JPH0269523A - Treatment of polymer electrolyte - Google Patents

Abstract

PURPOSE:To readily decompose a polymer electrolyte into low-molecular substances and to eliminate environmental pollution by irradiating a copolymer consisting of an unsaturated carboxylic acid, olefin and carbon monoxide with light rays of specific wavelength. CONSTITUTION:A polymer obtained from an unsaturated carboxylic acid (e.g., maleic acid or acrylic acid), an olefin (e.g., ethylene or propylene) and carbon monoxide is irradiated with light rays (e.g., high-pressure mercury vapor lamp, xenon short arc lamp or sunlight) having 2,200-6,000Angstrom wavelength and treated.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a novel method for treating a polymer electrolyte. More specifically, the present invention relates to a novel method for treating a polymer electrolyte that does not cause problems such as residual or accumulation in the environment after use by easily decomposing the polymer electrolyte.

Polymer electrolytes obtained by copolymerizing unsaturated carboxylic acids such as maleic anhydride and acrylic acid, olefins, and carbon monoxide have many carboxyl groups and/or their salts in the molecule, and many carbonyl groups in the main chain. has a group,
In addition to being widely used as a water-absorbing material, it is also used as a variety of thickeners, flocculants,
It is an extremely useful polymeric material that is used in a wide range of applications, including detergent builders.

"Prior Art" Many polymer compounds having a large number of carboxyl groups in their molecules have been known as polymer electrolytes.
Typical examples include polyacrylic acid and copolymers of maleic acid and olefin, but these polymer compounds have poor degradability and there is concern that the residue after use may cause environmental pollution. It was difficult to use it as a detergent, such as bilgu, which is discharged as wastewater after use.

On the other hand, the present inventors have developed a new method that combines carbon monoxide and unsaturated carboxylic acids such as maleic anhydride and/or acrylic acid in the coexistence of an olefin, which has superior decomposition properties compared to conventional polymer compounds. We have discovered a polymer compound containing ketone groups in its main chain obtained by polymerization.

``Problem to be solved by the invention'' However, even with the above-mentioned new polymer compound containing CO groups in its main chain, its degradability is such that there is no risk of environmental pollution due to waste after use. It is still not enough to greatly expand the range of applications and uses of polymer electrolytes such as super absorbent resins and detergent builders. Particularly in Japan, the use of condensed phosphates such as sodium tripolyphosphate containing phosphorus as a builder for detergents is practically prohibited because it causes eutrophication of lakes and rivers. The above-mentioned polymeric compound containing a CO group in its main chain is a novel builder that has excellent Hilder performance comparable to condensed phosphates such as sodium tripolyphosphate and does not cause pollution of lakes and rivers. Therefore, there was a need for a method to improve the decomposability.

"Means for Solving the Problems" The present inventors have repeatedly studied various ways to solve these problems, and as a result, they have found that the above-mentioned polymer compounds are easily degraded by light with a wavelength of 2200 to 6000 angstroms. The present invention was achieved by discovering that it is molecularized and decomposed extremely easily by microorganisms in the environment.

"Structure of the Invention" The copolymers of the present invention are copolymers with various linear, branched, and cyclic olefins such as ethylene, propylene, butenes, styrene, cyclopentene, cyclohexene, cyclooctene, and vinylcyclohexane. A polymer compound with a molecular weight of 5,000 to 1,000,000 that has COD in the main chain of the polymer is produced by copolymerizing three components: unsaturated carboxylic acids such as maleic acid and acrylic acid, and carbon monoxide. be.

This compound has a CO acid component of 0.1 to 20 mol% in the molecule.
%, preferably 1-15%, no more CO
If the content of 5 to 80%, preferably 20 to 70% respectively
%contains.

This polymer compound can be produced relatively easily by polymerizing maleic anhydride and/or acrylic acid (salt), olefins such as ethylene and propylene, and carbon monoxide in the presence of a catalyst or radical initiator. It is possible. For example, an initiation reaction using heat, light, radiation, etc. used in radical polymerization is also possible, but the most common method is to carry out the reaction in the presence of a radical initiator, which is commonly carried out. In addition, in order for this reaction to proceed in high yield, the coexistence of an olefin is essential, and other than that, there are no particular limitations on the reaction conditions, but preferably a carbon monoxide pressure of 2 to 800 atmospheres,
The olefin/carbon monoxide molar ratio is about 0.01 to 10, more preferably about 0.1 to 5.The reaction temperature is set according to the decomposition conditions of the radical initiator used, but is usually room temperature to 2.
A temperature range of around 50°C is used. As the radical initiator, any commonly used peroxide, azobisnitrile, etc. can be used, and inorganic peroxides such as hydrogen peroxide, persulfuric acid, azobisnitrile, azo and diazo compounds, organic peroxides, etc. oxides, other aromatic sulfinic acids, l
-Alkanesulfinic acids and their salts, etc. are also used.

The reaction solvent can be selected arbitrarily based on the solubility of the raw material maleic anhydride, the decomposability of the radical initiator, etc., but aromatic compounds such as benzene, toluene, ethylbenzene, xylene, chloroform, carbon tetrachloride, etc. Organic halides, ketones such as acetone and methyl ethyl ketone, and esters such as methyl acetate and ethyl acetate are generally used.

The average molecular weight of the copolymer composition can vary depending on conditions such as reaction temperature, raw material concentration, pressure, concentration and type of radical initiator, and ranges from s, ooo to 500.0 depending on the use.
Controlled within the range of 00.

Examples of light sources that emit light having a wavelength of 2,200 to 6,000 angstroms include high-pressure mercury lamps, xenon seat-arc lamps, and sunlight.

The irradiation time varies depending on the light source and the CO group content in the copolymer, but it is preferably selected appropriately so that the molecular weight of the decomposed product after light irradiation is 2.500 or less, preferably 2,000 or less. For example, when a 100W high-pressure mercury lamp is used, even when irradiated for about 8 hours with a 110 mol% CO containing lamp, a lamp with a weight average molecular weight of about 200,000
It decreases to 1000 or less. The total CO content after photolysis is traceable to several percent, and this is extremely easily decomposed by microorganisms.

"Examples" The present invention will be specifically explained below with reference to Examples, but it goes without saying that the present invention is not limited only to these Examples.

In the test method carried out in the Examples, the polymer electrolyte aqueous solution was measured using a photolysis device, and the change in molecular weight was measured by GPC.

Details are shown below.

[Photodegradability test conditions] 100W high-pressure mercury lamp temperature = 27°C 1% aqueous polymer electrolyte solution: 200ml [Molecular weight measurement conditions] GPC method column: 5hodex 0Hpak flow rate: 1 ml/min Column temperature: 40°C Eluent: 0 .05M-KC7! Aqueous solution [Comparative example] In a Hastelloy-C autoclave equipped with an induction stirrer and an external heater, 30 gr of maleic anhydride,
100 ml of a benzene solution containing 0.3 gr of "benzoylperoxy" was charged.The autoclave was then sealed, and the autoclave was replaced six times with 10 kg/c++ IC pressurized ethylene, and then G ethylene was introduced at 50 kg/c as calculated by pressure gauge. While stirring constantly, the temperature of the reaction mixture in the autoclave was adjusted to 70 ± 2°C using a heating heater, and the reaction was carried out for 4 hours.After that, the reactor was cooled and degassed, and then opened to form a slurry. I took out the slurry.
After adding to 00ml of ether, insoluble substances were filtered off, washed with ether, and dried to recover 22.3g of copolymer.

A certain amount of distilled water was added to this copolymer and it was neutralized by adding a 20% by weight aqueous NaOH solution until a value of pH 10 was maintained.

A colorless and transparent solution was obtained, and after adjusting the solute concentration to a constant value, the solution was treated in methanol to obtain a white powder of a polymer electrolyte.

As a result of analysis, the polymer electrolyte is a maleic acid and ethylene copolymer that does not contain any CO. The photodegradability test results are shown in Table 1 along with Examples.

[Example-11 200m equipped with induction stirrer and external heater
1. Seal the Hastelloy-C autoclave and store 10 kg.
/c+aG After replacing with pressurized ethylene 6 times, the pressure gauge shows 4
0kg/an! G of ethylene is introduced and then similarly 1
00 kg/cJG of carbon monoxide was introduced.

Using a high-pressure metering pump, supply 25 ml of benzene,
After adjusting the temperature of the reaction mixture in the autoclave to 70 ± 2 °C with a heating heater while performing constant stirring,
Maleic anhydride 15 gr, hensyl peroxide 0.
81.1 gr of a benzene solution containing 750 gr was reacted for 12 hours at a feed rate of 0.113 gr/min using a high-pressure metering pump. 19.5g of copolymer was recovered using the same method and conditions as in the comparative example, and analysis of the polymer electrolyte after saponification showed that the total CO content was 8.0 mol%. The photodegradability test results are shown in Table 1 along with comparative examples.

[Example-2] 1100 equipped with an induction stirrer and an external heater
ml Hastelloy-C autoclave is sealed and 10k
g/c (G After replacing with pressurized ethylene 6 times, the pressure gauge shows 4
0 kg/cfG of ethylene was introduced and then similarly 10 kg/cfG of ethylene was introduced.
0 kg/c++tG of carbon monoxide was introduced. Using a high-pressure metering pump, 250 ml of benzene was supplied, and the temperature of the reaction mixture in the autoclave was adjusted to 70 ± 2°C with a heater while stirring constantly, and then 75 gr of maleic anhydride and 5.630 g of benzoyl peroxide were added.
414.4 gr of a benzene solution containing gr was added at a feed rate of 0.576 gr/min using a high-pressure metering pump to 1
The reaction was carried out for 2 hours. 100.7g of copolymer was recovered using the same method and conditions as in the comparative example, and analysis of the polymer electrolyte after saponification showed that the total CO content was 12.1 mol%. The photodegradability test results are shown in Table 1 along with comparative examples.

[Table-1] Molecular weight double quantum uniform molecule! (MW) Rate of change i Mw (xhr) /Mw(Ohr)×10
0 [Example-3] A photolysis test was conducted using the polymer electrolyte of Example-2,
A biodegradability test was conducted on the material before and after the test. The test conditions were conducted using a closed system oxygen consumption measuring device in accordance with the method stipulated in the Chemical Substances Examination and Regulation Act. Test material in 200ml of basic culture medium! 50ppm sewage treatment activated sludge 1100p
p was prepared and the change in oxygen consumption was measured over time at 25°C. The polymer electrolyte photolyzed for 8 hours showed a high decomposition rate of 50% after 14 days, whereas the polymer electrolyte that did not undergo photolysis was hardly decomposed.

Patent applicant: Mitsubishi Yuka Co., Ltd.

Claims (1)

[Claims] A method for treating a polymer electrolyte, comprising irradiating a polymer obtained by a copolymerization reaction of an unsaturated carboxylic acid, an olefin, and carbon monoxide with light having a wavelength of 2,200 to 6,000 angstroms.