JPH064686B2 - Water and alcohol solvent dependent thermoreversible material and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel water- and alcohol-solvent-dependent thermoreversible material and a method for producing the same. More specifically, the present invention relates to a light shield, a temperature sensor, an adsorbent,
Further, the present invention relates to a water- and alcohol-solvent-dependent thermoreversible material that can be used for toys, interiors, printing agents, displays, separation membranes, mechanochemical element materials, etc., and a method for efficiently manufacturing these materials.

2. Description of the Related Art Some water-soluble polymer compounds show a special reversible dissolution behavior in which, in an aqueous solution state, when the temperature is higher than a certain temperature (transition temperature or cloud point), it becomes cloudy and precipitates, and below that temperature, it becomes transparent. This is called a hydrophilic-hydrophobic thermoreversible polymer compound, and in recent years it has been used as a light shielding material for greenhouses, chemical laboratories, tracer laboratories for radioisotopes, temperature sensors, or adsorbents for water-soluble organic substances. Has attracted attention as a material for.

As such thermoreversible polymer compounds, conventionally, partially saponified polyvinyl acetate, polyvinyl methyl ether,
Known are methyl cellulose, polyethylene oxide, polyvinyl methyl oxazolidinone, and polyacrylamide derivatives.

Among these thermoreversible polymer compounds, polyacrylamide derivatives are particularly useful because they are stable in water and can be produced at a relatively low cost, and thus far poly (N-ethyl (meth) acrylamide), poly (N-ethyl (meth) acrylamide) (Nn-propyl (meth) acrylamide, poly (N-isopropyl (meth) acrylamide, poly (N-cyclopropyl (meth) acrylamide), poly (N, N-diethylacrylamide), poly (N-methyl-N) -Ethyl acrylamide), poly (N-methyl-Nn-propyl acrylamide), poly (N-methyl-N-isopropyl acrylamide), poly (N-acrylic piperidine), poly (N-tetrahydrofurfuryl (meth) acrylamide ), Poly (N-methoxypropyl (meth) acrylamide), poly (N-ethoxy) Propyl (meth) acrylamide), poly (N- isopropoxypropyl (meth)
Acrylamide), poly (N-ethoxyethyl (meth)
Acrylamide), poly (N- (2,2-dimethoxyethyl) -N-methylacrylamide) and the like are known.

However, all of these thermoreversible polymer compounds show thermoreversible properties in an aqueous solution, but do not show such properties in other solvents such as alcohol solutions, so that the range of use is limited. I had to avoid being done.

DISCLOSURE OF THE INVENTION Under the circumstances, the present invention has a thermoreversible property even when dissolved in a solvent other than water in order to expand the application range of the hydrophilic-hydrophobic thermoreversible polyacrylamide derivative. Was made for the purpose of providing a novel acrylamide-based thermoreversible material having

Means for Solving the Problems The present inventors have conducted various studies in order to develop a novel material exhibiting thermoreversible properties even in a solvent other than water, and as a result, the formula (I) It was found that the polymerization product of the vinyl compound represented by the formula (3) exhibits a thermoreversible property of being insolubilized by a temperature change even when it is dissolved in alcohol as well as water, and the present invention has been completed based on this finding.

That is, the present invention has the formula (II) To provide a water- and alcohol-solvent-dependent thermoreversible material composed of a polymer having a molecular weight corresponding to the intrinsic viscosity [η] of a tetrahydrofuran solution at 27 ° C. [η] of 0.01 to 6.0. .

Hereinafter, the present invention will be described in detail.

The polymer constituting the thermoreversible material of the present invention is a novel substance which has not been published in the literature and can be easily produced by radical polymerization of the vinyl compound represented by the above formula (I).

The compound represented by the formula (I), that is, N-methyl-N- (1,3-dioxolan-2-ylmethyl) acrylamide is also a novel compound, for example, the reaction formula In accordance with the above, acrylic acid chloride, 2-methylaminomethyl-1,3-dioxolane and triethylamine were added in an amount of 0 to 1
Reaction in a solvent kept at 0 ° C or reaction formula Accordingly, acrylic acid chloride and 2-methylaminomethyl-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, but benzene, acetone, toluene and the like are usually used. Regarding the reaction temperature, if it is too high, a side reaction occurs, so it is preferable to carry out the reaction in the range of 0 to 10 ° C.

From the reaction mixture thus obtained, in order to isolate the target compound, usually, triethylamine hydrochloride or 2-methylaminomethyl-1,3-dioxolane hydrochloride is first removed by filtration or the like, and then the rotary evaporator is used. The solvent is distilled off from the filtrate using, followed by vacuum distillation for purification. The distillate at this time can be highly purified by repeating vacuum distillation if necessary.

The N-methyl-N- (1,3-dioxolan-2-ylmethyl) acrylamide thus obtained has a boiling point of
It is a colorless liquid at 117 ° C / 1mmHg, soluble in water, methyl alcohol, ethyl alcohol, acetone, tetrahydrofuran, chloroform, carbon tetrachloride, benzene and other solvents, but insoluble in n-hexane and n-heptane. .

The thermoreversible material of the present invention is the above-mentioned N-methyl-N- (1,
Although it can be produced by radical polymerization of 3-dioxolan-2-ylmethyl) acrylamide,
This polymerization is usually carried out by a solution polymerization method or a bulk polymerization method, using a peroxide such as benzoyl peroxide or peracetic acid, or an azo compound such as azobisisobutyronitrile as a polymerization initiator, ultraviolet rays, or radiation. It can be performed by irradiating active rays such as electron beams and plasma. The amount of the polymerization initiator used at this time is based on the weight of the monomer,
A range of 0.005 to 5% by weight, particularly 0.001 to 2% by weight is suitable.

Particularly preferred is N-methyl-N-by the solution polymerization method.
In this method, (1,3-dioxolan-2-ylmethyl) acrylamide is dissolved in an organic solvent at a concentration of 1 to 80% by weight and polymerized.

The solvent used in such a solution polymerization method is N-
Methyl-N- (1,3-dioxolan-2-ylmethyl)
There is no particular limitation as long as it dissolves acrylamide. For example, water, alcohols, acetone, tetrahydrofuran, chloroform, carbon tetrachloride, benzene, alkyl acetates and the like can be mentioned, and these may be used alone or in combination of two or more kinds.

The thermoreversible material of the present invention is a high temperature hydrophobizing material which is soluble in water in a low temperature region and insoluble in water in a high temperature region. The transition temperature of this product varies depending on the polymerization conditions, but it is usually 53-65.
It is in the range of ° C. This material is also an alcohol solvent-dependent material that is solubilized in an aliphatic primary alcohol by heating. For example, the transition temperature of a 1% by weight alcohol solution of this material varies depending on the polymerization conditions, but is 0 to 30 ° C. for methanol, 30 to 60 ° C. for ethanol, 30 to 50 ° C. for n-propanol, and 35 to 50 ° C. for sec-butyl alcohol.
50 ° C., 30 to 50 ° C. for n-amyl alcohol, and 50 to 65 ° C. for isopropyl alcohol, which generally differs depending on the type of alcohol.

The polymer constituting the thermoreversible material of the present invention has a -CON <
Since it has a group, a —CH ₂ —O— group, and a —CH <group, it can be identified by an infrared absorption spectrum or the like. The degree of polymerization of tetrahydrofuran solution
Intrinsic viscosity [η] at 27 ° C in the range of 0.01 to 6.0 is practical. Regarding the solubility in various solvents, it is soluble in cold water, tetrahydrofuran, chloroform, benzene, etc., cold alcohol, ethyl acetate, and acetic acid n-.
It is insoluble in amyl, isobutyl acetate and acetone.

Effects of the Invention The thermoreversible material of the present invention comprises a thermoreversible polyacrylamide derivative that reversibly dissolves in water in a low temperature range, is insoluble in water in a high temperature range, is soluble in alcohol in a high temperature range, and is insoluble in alcohol in a low temperature range. , Has a transition temperature different from that of conventionally known polyacrylamide derivative-based thermoreversible materials,
For example, it can be used for light shields in greenhouses, chemical laboratories, radioisotope laboratories, temperature sensors, adsorbents for surfactants, toys, interiors, textiles, displays, separation membranes, mechanochemical element materials, etc. You can

Examples Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Into an Erlenmeyer flask of Reference Example 1, 39.1 g of triethylamine, 39.1 g of 2-methylaminomethyl-1,3-dioxolane and 450 ml of toluene were placed, and the mixture was cooled with ice and the content liquid was kept at a temperature of less than 10 ° C while stirring, and acrylic acid chloride was added. A mixture of 27.6 ml and 50 ml of toluene was added dropwise using a dropping funnel over about 3 hours. After completion of the dropping, the reaction solution was kept in a refrigerator for a whole day and night for reaction. Then, the reaction solution was filtered, toluene was removed from the filtrate using a rotary evaporator, and further distilled under reduced pressure to obtain 42.6 g of a colorless transparent fraction (boiling point 117 ° C./1 mmHg).

The infrared absorption spectrum of this substance is shown in FIG.

From the measurement of the infrared absorption spectrum and the mass spectrum, it was confirmed that this was N-methyl-N- (1,3-dioxolan-2-ylmethyl) acrylamide.

Examples 1 to 6 Radical polymers of vinyl monomers obtained in Reference Examples were produced.

About 2.2 g of N-methyl-N- (1,3-dioxolan-2-ylmethyl) acrylamide was added to 20 ml of the polymerization solvent. This was placed in an ampoule, degassed under reduced pressure using liquid nitrogen, and then sealed, and the irradiation dose rate was 3.9 × 10 ⁴ R / hr and the temperature was 24 ° C.
The reaction was carried out by γ-irradiation from cobalt 60 for an hour. After the reaction, the solvent was removed, and then n-hexane was added to separate and collect the polymer. The results of the polymerization reaction are shown in Table 1.

The infrared absorption spectrum of the polymer of Example 2 is shown in FIG. By comparing the infrared absorption spectrum of the vinyl monomer with that of the polymer, it was confirmed that the vinyl group at 1603 cm ^-1 disappeared and that a polymer compound was produced.

The obtained polymer was used as a tetrahydrofuran solution, and the viscosity was measured at 27 ° C. using an Ubbelohde viscometer to determine the intrinsic viscosity [η]. In addition, the transition temperature was determined from the light transmissivity associated with the temperature change of the aqueous solution, and the thermal reversibility in water was investigated. That is, a polymer aqueous solution having a concentration of 1% by weight was prepared, and a light transmittance at a wavelength of 500 nm was measured by using a spectrophotometer with a temperature controller while heating at a temperature rising rate of 1 ° C./minute to obtain a transition temperature. This light transmittance is the initial transmittance
It was calculated from the temperature ( _TL ) at which 0.5 was obtained. Second of these results
Shown in the table.

Next, the transmittance-temperature curve of the aqueous polymer solution of Example 3 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.

Further, with respect to the polymer of Example 3, the transition temperature was determined from the light transmittance with temperature change of various alcohol solutions, and the thermal reversibility in alcohol was examined. That is, a polymer alcohol solution having a concentration of 1% by weight was prepared, and a light transmittance at a wavelength of 500 nm was measured using a spectrophotometer with a temperature controller while cooling at a temperature decreasing rate of 1 ° C./min. The light transmittance was calculated from the temperature ( _TL ) at which the initial transmittance was 0.5. The results are shown in Table 3.

The transmittance-temperature curve of the polymer alcohol solution of Example 3 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.

Examples 7 to 10 Radical polymers of vinyl monomers obtained in Reference Examples were produced.

Azobisisobutyronitrile was used as a polymerization initiator, and a predetermined weight of N- was added to 20 ml of a solvent having a concentration of 0.5 g / 100 ml.
Methyl-N- (1,3-dioxolan-2-ylmethyl)
Acrylamide was added, and this was placed in an ampoule, deaerated under reduced pressure using liquid nitrogen, sealed, and allowed to react in a thermostat at a temperature of 50 ° C. for 2 hours. After the reaction, the solvent is removed and then n
-Hexane was added to separate and collect the polymer. The results of the polymerization reaction are shown in Table 4.

The intrinsic viscosities and transition temperatures of these polymers are determined in Examples 1-6.
It asked in the same way as. The results are shown in Table 5.

The transition temperature of the polymer of Example 8 in various alcohols was measured in the same manner as in Example 3. The results are shown in Table 6.

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum diagram of the vinyl monomer of Reference Example 1, FIG. 2 is an infrared absorption spectrum diagram of the polymer of Example 2, and FIG. 3 is a polymer of Example 3 by the method of the present invention. Is a graph showing the transmittance-temperature curve in a 1% by weight aqueous solution, and FIG. 4 is a graph showing the transmittance-temperature curve in the 1% by weight alcohol solution of the polymer of Example 3 according to the method of the present invention.

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Claims (2)

[Claims] 1. A formula A water- and alcohol solvent-dependent thermoreversible material composed of a polymer having a molecular weight corresponding to the intrinsic viscosity [η] of a tetrahydrofuran solution at 27 ° C. [η] of 0.01 to 6.0. 2. A formula In the presence of a radical polymerization initiator, a vinyl compound represented by a polymerization reaction is carried out until a polymer having an intrinsic viscosity [η] of a tetrahydrofuran solution at 27 ° C. of 0.01 to 6.0 is formed, water and A method for producing an alcohol solvent-dependent thermoreversible polymer material.