JPS6332803B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polymer having an N-cyclopropylacrylamide group in a side chain and a method for producing the same.

High-temperature hydrophobic hydrophilic-hydrophobic thermoreversible polymer materials that are soluble in water at low temperatures and insoluble at high temperatures can be used as light shields, adsorbents, coatings, etc. based on their thermoreversible properties. It can be used in many ways, including as a printing agent and water-based adhesive.

The present inventors previously discovered N-isopropylacrylamide, N-isopropylmethacrylamide, N-isopropylmethacrylamide,
-The polymer of n-propylacrylamide or N-n-propylmethacrylamide is hydrophilic and its aqueous solution is transparent in the low temperature range below the transition temperature,
When heated to a temperature higher than the transition temperature, it becomes hydrophobic,
They discovered that it has the property of making it opaque, and proposed that this property could be used to make it into a light-shielding material.

However, all of the above polymers have a transition temperature of 45° C. or lower, which considerably limits their range of use.

The present inventors continued their research to develop materials with different transition temperatures and a wider range of applications, and as a result, they discovered a new polymer with the general formula () (In the formula, R may be the same or different for each unit and represents hydrogen or CH _3. ) The polymer represented by the formula has the property of being reversibly soluble in water at low temperatures and insoluble at high temperatures. Based on this finding, we have accomplished the present invention.

That is, the transition temperature of an aqueous solution of poly(N-cyclopropylacrylamide) radically polymerized in a solution state is 45°C, the transition temperature of an aqueous solution of poly(N-cyclopropylmethacrylamide) is 60°C, and the aqueous solution of a copolymer of both is 45°C. is 45 to 60 depending on its composition ratio.
It has a transition temperature between ℃ and ℃. Also, the general formula ()
A polymer consisting of a repeating unit represented by the formula and having a molecular weight corresponding to an intrinsic viscosity [η] of 0.01 to 6.0 at 30°C has an appropriate molecular weight, for example, an intrinsic viscosity [η] = 0.01 at 30°C in methanol solution. ~6.0 or so, especially 0.1~3.0
Preferably.

The solubility of the polymer represented by the general formula () in various solvents is as follows: soluble in cold water, methanol, and ethanol; swellable in chloroform, acetone, and tetrahydrofuran; and soluble in benzene, n-hexane, carbon tetrachloride, diethyl ether, and heat. Insoluble in water.

The monomer used in the present invention is synthesized, for example, according to the following formula.

(In the formula, R represents hydrogen or _CH3 ) From the above reaction formula, N-cyclopropylacrylamide
(Melting point 45℃) N-cyclopropyl methacrylamide
(melting point 60℃), mass spectrum, IR spectrum,
The substance was confirmed by NMR spectrum.

In the process according to the invention, N-cyclopropylacrylamide or N
- Cyclopropyl methacrylamide and a mixture of both are heated above their melting point and polymerized in a molten state, or solution polymerization is performed using a solvent capable of dissolving both of the above monomers or a mixture of both as a reaction medium. There are no particular restrictions on such solvents, but water, alcohols, N,N-dimethylformamide, N,N-diethylacetamide, dimethyl sulfoxide, acetone, dioxane, tetrahydrofuran, benzene, chloroform, carbon tetrachloride, etc. These can be used alone or in combination of two or more. Usually monomer components are dissolved at a concentration in the range of 1 to 80% by weight and irradiated with radiation, but polymerization can be carried out by any commonly known method such as heating or light irradiation in the presence of a conventional radical polymerization initiator. Can be done.

Next, the present invention will be explained in more detail with reference to Reference Examples and Examples.

(Reference example 1) Triethylamine 36.3 in a 1 volume Erlenmeyer flask
g, 20 g of cyclopropylamine, and benzene
450 ml of the solution was added and cooled with ice, and while stirring, a mixed solution of 30 ml of acrylic acid chloride and 20 ml of benzene was slowly dropped into the solution from a dropping funnel over a period of about 3 hours while keeping the content at a temperature below 10°C. After completion of the dropwise addition, the reaction solution was left to cool for a day and night, filtered, and benzene was removed from the filtrate using a rotary evaporator and concentrated. Then, a colorless and transparent fraction with a boiling point of 84° C./1 mmHg was recovered by distillation under reduced pressure. This crystallized immediately to give 29 g of product (melting point 45°C). In the mass spectrum of this substance, the parent peak was 111, which matched the molecular weight of N-cyclopropylacrylamide, confirming the substance.

In the same manner, N-cyclopropylmethacrylamide (molecular weight 125, melting point 60°C) was obtained.

Example 1 5.17 g of N-cyclopropylacrylamide obtained in Reference Example and 17.18 g of a benzene solution containing 1% azobisisobutyronitrile were placed in an ampoule, degassed under reduced pressure using liquid nitrogen, and the upper part was heated with a burner. Sealed. This ampoule was heated at a temperature of 75° C. for 6 minutes to carry out a polymerization reaction. At this time, as the polymerization reaction progressed, poly(N-cyclopropylacrylamide) was precipitated. After the polymerization reaction, the ampoule was opened and poured into benzene-n-hexane to dissolve unreacted monomers, and the insoluble portion was collected (yield
4.70g). The obtained polymer was made into a methanol solution, and the viscosity was measured using an Ubbelohde viscometer, and the intrinsic viscosity [η] was 2.20.

The obtained poly(N-cyclopropylacrylamide) was dissolved in water to prepare a 1% by weight aqueous solution, and while this aqueous solution was heated at a temperature increase rate of 1°C/min, transmission at 500 nm was measured using a spectrophotometer. The relationship between the rate and temperature is calculated, and the results are shown as a graph in the first part.
As shown in the figure.

As is clear from this graph, poly(N-cyclopropylacrylamide) is dissolved in water at low temperatures, but it begins to precipitate at 44°C, and the amount of precipitation increases rapidly as the temperature rises, reaching 500 nm at 46°C. It can be seen that the transmittance is 0%, indicating that it is insoluble in water.

Further, 2.767 mg of this polymer and 56.900 mg of water were placed in a sealed aluminum cell as a sample, and differential scanning calorimetry was performed at a heating rate of 1° C./min. The results are shown in A of FIG. Looking at this, the endothermic peak begins at 43.5°C and follows a broad curve up to 54°C. The temperature at the top of this endothermic peak was determined to be 46°C. Also, the amount of heat of transition at this time was 2.0 cal/g.

Example 2 4.95 g of N-cyclopropylmethacrylamide obtained in Reference Example and 17.44 g of a benzene solution containing 1% azobisisobutyronitrile were placed in an ampoule.
Degassing was performed under reduced pressure using liquid nitrogen, and the upper part was sealed with a burner. This ampoule was heated at a temperature of 75° C. for 1 hour to carry out a polymerization reaction. At this time, poly(N-cyclopropyl methacrylamide) was precipitated along with the polymerization reaction. After the polymerization reaction, the ampoule was opened and poured into benzene-n-hexane to dissolve unreacted monomers, and the insoluble portion was collected (yield
3.16g). The obtained polymer was made into a methanol solution, and the viscosity was measured using an Ubbelohde viscometer. As a result, the intrinsic viscosity [η] was 0.30.

The obtained poly(N-cyclopropylmethacrylamide) was dissolved in water to prepare a 1% by weight aqueous solution, and this aqueous solution was heated at a temperature increase rate of 1°C/min and measured at 500 nm using a spectrophotometer. The relationship between transmittance and temperature was determined. This result is shown in the third graph.
As shown in the figure.

As is clear from this graph, poly(N-cyclopropylmethacrylamide) dissolves at low temperatures, but begins to precipitate at 59°C, and the amount of precipitation increases rapidly as the temperature rises, reaching 500nm at 61°C. It can be seen that the transmittance is 0%, indicating that it is insoluble in water.

Further, 2.832 mg of this polymer and 58.741 mg of water were placed in a sealed aluminum cell as a sample, and differential scanning calorimetry was performed at a heating rate of 1° C./min. The results are shown in FIG. 4C. Looking at this, the endothermic peak is
A broad curve is drawn starting from 58.5℃ and ending at 69℃. The peak stop temperature of this endothermic peak was determined to be 61°C. The heat of transition at this time was 3.4 cal/g.

Example 3 0.84 g of N-cyclopropylacrylamide obtained in Reference Example, N-cyclopropylmethacrylamide
0.83 g and 5 ml of isopropyl alcohol were placed in an ampoule, degassed under reduced pressure using liquid nitrogen, and the upper part was sealed with a burner. This was irradiated with gamma rays from cobalt-60 at 24°C at an irradiation dose rate of 0.04 MR/hr for 10 hours to effect polymerization. After irradiation, the ampoule was opened and poured into tetrahydrofuran to dissolve unreacted monomers and collect the insoluble portion (yield: 1.60 g).
The obtained polymer was made into a methanol solution and the viscosity was measured using an Ubbelohde viscometer, and the limiting viscosity [η] was 0.45. Regarding the polymer composition of the obtained poly(N-cyclopropylacrylamide-N-cyclopropylmethacrylamide), elemental analysis showed that the N-cyclopropylacrylamide portion was 48%. The obtained polymer was dissolved in water to prepare a 1% by weight aqueous solution, and the relationship between transmittance at 500 nm and temperature was determined using a spectrophotometer while raising the temperature of this aqueous solution at a heating rate of 1°C/min. Ta. The results are shown in FIG. As is clear from this graph, the copolymer is dissolved in water at low temperatures, but it begins to precipitate at 54°C, and the amount of precipitation increases rapidly as the temperature rises, and at 56°C, the transmittance at 500 nm drops to 0.
It turns out that it is insoluble.

Further, 10.03 mg of this polymer and 59.15 mg of water were placed in a sealed aluminum cell as a sample, and differential scanning calorimetry was performed at a heating rate of 1° C./min. The results are shown in FIG. 4B. Looking at this, the endothermic peak is
A broad curve is drawn starting from 55.5℃ and ending at 66.0℃. The temperature at the top of this endothermic peak was determined to be 57°C. Further, the amount of heat of transition at this time was 2.13 cal/g.

[Brief explanation of drawings]

Figure 1 shows the poly(N-
Figure 2 is a graph showing the relationship between temperature and transmittance at 500 nm for a 1% aqueous solution of poly(N-cyclopropylacrylamide-N-cyclopropyl methacrylamide). temperature and
Figure 3 is a graph showing the transmittance at 500 nm, and Figure 4 is a graph showing the relationship between temperature and transmittance at 500 nm for a 1% aqueous solution of poly(N-cyclopropyl methacrylamide). These are differential scanning calorimetry curves for poly(N-cyclopropylacrylamide) A, poly(N-cyclopropylacrylamide-N-cyclopropylmethacrylamide) B, and poly(N-cyclopropylmethacrylamide) C.

Claims (1)

[Claims] 1. General formula (In the formula, R may be the same or different for each unit and represents hydrogen or CH _3. ) A polymer consisting of repeating units represented by . 2. Radical polymerization of N-cyclopropylacrylamide, N-cyclopropylmethacrylamide, or a mixture of the two monomers in a solution state by heating, γ-ray irradiation, or light irradiation in the presence of a radical polymerization catalyst. general formula (In the formula, R has the same meaning as above.) A method for producing a polymer comprising repeating units represented by the following formula and having a molecular weight corresponding to an intrinsic viscosity [η] of 0.01 to 6.0 at 30°C.