers include, for example, light-shielding bodies such as greenhouses, temperature sensors, toys, interiors, printing agents, displays, separation membranes,
In addition to mechanochemical element materials, etc., it can be used for copper ion indicator reagents, copper ion recovery, etc.

[0011]

The present invention will be described in more detail with reference to Reference Examples and Examples.

Example 1 N-acryloylbenzhydrazide 0.38 g, N, N
-Dimethyl acrylamide 1.78 g, methanol 20
ml and 0.0053 g of AIBN were placed in an ampoule, and this ampoule was connected to a vacuum line, frozen and thawed under reduced pressure to repeatedly remove oxygen in the ampoule, and then the ampoule was sealed. The polymerization reaction was carried out by heating the ampoule at 60 ° C. for 22 hours. The produced polymer was isolated as a solution of the solvent in acetone and then mixed in n-hexane. Then, it was dissolved in water and freeze-dried to obtain a polymer. The yield was 2.15g. Since the polymerization rate is close to 100%, the composition of the copolymer can be regarded as the same as the charged monomer composition. The N-acryloylbenzhydrazide composition of the copolymer is 10.0%.

Further, the heat-sensitive characteristics were investigated by measuring the light transmittance of the aqueous solution by thermal stimulation. Using a spectrophotometer with a temperature controller, the light transmittance of an aqueous solution having a concentration of 1% by weight at a wavelength of 500 nm was increased by 1 ° C./min at a temperature decrease rate of 1 ° C.
It was measured in minutes. The result is shown in FIG. Among them, the solid line is the data when the temperature is raised and the dotted line is the data when the temperature is lowered. The transition temperature is
It was determined from the temperature (T _L = 52.5 ° C.) at which the light transmittance of the aqueous solution at the time of temperature rise became 0.5 of the initial transmittance.

Example 2 N-acryloylbenzhydrazide 0.57 g, N, N
-Dimethylacrylamide 1.69 g, methanol 20
ml and 0.0053 g of AIBN were placed in an ampoule, and this ampoule was connected to a vacuum line, frozen and thawed under reduced pressure to repeatedly remove oxygen in the ampoule, and then the ampoule was sealed. The polymerization reaction was carried out by heating the ampoule at 60 ° C. for 22 hours. The produced polymer was isolated as a solution of the solvent in acetone and then mixed in n-hexane. Then, it was dissolved in water and freeze-dried to obtain a polymer. The yield was 2.25g. As in Example 1, the N-acryloylbenzhydrazide composition of the copolymer was 15.
It is 0%.

The transition temperature of the aqueous solution was determined in the same manner as in Example 1 (T _L = 19.5 ° C.).

Reference Example 1 N-acryloylbenzhydrazide 0.19 g, N, N
-Dimethylacrylamide 1.88 g, methanol 20
ml and 0.0053 g of AIBN were placed in an ampoule, and the ampoule was connected to a vacuum line, frozen and thawed under reduced pressure to repeatedly remove oxygen in the ampoule, and then the ampoule was sealed. The polymerization reaction was carried out by heating the ampoule at 60 ° C. for 22 hours. The produced polymer was isolated as a solution of the solvent in acetone and then mixed in n-hexane. Then, it was dissolved in water and freeze-dried to obtain a polymer. The yield was 2.06g. The N-acryloylbenzhydrazide composition of the copolymer was 5.0 in the same manner as in Example 1.
%.

Further, the heat-sensitive characteristics were investigated by measuring the light transmittance of the aqueous solution by thermal stimulation. A 1% by weight aqueous solution has a transmittance of 100% in the temperature range of 0 ° C to 100 ° C.
And was observed to be water soluble.

Reference Example 2 N-acryloylbenzhydrazide 0.76 g, N, N
-Dimethylacrylamide 1.59 g, methanol 20
ml and 0.0053 g of AIBN were placed in an ampoule, and this ampoule was connected to a vacuum line, frozen and thawed under reduced pressure to repeatedly remove oxygen in the ampoule, and then the ampoule was sealed. The polymerization reaction was carried out by heating the ampoule at 60 ° C. for 22 hours. The produced polymer was isolated as a solution of the solvent in acetone and then mixed in n-hexane. The yield was 2.06g. As in Example 1, the N-acryloylbenzhydrazide composition of the copolymer was 19.9%.
Is.

This copolymer has a temperature of 0 ° C to 100 ° C.
It was observed to be insoluble in water in the range of ° C.

[0020]

[Brief description of drawings]

1 is a transmittance-temperature curve of a 1% by weight aqueous solution of the copolymer of Example 1. FIG.

Claims (1)

[Claims] 1. N-acryloylbenzhydrazide-
N, N-dimethylacrylamide copolymer,
A thermosensitive copolymer having a chelating ability, wherein the composition of acryloylbenzhydrazide is 7 to 18 mol%.