JPS6018688B2 - Method for controlling viscosity of polymer solution by light irradiation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reversibly changing the spatial conformation of polymer chains by irradiating light to control the viscosity of a solution.

It is a well-known fact that the spatial conformation of polymer chains is significantly affected by solvent and temperature.

However, a polymer compound in which a compound that undergoes an isomerization reaction upon light irradiation is incorporated into the polymer chain easily changes its spatial conformation upon light irradiation, even without the change in the solvent or temperature, and the polymer solution It is completely unknown that the viscosity of a substance changes and that it returns to its original viscosity once the light irradiation is stopped. Benzospiropyrans having a skeleton of are, for example, as shown in the following isomerization reaction [1]
It is known that in benzene, it is colored by light irradiation in the ultraviolet range (intensity < 40 m) (maximum absorber input - 58 m), and the color fades within a few minutes in the dark, but the present inventors et al. researched the effects of light irradiation on polymer compounds incorporating penzospiropyrans into their polymer chains, and found that
The inventors found and discovered the unexpected fact that the viscosity of a polymer solution consisting of the polymer compound and its solvent changes immediately upon irradiation with light, and as a result of further research, the present invention was arrived at.

That is, in the present invention, a polymer solution consisting of a polymer compound in which penzospiropyrans, which undergo an isomerization reaction upon light irradiation, are incorporated into the royal chain or side chain, and its solvent is irradiated with light, and the viscosity of the polymer solution is reversibly changed. The present invention relates to a method for controlling the viscosity of a polymer solution using light irradiation, which is characterized by changing the viscosity of a polymer solution.

Polymer compounds incorporating penzospiropyrans that undergo an isomerization reaction upon light irradiation into the main chain or side chain can be used to homopolymerize benzospiropyrans, copolymerize penzospiropyrans with other suitable monomers, It can be obtained by methods such as grafting or block polymerization of a polymer containing benzospiropyrans with other suitable monomers, or grafting or block polymerization of benzospiropyrans onto a suitable polymer.

Among these polymer compounds, the following are examples of more common ones. ■ A homopolymer of penzospiropyrans.

@A copolymer with benzospiropyrans incorporated into its side chain, obtained by vinyl polymerization of penzospiropyrans and methyl methacrylate, ethyl acrylate, or methacrylic acid.

■ Polymers in which penzospiropyrans are incorporated into the main chain of various polyesters, polyamides, polyimides, or polyurethanes through condensation or polyaddition reactions.

The solvent for dissolving these polymeric compounds varies depending on the type of polymeric compound, and examples thereof include benzene, tresol, xylene, methylene chloride, dichloromethane, tetrahydrofuran, and ethyl acetate.

The viscosity of the polymer solution thus obtained can be changed in a short time by irradiation with light from a light source such as a xenon lamp or a high-pressure mercury lamp.

As is well known, changes in the viscosity of polymer solutions caused by temperature adjustment and solvent conversion require not only large-scale operations and equipment for temperature adjustment and solvent conversion, but also the viscosity change itself. However, since these methods are not quick, no consideration has been given to their industrial use as a method for controlling the viscosity of polymer solutions. However, the present invention can change the viscosity of a polymer solution in an extremely short time by a simple means of light irradiation, so it is expected to be industrialized, for example, for use in controlling distribution systems in the polymer manufacturing industry. It is. Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 Methyl methacrylate 0.3 and 6-methacryloxymeru 1'.3.3
-Trithimel-6-nitrose spiro [2H-1-penzopyran-2,2 indoline] (hereinafter referred to as BIPS) 2
50 of 9 and 1 of 1' in benzene at 60°C using azobisissoptilonitrile 20 of 9 as an initiator. After an hourly reaction, the product was precipitated in methanol, separated and dried to obtain a random copolymer with a BIPS content of about 20%.

A benzene solution (9/3' of 50) of this copolymer was prepared, and when it was irradiated with light at 30°C from an IKw high-pressure mercury lamp installed at a distance of 20 arcs, the copolymer The intrinsic viscosity of the solution immediately changed from 0.25 to 0.22, and when the light irradiation was stopped and dark conditions were resumed, the intrinsic viscosity of the copolymer solution returned to its original value. did. The drawing shows the decrease in viscosity (resp) due to light irradiation and its recovery after light irradiation, but this decrease in viscosity due to light irradiation and recovery of viscosity under dark conditions after light irradiation are repeated. Observed. Example 2 1′・1′-(Q・Q′1P-xylyl)-pis(6
-Hydroxymethyl-6 nitrose spiro [2H-1-benzopyrazo2,2 indrian] (hereinafter referred to as HBmS
A large excess of acid chloride (CIC0
(CH2)5COCI) was added and reacted at 35-400C for 2 hours.

This solution is then diluted with dichloromethane and added at 0° C. to an aqueous solution of sodium bisphenolate in the presence of an emulsifier (triphenylmethylarsonium iodide). The resulting polymer was purified by repeating dissolution and precipitation in chloroform and methanol, and then dried. This condensation copolymer was soluble in methylene chloride and benzene, had a molecular weight of about 20,000, and an HBI content of about 10%. A benzene solution (9/3 of 50) of the polymer was prepared, and when it was irradiated with light from an IKw mercury lamp placed at a distance of 20 skins, the polymer solution was immediately colored (max. skin).

The viscosity of this solution at 30°C was measured during light irradiation and in the dark, and the intrinsic viscosity was approximately 5% during light irradiation.
A decrease was observed.

[Brief explanation of drawings]

The drawings show the decrease in viscosity (sp) of the polymer solution in Example 1 due to light irradiation and the recovery after light irradiation.

Claims (1)

[Scope of Claims] 1. A polymer compound in which benzospiropyrans having the skeleton ▲ ▲ mathematical formula, chemical formula, table, etc. are included ▼ which undergoes an isomerization reaction upon irradiation with light is incorporated into the main chain or side chain, and its solvent. A method for controlling the viscosity of a polymer solution by light irradiation, the method comprising: irradiating a polymer solution with light to reversibly change the viscosity of the polymer solution.