JPH0297525A - Production of polyalkylene carbonate - Google Patents

Abstract

PURPOSE:To make it possible to use CO2 as industrial resource by producing a polycarbonate resin by copolymerizing CO2 with an epoxy compound in the presence of a solid catalyst obtained by mechanically grinding ZnO and an organic dicarboxylic acid. CONSTITUTION:A solid catalyst is prepared by grinding and mixing ZnO and an organic dicarboxylic acid such as glutaric acid with, e.g., a ball mill. A polyalkylene carbonate is obtained by copolymerizing CO2 with an epoxide (e.g., propylene oxide) in the presence of the above catalyst (desirably, under conditions including a CO2 pressure of 5-50kg/cm<2>, a polymerization temperature of 50-150 deg.C and a polymerization time of 1-10hr). This polymer has transparency, a feature of being completely decomposed by heating, and biodegradability, is applicable to general moldings, films, binders, medical materials, etc., and can exhibit excellent performances when used as a vibration-damping material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for polymerizing synthetic resins using carbon dioxide gas, which has hitherto been an unused resource in industry.

Large amounts of carbon dioxide are released onto the earth through industrial production activities or the respiration of living organisms, but due to its low reactivity, it has not been effectively used industrially as a resource until now. Utilizing this carbon dioxide gas as an industrial resource is also significant from the perspective of effectively utilizing the earth's limited resources.

Several proposals have been made regarding methods for synthesizing synthetic resins using carbon dioxide gas as a raw material. For example, as illustrated in the Journal of the Chemical Society of Japan, No. 2, 1982, 295 pages,
Reaction products of zinc acetate and aliphatic dicarboxylic acids,
A reaction product of alkylzinc and water is used as a catalyst, and Polymer Journal 1981
As illustrated in Vol. 13, p. 407, reaction products of zinc hydroxide and various carboxylic acids are used as catalysts.

However, these catalysts require the use of some kind of solvent during their synthesis, and their polymerization activity cannot be said to be sufficiently high.

As a result of intensive studies on the synthesis of polymers using carbon dioxide gas as a resource, the present inventors found that a dumbbell-containing solid catalyst component synthesized by bringing zinc oxide and an organic dicarboxylic acid into contact with each other using mechanical pulverization treatment means: The present inventors have discovered that a special melt is not required for its synthesis and that it exhibits high activity during polymerization, leading to the completion of the present invention.

The present invention has been made in view of the above-mentioned points, and is a method of obtaining polyalkylene carbonate in high yield by copolymerizing carbon dioxide and epoxide using a specific catalyst. The purpose of the present invention is to provide a method for producing polyalkylene carbonate that can be used.

Nine lessons learned: The method for producing polyalkylene carbonate according to the present invention involves the production of carbon dioxide and epoxide in the presence of a zinc-containing solid catalyst component obtained by bringing zinc oxide and organic dicarboxylic acid into contact with each other using mechanical pulverization treatment means. It is characterized by copolymerizing.

DETAILED DESCRIPTION The method for producing polyalkylene carbonate according to the present invention will be specifically explained below.

Tamawata 2L Egami Epoxides that can be used in the present invention are preferably monoepoxides, such as ethylene oxide, propylene oxide, 1-butene oxide, 2-butene oxide, inbutylene oxide, 1-pentene oxide, 2
-pentene oxide, 1-hexene oxide, 1-octene oxide, -decene oxide, cyclopentene oxide, cyclohexene oxide, styrene oxide,
Vinyl cyclohexane oxide, 3-phenylpropylene oxide, 3,3.3-4-lifluoropropylene oxide, 3-naphthylpropylene oxide, '3-phenoxypropylene oxide, 3-naphthoxypropylene oxide, butadiene monoxide, 3-vinyl Oxypropylene oxide, 3-trimethylsilyloxypropylene oxide, methylglycidyl carbonate, ethylglycidyl carbonate, cholesterylglycidyl carbonate, etc. can be displayed, among which propylene oxide,
Ethylene oxide and cyclohexene oxide are preferred, and these may be used alone or in combination with 2a or more.

The manufacturing method for the zinc oxide used in the synthesis of the catalyst in the present invention is not a particular problem; for example, zinc oxalate can be thermally decomposed to 400°C or higher, or zinc hydroxy carbonate can be dehydrated by heating. method, method of burning metal zinc,
Alternatively, zinc oxide produced by roasting zinc ore together with a reducing agent and oxidizing the generated zinc vapor in the air can be used.

Examples of organic dicarboxylic acids used in synthesizing the catalyst used in the present invention include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, 1.5- Pentanedicarboxylic acid, 1.6-hexanedicarboxylic acid, 1.8
-Aliphatic dicarboxylic acids such as octanedicarboxylic acid, 1.10-decanedicarboxylic acid, phthalic acid, inphthalic acid, terephthalic acid, 1.2-naphthalenedicarboxylic acid, 1
．． 3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid, 1.5-naphthalene dicarboxylic acid, 1.6
-Naphthalene dicarboxylic acid, 1.7-naphthalene dicarboxylic acid, 1,8-naphthalene dicarboxylic acid, 2.3-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2.6-naphthalene dicarboxylic acid, 2.7-naphthalene Examples include aromatic dicarboxylic acids such as dicarboxylic acids, and among them, glutaric acid and adipic acid are preferred, and these may be used alone or in combination of 28 or more.

The catalyst is synthesized by bringing the above-mentioned zinc oxide and organic dicarboxylic acid into contact with each other by mechanical pulverization treatment means and causing a reaction.

The contact with the zinc oxide and the organic dicarboxylic acid by mechanical pulverization is specifically carried out using, for example, a ball mill, a vibration mill, an impact mill, a Waring blender, a shearing mixer, or the like. Furthermore, the catalyst can be synthesized by simply mixing zinc oxide and an organic dicarboxylic acid. The charging ratio of zinc oxide and organic dicarboxylic acid during pulverization is usually 1 mole of zinc oxide to 0 organic dicarboxylic acid.
．． The amount ranges from 1 mol to 10 mol, preferably from 0.5 mol to 2 mol.

It is preferable to select the grinding conditions appropriately depending on the type of raw material and the grinding equipment, but if we take a rotary ball mill as an example, we will use a stainless steel ball cylinder with an internal volume of 800 ml and an inner diameter of 100 mm, and a stainless steel W4 ball with a diameter of 15++n+. 10
0 pieces and the amount of material to be processed is 20 to 40 tr, the vibration should be carried out at a rotation speed of 125 rpm, usually for 10 minutes to 30 days, preferably for 20 minutes to 7 days. Taking a mill as an example, a 2.8 kg stainless steel ball with a diameter of 15 mm is housed in a stainless steel ball cylinder with an internal volume of 800 m1 and an internal diameter of 100 m+.
When the amount of material to be processed is 20 to 40f, the acceleration of impact is 7
G level, usually 1 minute to 10 days, preferably 5 minutes to 4 days
It is sufficient to carry out the grinding process to the extent equivalent to one day's grinding process, and the temperature of the grinding process should normally be selected around room temperature, and if heat generation is significant, perform appropriate cooling and raise the temperature to 0°C to 150°C.
It is preferable to grind at a temperature of .

The zinc-containing solid catalyst component synthesized as above is
It is thought that the organic dicarboxylic acid and zinc oxide are chemically reacted. This is because, compared to the infrared absorption spectrum of the organic dicarboxylic acid that is the raw material, the stretching vibration absorption band of the carbonyl group shifts to the lower wave number side due to the reaction between the organic dicarboxylic acid and zinc metal. Because there is. Furthermore, the zinc-containing solid catalyst component used in the present invention can be heated to -
The organic dicarboxylic acid has the characteristic that it decomposes at a certain temperature.

Note that the catalyst synthesized as described above can be subjected to a polymerization reaction up to t, but usually, the water generated during the reaction acts as a polymerization inhibitor, so it is degassed before polymerization. Drying is preferred.

When copolymerizing carbon dioxide gas and epoxide using the above-mentioned catalyst, usually aliphatic hydrocarbons such as pentane, hexane, octane, decane, cyclohexane, benzene, toluene, xylene, etc. Aromatic hydrocarbons, tetraromethane, methylene dichloride, chloroform, carbon tetrachloride, 1,1-dichloroethane, 2-dichloroethane, ethyl chloride, trichloroethane, 1
- It is preferable to use one or more halogenated hydrocarbons such as chloropropane, 2-chloropropane, 1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane, chlorobenzene, and bromobenzene as the polymerization solvent. . In some cases, it is possible to use the monomer (epoxide) itself as a polymerization medium, and the above-described polymerization reaction according to the present invention may be carried out in a gas phase, for example, in a fluidized catalyst bed. The order in which the polymerization solvent, monomer (epoxide), carbon dioxide gas, and catalyst are added is not particularly limited.

The charging ratio of the solvent and the monomer (epoxide) is generally preferably in the range of 0:100 to 99:1, particularly 0:100 to 90:10, in terms of volume ratio.

The pressure of carbon dioxide gas supplied to the reaction system is not particularly limited, but Ohf/ti~200+r/d, preferably 3hg/-~100in/d, more preferably 5 kg
The tetrapolymerization temperature, which is preferably in the range of /cl to 50 kg/cd, is usually o'c to 200°C, preferably 50°C to 150°C.

In the present invention, by carrying out the polymerization reaction for a long time,
It is possible to increase the yield of polymer. Therefore, the polymerization time is not particularly limited, but is usually 30 minutes to 24 minutes.
The range is 0 hours, preferably 1 hour to 80 hours, more preferably 1 hour to 10 hours.

Further, the above polymerization reaction can be carried out in any of the batch, semi-continuous, and continuous methods, and it is also possible to carry out the polymerization in two or more stages under different reaction conditions.

After the polymerization reaction is completed, the catalyst residue can be removed by filtration or by washing with a dilute acid or dilute alkali aqueous solution. The resulting polymer can be recovered by flashing or evaporating the polymerization medium to dryness, or by precipitating the polymer dissolved in a good solvent in a poor solvent such as hexane or methanol.

According to the present invention, by using a specific catalyst, a useful polymer can be synthesized from carbon dioxide gas, which has not been used hitherto, as a raw material. This polymer has good transparency and is characterized by complete decomposition when heated. Therefore, this polymer can be used not only for general molded products, films, fibers, etc., but also as a material for optical fibers, optical disks, ceramic binder lost form casting, etc. Furthermore, since this polymer has the property of being degradable in vivo, it can be applied to applications that require biodegradability of medical materials.

Furthermore, when this polymer is used as a vibration damping material, it also exhibits excellent performance.

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to the following examples.

Catalyst Preparation> 10.0 g of commercially available zinc oxide and 16.2 g of glutaric acid were mixed in a stainless steel ball mill with an internal volume of 800 mm and an internal diameter of 100 mm, containing 100 stainless steel balls with a diameter of 15 mm. The oxidized fine stones and glutaric acid were placed in a cylinder and brought into contact with each other for 1 hour while rotating the ball mill cylinder at 25 rpm. The obtained solid treated product was dried under reduced pressure at 150°C to form a hexane slurry, which was then used as a catalyst.

Polymerization> 2000 il of propylene oxide, 700 nnl of hexane, and 5.4 g of catalyst in O-1 to crepe with an internal volume of 21
and supply carbon dioxide gas to the reaction system to raise the temperature inside the system to 80°C1.
Polymerization was carried out at a pressure of 20 kg/-.G for 2 hours while newly feeding consumed carbon dioxide into the system.

After the reaction was completed, the apparatus was cooled and depressurized, and a large amount of the white polymer (because it contained the catalyst), which was a hexane slurry, was filtered out. The weight of the polymer after drying was 45.4 g. The yield of polymer per gram of catalyst was 8.4 g.

A catalyst was prepared in the same manner as in Example 1, except that the contact time between zinc oxide and glutaric acid was changed as shown in Table 1. Polymerization was carried out in the same manner as in Example 1 using the obtained catalyst. The results are shown in Table 1.

-1 Preparation of commercially available zinc oxide and 16.2 g of glutaric acid in a 800 ml, inner diameter 100 mm container containing a 2.8 kHz stainless steel ball with a diameter of 15 mm. The sample was placed in a stainless steel ball mill cylinder and brought into pulverization contact for 15 minutes at an impact acceleration of 7G. The solid treated product was dried under reduced pressure in the same manner as in Example PA] and then subjected to polymerization as a hexane slurry.

<Polymerization> The polymerization was carried out in the same manner as in Example 1, except that the amount of catalyst was changed to 5 g. The average weight of the polymer after drying was 34.3 g. The polymer content per gram of catalyst was 6.9 g.

A catalyst was prepared in the same manner as in Example 5, except that the contact time between zinc oxide and glutaric acid was changed as shown in Table 2. Polymerization was carried out in the same manner as in Example 1 using the obtained catalyst. The results are shown in Table 2.

6--2 was 1g.

Comparative Example 1 was carried out in the same manner as in Comparative Example 1, except that a catalyst synthesized by dropping a methanol solution of dumbbell acetate into a methanol solution of glutaric acid was used. The yield of polymer per gram of catalyst was 1.7 g.

Catalyst Preparation> Dissolve 20 g of commercially available zinc acetate in 200 ml of methanol, and while stirring this /8 solution, add 12 g of glutaric acid into it.
A solution of 150+nl of methanol was prepared at room temperature for 30+nl.
It was dripped over several minutes. After stirring for another 2 hours at room temperature, the white precipitate was filtered and washed with methanol.
50'(?1''') was dried under reduced pressure and subjected to polymerization as a hegisane slurry.

Polymerization>

Claims (1)

[Claims] Production of polyalkylene carbonate characterized by copolymerizing carbon dioxide gas and epoxide in the presence of a zinc-containing solid catalyst component obtained by bringing zinc oxide and organic dicarboxylic acid into contact with each other by mechanical pulverization treatment means. Method.