JPS6133237A - Preparation of isomerization accelerating agent - Google Patents

Abstract

PURPOSE:To obtain an insoluble reaction accelerating agent which is easily separable by transforming a cross-linked polyethylene molded material into a large- surface area body with a swelling method while keeping the original shape, and grafting chloromethyl styrene onto said body. CONSTITUTION:A cross-linked polyethylene molded material is obtained by treating a polyethylene molded material with gamma-ray irradiation, electron-beam irradiation, or other vulcanization, etc. The cross-linked polyethylene molded material is temporarily immersed into a large amt. of a high-boiling point nonpolar solvent such as toluene and xylene, and heated for several hours while agitating gently to swell the material. Then the swollen polymer is separated by filtration, transferred into a large amt. of methanol, agitated, washed repeatedly with methanol, and then air-dried to obtain the large-surface area cross-linked polyethylene. Chloromethyl styrene is grafted onto said polyethylene, and polymerized.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a method for producing an insoluble reaction accelerator for various isomerization reactions.

(b) Prior Art Many organic isomerization reactions are significantly accelerated by certain organic low-molecular substances. For example, it is known that in photoisomerization reactions, ketone compounds with absorption bands in the ultraviolet region promote the reaction, and in reverse isomerization reactions, porphine-based organometallic carriers act as sensitizers or catalysts to accelerate the reaction. However, these reaction accelerators include:
It is desirable that the contact area with the reactant be large, that it has an affinity for the reactant, and that it has the effect of increasing the local concentration. On the other hand, it is a necessary requirement for process continuity that it can be easily separated from reactants, product substances, and the like.

As a specific example, we will discuss the exothermic back reaction of norbornadiene, a typical substance used in the chemical conversion of solar energy, in the dark.

Norbornagene is a useful liquid photochemical heat storage agent that exhibits a large increase in enthalpy when photoisomerized to quadricyclene.The photoisomerization reaction caused by sunlight and its opposite exothermic reaction are combined and repeated as a circular cycle. A usable light energy to thermal energy conversion storage system can be formed. However, Noi Rebornadien himself,
Since it does not have a suitable absorption band, it cannot directly utilize sunlight. Therefore, all photosensitizers are required, and the sensitizers are
It must not be such that the reverse reaction catalyst eM of the produced quadricyclene is dyed, and the reverse reaction catalyst U + - must not be
If contamination with the photoreaction chamber occurs, the generated quadrindrene will generate heat and return to norbornadiene, making it impossible to synthesize the entire system. Therefore, in this case, the photosensitizer, the agent, and the reverse reaction catalyst need to be easily and completely fractionated from the reaction solution. Catalysts have been used. However, conventional polymeric carriers for these reaction accelerators have been almost entirely composed of powder or fine bead-like porous polystyrene, which has a low degree of swelling, has little effect on increasing the local concentration of reactants, and has a low reaction accelerating effect.

In addition, many of them are in a form that obstructs the flow of the reaction solution.
Is the current situation far from practical use? 6ru. (For example, A, Ake
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sci, s, 95 (/ri 77)) The present invention relates to a method for producing an industrially applicable and TJ-capable insoluble isomerization reaction accelerator that overcomes the above-mentioned drawbacks. The objective is to produce an easily separable insoluble reaction accelerator that has a macroscopic morphology that utilizes selective adsorption to a high degree.

(d) Structure of the invention First, crosslinked polyethylene is used as a catalyst base material or carrier. The original polyethylene may be in the form of particles, film, fibers, or adhered to or mixed with other materials such as organic or inorganic metal fibers. For the crosslinking treatment, gamma ray irradiation, electron beam irradiation, or other vulcanization operations can be used, but a similar molded product of modified polyethylene for water crosslinking can also be made into crosslinked polyethylene using water or steam. . The size of the molded product is
There is no problem as long as the liquid can be easily separated.

After crosslinking, it is immersed in a large amount of a nonpolar solvent with a high #li point such as toluene or xylene, and heated and swelled for several hours while being gently stirred. Although the degree of swelling depends on the degree of crosslinking, the amount of solvent used is preferably 10 times or more in order to prevent the mutual adhesion of the swollen polyethylene. When swollen, the polyethylene is completely transparent, but after cooling it becomes an opaque bulk gel, and if the solvent concentration is sufficient, the solvent is separated as a supernatant. The swollen polymer is separated by filtration, transferred to a large amount of methanol, stirred, and washed with methanol without applying pressure. 1
By removing the mixture by air drying, a crosslinked polyethylene having a large surface area and maintaining the shape B of the molded article can be obtained.

Since the product is often soft and spongy, it is not desirable to apply pressure during the filtration. The obtained sponge-like polyethylene has a thickness of about /3;n? It is known to have a surface area of /9. Next, chloromethylstyrene is graft-polymerized onto this spongy polyethylene. The chloro, 'methylstyrene used may be pure or a commercially available p-lm-mixture, and may also be used with a stabilizer added or diluted with a solvent. As the grafting method, any of the various known methods may be used, including a method using an initiator, a method using ionizing radiation, an ultraviolet irradiation method, and an ultrasonic method. Although the example uses a liquid phase method using γ-ray irradiation, it is also possible to use a gas phase method using the same γ-rays. After the grafting reaction, unreacted chloromethylstyrene and hisono homopolymer are completely removed using a solvent such as benzene, and then washed with methanol etc.
When air-dried, a spongy polyethylene grafted with polychloromethylstyrene that maintains the same molded form as before is obtained. Finally, by reacting the grafted polychloromethylstyrene with a compound having the required reaction accelerating function, a gold-tin polyethylene molded body having a reaction accelerating function can be obtained.

Examples of reactive compounds with a reaction promoting function include g
-acetylbenzoic acid (p-ace1-phenonecarboxylic acid). This compound combines carboxyl x' with the benzene nucleus of acetophenone, which is well known as a triple photosensitizer.

It has a similar structure. Therefore, the carbonyl of the acetyl group of the compound is essential for its function as a photosensitizer, and even after bonding to polyethylene via polychloromethylstyrene,
The functionality will be retained.

Furthermore, the carboxyl group of the compound reacts with the chlorine of the chloromethylstyrene group and condenses with the loss of all water chloride, thereby linking the photosensitizing group structure to polyethylene.

In other words, the reactive compound with a reaction promoting function referred to here is:
It is a compound that has two functions: a reaction promoting function and its own reactivity or binding ability. Although the photointensification function by the aromatic carbonyl group has been exemplified as the reaction promoting function, various other catalytic functions can also be mentioned.

For example, the metalloporphyrin complex structure shown in Example 3,
It has a catalytic function that promotes the reverse reaction of quadricyclene to norbornadiene.

There are many organic compounds that are recognized to have various functions, not limited to these functional examples, and these functions can be bonded to crosslinked polyethylene by providing them with an appropriate reactive group. As the reactive group, the carboxyl group was mentioned above, but since chlorine in chloromethylstyrene is highly reactive, it condenses with amino groups, hydroxyl groups, sodium salts, potassium salts, etc. in the presence of carboxyl. Since they can be bonded to compounds, the combinations of functional groups and reactive groups are diverse. During the condensation, an excess amount of a reactive compound having a reaction promoting function is added to the polychloromethyl-renuthylene-grafted crosslinked polyethylene, preferably //~5x magnification,
This can be achieved by adding a suitable solvent such as benzene, dimethylformamide, etc., and heating for several hours while stirring. After the reaction, the insoluble isomerization reaction accelerator is obtained by washing with an appropriate solvent, filtering, and finally washing with methanol or the like and drying, which also maintains the form of the molded product. The mode of implementation will be shown below with reference to Examples.

<e> Example/ A high-density polyethylene pellet molded to a diameter of 3 to 41 ztn was used as a vacuum-sealed tube, and γ-rays from cobalt-60 were injected into the tube at room temperature. 2 x / (75R/hr
It was irradiated for 50 hours (edge line ffr, 707R) to achieve almost complete crosslinking. Gel fraction by solvent extraction method is 7%
It turned out. 20 pieces of this pellet and 3 xylene; 0 0
ml was added and the mixture was heated to near the boiling point and kept for 5 hours to swell. After cooling, briefly remove the supernatant liquid,
Next, solidified gel material t2I! of methanol, stirred for about 7 hours, repeated the operation sound twice, and finally filtered.
The product was washed with methanol and air-dried to obtain white spongy granular cross-linked polyethylene with a large surface area. Next, put the glue 6 tag into a sealed OMM test tube, add 10 trl of unpurified chloromethylstyrene and benzene. ; O
When mef was added, the mixture became such that almost all of the granular polyethylene was submerged.

This test tube was repeatedly frozen and degassed using liquid nitrogen, and after being evacuated, the tube was sealed with 10" IIMHg, and the gamma rays from cobalt-60 were irradiated at a dose rate of j x IO'R/hr at room temperature.
I irradiated it for an hour. After irradiation, granular polyethylene TFI
This was separated, washed with benzene, +=b, immersed in methanol, and air-dried after each house. /7g, the chlorine content was 3.7j%, and the grafting rate was 3.7j%. Next, polychloromethylstyrene-grafted crosslinked polyethylene particles 702 particles (approximately 50 particles) were placed in an Erlenmeyer flask, and 702 particles of polychloromethylstyrene grafted cross-linked polyethylene were placed in an Erlenmeyer flask. ! ;
yxl.

and benzene! ;0 ml was added, and the mixture was stirred and heated on a boiling water bath for 2 hours with a reflux condenser attached. After cooling, the polyethylene particles are filtered through a TP filter, washed repeatedly with benzene and methanol, and dried under reduced pressure to obtain sponge-like polychloromethylstyrene graft crosslinked polyethylene particles bonded with acetophenone groups. I got 9 & tag money. At a chlorine content of 2.77%, acetophenone groups were bonded to 29.0% of the polychloromethylstyrene residues.

Example 2 Two polychloromethy/I/7-ethylene grafted crosslinked polyethylene particles of Example were placed in an Erlenmeyer flask.
o-benzoylbenzoic acid (penzophenone carpho)
phosphoric acid)/: to IP, l-rich
Rua Min 03;mi.

benzene! The mixture was added to Ornl' and heated with stirring on a boiling water bath with a reflux condenser for 2 hours. After cooling,
The polyethylene grains kV-i were separated, washed twice with benzene and methanol, and dried under reduced pressure to obtain polychloromethylstyrene 7) mW polyethylene grains Og5-2 with benzophenone groups bonded. At a chlorine content of 70%, 34% of the chlorine in the chloromethyfurstyrene residue was substituted with benzophenone groups.

Example 3 Polychloromethylnutylene grafted crosslinked polyethylene particles with %l'MllJ/ 03! ;,29, cobalt-protoporphyrin 0.793119. Triethylamine 0./tttt and dimethylformamide Oxt were added and heated with stirring for an hour. After cooling, the polyethylene was separated, washed with hot dimethylformamide chloroform, and dried under reduced pressure to obtain cobalt-protoporphylynthylene grafted crosslinked polyethylene particles of 0/3.The chlorine content was 2.73%. This means that 239% of the chloromethylstyrene residues were bound to Coba I retauprotovoruphyrin.

(io) Effects of the Invention The reaction accelerator according to the present invention is insoluble, and while maintaining its macroscopic morphology, the crosslinked polyethylene that serves as the base material not only has a large surface area but also has an affinity for non-polar organic substances. The reaction is accelerated by shrinkage and adsorption of the reactant, and the reaction efficiency is extremely high.
It has the characteristic of being easy to distinguish. The effect will be shown in reference examples in comparison with cases where other insoluble carriers are used.

The following table shows the effect as a photosensitizer on the photoisomerization reaction of the polychloromethylnutylene grafted polyethylene grains with acetophenone groups and benzophenone groups synthesized in Examples and Co. This is what is shown.

The light used for this specification was ultraviolet rays (intensity/
0 5erg,/cJ-sec) Te,/on
Corner + 7) a BA 7c + 'Jj 1), 2 in cell
), add 3 sensitizer grains and add 3 me (7)
/ mol/j' m degrees of norbornadiene-chlorohexane solution was added, and the interior was irradiated while stirring, and the conversion to quadricyclene was measured using a gas chromatograph. Among the samples used in the table below, 3) is cellulose acetate fiber, 4) is cashmilon fiber, and 5) is activated ash fiber with an extremely large surface area, and chloromethylstyrene is directly grafted to each! After that, a benzophenone group was bonded, and the bonding number is also shown in the table.

As can be seen from the table, the crosslinked polyethylene particles, ie, 1) and 2), have the greatest reaction accelerating effect despite their small amounts and the amount of bonded sensitizing groups. 7 Report! It was found that the isomerization rate of renadiene to quadrindrene does not depend on the amount of photosensitizing groups in the sample or the surface area of the carrier, but largely depends on the swelling and adsorption properties of the base material. This clearly shows the effects of this invention.

Table/Isomerization reaction promotion effect of various insoluble photosensitizers/Length 77 fully bonded crosslinked polyethylene grains (approximately 0.3
9 '') Add it to the cyclohexane in the colander along with the quadrine from Ootza 2, and stir while stirring.
The heat generation rate and calorific value were measured using a twin-type constant temperature wall calorimeter at C. As a result, approximately 50 Joules of heat was generated, which was much higher than when cobalt-protoporphyrin was bonded to other fibrous materials, clearly demonstrating the effectiveness of the present invention.

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Claims (1)

[Claims] A cross-linked polyethylene molded product is made into a large surface area that maintains its original shape by a swelling method, and then chloromethylstyrene is grafted onto this product. By replacing the chlorine, a reactive group with a reaction accelerating function is bonded to it. A method for producing an isomerization reaction accelerator, the method comprising: