JPS5815494B2 - Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a hygroscopic resin, which comprises reacting a chlorine-containing polymer with a polyamide resin.

Many hygroscopic polymer compounds have been known for a long time, but
Most of them are soluble in water, such as polyvinyl alcohol and polyacrylamide.

If a resin that is insoluble in water and has a significantly large hygroscopic ability is developed, it is expected that it will be used in new applications as a hygroscopic functional material by applying hygroscopic phenomena such as adsorption, diffusion, and permeation of moisture.

The purpose of the present invention is to propose a method for producing a material that can meet such demands.

The method for producing a hygroscopic resin of the present invention is characterized by subjecting a chlorine-containing polymer and a polyamide resin to a crosslinking reaction, and removing ammonium chloride generated and liberated within the resin during this crosslinking reaction.

The resin thus obtained is of poor quality, has a high rate of adsorption and desorption, and has extremely small hysteresis in the amount of moisture absorbed during adsorption and desorption.

In the method of the present invention, chlorine-containing polymers that can be used to form resins include polyvinyl chloride, chlorine-containing vinyl resins represented by polyvinylidene chloride, or mixtures thereof, and chlorinated polyolefin resins represented by chlorinated polyethylene. Alternatively, it is a polymer having a chlorine atom in the main chain of the molecule, such as a mixture thereof, a chlorinated diene polymer represented by chlorinated rubber, a copolymer, a diethyl monoene copolymer, or a mixture thereof.

Next, polyamide resins are made by condensing polymerized fatty acids with alkylene polyamines such as ethylenediamine, diethylenetriamine, and triethylenetetraamine, and have many active amine groups that participate in the reaction with the chlorine-containing polymer. be.

The number of active amino groups preferably has an amine value of 100 or more.

A low-molecular substance having an active amine group can be added to these polyamide resins in order to increase their reactivity.

The above-mentioned chlorine-containing resin and polyamide resin easily undergo a crosslinking reaction between the two resins when heated, forming a uniform resin.

At the same time as this crosslinking reaction, chlorine atoms are released from the chlorine-containing polymer, and ammonium chloride is generated within the resin.

This ammonium chloride has the effect of extremely increasing the moisture absorption effect of the resin and reducing the mechanical strength when moisture is absorbed.

In the present invention, the effect of ammonium chloride was discovered, and ammonium chloride was removed from the resin, which is a reaction product, to improve stability when absorbing moisture.

Ammonium chloride is easily removed by immersing the resin formed by the above reaction in an alkaline solution to neutralize it, and then washing it with water.

The hygroscopic capacity of the hygroscopic resin obtained as described above is determined by the hygroscopic capacity of the polyamide resin and the reaction composition ratio of the polyamide resin.

The reaction composition ratio of the chlorine-containing polymer and the polyamide resin is preferably in the chemical equivalent ratio of the reactive chlorine concentration in the chlorine-containing polymer and the active amine group of the polyamide resin,
The amount of moisture absorbed by the resulting resin can be adjusted by adjusting the amount of polyamide above or below the equivalent.

In the method of the present invention, the hygroscopic resin is essentially formed by the reaction of a chlorine-containing polymer and a polyamide resin as described above, but in order to further increase the hygroscopic ability of the resin or improve its mechanical strength. In order to increase the basicity of the resin or to adjust the basicity of the resin, for example, low-molecular and high-molecular substances such as acid or acid anhydride rings can be added to the extent that the above reaction is not inhibited.

EXAMPLES The present invention will be explained in more detail below with reference to Examples.

Example 1 Polyamide resin (Tomide, amine value: 415, manufactured by Fuji Kasei Kogyo) consisting of condensation of 1 part by weight of chlorinated rubber resin with a chlorine content of 688 parts by weight and a polymerized fatty acid whose main components are alkylene polyamine and dimer acid. 3 parts by weight were dissolved in toluene, mixed well, and applied to a glass plate in the form of a film, followed by reaction at a temperature of 130° C. for 25 minutes to form a solid resin film.

Next, this resin film was immersed in a 0.1 N thorium hydroxide aqueous solution for about 30 minutes, and then thoroughly washed with water to remove ammonium chloride produced by the reaction.

The moisture absorption amount of the obtained resin was measured in an atmosphere at a temperature of 20°C.

The drawing is its moisture absorption isotherm curve.

This resin was insoluble in solvents such as toluene, tetralobenzene, hydroflash, alcohol, and water.

Example 2 1 part by weight of a chlorinated rubber resin with a chlorine content of 688 parts by weight and 4 parts by weight of a polyamide resin (Persamide, amine value: 345, manufactured by General Min Co., Ltd.) were dissolved in toluene, and Example 1 was prepared.
The reaction was carried out in the same manner and under the same conditions as above, and a hygroscopic resin was obtained by dechlorinating ammonium.

The saturated moisture absorption amount of the resin in an atmosphere with a temperature of 20° C. and a relative humidity of 95% was 31%.

Example 3 1 part by weight of polyvinylidene chloride resin, 4 parts by weight of polyamide resin (Thomide, amine value: 415) and 0.5 part by weight of triethylenetetraamine were dissolved in toluene and mixed well, and then Example 1 was prepared. A hygroscopic resin was obtained by reacting in the same manner and under the same conditions as above and performing ammonium dechlorination treatment.

The saturated moisture absorption amount of this resin in an atmosphere with a temperature of 20°C and a relative humidity of 95% was 34%.

In the above implementation, potassium hydroxide was used for the ammonium chloride treatment, but it goes without saying that similar results can be obtained with other alkaline solutions such as aqueous ammonia.

As described above, the hygroscopic resin obtained by the method of the present invention is characterized by being insoluble in water and having a large hygroscopic ability.
It has an excellent adsorption/exchange function for anions such as nitric acid, sulfuric acid, and carbonic acid, and can be applied to such fields.

[Brief explanation of the drawing]

The drawing is a moisture absorption isotherm diagram showing an example of the moisture absorption characteristics of the hygroscopic resin obtained by the method of the present invention.

Claims (1)

[Claims] 1. After reacting a polyamide resin with an amine value of 100 or more obtained by condensing an alkylene polyamine and a polymerized fatty acid with a polymer having a chlorine atom in the molecular main chain, the resulting resin is immersed in an alkaline solution. A method for producing a hygroscopic resin, which comprises neutralizing ammonium chloride generated during the reaction, and then washing the resin with water to remove the ammonium chloride.