JPH0613579B2 - Hydrophilic-hydrophobic thermoreversible polymer compound and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel hydrophilic-hydrophobic thermoreversible polymer compound and a method for producing the same. More specifically, the present invention provides a light shield, a temperature sensor, an adsorbent, a toy, an interior, a dye-proof paste, a display, a separation film,
The present invention relates to a hydrophilic-hydrophobic thermoreversible polymer compound that can be used as a mechanochemical material, and a method for efficiently producing this compound.

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 has recently attracted attention as a mechanochemical material, a dye-proof paste, a separation material, and the like.

As such a thermoreversible polymer compound, a polyvinyl acetate partially saponified product, polyvinyl methyl ether, methyl cellulose, polyethylene oxide, polyvinyl methyl oxazolidinone, polyacrylamide derivative and the like are conventionally known.

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, polyN-ethylacrylamide and polyN-n- Propyl (meth) acrylamide, poly N-isopropyl (meth) acrylamide, poly N-cyclopropyl (meth) acrylamide,
Poly N, N-diethyl acrylamide, poly N-methyl-N-ethyl acrylamide, poly N-methyl-Nn
-Propyl acrylamide, poly N-methyl-N-isopropyl acrylamide, poly N-acryloyl piperidine, poly N-acryloyl pyrrolidine, 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 -Dioxolan-2-yl) -N-methylacrylamide, poly N-8-acryloyl-1,4-dioxa-8-aza-spiro [4.5] decane and the like are known.

However, these thermoreversible polymer compounds have a limited transition temperature even if they are used for, for example, a temperature sensor or a light shield, and cannot be arbitrarily selected according to the purpose, so that the application range is limited. I had to avoid being done.

SUMMARY OF THE INVENTION Under the circumstances, an object of the present invention is to provide a hydrophilic-hydrophobic thermo-reversible polymer compound having different transition temperatures in order to expand the range of use. -It was made for the purpose of providing a hydrophobic thermoreversible polymer compound and a method for producing the same.

MEANS FOR SOLVING THE PROBLEM The present inventors have found that hydrophilicity having different transition temperatures
As a result of intensive studies to develop a hydrophobic thermoreversible polymer compound, Formula obtained by radical polymerization of vinyl compound represented by It consists of a repeating unit represented by, and the intrinsic viscosity [η] at a temperature of 27 ° C in a tetrahydrofuran solution is 0.01 to
It was found that a polymer compound having a molecular weight corresponding to 6.0 is a hydrophilic-hydrophobic thermoreversible polymer compound which is insoluble in water when heated, and the present invention has been completed based on this finding.

That is, the present invention has the formula Intrinsic viscosity [η] 0.01 to 6.
A polymer compound having a molecular weight corresponding to 0 provides a hydrophilic-hydrophobic thermoreversible polymer compound which is insoluble in water by heating and a method for producing the same.

The vinyl compound used in the present invention is a novel compound that has not been published in the literature, that is, N- (2-methoxyethyl) -Nn-
Propylacrylamide, for example, reaction formula According to the above, acrylic acid chloride, N- (2-methoxyethyl) -n-propylamine and triethylamine were
React in a solvent maintained at ~ 10 ℃, or Accordingly, acrylic acid chloride and N- (2-methoxyethyl) -n-propylamine 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 will occur, so
It is preferable to react in the range of 0 to 10 ° C.

To isolate the desired compound from the reaction mixture thus obtained, usually, triethylamine hydrochloride or N- (2-methoxyethyl) -n-propylamine hydrochloride is first removed by filtration or the like, The solvent is distilled off from the filtrate using a rotary evaporator, and then distilled under reduced pressure for purification. The distillate at this time can be highly purified by repeating vacuum distillation if necessary.

N- (2-methoxyethyl)-thus obtained
N-n-propyl acrylamide (boiling point 98 ℃ / 2mmH
g) A colorless liquid, which is soluble in solvents such as water, methyl alcohol, ethyl alcohol, acetone, tetrahydrofuran, chloroform, carbon tetrachloride, and benzene.

N- (2-methoxyethyl) -Nn- used in the present invention
Propyl _acrylamide, CH 2 = CH- group, -CO
Since it has an N <group, a —CH ₂ —O— group, a —CH ₃ group, etc., it can be identified by an ultraviolet absorption spectrum, a mass spectrum analysis, or the like.

N- (2-methoxyethyl) -Nn- used in the present invention
By radical polymerization of propylacrylamide, it is possible to produce a hydrophilic-hydrophobic thermoreversible polymer compound which is insoluble in water by heating, but this polymerization is usually carried out by a solution polymerization method or a bulk polymerization method. It can be carried out by using a peroxide such as benzoyl oxide or peracetic acid, or an azo compound such as azobisisobutyronitrile as a polymerization initiator, or irradiation with actinic rays such as ultraviolet rays, radiation, electron beams or plasma. . The amount of the polymerization initiator used in this case is preferably 0.005 to 5% by weight, particularly 0.001 to 2% by weight, based on the weight of the monomer.

Particularly preferred is a method in which N- (2-methoxyethyl) -Nn-propylacrylamide is dissolved in an organic solvent at a concentration of 1 to 80% by weight and polymerized by a solution polymerization method.

The solvent used in such a solution polymerization method is N-
There is no particular limitation as long as it can dissolve (2-methoxyethyl) -Nn-propylacrylamide. Examples thereof include water, alcohols, acetone, tetrahydrofuran, chloroform, carbon tetrachloride, benzene, alkyl acetates, and the like. These may be used alone or in combination of two or more depending on the case. .

The polymer compound of the present invention, -CON <group, _-CH 2 -O
- group, -CH <group, because it has a -CH ₃ group, it can be identified by infrared absorption spectrum. Regarding the degree of polymerization, it is practical that the intrinsic viscosity [η] at a temperature of 27 ° C. in a tetrahydrofuran solution is in the range of 0.01 to 6.0. Further, regarding the solubility in various solvents, cold water, alcohols such as methanol, ethanol and isopropanol, acetone, tetrahydrofuran, dioxane, chloroform, benzene, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate,
It is soluble in alkyl acetates such as sec-butyl acetate, tert-butyl acetate, n-amyl acetate and n-hexyl acetate, but insoluble in hot water, cyclohexane, n-hexane, n-heptane and the like.

The polymer compound of the present invention is a hydrophilic-hydrophobic thermoreversible polymer compound that reversibly dissolves in water in a low temperature range and becomes insoluble in a high temperature range. The transition temperature of this product varies depending on the polymerization conditions, but is usually in the range of 11 to 14 ° C.

EFFECTS OF THE INVENTION The polymer compound of the present invention is a polymer compound that has not been published in the literature, and is a hydrophilic-hydrophobic thermoreversible polymer compound that reversibly dissolves in water at low temperatures and becomes insoluble at high temperatures. In addition, it has a transition temperature different from that of conventionally known thermoreversible polyacrylamide derivatives, and is, for example, a light shield in a greenhouse, a chemical laboratory, a radioisotope laboratory, a temperature sensor, an adsorbent for a surfactant. Furthermore, it can be used for toys, interiors, dye-proof pastes, displays, separation membranes, mechanochemical element materials and the like.

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

Reference Example Triethylamine 87.549N- (2
-Methoxyethyl) -n-propylamine (101.31 g) and toluene (450 ml) were added, and the mixture was cooled with ice while keeping the content liquid at a temperature of less than 10 ° C while stirring, and a mixed liquid of acrylic acid chloride (70 ml) and toluene (50 ml) was added using a dropping funnel. It dripped 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 117.4 g of a colorless transparent fraction (boiling point 98 ° C / 2 mmHg).

The results of these spectral analyzes are as follows.

Mass spectrum: m / e M + 1 = 172 M = 171 M- -CH 2 -O-CH 3 = 126 -CH 2 -N-CH 2 CH 2 -O- = 72 CH 2 = CH-CO- = 55 CH 2 = CH- = 27 Infrared absorption spectrum analysis: -N <= 3495 cm ^-1 CH ₂ = CH- = 1612 cm ^-1 -O- = 1115 cm ^-1 > C = O = 1648 cm ^-1 > CH- = 2975,2940 cm ^-1 From the above analysis results, N- (2-methoxyethyl) -N
It was confirmed to be -n-propylacrylamide.

Example 1 A vinyl monomer polymer compound obtained in Reference Example was produced.

100 ml of benzene, N- (2-methoxyethyl) -Nn
-Propylacrylamide 19.41 g and azobisisobutyronitrile 0.5 g were added to a 150 ml sealed tube and dissolved. Then, after returning the cooling and degassing operation using liquid nitrogen, seal the tube,
The polymerization was carried out at a polymerization temperature of 50 ° C. for 3 hours in a thermostat. After the reaction, 200 ml of methanol was added to stop the polymerization reaction.
The produced polymer compound was isolated by once drying the reaction solution and then making it into an ethanol solution and precipitating it in a large amount of water at 30 ° C. or higher. Yield 19.05g.

By comparing the infrared absorption spectrum of the vinyl monomer with that of the polymer compound, it was confirmed that the spectrum based on the vinyl group of 1612CM ^-1 disappeared and the polymer compound was produced.

The obtained polymer compound was used as a tetrahydrofuran solution, and the viscosity was measured at 27 ° C. using an Ubbelohde viscometer to determine the intrinsic viscosity [η]. Intrinsic viscosity [η] = 1.46 In addition, the transition temperature was determined from the light transmittance with the temperature change of the aqueous solution, and the thermal reversibility in water was investigated. FIG. 1 shows the transmittance-temperature curve of a 1 wt% concentration aqueous solution of a polymer compound. Among them, the solid line is the data when the temperature is raised, and the broken line is the data when the temperature is lowered. That is, by adjusting a 1 wt% concentration aqueous solution of a polymer compound and using a spectrophotometer with a temperature controller to raise the temperature at a temperature rising rate of 1 ° C / min, a wavelength of 500 nm is obtained.
Was measured, and the transition temperature was determined from the temperature (T _L ) at which this light transmittance was 0.5 of the initial transmittance.

Transition temperature T _L = 12.4 ° C. Example 2 Methanol 20 ml, N- (2-methoxyethyl) -Nn
-Propylacrylamide 4.82 g and azobisisobutyronitrile 4 mg were added to and dissolved in a 30 ml sealed tube. Then, after cooling and degassing operation using liquid nitrogen was repeated, the tube was sealed and allowed to react at a polymerization temperature of 50 ° C. for 5 hours in a constant temperature bath. After the reaction, the produced polymer compound was isolated by once drying the reaction solution and then making it into an ethanol solution and precipitating it in a large amount of water at 30 ° C. or higher. Yield 1.91g.

By comparing the infrared absorption spectrum of this polymer compound with that of a vinyl monomer, 1612CM ^-1
The generation of the polymer compound was confirmed by the disappearance of the spectrum based on the vinyl group.

The intrinsic viscosity in a tetrahydrofuran solution at 27 ° C. was determined by the same method as in Example 1.

The intrinsic viscosity [η] = 0.51 shows the transmittance-temperature curve of the aqueous solution of the polymer compound having a concentration of 1% by weight in FIG. Among them, the solid line is the data when the temperature is raised, and the broken line is the data when the temperature is raised. The transition temperature was determined by the same method as in Example 1.

Transition temperature T _L = 12.0 ℃

[Brief description of drawings]

FIG. 1 is a transmittance-temperature curve of a 1% by weight aqueous solution of the polymer compound of Example 1 according to the method of the present invention, and FIG. 2 is 1 wt% of the polymer compound of Example 2 according to the method of the present invention. Shows a transmittance-temperature curve in a% aqueous solution.

Claims (2)

[Claims] 1. A formula It consists of the repeating unit represented by, and has an intrinsic viscosity [η] of 0.01 to 6.0 at a temperature of 27 ° C in a tetrahydrofuran solution.
A hydrophilic-hydrophobic thermoreversible polymer compound having a molecular weight corresponding to. 2. A formula A formula characterized by radically polymerizing a vinyl compound represented by Consisting of repeating units represented by, and consisting of repeating units represented by tetrahydro, having a molecular weight corresponding to the intrinsic viscosity [η] 0.01 to 6.0 at a temperature of 27 ° C. in a tetrahydrofuran solution of hydrophilic-hydrophobic thermoreversible type. Method for producing polymer compound.