JP2001181379A - Poly(ketoester-ester) copolymer and its preparation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preparation method of a novel high-molecular weight poly(ketoester-ester) copolymer from a polyester resin, particularly, from a waste such as a recovered PET bottle. SOLUTION: The novel poly(ketoester-ester) copolymer comprising a repeating unit (A) and (B) represented by formula 5 (formula 1 or 3) (wherein m is an integer of 5-500; R1 is a 2-20C dihydric organic group) and formula 6 (formula 2 or 4) (wherein n is an integer of 1-500; R2 is a 1-20C aliphatic, aromatic, aliphatic-aromatic or alicyclic dihydric organic group; R3 is a 2-200C dihydric organic group) respectively, is prepared by (1) reacting a polyester resin with a diester compound having α-active hydrogen in the presence of an alcoxide compound in a nonprotic solvent, or further (2) by adding a carboxylic acid activator and/or an inorganic salt thereto and reacting them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a poly (ketoester-ester) copolymer and a method for producing the same.
The present invention relates to a high molecular weight poly (ketoester-ester) copolymer and a method for advantageously producing the same.

[0002]

2. Description of the Related Art Polyethylene terephthalate resin (hereinafter abbreviated as PET), polybutylene terephthalate resin, polyarylate resin and the like as a polyester resin are plastics having excellent mechanical and electrical properties and good moldability. As such, it is produced in large quantities today. In particular, the production amount of PET is expected to increase remarkably in recent years as a bottle of soft drink and the like, and further expand.

[0003] However, the expanding production of PET bottles has caused serious garbage problems on the one hand, and has become a social problem. Therefore, many recycling processes have been proposed for the purpose of recycling used PET bottles. For example, (1) washing the collected bottle,
Reuse (reuse). (2) The collected bottles are pulverized, melt-kneaded, and again formed into PET pellets, and then reprocessed into fibers, various molded products, and the like. (3) Recovered PET
The bottle is decomposed into monomer monomers by hydrolysis or the like, and polycondensed again to form PET. Some of these methods are:
Although it has been put into practical use, it has many problems at present. The most common of these issues is
It is a cost issue. In other words, not only in PET but also in recycling iron, aluminum, paper, etc., the recycled material obtained by recycling is less valuable than the original material (virgin material), so the selling price of recycled material is higher than that of virgin material It never happens. Therefore, the costs required in the recycling process for collection, separation, and re-manufacturing cannot be recovered, and the recycling business will not be established as a company unless special social conditions or some kind of compensation are provided.

[0004]

Therefore, the present inventor has set forth
First, it was examined whether another high-value-added material could be newly synthesized from PET, and a method of synthesizing a heat-resistant polyamide resin was proposed (Japanese Patent Application Laid-Open Nos. 9-324037 and 11-240).
106504). However, in order to cope with the increasing waste of PET bottles, the development of a route for synthesizing another useful material using a polyamide resin alone is not sufficient in quantity.

Here, the present invention has been made in view of such circumstances, and a problem to be solved is to provide a new high value-added resin other than polyamide resin from increasing PET bottle waste. It is to synthesize.

[0006]

Means for Solving the Problems In order to solve such problems, the present invention provides a repeating unit (A) and a repeating unit (A) represented by the following chemical formulas (1) and (4), respectively. (B), comprising a novel poly (ketoester-ester) copolymer,

Embedded image (Where m is an integer of 5 to 500, and R ₁ is a divalent organic group having 2 to 20 carbon atoms)

Embedded image (However, n is an integer of 1 to 500, R ₂ is an aliphatic, aromatic, aliphatic-aromatic, alicyclic divalent organic group having 1 to 20 carbon atoms, R _{3 is a} divalent organic group having 2 to 200 carbon atoms. A polyester resin and a diester compound having α-active hydrogen in the presence of an alkoxide compound in an aprotic solvent, and further adding a carboxylic acid activator and / or an inorganic salt. The present invention has been accomplished by knowing that they can be synthesized by reacting. By employing such a method of the present invention, the desired poly (ketoester-ester) copolymer can be efficiently produced with a high molecular weight.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

By the way, the poly (ketoester-ester) copolymer referred to in the present invention is a polyketoester structure represented by the above formula (4) and a repeating unit represented by the above formula (3) And a polyester structure having the formula: The ratio between the polyketoester structure and the polyester structure is such that the polyketoester structure is 10%.
0 to 5% by weight (polyester structure is 0 to 95% by weight),
Preferably 100 to 10% by weight (polyester structure is 0%
To 90% by weight), more preferably 100 to 15% by weight.
(0 to 85% by weight of polyester structure). If the polyketoester structure is less than 5% by weight, even if the polyketoester structure is introduced into the polyester molecule, the polyester resin cannot be given excellent properties due to the polyketoester structure. When the proportion of the polyester structure is 0% by weight, the poly (ketoester-ester) copolymer becomes a polyketoester homopolymer.

Now, the poly (ketoester-ester) copolymer of the present invention has the following properties:
The diester compound having α-active hydrogen is reacted in an aprotic solvent in the presence of an alkoxide compound, or (2) at least one of a carboxylic acid activator and an inorganic salt is reacted with the reaction system of (1). Obtained by additional addition to

In the present invention, the polyester resin generally means terephthalic acid or a derivative thereof (a dicarboxylic acid component) and a dihydric alcohol compound (a diol component).
Alternatively, it is obtained by a polycondensation reaction of a dihydric phenol compound. Here, as the dihydric alcohol compound, ethylene glycol, butane-1,3-diol,
Butane-1,4-diol (tetramethylene glycol) and the like, and examples of the dihydric phenol compound include various bisphenols such as bisphenol A.
In addition, as part of the dicarboxylic acid component, various aliphatic, aromatic or alicyclic dicarboxylic acids and derivatives thereof other than terephthalic acid or its derivatives, and diol / phenol components, as long as they do not depart from the gist of the present invention. Other than the above, a dihydric alcohol compound or a dihydric phenol compound may be used. However, it is desirable that the other partially used dicarboxylic acid or dihydric alcohol / phenol compound be in a proportion of 50 mol% or less in each component.

[0011] Specific examples of the polymer having a polyester structure in the present invention include polyethylene terephthalate resin, polybutylene terephthalate resin,
Polyaryl resins (U-polymer and the like) and the like can be mentioned.
In particular, a polyethylene terephthalate (PET) resin, in particular, a recycled (recovered) PET resin is desirable.

The limiting viscosity of the polyester resin used as such a raw material is 0.2 dl / g or more, preferably 0.3 dl, measured at a temperature of 30 ° C. using hexafluoroisopropanol as a solvent. /
g or more. However, if the intrinsic viscosity is less than 0.2 dl / g, the intrinsic viscosity of the poly (ketoester-ester) copolymer obtained by the present invention is small, and even if solid-phase polycondensation or melt polycondensation is performed later, This is because the effect of improving the degree is low, and an industrially useful high molecular weight poly (ketoester-ester) copolymer cannot be obtained.

The shape of the polyester resin used here is not limited, but preferably, a powdery shape having an average particle size of 1 mm or less is advantageously used. The water content is generally 1000 ppm or less, preferably 500 ppm
pm or less.

On the other hand, specific examples of the diester compound having α-active hydrogen, which is another reaction raw material, which can be reacted with the polyester resin, include ethylene glycol diacetate, propanediol diacetate, butanediol diacetate, Examples include ethylene glycol propionate, ethylene glycol dibutyrate, ethylene glycol diphenylacetate, polyethylene glycol diacetate, polypropylene glycol diacetate, and polybutylene glycol diacetate. The diester compounds having α-active hydrogen may be used alone or in combination of two or more. Further, the diester compound having such α-active hydrogen is used in an amount of 0.01 to 1.
It is preferably used in a proportion of 5 moles. It ’s
If the amount is less than 0.01 mol, the polyester resin is not enough to be converted into a poly (ketoester-ester) copolymer, and if the amount is 1.5 mol or more, the effect becomes more than necessary and becomes saturated.

Next, such a poly (ketoester)
Specific examples of the alkoxide compound acting as a catalyst for the formation of the (ester) copolymer include sodium methoxide, sodium ethoxide, potassium isopropoxide, sodium butoxide and the like. These alkoxide compounds can be used alone or in combination of two or more. The alkoxide compound is used in an amount of 0.001 to 1 mol of the diester compound having α-active hydrogen.
It is preferably used in a proportion of about 0.5 mol. If the amount is less than 0.001 mole, poly (ketoester-
No formation of an (ester) copolymer is observed, and when the amount is 0.5 mol or more, the molecular weight of the resulting poly (ketoester-ester) copolymer becomes extremely small.

Further, the polyester resin described above and α-
As a reaction medium for efficiently obtaining a poly (ketoester-ester) copolymer by reacting a diester compound having active hydrogen in the presence of an alkoxide compound, a specific solvent, especially an aprotic A solvent is used. And specific examples of such aprotic solvents include n-butane, i-butane, n-pentane, 2-methylbutane, 2,2′-dimethylpropane,
n-methylpentane, 3-methylpentane, dimethylbutane, n-hexane, 2-methylpentane, 2,3-dimethylbutane, n-heptane, 2-methylhexane,
-Methylhexane, 2,3-dimethylpentane, n-octane, n-nonane, n-decane, i-decane, n-tridecane, benzene, toluene, xylene, ethylbenzene, cumene, n-propylbenzene, n-butylbenzene , N-octylbenzene, dodecylbenzene (linear, branched), cyclopentane, cyclohexane, decalin, tetralin, methylcyclopentane, methylcyclohexane, etc., aliphatic, aromatic, aliphatic-aromatic, or alicyclic carbonization Hydrogen-based solvent; 1,2-dichloroethane,
1,1,1-trichloroethane, chlorobenzene, p-
Halogenated hydrocarbon solvents such as chlorotoluene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, 3,4-dichlorotoluene, 1,2,3-trichlorobenzene; diethyl ether, dipropyl ether, di Butyl ether, dihexyl ether, ethyl vinyl ether, butyl vinyl ether, anisole,
Phenetol, butylphenyl ether, pentylphenylether, methoxytoluene, benzylethylether, diphenylether, dibenzylether, trioxane, 2-methylfuran, tetrahydrofuran, tetrahydropyran, 1,2 dimethoxyethane, 1,2
Ethers such as diethoxyethane, 1,2-butoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol diethyl ether, diethyl acetal, and acetal solvents;
Acetonitrile, sulfolane, 3-sulfolane, N-
Non-protonic phophophobic solvents such as methylpyrrolidone and 2-pidolidone; N, N'-dimethylformamide, N, N
Non-protic protic solvents such as N'-dimethylacetamide, dimethylsulfoxide, hexamethylphosphoric triamide and the like can be mentioned. These solvents may be used alone or in combination of two or more. Therefore,
The reaction solvent in the present invention also includes petroleum ether, petroleum benzine, gasoline, kerosene, and solvent naphtha. The water content in such a solvent is 5000 ppm
It is desirable that the content be not more than 1,000 ppm, more preferably not more than 500 ppm. Furthermore,
The ratio of the reaction solvent to the polyester resin is 100 to 5000 parts by weight, preferably 200 to 3000 parts by weight, based on 100 parts by weight of the polyester resin. In addition,
If the amount is less than 100 parts by weight, there is a problem that the polyester resin is not sufficiently dispersed in the reaction solvent and the reaction does not proceed uniformly. If the amount exceeds 5000 parts by weight, the reaction system becomes too dilute and the polyester resin becomes too thin. There is a problem that the reaction between the compound and the diester compound having α-active hydrogen does not proceed sufficiently.

According to another embodiment of the method for producing a poly (ketoester-ester) copolymer according to the present invention, a polyester resin and a diester compound having α-active hydrogen are reacted with an alkoxy compound as described above. When the reaction is carried out in an aprotic solvent, at least one of a carboxylic acid activator and an inorganic salt is further added, whereby the reaction is carried out by the carboxylic acid activator and / or In the presence of an inorganic salt, it is advantageously allowed to proceed. That is, in a reaction between a polyester resin and a diester compound having an α-active hydrogen in an aprotic solvent in the presence of an alkoxy compound, a carboxylic acid activator and / or an inorganic salt are added to allow the presence thereof to be relatively present. It is possible to produce a poly (ketoester-ester) copolymer having a very high molecular weight in a higher yield.

The reason why such excellent functions and effects can be achieved has not yet been sufficiently elucidated. However, according to the study of the present inventors, the polyester resin and the α-active hydrogen have been In the reaction with the diester compound, the polyester resin is hydrolyzed by a trace amount of water present in the reaction system, and the reaction of the present invention does not further proceed due to the terminal carboxylic acid of the polyester resin generated thereby. The addition of a carboxylic acid activator and / or an inorganic salt activates the terminal carboxylic acid,
It is presumed that water is removed from the reaction system to promote the reaction. Of course, it is needless to say that the present invention is not limited by such a guess.

Here, the carboxylic acid activator which is present in such a reaction system according to the present invention generally means a carboxylic acid which reacts with a carboxylic acid to form an acid chloride, an acid anhydride, an active ester or the like. Which form an acyl intermediate compound, for example, phosphites, phosphates, dichloride phosphites, dichloride phosphates, chloride phosphites, chloride phosphates, Amidophosphates, phosphines, phosphinous acids, phosphinic acids, phosphonous acids, phosphonic acids, phosphorus pentoxide, phosphorus pentachloride,
Examples thereof include phosphorus compounds such as phosphorus trichloride and thionyl chloride. In the present invention, among such carboxylic acid activators, aryl phosphite, aryl phosphate, aryl phosphine, aryl phosphite, aryl phosphite,
Phosphorous esters having an aryl group such as phosphonous acid aryl ester and phosphonic acid aryl ester, phosphorus pentoxide, phosphorus trichloride, and thionyl chloride are preferably used.

The phosphorus-based ester having an aryl group preferably used as the carboxylic acid activator in the present invention includes triphenyl phosphite, diphenyl phosphite, trinonylphenyl phosphite, phosphorus phosphite Phenyl chloride, triphenyl phosphate, diphenyl phosphate, triphenyl phosphine, triphenyl phosphine dichloride, phenyl diphenyl phosphite, phenyl diphenyl phosphinate, diphenyl phosphinous chloride, diphenyl phenyl phosphonate, diphenyl phenyl phosphonate Phenylphosphonous dichloride, diphenyl-2,3-dihydro-
1,3-benzisoxazol-3-ylphosphonate, phenylbis (2,3-dihydro-2-oxobenzothiazol-3-yl) phosphinate, diphenyl (2,3-dihydro-2-oxo-3-benzothiazolyl) Phosphonates and the like can be mentioned. Also, a tertiary amine such as pyridine or triethylamine may be added or compounded to such a carboxylic acid activator as a proton scavenger or an acid scavenger.

In the present invention, such a carboxylic acid activator is used in an appropriate amount so that the above-mentioned effects can be sufficiently exerted. Is added to the reaction system so as to be present in a proportion of 0.001 to 0.5 mol, preferably 0.005 to 0.3 mol, per 1 mol of the repeating unit (1), and is present. When the amount of the carboxylic acid activator in the reaction system is less than 0.001 mol, the initial effect cannot be sufficiently exerted. Conversely, when the amount exceeds 0.5 mol, the amount becomes less. You will not be able to get the effect you want.

On the other hand, in the present invention, the inorganic salt which is present in the reaction system between the polyester resin and the diester compound having α-active hydrogen is a compound formed by neutralizing the charge with a metal ion and an anion. In general, as such an inorganic salt, those composed of a metal ion such as an alkali metal ion, an alkaline earth metal ion, or a transition metal ion, and an anion such as a chloride ion, a bromine ion, or an iodide ion are advantageously used. Will be done. Specific examples of such inorganic salts include lithium chloride, sodium chloride, potassium chloride, lithium bromide, potassium bromide,
Lithium iodide, calcium chloride, magnesium chloride,
Examples thereof include nickel chloride and copper iodide. Among them, lithium chloride, calcium chloride, and copper iodide are particularly preferably used.

In the present invention, such an inorganic salt is used to such an extent that the above-mentioned effective effects can be effectively exerted. Usually, the aprotic solvent as the reaction solvent is used. For 100 parts by weight of
In a ratio of 0.1 to 10 parts by weight, preferably 0.5
It will be present in addition to the reaction system in a proportion of up to 5 parts by weight. This is because if the amount of the inorganic salt used is less than 0.1 part by weight, a sufficient effect cannot be exhibited, while if it exceeds 10 parts by weight, the effect corresponding to the amount cannot be obtained.

The polyester resin, the diester compound and alkoxide compound having α-active hydrogen, the reaction solvent, the reaction solvent, and the like are used so that the desired poly (ketoester-ester) copolymer is finally obtained. If necessary, a carboxylic acid activator and an inorganic salt, respectively, in their required amounts, are charged to a suitable reaction vessel having a stirrer, and by heating, such polyester resin and a diester compound having α-active hydrogen, A so-called cross Claisen condensation reaction occurs.

It should be noted that such a polyester resin and α-
To make the reaction with the diester compound having active hydrogen ideally proceed, first, the polyester resin is dissolved or dispersed in the reaction solvent, and then the alkoxy compound is added, and then the diester compound having α-active hydrogen Are desirably sequentially added little by little, but the necessary amounts of the alkoxy compound and the diester compound having α-active hydrogen may be mixed in advance, and then added little by little.

Now, such a polyester resin and α-
The reaction time with the diester compound having active hydrogen varies depending on the reaction pressure, the reaction time, the stirring state, etc., in addition to the reaction raw materials used, but it is usually 50 ° C. or higher, preferably 80 ° C. or higher.
℃ or more. If the reaction time is less than 50 ° C., it takes too much time to generate a reaction product. However, when the reaction temperature is set to be equal to or higher than the boiling point or the sublimation temperature of the reaction raw material or the solvent to be used, it is desirable to seal or pressurize the reaction vessel during the reaction.
Further, in the reaction time for reacting the polyester resin and the diester compound having α-active hydrogen,
Similarly to the above-mentioned reaction temperature, although it depends on many factors, it is generally 0.1 hours to 50 hours, preferably 0.2 hours to 30 hours. Keda, 0.1
If the reaction time is less than 50 hours, the production of the desired reaction product is not sufficient, and if the reaction time exceeds 50 hours,
This is because the effect obtained by extending the time further is small.

The reaction solvent between the polyester resin and the diester compound having α-active hydrogen in the presence of (1) the alkoxy compound and further (2) the presence of a carboxylic acid activator and / or an inorganic salt. The poly (ketoester-ester) copolymer as a reaction product present in the liquid is separated and recovered. The method for separating and recovering is to disperse the reaction product in a slurry in the reaction solvent. If it is dissolved, as it is, if a solvent spray-drying method is employed or an appropriate precipitant is added thereto to precipitate the reaction product, a conventional method such as a filtration method or a centrifugation method is used. And a separation technique is employed. Also,
The obtained isolate is dried by a known drying method using a hot-air drier, a vacuum drier, or the like, whereby an intended poly (ketoester-ester) copolymer is obtained. , The resulting poly (ketoester-ester)
In the case of the copolymer, its intrinsic viscosity is usually 0.3 to
It becomes about 2.5 dl / g.

When it is necessary to further increase the molecular weight of the poly (ketoester-ester) copolymer as a reaction product obtained in this embodiment, a so-called solid-phase polycondensation method The polycondensation method will be additionally performed.

Here, the solid-phase polycondensation is a method in which a polycondensation reaction is advanced while maintaining a solid state to increase the degree of polymerization, that is, to increase the molecular weight. Usually, the reaction product poly (ketoester-
Ester) From a temperature 50 ° C. higher than the glass transition temperature of the copolymer to a flow start temperature, preferably from 80 ° C. higher than the glass transition temperature to a temperature 20 ° C. lower than the flow start temperature, 1000 Pa or less, preferably 300 Pa or less The heat treatment is performed under reduced pressure or under an inert gas. The time for performing such a heat treatment varies depending on the temperature, the amount and shape of the reaction product, the shape of the apparatus, and the like, but is generally 0.2 hours to 20 hours, preferably 0.5 hours to 10 hours. Is done.

The melt polycondensation method is a method in which a poly (ketoester-ester) copolymer as a reaction product is heated and melted under reduced pressure or an inert gas, and the polycondensation is carried out while maintaining the state. Let the reaction proceed, the degree of polymerization,
That is, it is a method of increasing the molecular weight. The melting temperature employed in this heating and melting is not lower than the flow starting temperature of the reaction product and not higher than the thermal decomposition temperature of the reaction product, preferably 20 ° C. or higher than the flow starting temperature of the reaction product and 30 ° C. or lower than the decomposition temperature. Temperature. In addition, the time for performing such processing is 0.2 minutes or more and 15 minutes or less, preferably 0.1 minute or less.
It is desirable that the time is 5 minutes or more and 10 minutes or less. As a device used for carrying out such a melt polycondensation, any device capable of kneading a high-viscosity polymer under heating conditions can be used. For example, rolls, extruders, kneaders and the like are among them. Among them, kneading under high temperature is easy, high molecular weight can be realized in a short time, and recovery of the produced polymer is easy. A vented extruder or kneader is preferred. And as such an extruder, a single-screw or multi-screw extruder is used,
By removing the reaction by-products from the vent under reduced pressure, a high molecular weight poly (ketoester-ester) copolymer can be easily obtained in a pellet form in a short time. In this case, the degree of pressure reduction of the vent is generally 1000 Pa or less, preferably 300 Pa or less.

The poly (ketoester-ester) copolymer obtained according to the present invention as described above includes
If necessary, known heat stabilizers, light stabilizers, coloring agents, lubricants, reinforcing materials, various compounding agents for fillers and the like can be compounded alone or in combination, and can be compounded by a usual melt molding method, for example, compression. The desired molded product is molded by molding, injection molding, or extrusion molding, or such a poly (ketoester-ester) copolymer is dissolved in a solvent, and a film, fiber, and coating layer are formed by a casting method. It will be done.

Hereinafter, several embodiments of the present invention will be described.
Although the present invention will be more specifically described, it goes without saying that the present invention is not limited by the description of such embodiments. In addition, the present invention, in addition to the following examples, in addition to the above specific description, various modifications based on the knowledge of those skilled in the art, unless departing from the spirit of the present invention,
It should be understood that modifications, improvements and the like can be made.

[0033]

【Example】

Example 1 A commercially available PET bottle was collected, washed, crushed, and sieved to obtain a 10-mesh wire mesh pass product. Then, the obtained recycled P
Moisture content (measured by a moisture meter manufactured by Mitsubishi Chemical Corporation) by drying the ground ET product at 130 ° C for 3 hours.
Was 100 ppm. The intrinsic viscosity of PET used here was 0.65 dl / g. On the other hand, ethylene glycol diacetate (first grade reagent, manufactured by Wako Pure Chemical Industries, Ltd.) as a diester compound having α-active hydrogen is passed through a packed column of molecular sieve (4A, manufactured by Wako Pure Chemical Industries, Ltd.) and dried. I let it.
Also, sodium ethoxide (reagent first grade, manufactured by Wako Pure Chemical Industries, Ltd.) as an alkoxy compound was dried at 80 ° C. under reduced pressure. Further, sulfolane (99% product, manufactured by Tokyo Chemical Industry Co., Ltd.) as a reaction solvent was purified by precision distillation after washing with sodium hydroxide.

Next, 20.0 g of the dry and pulverized PET product obtained above (calculated in repeating units; 0.104 mol)
Was charged into a 300 ml four-neck separable flask together with 200 ml (252 g) of purified sulfolane, and heated and stirred at 180 ° C. while filling the inside with nitrogen gas to dissolve. When PET was completely dissolved, the temperature of the inside was lowered to 130 ° C., and 0.30 g of the above sodium ethoxide (4.
4 × 10 ^{- 3} moles) was added. Thereafter, 15.2 g of the above ethylene glycol diacetate (equimolar ratio to the repeating unit of PET) was added at a rate of 0.05 ml / min for 5 hours to a precision metering pump (manufactured by Tokyo Rikakikai Co., Ltd.
(Micro tube pump, MP-A type). After injecting all the ethylene glycol diacetate, the reaction was further carried out at 130 ° C. for 2 hours, and then the temperature was lowered to room temperature. Next, the obtained cloudy reaction solution is poured into a large amount of acetone, and the reaction product is precipitated, collected by filtration, and further, the obtained collected product is vacuum-dried at a temperature of 120 ° C. for 12 hours. As a result, 18.2 g of a white powdery reaction product was obtained.

The reaction product thus obtained was analyzed by infrared spectroscopy. As a result, the ester structure (1720
cm ^{- 1)} and ketone structure (1690 cm ^{- 1)} increases due to be broad absorption 1750~1650cm ^{- 1}
Was recognized over a period of time. The intrinsic viscosity at 30 ° C. in hexafluoroisopropanol was 0.40 dl / g. From this fact, it is recognized that the reaction product is a poly (ethylene terephthaloyl diacetate-ethylene terephthalate) copolymer.

[0036]

Comparative Example 1 For comparison, Example 1 was repeated except that sodium ethoxide was omitted. As a result, 19.8
g of a white powdery reaction product was obtained. Its infrared spectrum was completely consistent with that of the starting PET. The intrinsic viscosity at 30 ° C. in hexafluoroisopropanol was 0.62 dl / g. From the results of Comparative Example 1,
In the absence of sodium ethoxide, it was confirmed that PET and ethylene glycol diacetate did not react at all.

[0037]

Comparative Example 2 Example 1 was repeated except that ethylene glycol diacetate was omitted. As a result, 10.5 g of a white powdery reaction product was obtained. The infrared spectrum of the raw material PE
This was completely consistent with the infrared spectrum of T. The intrinsic viscosity at 30 ° C. in hexafluoroisopropanol is 0.1
0 dl / g or less. From the results of Comparative Example 2, it was found that when ethylene glycol diacetate was not present, only hydrolysis of PET by sodium ethoxide occurred.

[0038]

Comparative Example 3 Example 1 was repeated except that 20.2 g of dimethyl terephthalate (reagent first grade, manufactured by Wako Pure Chemical Industries, Ltd.) vacuum-dried at 60 ° C. for 12 hours was used instead of PET. The same experiment was performed. As a result, 11.5 g of a white powdery reaction product was obtained. Its infrared spectrum, as in Example 1, from 1,750 to 1,650 cm ^- had a broad absorption large ^one, in hexafluoroisopropanol, the intrinsic viscosity at 30 ° C., 0.21 d
It was as small as 1 / g. From comparison with Example 1, it is understood that a high molecular weight poly (ethylene terephthaloyl diacetate-ethylene terephthalate) copolymer can be obtained only when high molecular weight PET is used.

[0039]

Example 2 18.2 g of ethylene glycol diacetate
(0.125 mol, 1.2 mol ratio to PET)
Other than the above, the same experiment as in Example 1 was performed. The result
As a result, 22.1 g of a white powdery reaction product was obtained. That
The infrared spectrum is 1740 cm ^{― 1}And 1690cm^{― 1}
, A large absorption peak was observed. Hexafloroy
The intrinsic viscosity at 30 ° C. in sopropanol is 0.41 d
1 / g. From this fact, the reaction product
Must be lenterephthaloyl diacetate homopolymer
Is recognized.

[0040]

Example 3 7.6 g of ethylene glycol diacetate
(0.052 mol, 0.5 mol ratio to PET)
Other than the above, the same experiment as in Example 1 was performed. The result
As a result, 13.8 g of a white powdery reaction product was obtained. That
The infrared spectrum is 1720 cm^{― 1}Sharp absorption peak
Showed 1690 cm^{― 1}Near absorption peak near
Only a click was found. Hexafluoroisopropano
The intrinsic viscosity at 30 ° C. in the solution is 0.35 dl / g.
Was. This fact indicates that the reaction product is ethylene terephthalate.
Poly (ethylene terephthaloyl diacete)
Terephthalate) copolymer
Is shown.

[0041]

Example 4 As a carboxylic acid activator, 6 g (0.01 g) was used.
9 mol) of triphenyl phosphite (Wako Pure Chemical Industries, Ltd.)
And the same experiment as in Example 1 was performed.
gave. As a result, the yield was greatly improved and 27.4 g
A white powdery reaction product was obtained. In addition, its infrared spec
Torr is 1750 to 1650 cm as in Example 1. ^{― 1}
Over 1750 cm^{― 1}One
Absorption was biased. In hexafluoroisopropanol, 3
The intrinsic viscosity at 0 ° C. was 0.50 dl / g. This
As a result, triphenyl phosphite as a carboxylic acid activator
The reaction is accelerated by the addition of
(Ethylene terephthaloyl diacetate
(Phthalate) copolymer can be obtained in higher yield
found.

[0042]

EXAMPLE 5 The reaction product obtained in Example 1 was
Heat treatment under vacuum of 1 torr for 1 hour (solid-state polycondensation)
Was carried out. The infrared spectrum of the obtained solid-phase polycondensate was substantially the same as the infrared spectrum of Example 1, but the intrinsic viscosity at 30 ° C. in hexafluoroisopropanol increased to 0.52 dl / g. did. From this fact, it was found that the molecular weight of the reaction product can be improved by solid-phase polycondensation.

[0043]

As is apparent from the above description, according to the process for producing a poly (ketoester-ester) copolymer according to the present invention, a novel poly (ketoester-ester) can be produced from waste such as PET bottles. This makes it possible to advantageously produce a (ketoester-ester) copolymer.

Claims (6)

[Claims] 1. A poly (ketoester-ester) copolymer containing repeating units (A) and (B) represented by the following chemical formulas 1 and 2, respectively. Embedded image (Where m represents an integer of 5 to 500, and R ₁ represents a divalent organic group having 2 to 20 carbon atoms). (However, n is an integer of 1 to 500, R ₂ is an aliphatic, aromatic, aliphatic-aromatic, alicyclic divalent organic group having 1 to 20 carbon atoms, R _{3 is a} divalent organic group having 2 to 200 carbon atoms. (Indicating a divalent organic group) 2. A method for producing a poly (ketoester-ester) copolymer according to claim 1, wherein a polyester resin and a diester compound having α-active hydrogen are dissolved in an aprotic solvent in the presence of an alkoxide compound. Production of poly (ketoester-ester) copolymers. 3. A poly (ketoester-ester), characterized in that at least one of a carboxylic acid activator and an inorganic salt is present in the reaction system according to claim 2.
A method for producing a copolymer. 4. The poly (ketoester-ester) according to claim 2, wherein after the reaction, the obtained reaction product is further subjected to solid phase polycondensation or melt polycondensation.
A method for producing a copolymer. 5. The method for producing a poly (ketoester-ester) copolymer according to claim 2, wherein the polyester resin is a polyethylene terephthalate resin. 6. A method for producing a poly (ketoester-ester) copolymer in which the polyethylene terephthalate resin in claim 5 is a recovered polyethylene terephthalate resin.