JPH06145245A - Heat-sensitive polymer compound undergoing phase transfer in alcohol solvent and its production - Google Patents

Abstract

PURPOSE:To obtain the subject polymer compound useful as light screening material, temperature sensor, etc., having a given intrinsic viscosity efficiently and in high yield by radically polymerizing a specific vinyl compound. CONSTITUTION:N-2-(1,3-Dioxolan-2-yl)ethylacrylamide of formula I is radically polymerized to give the objective polymer compound comprising a repeating unit of formula II, having a molecular weight corresponding to 0.01-6.0 intrinsic viscosity [eta]in an aqueous solution at 27 deg.C. The compound of formula I is a new substance and is obtained by reacting acrylic acid with 2-(2- aminoethyl)-1,3-dioxolan.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel thermosensitive polymer compound which undergoes a phase transition in an alcohol solvent and a method for producing the same. More specifically, the present invention relates to a light shield, a temperature sensor, an adsorbent, a toy, an interior,
The present invention relates to a heat-sensitive polymer compound having a phase transition in an alcohol solvent, which can be used as a printing agent, a display, a separation membrane, a mechanochemical material, and the like, and a method for efficiently producing the same.

[0002]

2. Description of the Related Art Among water-soluble polymer compounds, they 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 they become soluble and transparent below the temperature. These are also called hydrophilic-hydrophobic thermoreversible polymer compounds or heat-sensitive polymer compounds, and in recent years, such as greenhouses and other light-shielding substances, temperature sensors or nonionic surfactant adsorbents, etc. It has come to be noticed as a material.

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

Among these heat-sensitive polymer compounds, polyacrylamide derivatives are particularly useful because they are stable in water and can be produced at a relatively low cost. So far, poly (N-ethylacrylamide) and poly (acrylamide) have been used. (Nn-propyl (meth) acrylamide), poly (N-isopropyl (meth) acrylamide), poly (N-cyclopropyl (meth) acrylamide), poly (N, N-diethylacrylamide), poly (N-methyl) -N-ethylacrylamide), poly (N-methyl-Nn-propylacrylamide), poly (N-methyl-N-isopropylacrylamide), poly (N-acryloylpiperidine), poly (N-acryloylpyrrolidine), poly (N
-Tetrahydrofurfuryl (meth) acrylamide),
Poly (N-methoxypropyl (meth) acrylamide), poly (N-ethoxypropyl (meth) acrylamide), poly (N-isopropoxypropyl (meth) acrylamide), poly (N-ethoxyethyl (meth) acrylamide), poly (N- (2,2-dimethoxyethyl) -N-methylacrylamide), poly (N-1-methyl-2-methoxyethyl (meth) acrylamide),
Poly (N-1-methoxymethylpropyl (meth) acrylamide), poly (N- (1,3-dioxolane-2-
Ilmethyl) -N-methylacrylamide), poly (N
-8-acryloyl-1,4-dioxa-8-aza-spiro [4.5] decane) and the like are known.

However, all of these heat-sensitive polymer compounds are heat-sensitive in an aqueous solution, but are not heat-sensitive in other solvents. Polymers exhibiting heat sensitivity in alcoholic solvents include poly (N- (1,3-dioxolan-2-ylmethyl) -N-methylacrylamide) and poly (N-1,3-dioxolan-2-ylmethyl) acrylamide. And poly (N- (1,3-dioxolan-2-yl) ethyl-N-methylacrylamide)
Unlike the above heat-sensitive polymer, it is insoluble at a temperature below the transition temperature and soluble at a temperature above the transition temperature (Japanese Patent Application Laid-Open No. 63-243112, Japanese Patent Application No. 2-72995).
And Japanese Patent Application No. 2-195246).

[0006]

Under these circumstances, the object of the present invention is to obtain a high heat-sensitive compound which undergoes a phase transition by thermal stimulation in an alcohol solvent in order to expand the range of application of the heat-sensitive polymer compound. The purpose of the present invention is to provide a molecular compound and a method for producing the same.

[0007]

Means for Solving the Problems The present inventors have conducted extensive studies to develop a thermosensitive polymer compound that undergoes a phase transition in an alcohol solvent, and as a result, the general formula

A general formula obtained by radical polymerization of a vinyl compound represented by the formula

It has a repeating unit represented by the following formula and has an intrinsic viscosity [η] at a temperature of 27 ° C. of 0.01 to 6 in an aqueous solution.
It was found that a polymer compound having a molecular weight corresponding to 0 is a thermosensitive polymer compound that undergoes a phase transition in an alcohol solvent, and the present invention has been completed based on this finding.

The polymer compound of the present invention is a novel compound, poly (N-2- (1,3-dioxolane-2-
It is ethyl) ethyl acrylamide and can be easily produced by radical polymerization of the above vinyl compound.

This vinyl compound, namely N-2-
(1,3-Dioxolan-2-yl) ethyl acrylamide is also a new compound, for example, the compound of the general formula

[Chemical 3] According to the following, acrylic acid chloride, 2- (2-aminoethyl) -1,3-dioxolane, and triethylamine,
The reaction is carried out in a solvent maintained at 0 to 10 ° C, or

[Chemical 4] Accordingly, acrylic acid chloride and 2- (2-aminoethyl) -1,3-dioxolane can be obtained by reacting them in a solvent kept at 0 to 10 ° C.

The solvent used in these methods is not particularly limited as long as it is inert to acrylic acid chloride, and benzene, acetone, toluene and the like are generally used. Regarding the reaction temperature, if it is too high, side reactions occur, so it is preferable to react in the range of 0 to 10 ° C.

From the reaction mixture thus obtained,
To isolate the target compound, usually, first, triethylamine hydrochloride or 2- (2-aminoethyl) -1,3-dioxolane hydrochloride is removed by filtration or the like, and then the solvent is distilled off from the filtrate using a rotary evaporator. Leave
Then, the product is purified by vacuum distillation according to a conventional method. At this time, if necessary, vacuum distillation may be further repeated to obtain a highly pure product.

The N-2- (1,3 thus obtained)
-Dioxolan-2-yl) ethyl acrylamide is a colorless liquid (boiling point 138 ° C / 2 mmHg), water,
It is soluble in solvents such as methyl alcohol, ethyl alcohol, acetone, tetrahydrofuran, chloroform and benzene, but insoluble in n-hexane and n-heptane.

The heat-sensitive polymer compound of the present invention which undergoes a phase transition in an alcohol solvent can be produced by radically polymerizing the above-mentioned N-2- (1,3-dioxolan-2-yl) ethylacrylamide. However, this polymerization is usually a solution polymerization method or a bulk polymerization method, using a benzoyl peroxide, a peroxide such as 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 0.005 based on the weight of the monomer.
A suitable range is 5% by weight, especially 0.001 to 2% by weight.

Particularly preferred is the solution polymerization method, N-2.
-(1,3-dioxolan-2-yl) ethylacrylamide was dissolved in an organic solvent at a concentration of 1 to 80% by weight,
It is a method of polymerizing. The solvent used in such a solution polymerization method is N-2- (1,3-dioxolane-
There is no particular limitation as long as it is soluble in 2-yl) ethyl acrylamide. For example, water, alcohols, acetone, tetrahydrofuran, chloroform, benzene, alkyl acetates and the like can be mentioned, and these may be used alone or in combination of two or more depending on the case.

The polymer compound of the present invention is soluble in alcohol at a transition temperature or higher. The transition temperature of this product also differs depending on the type of alcohol.

The polymer compound of the present invention is -CONH-
Since it has a group, a —CH ₂ —O— group, a —CH <group, a —CH ₃ group, etc., it can be identified by an infrared absorption spectrum or the like. Regarding the degree of polymerization, the intrinsic viscosity [η] at a temperature of 27 ° C. in an aqueous solution is 0.01 to
The range of 6.0 is practical. Regarding the solubility in various solvents, it is soluble in water, methanol, acetone, benzene, tetrahydrofuran, methyl acetate, ethyl acetate, hot alcohols, ethylene glycol, chloroform, etc., cold monohydric alcohols (excluding methanol and ethanol) , Cyclohexane, n-hexane, n-
It is insoluble in heptane.

The polymer compound of the present invention has the property that it dissolves in alcohol above the transition temperature and becomes insoluble below the transition temperature. For example, the transition temperature of a 1% alcohol solution of this polymer compound varies depending on the molecular weight and the solution concentration, but is 6 to 22 ° C. for n-propanol, 14 to 24 ° C. for isopropanol, and 1 for tert-amyl alcohol.
The temperature is 4 to 31 ° C., and that of isoamyl alcohol is 19 to 32 ° C., which generally differs depending on the type of alcohol.

[0018]

Industrial Applicability The polymer compound of the present invention is a polymer compound that has not been described in the literature, and has the property of being dissolved in alcohol at high temperatures and insoluble in alcohol at low temperatures. These polymers can be used in, for example, light-shielding bodies such as greenhouses, temperature sensors, toys, interiors, textile printing agents, displays, separation membranes, cosmetic substrates, mechanochemical element materials, and the like.

[0019]

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

Reference Example Triethylamine (39.27 g), 2
-(2-Aminoethyl) -1,3-dioxolane (46.1
Add 1g) and toluene (1l), cool with ice, keep the content liquid at a temperature of 10 ° C or lower, and stir while stirring, dilute acrylic acid chloride (32.6ml) with toluene (100ml) and add about 3 from the dropping funnel. Slowly added dropwise over time. After completion of the dropwise addition, the reaction solution was left in the refrigerator for a whole day and night to complete the reaction, then filtered, and toluene was distilled off using a rotary evaporator to obtain crude N-2- (1,3-dioxolane-2-
Ill) ethyl acrylamide was concentrated. Then, vacuum distillation was carried out by a conventional method to obtain 27.54 g of a liquid substance having a boiling point of 138 ° C./2 mmHg.

The infrared absorption spectrum of this substance is shown in FIG.
Tables 1 and 2 show the results of infrared spectrum analysis and mass spectrum analysis.

[Table 1]

[Table 2]

From the above analysis results, N-2- (1,3-
It was confirmed to be dioxolan-2-yl) ethyl acrylamide.

Example 1 The vinyl monomer polymer compound obtained in Reference Example was produced. 2.42 g of N-2- (1,3-dioxolan-2-yl) ethylacrylamide, 10 ml of ethanol and 0.05 g of AIBN are placed in an ampoule, and this ampoule is connected to a vacuum line and frozen and thawed repeatedly under reduced pressure to repeat the inside of the ampoule. After removing oxygen from the ampoule, the ampoule was sealed.
The polymerization reaction was carried out by heating this ampoule at 60 ° C. for 6 hours. The produced polymer was desolvated and then used as an acetone solution to produce n-
Isolated by mixing in hexane. Then, it was dissolved in water and freeze-dried to obtain a polymer. Yield 2.41
It was g.

The infrared absorption spectrum of this polymer compound is shown in FIG. Comparison of infrared absorption spectrum of vinyl monomer with that of polymer compound shows 1,626 cm
^It was confirmed that the vinyl group of ^-1 disappeared and a polymer compound was produced.

The obtained polymer compound was made into an aqueous solution and its viscosity was measured at 27 ° C. using an Ubbelohde viscometer.
The intrinsic viscosity [η] was determined. The intrinsic viscosity was 0.20.

Further, the heat-sensitive property was examined by measuring the light transmittance of the alcohol solution by thermal stimulation. The light transmittance of a 1 wt% concentration alcohol solution at a wavelength of 500 nm was measured using a spectrophotometer with a temperature controller at a rate of temperature increase of 1 ° C./min and a rate of temperature decrease of 1 ° C./min. The transmittance-temperature curve of the n-butyl alcohol solution of the polymer of Example 1 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 was determined from the temperature ( _TL ) at which the light transmittance of the alcohol solution when the temperature was lowered was 0.5 of the initial transmittance. Table 3 shows the transition temperatures of the alcohol solutions.

[Table 3]

Example 2 2.51 g of N-2- (1,3-dioxolan-2-yl) ethylacrylamide, 20 ml of benzene and AIB
N2 of 0.02 g was put 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 this ampoule at 60 ° C. for 7 hours. The resulting polymer was isolated by mixing in n-hexane with the reaction solvent. Then, it was dissolved in water and freeze-dried to obtain a polymer. The yield was 2.41 g.

The production of a polymer compound was confirmed by the same method as in Reference Example 1 below. The intrinsic viscosity [η] at 27 ° C in an aqueous solution was 0.56.

The transition temperature of the alcohol solution was determined in the same manner as in Reference Example 1. Table 4 shows the transition temperatures of these in alcohol solutions.

[Table 4]

[0030]

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum of a vinyl monomer of Reference Example.

2 is an infrared absorption spectrum of the polymer compound of Example 1. FIG.

FIG. 3 is a transmittance-temperature curve of the polymer compound of Example 1 in a 1 wt% n-butyl alcohol solution.

Claims (2)

[Claims] 1. A general formula: Radical polymerization of a vinyl compound represented by the following general formula: Consisting of a repeating unit represented by
A method for producing a heat-sensitive polymer compound having an intrinsic viscosity [η] at a temperature of ° C of 0.01 to 6.0. 2. An intrinsic viscosity [η] at a temperature of 27 ° C. in an aqueous solution of 0.01 to 6 consisting of a repeating unit represented by the general formula:
A heat-sensitive polymer compound having a molecular weight corresponding to 0.